The

PAN-PACIFIC

ENTOMOLOGIST

- --

Volume 71

January 1995

Number 1

Published by the PACIFIC COAST ENTOMOLOGICAL SOCIETY
in cooperation with THE CALIFORNIA ACADEMY OF SCIENCES

(ISSN 0031-0603)

The Pan-Pacific Entomologist

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PAN-PACIFIC ENTOMOLOGIST
71(1): 1-2, (1995)

OBITUARY:

CELESTE GREEN, SCIENTIFIC ILLUSTRATOR,

1913-1994

E. Gorton Linsley and John Chemsak

Department of Environmental Science Policy and Management
University of California, Berkeley 94720

The literature of biology, especially entomology, lost one of its finest artists on
10 Jan 1994. Celeste Green provided accurate and beautiful pictorial support for
hundreds of new species of insects, primarily Coleoptera (Cerambycidae), but also
Diptera, Hemiptera and a few other orders. Her finest illustration, of a bee (Pro-
toxaea ), a magnificent framed 8x 10" painting, presented to EGL upon his re¬
tirement, was unfortunately lost in the Oakland-Berkeley Hills Fire of 1992.

Celeste was bom on 16 Nov 1913. Her early childhood was spent in Carmel,
California, where her father managed the famous Highland Inn Hotel. Her artistic
ability became evident early, and she won several local talent contests. Later, in
Oakland, she attended high school and upon graduation pursued her art training
at the California College of Arts and Crafts. Her first professional work was in
the field of fashion illustrating in Oakland, and later she taught this subject at the
prestigious Jean Turner Art School in San Francisco.

Since the mid-1950s, when she was employed by the Department of Ento¬
mology, as Senior Scientific Illustrator, her many contributions have enriched
publications in The Pan-Pacific Entomologist, the University of California Pub¬
lications in Entomology, the Bulletin of the California Insect Survey, the Pro¬
ceedings of the California Academy of Sciences, and other journals, domestic and
foreign.

She also contributed examples of her work to a general text book on scientific
illustration and as chapter headings to an autobiography of R. L. Usinger. Un¬
fortunately, the high cost of color illustration limited the use of her talent in this
field. However, two particularly fine examples may be seen: one of Plinthocoelium
suaveolens plicatum (LeConte), as the Frontispiece of Linsley (1964), and another
of Crossidius spp., as plates 1 and 2 of Linsley & Chemsak (1961).

Retirement, in 1980, took Celeste to Indiana to be closer to her children, and
in 1986 she moved to the northwest (Gig Harbor, Washington), where she re¬
mained until her death. Her daughter, Kathleen Petrilli, gives this account of these
chapters in her life:

She first moved to Indiana, where she became fascinated in researching and
making com husk dolls, i.e., doll-size figures made from dried com husks.
Many of these dolls depicted pioneer life in mid-America. During this time,
Celeste was living in Carmel, Indiana and she created a replica of the historic
train station complete with com husk figures. This train station was on
display in the city of Carmel for several months.

During this time in the mid-West, both Celeste and her sister Pat developed
a small antique/pottery mending business. They did repair work for local
antique dealers. Although they kept this business small, their reputation
quickly grew and there was continual demand for their skills and services.

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Figure 1. Celeste Green. 1967.

Her final move was to the Pacific Northwest and her life in her beloved
“brown house” on the waterfront of Gig Harbor, Washington.

This was the period when Celeste’s artistic interests turned to undersea life
and Native American Indians of the N.W. She began making fish and sea
creatures out of a clay-like substance called sculpey which could be baked
and hardened in the oven. In 1992, she created a complete coral reef depicting
undersea life in the Puget Sound region.

During her sojourn in the N.W., Celeste became interested in Indian history
and folk lore particularly the history of Indian Kachina dolls. Both she and
her sister Pat created wonderful Indian masks and dolls that now adorn our
home. (For me, they truly embody the creative spirit that was my mother’s
special gift.)”

But these tributes to her talent and artistic ability do not record Celeste’s
personality and humanity. She was a lovely individual, loved by those who knew
her well, and respected by those with less frequent contacts. Within the University,
these included faculty, staff, and students—graduate and undergraduate. We had
the unique privilege of sharing a museum laboratory with her and we are honored
to have an opportunity to publish this tribute to her memory.

Literature Cited

Linsley, E. G. 1964. The Cerambycidae of North America. Part V. Taxonomy and classification of
the subfamily cerambycinae, tribes Callichromini through Ancylocerini. Univ. Calif. Publ.
Entomol., 22.

Linsley, E. G. & J. A. Chemsak. 1961. A distributional and taxonomic study of the genus Crossidius
(Coleoptera, Cerambycidae). Misc. Publ. Entomol. Soc. Am., 3: 26-64.

PAN-PACIFIC ENTOMOLOGIST
71(1): 3-12, (1995)

CANOPY ARTHROPOD DIVERSITY IN A
NEW CALEDONIAN PRIMARY FOREST
SAMPLED BY FOGGING 1

Eric Guilbert, Michel Baylac, and Judith Najt 2

Laboratoire d’Entomologie, Museum National d’Histoire Naturelle,

Paris, France

Abstract.— We collected 9608 specimens during three fogging samples in a New Caledonian
rainforest. The most abundant arthropod taxa in number of specimen were Collembola, Diptera,
Coleoptera, Hymenoptera and Psocoptera. The fogging in New Caledonia indicated a high
percentage of Psocoptera and Diptera; however the effects of sample biases should be assessed
before any comparison can be drawn.

Key Words.— Arthropoda, biodiversity, canopy, fogging, New Caledonia

Fogging as a collecting technique was first employed in 1966 by Martin (Erwin
1983). Since then, numerous studies of canopy arthropods have used this tech¬
nique: in Ontario (Martin 1966), Costa Rica (Roberts 1973), Hawaii (Gagne 1979),
Panama (Erwin & Scott 1980), South Africa and Great Britain (Southwood et al.
1982), Amazonia (Erwin 1983, 1989; Adis et al. 1984), Japan (Hijii 1983, 1986),
Borneo (Stork 1987, 1988, 1991), Sulawesi (Noyes 1989), Thailand (Watanabe
& Ruaysoongnern 1989) and Australia (Basset 1988, 1990, 1991). However, few
studies dealt with the arthropod fauna of West Pacific islands and no comparison
among arthropod faunas of the locations listed above has been attempted.

New Caledonia includes 3.5% of the area covered by extant tropical rainforests,
and is one of the 10 “hot spots” identified by Myers (1988) on the basis of its
species diversity and fragility. Studies of the fauna and flora from the Riviere
Bleue reserve by the Museum National d’Histoire Naturelle and ORSTOM show
high endemicity (80% of animal species, 73% of plant species).

The present study determined the composition of the arthropod fauna from
the tree crowns in the rainforest of the Riviere Bleue Reserve sampled by insec¬
ticidal fogging.

Methods and Materials

Study Area.— Samples were gathered in the Riviere Bleue reserve (20° S, 166°
E), which has been a territorial park since May 1980. Geological and floristic
characteristics of the location were described by Bonnet de Larbogne et al. (1991).
The reserve is located in the great Southern massif of New Caledonia in the region
of the Haute Yate basin. The study was carried out in evergreen forest on alluvium
in the flat bottom of the valley, 50 m from the river at a mean altitude of 160
m; this parcel is occasionally flooded.

Samples.— Fogging was carried out from the ground with a Dyna-fog Golden
eagle backpack 2980, using a mixture of 200 cc cyfluthrin in water and polyhydric

1 Authors’ page charges partially offset by a grant from the C. P. Alexander Fund, PCES.

2 CNRS et UC 1338 MNHN, 45, rue Buffon, F-75005 Paris.

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

alcohols (Solfac EW 050) in 2 liters Maxifog solvent. Each fogging lasted 15 min.
The collecting surface was arranged in six rows of five white plastic sheets of 1
m 2 , separated by 0.5 m, giving a total surface area of 60 m 2 . One half was placed
on the soil and the other half on stands, 50 cm above the soil. The specimens
that fell on the sheets were collected either by brushing (first fogging) or by washing
with water (second and third fogging).

Three fogging samples were collected: the first (Fogl) and second (Fog2) in the
same place, and the third (Fog3) 100 meters away. The first fogging (18 Jan 1991,
20° C, hygrometry: 90%) took place during the rainy season, the second (23 Jul
1991, 22° C, hygrometry: 85%) and third ones (1 Aug 1991, 20° C, hygrometry:
90%) during the dry season. Fog3 was carried out one week after Fog2. The aim
was to sample the biotope, not particular tree species.

All arthropods were sorted at least to order level, and to family level for the
most abundant orders: Hymenoptera, Diptera, Coleoptera in Fogl and Fog3 and
Orthoptera, Hemiptera in Fogl. When taxonomic expertise was available and in
order to allow ecological and trophic precision, some families from Fogl were
sorted into subfamilies and tribes (Staphylinidae), species (Formicidae) and tro¬
phic guilds (Cecidomyiidae). The Collembola were sorted to species in the three
foggings.

Results

Faunistic Composition.—Over the three foggings, 9608 specimens were col¬
lected (106.76 specimens/m 2 ) belonging to 107 families within 20 orders: 2227
in Fogl (74.23/m 2 ), 3191 in Fog2 (106.37/m 2 ) and 4190 in Fog3 (139.67/m 2 ).
These seem low when compared with other fogging samples: 35 to 161/m 2 in
Amazonian samples (Adis et al. 1984), and 51 to 218/m 2 in Bornean samples
(Stork 1991). Hijii (1983) found 200 to 3500/m 2 by the smoking method. The
lower abundance in Fogl within our samples is due to the collection method.

When the three samples are considered together, the dominant orders are Col¬
lembola (18.6% of the specimens), Diptera (18.4%), Coleoptera (13.6%), Hyme¬
noptera (12.7%) and Psocoptera (11.4%). The frequencies of the other orders do
not exceed 7%. Nematocera are more abundant than Brachycera and the majority
of Hymenoptera were Formicidae (Table 1). Diptera and Coleoptera are repre¬
sented respectively by 27 and 31 families; Hymenoptera are represented by at
least 14 families (Chalcidoidea were considered a single taxon).

As reflected by the standard deviation of their abundance in subsamples within
each fogging (Table 2), some abundant groups were not distributed evenly across
the sample surface: Coleoptera, Nematocera, Collembola, and Psocoptera. For¬
micidae are patchy in Fogl and Fog2, Nematocera in Fog2 and in Fog3, Acarina
in Fogl and Fog3, Thysanoptera in Fog2 and Homoptera in Fog3. Other groups,
which are less abundant, are well spread throughout the collecting surface: Lep-
idoptera in the three samples, Acarina, Amphipoda, Dermaptera in Fogl and
Fog2, Orthoptera in Fog2 and Fog3. Among samples, some groups vary greatly
in abundance: Collembola, Acarina and Nematocera; while others are quite con¬
stant: Hymenoptera, Brachycera, Lepidoptera and Dermaptera.

The abundance of Collembola varies greatly among foggings, from 6.3% to 24%
to 21% of the sampled insects. A total of 29 species of Collembola were collected.
The number of species among samples is nearly the same; but only nine species

1995

GUILBERT ET AL.: CANOPY ARTHROPODS

5

Table 1. Absolute and relative frequencies of individuals belonging to major taxa collected by
fogging.

Fogging 1 Fogging 2 Fogging 3 Total fogging

Taxa

Nber

%

Nber

%

Nber

%

Nber

%

1. Other Hymenoptera

144

6.5

188

5.9

197

4.2

529

5.5

2. Formicidae

126

5.7

471

14.8

94

2.0

691

7.2

3. Nematocera

612

27.5

323

10.1

299

6.4

1234

12.8

4. Brachycera

75

3.4

172

5.4

253

5.4

500

5.2

5. Heteroptera

63

2.8

61

1.9

49

1.1

173

1.8

6. Homoptera

40

1.8

64

2.0

233

5.0

337

3.5

7. Orthoptera

31

1.4

17

0.5

26

0.6

74

0.8

8. Coleoptera

269

12.1

301

9.4

736

15.8

1306

13.6

9. Araneae

197

8.8

174

5.5

277

6.0

648

6.7

10. Collembola

140

6.3

766

24.0

885

19.0

1791

18.6

11. Lepidoptera

10

0.4

17

0.5

31

0.7

58

0.6

12. Psocoptera

392

17.6

428

13.4

275

5.9

1095

11.4

13. Thysanoptera

28

1.3

65

2.0

145

3.1

238

2.5

14. Dictyoptera

42

1.9

9

0.3

81

1.7

132

1.4

15. Acarina

15

0.7

102

3.2

413

8.9

530

5.5

16. Amphipoda

2

0.1

5

0.2

30

0.6

37

0.4

17. Others

7

0.3

6

0.2

18

0.4

31

0.3

18. Pseudoscorpionida

1

0.04

0

0.0

44

0.9

45

0.5

19. Dermaptera

1

0.04

5

0.2

17

0.4

23

0.2

20. Larvae undetermined

32

1.4

17

0.5

87

1.9

136

1.4

21. Total

2227

100

3191

100

4190

100

9608

100

are common to the three samples, and three of them are abundant (Table 3). Four
species are abundant in Fog2 and Fog3, but not in Fogl. The scarcity and absence
of some species in the Fogl may be due either to seasonal variation or to collecting
technique. So the occurrence and the abundance of Rastriopes fuscus Yosii and
R. sp. could characterize respectively Fog2 and Fog3 or could be a consequence
of the sampling method or seasonal variation.

The low percentage of Collembola from Fogl may be an artifact related to the
collecting technique: according to Hijii (1983), one should wash the sheets with
appropriate liquids after fogging in order to avoid the loss of microarthropods
such as Collembola and Acarina. However, the percentage in Fogl is high in
comparison with the results of previous studies, and could be due to contamination
of the sample by ground-dwelling Collembola jumping onto the sheets during
fumigation and collection. However, Hijii (1983) and Watanabe & Ruaysoongnem
(1989) found a great abundance of Collembola in Japan and Thailand respectively.
Watanabe & Ruaysoongnem (1989) suggested that the great number of Collembola
is related to seasonal flooding of the forest floor. Most Collembola found in fogging
samples may also come from tree trunks, and/or from organic matter in the canopy
(Stork 1988, Nadkarni & Longino 1990).

When comparing Collembola fauna from canopy and soil, their average richness
is similar in the fogging samples (18 species) and in malaise trap sample (19
species) (Guilbert, unpublished data). Similarity in the ground and canopy fauna
has also been observed in Costa Rica (Nadkarni & Longino 1990). However,
Martin (1966) found 22 soil species compared to 10 species from crown stratum

6

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Table 2. Simple statistics within samples of the major taxa sorted by sheets.

Taxa

Range

Sum

Mean

SD

Fogl

Hymenoptera

0-9

144

4.80

2.63

Formicidae

1-17

126

4.20

3.45

Nematocera

7-40

612

20.40

7.29

Brachycera

0-5

75

2.50

1.55

Heteroptera

0-7

63

2.10

1.79

Homoptera

0-7

40

1.33

1.52

Orthoptera

0-5

31

1.03

1.30

Coleoptera

0-68

269

8.97

12.42

Araneae

1-21

197

6.57

4.04

Collembola

0-22

140

4.67

5.02

Lepidoptera

0-2

10

0.33

0.61

Psocoptera

1-54

392

13.07

12.74

Thysanoptera

0-4

28

0.93

1.01

Dictyoptera

0-6

42

1.40

1.61

Acarina

0-3

15

0.50

0.82

Amphipoda

0-1

2

0.07

0.25

Pseudoscorpionida

0-1

1

0.03

0.18

Dermaptoptera

0-1

1

0.03

0.18

Larvae

0-4

32

1.07

1.17

Fog2

Hymenoptera

1-14

188

6.27

3.05

Formicidae

0-345

471

15.70

62.33

Nematocera

4-18

323

10.77

3.70

Brachycera

0-49

172

5.73

8.62

Heteroptera

0-10

61

2.03

2.11

Homoptera

0-14

64

2.13

3.03

Orthoptera

0-3

17

0.57

0.86

Coleoptera

3-24

301

10.03

5.05

Araneae

0-10

174

5.80

2.82

Collembola

0-73

766

25.53

19.30

Lepidoptera

0-2

17

0.57

0.77

Psocoptera

0-30

428

14.27

7.58

Thysanoptera

0-20

65

2.17

3.60

Dictyoptera

0-3

9

0.30

0.65

Acarina

0-9

102

3.40

2.79

Amphipoda

0-2

5

0.17

0.46

Pseudoscorpionida

0-0

0

0

0

Dermaptoptera

0-3

5

0.17

0.59

Larvae

0-3

17

0.57

0.77

Fog3

Hymenoptera

2-14

197

6.57

2.74

Formicidae

0-11

94

3.13

2.67

Nematocera

4-24

299

9.97

4.54

Brachycera

2-23

253

8.43

5.24

Heteroptera

0-6

49

1.63

1.67

Homoptera

3-16

233

7.77

3.62

Orthoptera

0-3

26

0.87

0.97

Coleoptera

8-46

736

24.53

6.87

Araneae

2-26

277

9.23

5.26

Collembola

4-55

885

29.50

11.61

Lepidoptera

0-4

31

1.03

0.93

1995

GUILBERT ET AL.: CANOPY ARTHROPODS

7

Table 2. Continued.

Taxa

Range

Sum

Mean

SD

Psocoptera

1-22

275

9.17

4.56

Thysanoptera

0-11

145

4.83

3.01

Dictyoptera

0-11

81

2.70

2.55

Acarina

2-46

413

13.77

9.28

Amphipoda

0-7

30

1.00

1.72

Pseudoscorpionida

0-5

44

1.47

1.48

Dermaptoptera

0-6

17

0.57

1.45

Larvae

0-9

87

2.90

2.37

in Ontario, and Hijii (1989) found a greater abundance of specimens of Collembola
in the soil than in the canopy in Japan.

Two epiedaphic groups of Collembola, the Entomobryomorpha and Symphy-
pleona, are very abundant in both New Caledonian canopy fogging and malaise
trap samples. Most species belonging to these taxa found in our samples exhibit
long claws, which probably constitute an adaptive character and when associated
with their large ecological valency, allows invasion of all above-ground habitats.
Nevertheless, some species probably live in epiphytic plants or suspended soil
and may be restricted to the canopy (e.g., Pseudoparonella (Pseudoparonella ) sp.,
Lepidosira ( Nusasira ) sp. and Dicyrtomina sp. 1 that occur in the fogging but not
in the malaise trap samples).

Diptera represent 14.9% of specimens of the entire study. Nematocera are more
abundant and diverse than the Brachycera. Ceratopogonidae, Chironomidae, Cec-
idomyiidae and Sciaridae are dominant and constitute 91.2% of Nematocera.
Sixteen families of Brachycera were found, of which three accounted for 80.2%
of the Brachycera individuals: the Chloropidae, Dolichopodidae and Drosophil-
idae.

With 27 families of Diptera, the canopy of the Riviere Bleue forest is poorer,
particularly in Brachycera than forest in Ontario (44 families: Martin 1966); but
it is richer than Queensland (12 families, mostly Nematocera: Basset 1991). The
abundance of Diptera is greater in our samples (13.2 to 30.8%) than anywhere
else (around 20%) except for Borneo (48 to 83%; Stork 1991). Family frequency
depends on their activity around the tree: some flies pass through the sample area
and are caught by the insecticidal cloud. Other families such as Phoridae, Chlo¬
ropidae and Dolichopodidae are typically arboreal (Basset 1991); the occurrence
of some families such as the Phoridae in only one of the two sites sampled may
be related to differences in floristic composition. Greater abundance of Cerato¬
pogonidae, Chironomidae, Cecidomyiidae and Sciaridae in Queensland, New-
Caledonian and Bornean samples may due to the proximity of rivers or water
spots (Stork 1991) as Riviere Bleue samples were collected 50 meters from a river.

The Cecidomyiidae belong to three different trophic guilds: predators, phyto¬
phages and mycetophages (Table 4). Mycetophage species (that belong mainly to
the two primitive subfamilies Lestremiinae and Porricondylinae) are absent from
the canopy, whereas they constitute 4.49% of malaise trap sample (EG, unpub¬
lished data). Larvae from the latter subfamilies are known to inhabit soil litter,
mosses and dead wood. Their absence in the fogging samples is striking and should

8

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 71(1)

Table 3. Number of specimens of Collembola per species and per collection obtained by fogging
(Fogl, Fog2, Fog3).

Species

Fogl

Fog2

Fog3

Neanuridae

Pseudachorutes tillieri Najt & Weiner

0

0

0

Hypogasturidae

Xenylla sp.

0

5

0

Isotomidae

Proisotoma sp.

0

1

0

Cryptopygus sp.

0

3

10

n.g. 1

0

0

2

Entomobryidae s.l.

Pseudoparonella ( Plumachaeta) oceanica Yoshii

4

0

18

Epimetrura sp.

29

127

124

Willowsia sp.

2

11

13

Salina ( Salina) oceanica Yoshii

63

86

295

Pseudoparonella ( Oceaniella ) shibatai Yosii

16

13

96

Pseudoparonella (Pseudoparonella ) sp. 1

1

6

8

Pseudoparonella ( Pseudoparonella ) novae-caledoniae Yosii

0

5

34

Lepidocirtoydes novae-caledoniae Yosii

0

0

5

Pseudoparonella ( Oceaniella ) griseocoerulea Yoshii

8

0

4

Pseudosinella ( Austrocyrtus ) speciosa Yoshii

0

0

0

Lepidosira ( Nusasira ) vicina Yoshii

2

11

15

Seira sp.

2

0

0

Pseudoparonella (Pseudoparonella) sp. 2

0

0

4

Lepidosira (Nusasira ) sp.

0

6

4

Lepidosira sp. 1

0

0

3

Lepidosira sp. 2

0

1

0

Pseudoparonella ( Oceaniella ) bicincta Yoshii

1

0

0

Entomobrya (Entomobrya ) sp.

1

0

0

Sminthuridae

Parasphyrotheca sp.

1

15

15

Sphaeridia sp.

0

0

0

Sphyrotheca sp. 1

1

27

0

Sphyrotheca sp. 2

2

0

0

Bourletiellidae

Bourletiellidae n.g.

0

1

0

Rastriopes fuscus Yosii

4

128

0

Rastriopes sp.

0

0

119

Dicyrtomidae

Dicyrtomina sp. 1

1

37

10

Dicyrtomina sp. 2

2

283

106

Total

140

766

885

be further investigated. It could be related either to seasonal variations or to the
canopy microclimate. The samples are also characterized by the reverse propor¬
tions in the two major predator genera (Table 4). This result is similar to obser¬
vations in Europe where Trisopsis is mainly confined to the forest litter while
Lestodiplosis has a broader ecological valence (MB, unpublished data). The phy-

1995

GUILBERT ET AL.: CANOPY ARTHROPODS

9

Table 4. Trophic guilds of Cecidomyiidae from canopy (Fogl) and ground layers (malaise trap).

Trophic guild

Taxa

Fogging percentage

Malaise percentage

Predators

Cecidomyiinae

Trisopsis

9.24%

28.41%

Lestodiplosis

14.55%

5.98%

Mycophages

Porricondylinae

0.%

1.09%

Lestremiinae
Micromyiini spp.

o.%

3.08%

Lestremiini spp.

o.%

0.32%

Phytophages

Cecidomyiinae

76.21%

61.12%

Total specimens

149.

1556.

tophagous Cecidomyiidae represent 76.5% in the canopy, vs. 61.1% at the soil
level.

The Coleoptera are the most diversified order in terms of number of families
(31). Only 16 families are present in both Fogl and Fog3; most of the other
families are represented by fewer than five specimens each in a single sample.
There were fewer families than in Queensland (54 families: Basset 1991) or in
Amazonian samples (57 families: Erwin 1983). As in those regions and in Panama,
the Curculionidae, Corylophidae, Chrysomelidae and Staphylinidae are the most
abundant (Basset 1991, Erwin 1983, Erwin & Scott 1980). Pselaphidae are more
abundant in our samples than in any other published results. Coccinellidae are
more abundant than in other regions (Basset 1991, Erwin & Scott 1980). In
contrast to Queensland and Zaire, no Scolytidae and few Cerambycidae were
found (Basset 1991, Sutton & Hudson 1980).

Most Hymenoptera collected belong to Parasitica and Formicidae. Formicidae
are dominant with 7.2%, whereas other Hymenoptera represent 5.5% of the three
fogging samples. Very few Symphyta are present, all of them belonging to the
Sphecidae. Formicidae constitute 5.7, 14.8 and 2.0% of the specimens in each
fogging sample. They are represented by 14 species and 7 genera, 11% of the
genera cited by Taylor (1987) for the whole territory. Paratrechina, with 42.2%
and Camponotus, with 16.4% of the total Formicidae in the Fogl, are the most
abundant genera. The presence of Pheidole, which is terricolous, reflects the oc¬
currence of epiphytes and suspended soil in the trees. Although not cited by Taylor
(1987) and up to now unknown in New Caledonia, Crematogaster has been found
in the fogging samples and, therefore, occurs in the canopy. Representatives of
Iridomyrmex, Monomorium and Adelomyrmex are scarce.

Formicidae are less abundant here than in Amazonian or Bornean samples
(Erwin 1983, Adis et al. 1984, Stork 1988). As in Queensland, the paucity of ants
is more typical of temperate forests than of tropical ones (Basset 1991). Parasitica
like Scelionidae are usually abundant in tropical samples (Basset 1991, Noyes
1989), but are poorly represented here; because they reflect the abundance of their
host taxa in the canopy, the latter are probably scarce in New Caledonia.

The Psocoptera, although usually scarce in fogging samples (1.9 to 12.1% in
previous studies), represent 11.4% of the three samples. Psocoptera abundance is
higher in Japan and Ontario (Hijii 1986, Martin 1966). They are more frequently
found on tree trunks than in the canopy. Stork (1987) suggested that the distance

10

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

of the sheets from the tree trunks may considerably influence Psocoptera collection
efficiency, and their abundance in the Riviere Bleue rainforest may indicate a high
density of tree trunks when compared with other forests.

Eleven families of Araneae were found. The Clubionidae, Lyniphiidae, Saltic-
idae and Pholcidae are the most abundant with respectively 29.4%, 19.8%, 12.7%
and 12% of the specimens. No other family exceeds 3.5%. The greater abundance
of Araneae here than in other regions of the world may be related to the reduced
abundance and richness of Formicidae, which may supplant the spiders in the
canopy (Majer 1990). However, Stork found 21 families in Bornean samples (Stork
1991). Fewer Salticidae (6.6%) and more Thomisidae (38%) were recorded in
Ontario (Martin 1966). Theridiidae (1%) are less abundant than in Queensland
(31.2%: Basset 1991) and Borneo (22.9%: Stork 1991).

The Acarina are more abundant in Fog2 and Fog3, possibly because the sheets
from these foggings were washed. With 5.5% of all the specimens from fogging
samples, they are more abundant than in most other regions. However, they were
recorded as a dominant group in Japan (Hijii 1983, 1986), in Ontario (Martin
1966) and in canopy organic matter in Costa Rica (Nadkami & Longino 1990).

Other arthropod orders, Lepidoptera, Dermaptera and Neuroptera, are scarce
in the three fogging samples. Some groups, such as Thysanoptera, Pseudoscor-
pionida, Amphipoda, are scarce in Fogl and Fog2 and abundant in Fog3. This
variation may be related to seasonal flooding, as observed by Watanabe & Ruay-
soongnem (1989) for Thysanoptera in Thailand, or to the fioristic composition
of the canopy.

Discussion

New Caledonian Fauna Composition. — The abundance of Collembola and Ac¬
arina varies strongly among samples from other locations (see literature cited
above). This variation may be related to canopy cover, presence of suspended
soil or to the method used by the authors. These taxa are usually not abundant
when collected by fogging. Acarina were the most abundant group collected by
hand by Nadkami & Longino (1990). According to some authors, variations of
abundance and composition of soil faunal taxa such as Collembola are due to
transfer between canopy and soil layers (Adis et al. 1984).

The abundance of Hymenoptera, Heteroptera, Orthoptera, Araneae, Lepidop¬
tera and Psocoptera exhibits little variation in the three Caledonian samples. They
seem to be unaffected by changes in the composition of the flora between the two
sites, or by seasonal variations. These taxa are more abundant in the dry season
in Thailand (Watanabe & Ruaysoongnem 1989). According to Basset (1991),
some arthropod taxa are more abundant during flowering and leaf flush in Queens¬
land.

Our observations are based upon three samples only and major taxa and sam¬
pling biases may be expected. For example, the abundance of Formicidae in the
Fog2 is due to an aggregation of one species which represents 7 3% of all Formicidae
in this fogging. Stability in abundance of major taxa could hide variations of
composition inside these taxa. Further sampling is needed to test these obser¬
vations.

1995

GUILBERT ET AL.: CANOPY ARTHROPODS

11

Conclusions

Riviere Bleue’s fauna shows differences with other faunas in the world at family
levels. In addition, it differs from faunas of other forests in New Caledonia (EG,
unpublished data) and at the species level (Collembola) between two locations in
the same forest. The arthropod fauna of New Caledonia is characterized by the
importance of the Psocoptera and of the Diptera. It is similar to the fauna of
Queensland because of the importance of the Psocoptera, and of the Bornean
fauna, which is characterized by the importance of the Diptera.

Composition of the sample is influenced by multiple variables of the sampling
method: escape of strong fliers from the insecticidal cloud (Noyes 1989), death
of insects under bark and inside epiphytes without falling down, position of the
sheets laying on the ground or suspended, collecting technique, position of the
fogger and collecting time. All these factors possibly contribute to obfuscate general
patterns that may have historical (i.e., biogeographical), as well as functional (i.e.,
ecological), explanations. Fogging and sorting methods should be standardized in
order to eliminate these sources of noise and to increase significance of observed
patterns.

Acknowledgment

Jean Chazeau and Lydia Bonnet de Larbogne (ORSTOM Noumea) have sam¬
pled the canopy fauna and assisted in every aspect of field work. Nicole Berti,
Thierry Bourgoin, Loic Matile, Christine Rollard, Claire Villemant, and Janine
Weulersse (Museum national d’Histoire naturelle) kindly provided their taxo-
nomical assistance. Simon Tillier (Museum national d’Histoire naturelle) man¬
aged the program: “Evolution et vicariance en Nouvelle-Caledonie” which made
this study possible and supported the author while preparing this manuscript.

Literature Cited

Adis, J., Y. D. Lubin & G. Montgomery. 1984. Arthropods from the canopy of inundated and Terra
firme forest near Manaus, Brazil, with critical considerations on the pyrethrum-fogging tech¬
nique. Studies Neotr. Fauna Environ., 19: 223-236.

Basset, Y. 1988. A composite interception trap for sampling arthropods in tree canopies. J. Aust.
Entomol. Soc., 27: 213-219.

Basset, Y. 1990. The arboreal fauna of the rainforest tree Argyrodendron actinophyllum as sampled
with restricted canopy fogging: composition of the fauna. The Entomologist, 109: 173-183.
Basset, Y. 1991. The taxonomic composition of the arthropod fauna associated with an Australian
rainforest tree. Aust. J. Zool., 39: 171-190.

Bonnet de Larbogne, L., J. Chazeau, A. Tillier & S. Tillier. 1991. Milieux naturels neo-caledoniens:
la Reserve de la Riviere Bleue. pp. 9-17. In Chazeau, J. & S. Tillier (eds.). Zoologia Neoca-
ledonica, 2. Mem. Mus. natn. Hist, nat., Paris.

Erwin, T. L. 1983. Beetles and other insects of tropical forest canopies at Manaus, Brazil, sampled
by insecticidal fogging, pp. 59-79. In Sutton, S. L., et al. (eds.). Tropical rainforest ecology and
management. Blackwell Press, Oxford.

Erwin, T. L. 1989. Canopy arthropod biodiversity: a chronology of sampling techniques and results.
Rev. Entomol. Peruana, 32: 71-77.

Erwin, T. L. & J. C. Scott. 1980. Seasonal and size patterns, trophic structure and richness of
Coleoptera in the tropical arboreal ecosystem: the fauna of the tree Luehea seemannii Triana
and Planch in the canal zone of Panama. Coleopt. Bull., 34: 305-321.

Gagne, W. C. 1979. Canopy-associated arthropods in Acacia koa and Metrosideros tree communities
along an altitudinal transect on Hawaii island. Pac. Ins., 21: 56-82.

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Hijii, N. 1983. Arboreal arthropod fauna in a forest: seasonal fluctuations in density, biomass, and
faunal composition in a Chamaecyparis obtusa plantation. Jap. J. Ecol., 33: 435-444.

Hijii, N. 1986. Density, biomass, and guild structure of arboreal Arthropod as related to their
inhabited tree size in a Cryptomeria japonica plantation. Ecol. Res., 1: 97-118.

Hijii, N. 1989. Arthropod communities in japanese cedar (Cryptomeria japonica D. Don) plantation:
abundance, biomass and some properties. Ecol. Res., 4: 243-260.

Majer, J. D. 1990. The abundance and diversity of arboreal ants in northern Australia. Biotropica,
22: 191-199.

Martin, J. L. 1966. The insect ecology of red pine plantations in central Ontario. IY. The crown
fauna. Can. Entomol., 98: 10-27.

Myers, N. 1988. Threatened biotas: “hot spots” in tropical forests. The Environmentalist, 8: 187—
208.

Nadkami, N. M. & J. T. Longino. 1990. Invertebrates in canopy and ground organic matter in a
neotropical montane forest, Costa Rica. Biotropica, 22: 286-289.

Noyes, J. S. 1989. A study of five methods of sampling Hymenoptera (Insecta) in a tropical rainforest,
with special reference to the Parasitica. J. Nat. Hist., 23: 285-298.

Roberts, H. F. 1973. Arboreal Orthoptera in the rain forest of Costa Rica collected with insecticide:
a report of the grasshoppers (Acrididae) including new species. Proc. Acad. Nat. Sc., Philadel¬
phia, 125: 46-66.

Southwood, T. R. E., V. C. Moran & C. E. J. Kennedy. 1982. The richness, abundance and biomass
of the arthropod communities on trees. J. Animal. Ecol., 51: 635-649.

Stork, N. E. 1987. Arthropod faunal similarity of Bornean rain forest trees. Ecol. Entomol., 12: 219—
226.

Stork, N. E. 1988. Insect diversity: facts, fiction and speculation. Biol. J. Linn. Soc., 35: 321-337.

Stork, N. E. 1991. The composition of the arthropod fauna of Bornean lowland rain forest trees. J.
Tropical Ecol., 7: 161-180.

Sutton, S. L. & P. J. Hudson. 1980. The vertical distribution of small flying insects in the lowland
rain forest of Zaire. Zool. J. Linn. Soc., 68: 111-123.

Taylor, R. W. 1987. A checklist of the ants of Australia, New Caledonia and New Zealand (Hy¬
menoptera: Formicidae). CSIRO Aust. Div. Entomol. Rep., 41: 1-92.

Watanabe, H. & S. Ruaysoongnem. 1989. Estimation of arboreal arthropod density in a dry evergreen
forest in northeastern Thailand. J. Trop. Ecol., 5: 151-158.

PAN-PACIFIC ENTOMOLOGIST
71(1): 13-17, (1995)

FEEDING AND PREY PREPARATION IN THE SOLPUGID,
EREMORHAX MAGNUS HANCOCK
(SOLPUGIDA: EREMOBATIDAE)

Fred Punzo

Department of Biology, University of Tampa,

Tampa, Florida 33606

Abstract. — Prey preparation as an important component of handling time is demonstrated for
the first time in a solpugid ( Eremorhax magnus Hancock). Prey body parts (from the grasshopper,
Trimerotropis pallidipennis Walker) characterized by high chitin content (head, antennae, wings,
legs) are selectively removed prior to ingestion. Head capsules were removed in 77-84% of the
feeding trials, depending on the size of the prey, followed by forewings (54%) and hindwings
(37%). Body parts possessing lower amounts of chitin (abdomen, thorax, hind femur) are pro¬
cessed and ingested thereby supporting the nutrient concentration hypothesis. Prey is initially
detected via the palpi which are then used to pull the prey toward the chelicerae. The prey is
then grasped by the chelicerae which are then used to fragment and grind the prey for ingestion.
Ingestion time ranged from 6.2-17.4 min for small hoppers, and 11.6-28.3 min for larger prey.

Key Words.— Arachnida, Solpugida, Eremorhax, prey preparation, feeding

Previous studies have shown that predators frequently consume only certain
parts of their prey (Haynes & Sisojevic 1966, Sih 1980) and often show strong
preferences for specific tissues and body regions (Curio 1976; Punzo 1989, 1992).
For example, insectivorous birds frequently remove the wings, legs and head
capsule, and swallow the thorax and abdomen (Sherry & McDade 1982). Some
lycosid and thomisid spiders preferentially ingest the softer tissues of an insect’s
abdomen while rejecting other body regions depending on the degree of hunger
(Haynes & Sisojevic 1966, Nentwig 1987, Punzo 1991). In many cases insectiv¬
orous birds and mammals will modify or remove specific prey parts before in¬
gestion is initiated (Curio 1976). This has also been reported for a few arthropod
predators such as mantids and some decapod crustaceans (Krebs & McCleery
1984). Although this type of behavior, known as prey preparation, increases the
overall handling time, it can help to optimize energy budgets by targeting the
ingestion of those body parts possessing a higher concentration of essential nu¬
trients (Hespeheide 1973, Kaspari 1990). One way for insectivores to maximize
nutrient intake rate would be to reject those prey parts having a high chitin content.
Chitin is either indigestible or poorly digested by insectivores in general (Punzo
1989, Scott et al. 1976).

Research on optimal foraging has focused on energy expenditure associated
with search, pursuit, capture, ingestion and resource depression (Chamov 1976,
Lucas 1983, Punzo 1989, Punzo & Garman 1989) whereas prey preparation has
received little attention (Kaspari 1990). The few available studies focus on ver¬
tebrate predators (see reviews by Curio 1976, Krebs & McCleery 1984, O’Brien
et al. 1990). In this paper, I explore the relationship between chitin content and
prey preparation in the solpugid, Eremorhax magnus (Hancock). This is the first
demonstration that solpugids make decisions concerning which prey parts should
be selectively consumed.

14

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Materials and Methods

Eremorhax magnus is a common inhabitant of the desert regions of southern
California (Muma 1951). Adult females (29-35 mm, total body length) were
collected as they wandered the surface at night during June-August, 1992. Sol-
pugids were collected within a 10-km radius of Victorville (San Bernardino Coun¬
ty), CA. A helmet-mounted light with a red filter was used to locate and observe
solpugids as described by Punzo (in press). A total of 56 females were collected
and transported back to the laboratory. Solpugids were housed individually in
plastic cages (30 x 14 x 8 cm), provided with water, and fed once per week on
a diet of mealworm larvae ( Tenebrio molitor L.).

Twenty solpugids were randomly assigned to one of two experimental groups.
Each experimental group was allowed to feed on one of two prey size classes: (1)
small (juveniles): total body length (TBL): 12-16 mm; body weight (BW): 0.31
± 0.02 g; (2) large: TBL: 17-22 mm; BW: 0.84 ± 0.03 g. I chose pallid-winged
grasshopper females ( Trimerotropis pallidipennis Walker) as the prey species for
all feeding experiments. This grasshopper is common in this area (personal ob¬
servation) and three of the solpugids had a pallid-winged grasshopper in their
chelicerae when they were collected. Specimens of T. pallidipennis were collected
with a sweep net and also brought back to the laboratory for subsequent use in
feeding trials. All solpugids were deprived of food for 72 h prior to testing.

Grasshoppers from each prey size class were used to assess the chitin content
(mean weight and percent chitin) of various body parts: head, antennae, abdomen,
hind femur, foreleg, midleg, thorax, forewing and hindwing. Chitin weight was
determined according to the method described by Zach & Falls (1978). Body parts
were freeze-dried, weighed on a Metier electronic analytical balance, immersed
in 2.0 M KOH for 72 h, rinsed, dried again and reweighed. KOH dissolves all
tissues except chitin.

For feeding trials, each solpugid was presented with a grasshopper from one of
the designated size classes. Feeding trials were recorded with a Cine-8 High Speed
Camera (Visual Instrumentation Corp.) at 100 frames/sec. A Lafayette Super 8
Analyzer (Model 1026) was used for frame-by-frame analysis as described by
Punzo (1989). I recorded the removal time (sec), defined as the amount of time
that elapsed from the moment the prey was grasped until a particular body part
was detached.

I used the data recorded for chitin content to determine whether or not there
was any evidence of nutrient concentration. According to the nutrient concentra¬
tion hypothesis (Foster 1987, Kaspari 1990), the removal of prey parts possessing
high amounts of indigestible chitin (prey preparation) should result in the con¬
centration of utilizable nutrients while maximizing the amount of space in the
gut available for additional food items. I calculated the difference in nutrient
concentration when a particular body part was removed from the grasshopper
using the data collected on chitin content. The various body parts were subse¬
quently ranked by dividing the mean removal time for each body part by its chitin
content as described by Kaspari (1991).

Statistical analyses followed procedures described by Sokal & Rohlf (1981).
Prey-part rankings were obtained by Tukey’s multiple comparison test; this yield¬
ed statistical clusters of body parts. These clusters related to predicted perfor-

1995

PUNZO: EREMORHAX MAGNUS PREY PREPARATION

15

Table 1. Mean chitin weight (mg) and percent chitin (%) of several body parts for two size classes
of the grasshopper, Trimerotropis pallidipennis.

Body part

Grasshopper size class

Small

Large

n

Mean weight

SD

%

n

Mean weight

SD

%

Head

10

2.34

0.32

37.7

9

5.85

0.84

40.4

Antennae

10

0.13

0.02

41.2

10

0.32

0.03

43.6

Abdomen

9

2.77

0.41

9.7

8

6.47

0.72

12.3

Thorax

10

0.51

0.14

21.1

10

1.24

0.31

25.2

Hind femur

10

1.91

0.17

17.4

9

2.87

0.26

18.3

Foreleg

10

0.31

0.04

43.4

10

0.54

0.07

41.2

Midleg

8

0.20

0.02

35.4

10

0.42

0.03

39.7

Front wing

8

1.10

0.16

48.7

Hindwing

10

1.57

0.38

61.4

mances of the solpugids at each combination of predator and prey size. Kendall’s
measure of concordance was used to assess between-predator and between-prey
size similarity in consumption frequencies. For all solpugids, I determined the
mean consumption frequency for each prey body part in order to estimate any
possible preferences as described by Lucas (1983) and Kaspari (1990). Tukey’s
multiple comparison test clustered prey parts according to similar consumption
frequencies. All tests were two-tailed with significance levels set at P = 0.05.

Results and Discussion

Values for mean chitin weights and percentages for various body parts of T.
pallidipennis are listed in Table 1. Head capsules, antennae, forelegs, midlegs and
both pairs of wings are all characterized by relatively high chitin content (35.4-
61.4%) as compared to the abdomen (9.7-12.3%), thorax (21.1-25.2%) and hind
femur (17.4-18.3%). Analyses of feeding trials indicate that E. magnus selectively
removes the head capsule and wings (Table 2) and focuses its feeding on those
body parts containing the least amount of indigestible chitin such as the abdomen,
thorax and hind femur.

Table 2. Removal time (sec) of Eremorhax magnus for grasshopper body parts from two different
size classes.

Body part

Grasshopper size class

Small

Large

n

Mean (SD)

n

Mean (SD)

Head and antennae 3

20

37.3 (7.4)

23

72.4 (9.1)

Abdomen

17

NR b

15

NR

Thorax

19

NR

20

NR

Hind femur

18

NR

14

NR

Forewing

12

14.8 (3.6)

Hindwing

14

17.1 (6.1)

a Significant between-grasshopper size differences (P < 0.01).
b NR = body part not removed (grinded vigorously between chelicerae).

16

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Solpugids consumed prey parts from each prey size class in similar frequencies
(Kendall’s W = 0.57, P < 0.05 for small prey; W = 0.84, P < 0.01 for large prey)
except for fore- and hindwings which were very small in the smaller hoppers and
usually ingested with the rest of the thorax. The Tukey tests indicated the following
clusters of consumption frequencies: for the larger prey size category, the head
capsules were removed in 84% of the feeding trials whereas forewings and hind-
wings were removed in lower frequencies (54 and 37%, respectively). For the small
grasshoppers, head capsules were removed in 77% of the feeding trials. Kendall’s
concordance was significant (W = 0.852, P < 0.01) for the mean consumption
frequencies of body parts for each prey size class indicating that the same criteria
were involved in decisions to remove prey parts from both small and large prey.

Video recordings also showed a rather stereotyped feeding behavior pattern for
these solpugids feeding on grasshoppers. In all cases, E. magnus females responded
quickly to tactile stimuli upon contact of prey with their palpi or legs. Following
initial contact, the grasshopper is pulled toward the chelicerae by the palpi. The
prey is then grasped firmly with the chelicerae. This is followed by a vertical
motion of the movable cheliceral finger against the upper fondal teeth resulting
in the fragmentation and grinding of prey tissues. During the movement of the
prey through the cheliceral mill, certain body parts are severed and removed, and
others are retained for further processing and subsequent ingestion (Table 2).
Although the forelegs, midlegs and hind tibiae were discarded, the hind femur
was processed through the chelicerae allowing these solpugids to ingest the mass
of muscle tissue associated with these saltatorial legs. This was not observed when
E. magnus fed on other types of arthropods such as beetles and spiders. Previous
observations on feeding behavior in other species have indicated that in some
cases the prey is actually stabbed with the chelicerae upon initial contact (Bolwig
1952, Cloudsley-Thompson 1977, Turner 1916). This was not observed in E.
magnus for any feeding trial. Some investigators have reported stalking of prey
by some solpugids such as Hemerotrecha californica Chamberlin and Galeodes
sp. (Muma 1966) but this behavior was not observed forii. magnus. The amount
of time required by E. magnus to ingest small grasshoppers ranged from 6.2-17.4
min; for larger grasshoppers ingestion time ranged from 11.6-28.3 min.

The results from this study are the first demonstration that prey preparation is
an important component of handling time for a solpugid. By removing body parts
difficult to digest, E. magnus is maximizing the concentration of nutrients that
can be digested and absorbed as well as the amount of space available in the gut
to receive additional food. These benefits may outweigh the cost associated with
an increase in the overall handling time that accompanies prey preparation.

Acknowledgment

I thank T. Punzo and J. Bottrell for assistance in the collection of specimens
in the field, B. Garman for consultation on statistical procedures, D. Donohue
for permission to collect on private property, and W. Price and T. Snell for critical
input and constructive criticism provided on earlier drafts of the manuscript. A
Faculty Development Grant from the University of Tampa made much of this
work possible.

1995

PUNZO: EREMORHAX MAGNUS PREY PREPARATION

17

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Curio, E. 1976. The ethology of predation. Springer Verlag, New York.

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Muma, M. H. 1966. Feeding behavior of North American Solpugida (Arachnida). Fla. Ent., 49:
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O’Brien, W. J., H. Browman & B. I. Evans. 1990. Search strategies and foraging animals. Am. Sci.,
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Punzo, F. 1991. Field and laboratory observations on prey items taken by the wolf spider, Lycosa
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PAN-PACIFIC ENTOMOLOGIST
71(1): 18-23, (1995)

NEST AND COLONY STRUCTURE IN THE PRIMITIVE ANT,
HARPEGNATHOS VENATOR (SMITH)
(HYMENOPTERA: FORMICIDAE)

Michael W. J. Crosland

Department of Biology, Chinese University of Hong Kong,

Shatin, N.T., Hong Kong

Abstract .—Colonies of the primitive ant Harpegnathos Venator were found to make a simple
nest of uniform design with only two nest chambers. Nests were found in clay embankments.
Such simple nests are unusual in mature colonies of ants. Interesting characteristic funnels were
found constructed both between the chambers and at the nest entrance. Colonies comprised a
mean of only 35 workers and a maximum of 72 workers (from 26 colonies excavated). Dealate
queens were present in nests. Twenty-one nests contained one queen and 5 nests contained 2
queens. This contrasts with some other primitive ant species where the queen caste has been
secondarily lost. Queens, though morphologically distinct, were little larger than workers. Queen
weight averaged only 1.4 times the mean worker weight.

Key Words.— Insecta, Hymenoptera, Formicidae, ant, primitive ant, Harpegnathos, nest

Harpegnathos is amongst the most bizarre and little-known genera of ants.
Recent investigations of the southern Indian species, Harpegnathos saltator Jer-
don, were prompted by the 1990 International Social Insect conference (IUSSI)
held in India, where this ant was made the symbol of the conference because of
its extraordinary appearance. Harpegnathos is frequently compared (Shivashankar
et al. 1989, Nascimento et al. 1993) with the primitive Myrmecia ants from
Australia which also have large size, elongated mandibles, large eyes and primitive
traits, such as workers foraging individually. Harpegnathos, however, belongs to
a different subfamily (subfamily Ponerinae, tribe Ponerini). Its very elongated
mandibles are upturned at the end in a most bizarre fashion and it readily makes
jumps of more than 10 cm to catch insect prey (Musthak Ali et al. 1992).

In this paper, I investigate a second species of Harpegnathos. Nothing is pub¬
lished about H. senator, except its taxonomy (Wu 1941). In Hong Kong, where
it has been previously recorded (Wu 1941), it is known as “The Jumping Ant”
and described as “uncommon” (Hill et al. 1982).

Ponerine ants are particularly interesting because of the secondary loss of the
queen caste in a number of species. In this situation, reproductive workers take
over the function of the queen caste (Peeters 1991). Nothing has been published
about colony size, nest structure, or presence or absence of a queen caste in any
species of Harpegnathos. I provide this information in this paper for H. Venator
and describe the remarkably simple nest structure of this species.

Materials and Methods

Twenty-six colonies of Harpegnathos Venator were excavated in 1992 and 1993
from Tai Po Kau Nature Reserve and Sha Lo Tung in the New Territories in
Hong Kong. Detailed notes and measurements of nest structure were made during
nest excavation. All ants present in colonies were collected and brought to the
laboratory where queens and workers were counted and measured.

1995

CROSLAND: HARPEGNATHOS VENATOR NEST STRUCTURE

19

Results

Nest Locations.— All nests were found on steep slopes, typically cut into a
hillside beside a constructed footpath. Slopes with Harpegnathos nests were all
in partially shaded locations in mixed deciduous wooded areas (largely replanted
since 1945). All slopes were of exposed clay and sparsely vegetated with occasional
moss and small ferns.

Workers. —Nests contained from 8 to 72 workers with a mean of 35.0 workers
(interquartile range 25-49). Most workers were found in the upper nest chamber.
Workers were remarkably timid. Many remained stationary at (or retreated to)
the back wall of their nest chamber, with few workers moving forward out of their
nest chamber, even when the nest chamber was broken open. Workers were
monomorphic and had a slow “tempo” (i.e., slow, deliberate movements, Holl-
dobler & Wilson 1990).

Queens. — A queen caste was found in H. Venator. Of the 26 colonies excavated,
21 colonies contained a single queen and 5 colonies contained 2 queens. Queens
were usually found in the upper nest chamber. Queens were morphologically very
similar to workers though they could be clearly distinguished by their maximum
thorax width (i.e., thorax width at the widest point of the fused meso- and meta¬
thorax). (Mean maximum thorax width of queens = 2.25 mm, range 2.20-2.35
mm, n = 10. For workers, mean = 1.67 mm, range 1.45-1.90 mm, n = 100.)
Queens were found to possess the full complement of flight-associated sclerites,
typical of a generalized hymenopterous thorax (e.g., Wheeler 1910, Bolton 1986,
Holldobler & Wilson 1990). Virgin queens, found newly-eclosed in summer, all
possessed full-length wings with hind-wings extending past the abdominal tip
(none were brachypterous). Overall, however, queens were little larger than work¬
ers. Queens were an average of only 1.4 times average worker weight. (Mean dry
weight of queen =16.5 mg, range 15.5-17.0 mg, n = 10. For workers, mean =
11.5 mg, range 8.0-14.5 mg, n = 100.)

Nest Entrance. — Nest entrances extend 1-4 cm out from the slope to form a
characteristic funnel (Fig. 1). The funnel is oval, typically about 3 cm in diameter
(though occasionally larger) but often narrower where it joins the slope. A narrow
nest entrance, open throughout the year in most nests, is present in the middle
of the funnel.

Nest Chambers. — All 26 nests excavated had two nest chambers, although col¬
onies collected varied considerably in size (8 to 72 workers). Larger colonies also
had only two nest chambers but enlarged. (The nests were mature since they
seasonally contained multiple alates of both sexes). However, one large colony
(59 workers) had a third rather irregular nest chamber.

The two nest chambers are typically disk-shaped and slightly domed in the
center (Fig. 1). The wall to the nest chamber is very smooth and evenly sculptured
in the clay. Workers often congregate in occasional small extensions to the cham¬
bers (“alcoves,” Fig. lb). The upper and lower chambers are separated by a thin
partition and connected by a single funnel.

Funnel Connection. — A remarkable funnel provides the only connection be¬
tween the upper and lower nest chambers (Fig. 2). The funnel is typically about
2 cm in diameter with a narrow 5-8 mm hole for the ants to pass through. The
funnel is above the highest part of the domed lower chamber and connects to the

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THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

F

Figure 1. Typical nest structure of Harpegnathos Venator, (a) Vertical lateral cross-section of nest,
(b) View from above. Typical measurements are: A = 1.5-2 cm; B = 5-12 cm and; C = 6-16 cm. D
= Nest entrance, E = Lower chamber, F = Funnel connection between lower and upper chamber, G
= Upper chamber, H = “Alcove.”

1995

CROSLAND: HARPEGNATHOS VENATOR NEST STRUCTURE

21

• ••)
Dll)

I i I g

Figure 2. Funnel between upper and lower nest chambers, (a) Vertical lateral cross-section, (b)
View of circular funnel from below. A = Lower nest chamber; B = Upturned lip of funnel; C = Upper
chamber; D = Diameter of funnel = about 2 cm.

front of the upper chamber. The circular funnel is sculptured from clay and has
an upturned lip (Fig. 2).

Discussion

The present paper describes the two-chambered nest of H. Venator which is
amongst the simplest recorded in mature colonies of ants, though the nest also
has a remarkable internal funnel connection. Primitive characteristics of H. vena-
tor included small colony size and little size differentiation between queens and
workers.

Nests of mature ant colonies typically contain a complex of multiple nest cham¬
bers, (often dozens or even hundreds, Sudd 1967, Dumpert 1981, Holldobler &
Wilson 1990). Even primitive Myrmecia ants in Australia have large complex
nests with multiple nest chambers (Gray 1971). The uniformity in the design of
the simple two-chambered nest among H. Venator colonies was most striking.
Only small variations occurred among nests, for example, as a result of large rocks
in the clay interfering with the typical disk-shaped nest chambers.

The funnel connection between the two nest chambers is interesting, with no

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similar structure being recorded in the major reviews on ant nest structure (Whee¬
ler 1910, Sudd 1967, Dumpert 1981, Holldobler & Wilson 1990). The funnel is
typically about 2 cm above the floor of the lower chamber. R. Winney (personal
communication) speculates that H. Venator may need their jumping ability to get
from the lower chamber into the funnel. Most ants were found in the upper
chamber and clearly evacuation to the upper chamber would facilitate escape
against arthropod predators entering the nest.

Primitive characteristics found in H. Venator included nesting in soil, small
colony size, slow tempo of worker movement and little size differentiation between
queens and workers. Nests of ants are thought to have first evolved in soil and
later developed a diversity of locations, e.g., nesting inside plants, tree-trunks or
using leaves of trees to build nests (Dumpert 1981). The small colony size found
in H. Venator (a mean of only 35 workers) further points to their primitiveness
(no large complex society having evolved). This colony size is amongst the lowest
known in ants (Holldobler & Wilson 1990), though at least three ant species are
known with even smaller colonies (Peeters et al. 1991). However, most ant species
including the primitive Myrmecia ants have evolved the ability to develop much
larger colonies (typically several hundred workers in Myrmecia, Holldobler &
Wilson 1990).

True morphologically-distinct queens were found in nests of H. Venator. This
contrasts with some other primitive ponerine ants where the queen caste has been
replaced by reproductive workers (Peeters 1991). Interestingly in the other major
group of primitive ants, the subfamily Myrmeciinae, the queen caste is always
found in all species so far examined (Haskins 1970; Crosland, unpublished data).
Queens of H. Venator are little larger than workers. Similar queens, little larger
than workers, are also found in some primitive Myrmecia species (reviewed in
Wilson 1971). Worker-like queens are sometimes referred to as “ergatoid.” How¬
ever, the recent suggestion is to reserve the term “ergatoid” for intermediates
between normal queens and workers that can replace the ordinary queen caste
(Holldobler & Wilson 1990). Hence H. Venator queens are not ergatoid. Queens
of Myrmecia and H. Venator contrast with those of higher ants such as Camponotus
where queens are approximately 20 times the weight of minor workers (Crosland
1990).

Ant queens typically found colonies claustrally, in a closed underground cham¬
ber where the first larvae are fed on food reserves and digested alary muscles from
the body of the lone queen. Worker-like Myrmecia queens are primitive amongst
ants in that the single colony-founding queen periodically leaves her underground
chamber to forage, presumably because her worker-like body has insufficient food
reserves to rear her first brood (Wilson 1971). Experiments are planned to test
whether similar queen foraging also occurs in H. Venator.

Acknowledgment

Thanks to Phil Ward for pointing out this interesting species and to Dick
Winney, Christian Peeters and an anonymous referee for help with this work.
This work was supported by a Direct Grant from the University and Polytechnic
Grants Council to the Chinese University of Hong Kong.

1995

CROSLAND: HARPEGNATHOS VENATOR NEST STRUCTURE

23

Note added in proofs: The nest architecture of Harpegnathos saltator will soon be published in: Peeters,

C., B. Holldobler, M. Moffett & T. M. Mustak Ali. 1994. “Wall-papering” and elaborate nest

architecture in the ponerine ant Harpegnathos saltator. Insectes Sociaux (in press).

Literature Cited

Bolton, B. 1986. Apterous females and shift of dispersal strategy in the Monomorium salomonis-
group (Hymenoptera: Formicidae). J. Natur. Hist., 20: 261-212.

Crosland, M. W. J. 1990. The influence of the queen, colony size and worker ovarian development
on nestmate recognition in the ant Rhytidoponera confusa. Anim. Behav., 39: 413—425.

Dumpert, K. 1981. The social biology of ants. Pitman, London.

Gray, B. 1971. Notes on the biology of the ant species Myrmecia dispar (Clark). (Hymenoptera:
Formicidae). Insectes Sociaux, 18: 71-80.

Haskins, C. P. 1970. Researches in the biology and social behavior of primitive ants. pp. 355-388.
In Aronson, L. R., E. Tobach, D. S. Lehrman & J. S. Rosenblatt (eds.). Development and
evolution of behavior. W. H. Freeman, San Francisco.

Hill, D. S., P. Hore & I. W. B. Thornton. 1982. Insects of Hong Kong. Hong Kong University Press,
Hong Kong.

Holldobler, B. & E. O. Wilson. 1990. The ants. Belknap Press, Cambridge, Massachusetts.

Musthak Ali, T. M., C. Baroni Urbani & J. Billen. 1992. Multiple jumping behaviors in the ant
Harpegnathos saltator. Naturwissen., 79: 374-376.

Nascimento, R. R., J. Billen & E. D. Morgan. 1993. The exocrine secretions of the jumping ant
Harpegnathos saltator. Comp. Biochem. Physiol., 104B: 505-508.

Peeters, C. 1991. The occurrence of sexual reproduction among ant workers. Biol. J. Linn. Soc., 44:
141-152.

Peeters, C., S. Higashi & F. Ito. 1991. Reproduction in ponerine ants without queens: monogyny
and exceptionally small colonies in the Australian Pachycondyla sublaevis. Ethology Ecology
& Evolution, 3: 145-152.

Shivashankar, T., H. C. Sharathchandra & G. K. Veeresh. 1989. Foraging activity and temperature
relations in the ponerine ant Harpegnathos saltator Jerdon (Formicidae). Proc. Indian Acad.
Sci. (Anim. Sci.), 98: 367-372.

Sudd, J. H. 1967. An introduction to the behaviour of ants. E. Arnold Publishers, London.

Wheeler, W. M. 1910. Ants, their structure, development and behavior. Columbia University Press,
New York.

Wilson, E. O. 1971. The insect societies. Belknap Press, Cambridge, Massachusetts.

Wu, C. F. 1941. Catalogus insectorum sinensium. Volume 6. Published by Yenching University,
Peiping, China.

PAN-PACIFIC ENTOMOLOGIST
71(1): 24-30, (1995)

TETHERED FLIGHT CHARACTERISTICS OF MALE AND
FEMALE PEAR PSYLLA (HOMOPTERA: PSYLLIDAE):
COMPARISON OF PRE-REPRODUCTIYE AND
REPRODUCTIVE INSECTS

David R. Horton and Tamera M. Lewis
USDA-ARS, 1 Yakima, Washington 98902

Abstract.— In tethered flight experiments, female winterform pear psylla (Cacopsylla pyricola
Foerster) exhibited longer mean flight durations and a higher frequency of long duration flights
(> 15 min) than did males. Pre-reproductive psylla (collected from the field in mid-winter)
exhibited longer duration flights than did psylla collected from the same orchard after egg-laying
had commenced. Flight durations decreased with consecutive flights. Although tibia length and
wing size were larger for females than males, there was no evidence within sexes or collection
dates that body size and flight duration were correlated.

Key Words. — Insecta, tethered flight, pear psylla, body size

Pear psylla, Cacopsylla pyricola Foerster, is a specialist pest of pears in many
pear growing regions of the world. The species is seasonally dimorphic (Oldfield
1970). The overwintering generation (winterform) undergoes a reproductive dia¬
pause in the fall, characterized by a lack of mating and immature ovaries (Krysan
& Higbee 1990), and (for a large fraction of the population) dispersal from pear
orchards (Horton et al. 1992). Reentry into pear orchards, ovarian development,
and egg-laying occur in early spring as temperatures rise (Krysan & Higbee 1990,
Horton et al. 1992).

For many insect species, diapause, reproductive status, and dispersal are closely
linked life history components (Johnson 1969). Earlier work failed to demonstrate
large differences between tethered flight activity of diapausing and post-diapause
(but pre-reproductive) female winterforms (Horton, unpublished data). This study
compared flight characteristics of psylla collected from the field in mid-winter
(pre-reproductive) with those of psylla collected from the same orchard once egg-
laying had commenced. We also compared flight characteristics of males and
females for both pre-reproductive and reproductive psylla. In several other insect
species, females appear to be the more dispersive sex (Adesiyun & Southwood
1979, Reader & Southwood 1984, Davis 1986). Finally, we recorded several wing-
and body-size measurements to determine whether flight capacity was related to
body size.

Materials and Methods

Flight Methods. —Winterform pear psylla were collected from a commercial
pear orchard in Yakima, Washington on two occasions: 19-22 Jan 1993 and 29-
31 Mar 1993. Egg-laying had commenced in the field by the March collection;
dissections indicated that psylla collected in mid- to late-January had immature
ovaries (first mature eggs in dissections were not noted until the first week of
March: DRH, unpublished data). Psylla were separated by sex and placed in 150

1 3706 W. Nob Hill Blvd.

1995

HORTON & LEWIS: PEAR PSYLLA FLIGHT

25

ml screened vials (5 per vial) on field-collected pear shoots. Vials and psylla were
placed in the flight room (25° C; 85% RH; 10:14 h [L:D]) for 24 h; psylla were
flown in the morning (0900 PST) and afternoon (1300 PST) of the day following
collection.

The tip of a nylon brush bristle (5-8 mm in length) was attached to the me-
sothorax of psylla using a small drop of a cyanoacrylate glue (INSTA-CURE®,
Bob Smith Industries, Atascadero, CA). The other end of the bristle was attached
to an insect pin, which in turn was stuck in a styrofoam block. Psylla were
immobilized for gluing by lightly etherizing them. After being glued, psylla were
placed in a cold room (3° C) for 30 min to recover from handling.

The flight chamber was a0.5m x 0.5 m x 0.5 m box with white sides, a
plexiglass top, and an open front. The chamber was illuminated by two 20 watt
cool white fluorescent bulbs that were suspended 1 m over the box. Flight durations
were timed with the aid of a personal computer and BASIC program. Upon
removal from the cold room, psylla were allowed a 15 min “warm-up” period
before initiation of the experiment. If flight was not initiated voluntarily, we lightly
blew a puff of air at the posterior end of the psylla. Each psylla was flown 5 times,
with a 5 min rest period between consecutive flights. Exceptions were psylla that
flew continuously for at least an hour; for these psylla, the experiment was ended
at 1 h. Sample sizes were 32 to 39 psylla for each sex x collection date combination.

Body Size Measurements.— Following the flight experiments, body size mea¬
surements were made using a dissecting scope and ocular micrometer. Measure¬
ments were made of tibia length and four wing characteristics. For tibia length,
a hind leg was cut off at mid-femur and laid flat on the platform, with the outward
portion of the leg facing up. The tibia was measured from the posterior distal
point to the knob at the anterior proximal end. For wing size, a forewing was cut
off near the base, laid convex side up, and then covered with a glass cover slip.
Wing measurements included the distances between the following: (1) fork of the
median (M) and cubitus (Cu) veins to the fork of Cu la and Cu lb veins (measure
LRC in Nguyen 1985); (2) fork of the Cu la and Cu lb veins to the fork of the M 1+2
and M 3+4 veins (measure LCM in Nguyen 1985); (3) fork of the M and Cu veins
to the apex of the wing; (4) termination of the Cu lb vein to the costal vein break.
The latter two estimates were included to provide some indication of overall wing
length and width, respectively.

Data Analysis.— For each insect, three measures of flight duration were mon¬
itored: duration of the longest flight, mean flight duration (of consecutive flights
[up to 5 flights per insect]), and duration of the first flight. Flights of 60+ min
were scored as 60 min. These data were analyzed with two-way (sex x reproductive
status) analysis of variance (ANOVA). We caution here that the data departed
significantly from the assumption of normality (even if transformed), results not
uncommon in studies of tethered flight (Davis 1980). Because ANOVA assump¬
tions were not met, marginally significant results should be accepted only cau¬
tiously. For insects that completed 5 flights, we included flight number (first
through fifth) as a factor in a repeated measures ANOVA; this analysis allowed
us to determine whether flight duration changed between one flight and a sub¬
sequent flight. Body size measurements were compared between sexes and col¬
lection dates using multivariate analysis of variance (MANOVA). All analyses
were done in the PROC GLM package of SAS (SAS Institute 1987).

26

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SHORT INTERMED. LONG
FLIGHT DURATION

Figure 1. Observed (symbols) and fitted (lines) proportion of pear psylla for which the longest
flight was short-duration (< 5 min), intermediate-duration (5-15 min), or long-duration (> 15 min).
Lines show predictions from multiway categorical analysis: sex —% 2 = 6.81, P = 0.033; reproductive
status—x 2 = 5.46, P = 0.065; likelihood ratio (= interaction): P = 0.996. For first flight (frequencies
very similar to those shown for longest flight): sex—x 2 = 7.1, P = 0.029; reproductive status—x 2 =
6.4, P = 0.04; likelihood ratio (= interaction): P = 0.994. For average flight (data not shown), P -values
both > 0.25.

We also classified flight durations (longest, first, mean) into one of three cate¬
gories: short flight (< 5 min); intermediate flight (5-15 min); long flight (> 15
min). These data were analyzed as a 2 x 2 x 3 (sex x reproductive status x
flight category) multiway categorical table using PROC CATMOD (SAS Institute
1987).

Product-moment correlation was used to determine whether there was any
relationship between tibia length or the four wing measurements and the three
estimates of flight duration (longest, mean, first). Analyses were done separately
for each sex x collection date combination using the PROC CORR package of
SAS (SAS Institute 1987).

Results

For longest flight and first flight, proportion of psylla falling in the short-,
intermediate-, or long-duration flight categories varied with both sex and repro¬
ductive status (Fig. 1; results shown only for longest flight, as results for first flight
were virtually identical). For both sexes, probability of intermediate- or long-
duration flight was larger for pre-reproductive psylla than for reproductive psylla,
whereas the converse was true for short-duration flights; i.e., for the latter, about
40% of reproductive psylla exhibited short-duration flight, whereas only about
25% of pre-reproductive psylla exhibited flights of this duration (Fig. 1). The

1995

HORTON & LEWIS: PEAR PSYLLA FLIGHT

27

LONGEST FIRST AVERAGE

Figure 2. Mean (± standard error) flight durations (longest, first, average) for pre-reproductive
(PRE-R) and reproductive (REP) pear psylla. Results of ANOVA (all effects df = 1,142); longest: sex—
F = 4.8, P = 0.029; reproductive status —F = 8.1, P = 0.005; interaction —P = 0.27; first flight: sex—
F = 4.6, P = 0.034; reproductive status —F = 8.7, P = 0.004; interaction —P = 0.23; average: sex—
F= 5.8, P = 0.017; reproductive status— F= 4.0, P = 0.049; interaction —P = 0.31.

greatest difference between the sexes was in frequency of intermediate- and long-
duration flights. Females exhibited a higher frequency of long-duration flights
than did males, whereas males flew primarily intermediate-duration flights. Re¬
sults are not shown for average flight duration, as reproductive status and sex
effects were not significant (see Fig. 1 caption).

Mean flight durations varied with sex and reproductive status for all three
estimates of flight duration (Fig. 2). For all measures, females exhibited larger
mean durations than did males, and pre-reproductive psylla flew longer than did
reproductive psylla (although P = 0.049 for reproductive status [average flight
duration]; see Fig. 2 caption). There is a suggestion of a sex x reproductive status
interaction for all three response variables (Fig. 2); however, in no case was the
interaction significant (Fig. 2 caption).

For psylla that completed 5 flights, there was a significant decay in mean flight
duration between the first flight and subsequent flights (Fig. 3). There was also a
significant flight number x reproductive status interaction (Fig. 3 caption); the
interaction was apparently due to large differences in flight durations between
reproductive and pre-reproductive psylla for the first flight, but not for subsequent
flights (univariate ANOVA for the first flight: reproductive status —F = 7.8; df =
1,133; P = 0.006; similar analyses for flights 2-5 were non-significant).

Males were significantly smaller than females (Table 1). However, within each
sex x reproductive status category, correlations between the body size measure¬
ments and the three measures of flight duration (longest, mean, first) were non¬
significant.

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12 3 4 5

FLIGHT NUMBER

Figure 3. Mean (± standard error) flight durations of consecutive flights for pear psylla that
completed 5 flights. Results of repeated measures ANOVA (within-subjects statistics from Wilks’
lambda): flight number— F = 28.3, df =4,130 , P < 0.0001; flight number x reproductive status— F
= 2.5, df = 4,130, P = 0.04; flight number x sex—i 7 = 1.5, df = 4,130, P = 0.21; flight number x
reproductive status x sex —F = 2.0, df = 4,130, P = 0.10; reproductive status —F = 5.7, df = 1,133,
P = 0.018; sex —F <c 1.0; reproductive status x sex —F < 1.0.

Discussion

Studies have suggested or shown for other insect species that females are more
dispersive than males (Adesiyun & Southwood 1979, Reader & Southwood 1984,
Stewart & Gaylor 1991) or that females exhibit longer flight durations than males
in laboratory flight experiments (Dingle 1966, Davis 1986). In this study, female
winterform pear psylla exhibited larger mean flight durations (Fig. 2) and a higher
frequency of long (> 15 min) flights than did males (Fig. 1). Also, of the 146
insects tested, three flew continuously for 1 + h before being interrupted; all three
were females (longest male flight was 46 min). As females are larger than males
(Table 1), it is tempting to hypothesize that body size affected flight durations, as
shown for other species (Dingle et al. 1980, Davis 1986, Saks et al. 1988, Rolf
1991); however, we were unable to demonstrate a relationship between body size
and flight duration within any of the 4 sample groups.

Fall-collected and spring-collected pear psylla did not differ substantially in
flight duration, despite differences between the collections in ovarian development
of psylla (DRH, unpublished data). Long-duration flights in many insects occur
before significant ovarian development (Johnson 1969), so the results of the earlier
study were unanticipated; but, see the discussion in Sappington & Showers (1992).
In this study, there were significant differences in flight activities between the two
collection dates, as psylla collected in late-March had reduced flight durations
relative to psylla collected in January. One difference between this study and a
previous study (DRH, unpublished data) is that the spring sample taken here
occurred well after egg-laying had commenced in the field, whereas the spring
sample in the other study occurred before egg-laying (March 1). This result suggests

1995

HORTON & LEWIS: PEAR PSYLLA FLIGHT

29

Table 1. Mean (± standard error) body size measures (mm) of male and female winterform pear
psylla collected in January (pre-reproductive) and late March (reproductive), 1993.

Measure 1 ’”

Pre-reproductive

Reproductive

Females

Males

Females

Males

Tibia

0.56 (0.004)

0.54 (0.004)

0.55 (0.004)

0.54 (0.004)

LRC

0.65 (0.006)

0.56 (0.006)

0.63 (0.006)

0.57 (0.006)

LCM

0.55 (0.006)

0.51 (0.006)

0.55 (0.006)

0.50 (0.006)

Length

1.87 (0.014)

1.66 (0.012)

1.86 (0.012)

1.66 (0.012)

Width

1.07 (0.008)

0.97 (0.008)

1.06 (0.008)

0.97 (0.008)

a Final four measures are wing measures (see Materials and Methods).

b MANOVA (F-statistics from Wilks’ lambda): sex—F = 60.1, df = 5,130, P < 0.0001; reproductive
status— F = 0.5, df = 5,130, P = 0.79; sex x reproductive status— F = 2.3, df = 5,130, P = 0.048.
Univariate tests: all five measurements differed between males and females (P < 0.0001, df = 1,134);
for LRC, the sex x reproductive status interaction is significant (P = 0.012, df = 1,134); reproductive
status main effects were non-significant for all five measures (P > 0.25).

that long duration flights decreased in frequency as psylla became fully engaged
in egg-laying.

Acknowledgment

The comments of Rick Redak (University of California, Department of En¬
tomology, Riverside), Dave Thompson (New Mexico State University, Las Cru¬
ces), Tom Unruh (USDA-ARS, Yakima, Washington), and Tom Weissling (USDA-
ARS, Yakima, Washington) on an earlier draft are appreciated. We thank Mark
Weiss (USDA-ARS, Yakima, Washington) for writing the BASIC program used
in recording flight data. The Washington Tree Fruit Research Commission (Yak¬
ima), Winter Pear Bureau (Portland, Oregon), and the Western Regional IPM
Grants Program (WRCC 69) provided financial support.

Literature Cited

Adesiyun, A. A. & T. R. E. Southwood. 1979. Differential migration of the sexes in Oscinella frit
(Diptera: Chloropidae). Entomol. Exp. Appl., 25: 59-63.

Davis, M. A. 1980. Why are most insects short fliers? Evol. Theory, 5: 103-111.

Davis, M. A. 1986. Geographic patterns in the flight ability of a monophagous beetle. Oecologia,
69: 407-412.

Dingle, H. 1966. Some factors affecting flight activity in individual milkweed bugs ( Oncopeltus ). J.
Exp. Biol., 44: 335-343.

Dingle, H., N. R. Blakely & E. R. Miller. 1980. Variation in body size and flight performance in
milkweed bugs ( Oncopeltus ). Evolution, 34: 371-385.

Horton, D. R., B. S. Higbee, T. R. Unruh & P. H. Westigard. 1992. Spatial characteristics and effects
of fall density and weather on overwintering loss of pear psylla (Homoptera: Psyllidae). Environ.
Entomol., 21: 1319-1332.

Johnson, C. G. 1969. Migration and dispersal of insects by flight. Methuen, London.

Krysan, J. L. & B. S. Higbee. 1990. Seasonality of mating and ovarian development in overwintering
Cacopsylla pyricola (Homoptera: Psyllidae). Environ. Entomol., 19: 544-550.

Nguyen, T. X. 1985. Establishment of a morphometric range of Psyllidae (Insecta-Homoptera);

seasonal polymorphism of Psylla pyri L. C.R. Acad. Sc. Paris, 301: 369-372.

Oldfield, G. N. 1970. Diapause and polymorphism in California populations of Psylla pyricola
(Homoptera: Psyllidae). Ann. Entomol. Soc. Amer., 63: 180-184.

Reader, P. M. & T. R. E. Southwood. 1984. Studies on the flight activity of the Viburnum whitefly,
a reluctant flyer. Entomol. Exp. Appl., 36: 185-191.

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Vol. 71(1)

Roff, D. A. 1991. Life history consequences of bioenergetic and biomechanical constraints on mi¬
gration. Amer. Zool., 31: 205-215.

Saks, M. E., M. A. Rankin & R. E. Stinner. 1988. Sexually differentiated flight responses of the
Mexican bean beetle to larval and adult nutrition. Oecologia, 75: 296-302.

Sappington, T. W. & W. B. Showers. 1992. Reproductive maturity, mating status, and long-duration
flight behavior of Agrotis ipsilon (Lepidoptera: Noctuidae) and the conceptual misuse of the
oogenesis-flight syndrome by entomologists. Environ. Entomol., 21: 677-688.

SAS Institute. 1987. SAS/STAT guide for personal computers. Version 6 Edition. Cary, North
Carolina.

Stewart, S. D. & M. J. Gaylor. 1991. Age, sex, and reproductive status of the tarnished plant bug
(Heteroptera: Miridae) colonizing mustard. Environ. Entomol., 20: 1387-1392.

PAN-PACIFIC ENTOMOLOGIST
71(1): 31-60, (1995)

NON-MONOPHYLY OF AUCHENORRHYNCHA
(“HOMOPTERA”), BASED UPON 18S rDNA PHYLOGENY:
ECO-E VOLUTIONARY AND CLADISTIC IMPLICATIONS
WITHIN PRE-HETEROPTERODEA HEMIPTERA (S.L.) AND
A PROPOSAL FOR NEW MONOPHYLETIC SUBORDERS

John T. Sorensen, 1 Bruce C. Campbell, 2 Raymond J. Gill, 1
and Jody D. Steffen-Campbell 2

1 Insect Biosystematics, Plant Pest Diagnostics Center, 3
California Dept, of Food & Agriculture, Sacramento, California 95832-1448.
2 Western Regional Research Center, USDA-ARS,

Albany, California 94710-1100.

Abstract.— Parsimony-based phylogenetic analyses of full 18S rRNA genes (18S rDNA) were
conducted to determine the basal clade topology of Hemiptera. The single most parsimonious
topology, which attenuated homoplasy and retained only the most conservative base sites,
showed: (a) Stemorrhyncha and Euhemiptera are sister-clades; (b) Cicadomorpha (composed of
Cicadidae and sister-clade Cercopidae+Membracidae) is sister-clade to the remaining Euhem¬
iptera; and (c) Fulgoromorpha is sister-clade to Heteropterodea (Coleorhyncha+Heteroptera).
Supportive morphological synapomorphies for the 18S rDNA topology are listed. Less parsi¬
monious, but competitive topologies indicate association of Heteroptera with extant Cicado¬
morpha. Thus, Auchenorrhyncha is unlikely (< 10%) to be monophyletic, as previously assumed,
and its morphological synapomorphies (tymbal acoustic systems, aristoid antennae, ScP+R vein
fusion) are homoplasious; the misinterpretation, selection, and convergence of these traits is
discussed. Current paleontological assessments of the basal Hemiptera are reviewed and also
suggest non-monophyly for Auchenorrhyncha. A Lower Cretaceous fossil, Megaleurodes me-
gocellata Hamilton, previously assigned to Aleyrodoidea: Boreoscytidae, is tentatively reassigned
to fossil superfamily Fulgoridioidea of Fulgoromorpha. Use of paraphyletic Auchenorrhyncha
should be abandoned as a hemipteran suborder; instead recognition of the four monophyletic
basal clades of Hemiptera as its suborders is appropriate. Three new suborder names are proposed
because of potential confusions or varying definitions (discussed) involving existing names:
Clypeorrhyncha (= extant, monophyletic Cicadomorpha), Archaeorrhyncha (= Fulgoromorpha),
and Prosorrhyncha (= Heteropterodea, as clade Coleorhyncha+Heteroptera); Stemorrhyncha
is retained. Clade name Neohemiptera is proposed for the clade Fulgoromor¬
pha +Heteropterodea. An eco-evolutionary scenario for cladogenesis among the basal hemipteran
clades is presented. Evidence indicates a saltational, punctuated equilibrium mode of evolution
occurred among the clades during, or near, the Permian.

Key Words.— Insecta, Cicadomorpha, Fulgoromorpha, molecular phylogeny, cladistics

The hierarchical, ordinal relationship among the names “Hemiptera,” “Het¬
eroptera,” and “Homoptera” has been confused since Latreille (1810) first rec¬
ognized the latter two names as sections of his “Hemiptera” (sensu lato). This
was done in response to Fabricius’ (1775) mouthpart-based modification of Lin¬
naeus’ (1758) original wing-based classification of insect orders; see Henry &
Froeschner (1988: xii-xiii) for discussion. Current schemes for recognition of (an)
order(s) for all hemipterans differ confusingly among workers and regions. Some
prefer the separate orders Homoptera and Hemiptera (sensu strictu, sensu La-

3 3294 Meadowview Road.

32

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

treille’s Heteroptera), following the revisions of Borror & DeLong’s (e.g., 1971)
books. Others use order Hemiptera (s.l., sensu Latreille) with suborders Homop-
tera and Heteroptera. Still others use the separate orders Homoptera and Het¬
eroptera.

Although sometimes presenting operational problems for a classification (Sor¬
ensen 1990: 402), application of monophyly through cladistic philosophy is being
used to solve the dilemma of hierarchical grouping in Heteroptera (Schuh 1986),
and hopefully for all hemipterans here. On the basis of morphology, cladistic
workers (Kristensen 1975, 1991; Hennig 1981; Popov 1981; Schuh 1979; Wootton
& Betts 1986) now recognize that Homoptera is a paraphyletic grade at the base
of monophyletic Heteroptera, with the entire greater clade usually recognized as
Hemiptera. Accordingly, order Homoptera must be abandoned under a mono¬
phyly criterion, despite the resistance of many homopterists to having their groups
incorporated into Hemiptera because they associate that name with a usage now
replaced by Heteroptera (e.g., Henry & Froeschner 1988).

Recent treatments (e.g., Carver et al. 1991: 443) of Hemiptera retain Stemor-
rhyncha and Auchenorrhyncha as hemipteran suborders, based on their respective
assumed monophyly 4 . Stemorrhyncha is now considered a sister-group (Schuh
1979, Carver et al. 1991, Wheeler et al. 1993) to Auchenorrhyncha+Heteroptera 5
(= Euhemiptera sensu Schuh 1979). Now, Campbell et al. (1994) show irrefutable
evidence of the monophyly of Stemorrhyncha, as a synapomorphy having a unique
nucleotide expansion area of 18S rDNA. Thus, Stemorrhyncha is a cladistically
valid hemipteran suborder. In Campbell et al.’s (1994) analysis, however, Au¬
chenorrhyncha was paraphyletic, a result that is cladistically incompatible with
its use as a hemipteran suborder.

Wheeler et al. (1993) used discontinuous, short sections of 18S rDNA and
morphological data, alone and in combination, in a parsimony analysis to show
in their most resolute indications that their “Auchenorrhyncha” were a mono¬
phyletic grouping. However, because that analysis was chiefly concerned with
relationships within Heteroptera, it included only minimal representatives of
Cicadomorpha 6 (sensu Carver et al. 1991, and here), and showed their monophyly
to be based upon two 18S rDNA sites that were homoplasious when considered
over their entire generated tree. Unfortunately, they excluded Fulgoromorpha,
the putative sister-group to Cicadomorpha (Carver et al. 1991: 445). As a con¬
sequence, Wheeler et al.’s (1993) analysis established only: (a) tentative mono¬
phyly, based upon nucleotide homoplasy under parasimony, for their treated
cicadomorphans rather than among all auchenorrhynchous groups; and (b) that
(in the absence of Fulgoromorpha) their cicadomorphan taxa Cercopidae,
Membracidae) formed a sister-group to Heteropterodea, the latter as clade Co-
leorhyncha+Heteroptera (sensu Schlee 1969, Schuh 1979).

4 Hamilton (1981) considered Auchenorrhyncha to be polyphyletic, based on head morphology,
with its groups surrounding his “Aphidomorpha” (= Stemorrhyncha); however, he considered the
Homoptera, itself, to be monophyletic and the sister-group of Heteropterodea (sensu Schuh 1979).

5 Carver et al. (1991) use Heteroptera [sensu lato] to include Coleorhyncha+Heteroptera [sensu
stricto: e.g., Henry & Froeschner (1988)], a clade considered Heteropterodea (Schuh 1979) [= Het-
eropteroidea (Schlee 1969)] here.

6 Wheeler et al. (1993) used a single Cicadidae [Tibicen sp.] and two Cicadellidae [Graphocephala
coccinea (Forster), Oncometopia orbona (Fabr.)] species.

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 33

In contrast, Campbell et al.’s (1994) analysis included exemplar taxa from
Fulgoromorpha (Flatidae), Cicadomorpha (Cercopidae, Cicadidae, Membraci-
dae), Stemorrhyncha (Psyllidae, Aphididae, Diaspididae, Aleyrodidae) and Het-
eroptera (Miridae). They mention, but do not discuss, the paraphyly of Auchen-
orrhyncha because that study’s purpose was only to establish monophyly for
Stemorrhyncha and its internal phylogeny with reference to the derivation of
Aleyrodidae.

This article: (a) analyzes an expanded set of the 18S rDNA nucleotide sequences
used by Campbell et al. (1994) and derives the basal phylogenetic topology among
major clades of hemipterans; (b) discusses the morphological characters previously
assumed to be valid synapomorphies for Auchenorrhyncha, but that must rep¬
resent homoplasies according to our 18S rDNA analyses; (c) lists supporting
morphological synapomorphies for the 18S rDNA-based tree; (d) discusses the
eco-evolutionary scenario involved with cladogenesis of the 18S rDNA-based
tree; and (e) proposes cladistically compatible category names to reflect the re¬
alignment of the basal phylogeny of Hemiptera.

Discussion of Methods

Chemically-Based Procedures. —Preparation followed Campbell et al. (1994).
Total genomic DNA was purified by homogenizing fresh insects, or parts thereof,
in micro-centrifuge tubes with a pestle in 200 /A of sterile buffer (10 mM Tris,
2.5 mM MgCl 2 , 50 mM KC1), 200 phenol and 10 g 1 20% SDS. The phases
were separated using centrifugation, and the DNA was precipitated using ethanol
and resuspended in 20 g\ TE (10 mM Tris [pH 8.0], 1 mM EDTA).

PCR (Polymerase Chain Reaction) was performed using the Gene Amp® Kit
(Perkin Elmer Cetus, Norwalk, Connecticut) with 25-/A reactions: 1 g\ DNA
template (« 100 ng), 2.5 g\ PCR buffer, 0.5 g\ each dNTP, 2 g\ (50 nM) each
respective forward and reverse primer, 0.125 /A Taq DNA polymerase and 15.25
g\ water. The PCR cycling program was: 30 sec at 95°C, followed by 39 cycles of
1 min at 95°C, 2 min at 50°C and 4 min at 74°C, with 7 min at 74°C after the
last cycle.

Because the 18S rDNA used was difficult to PCR amplify as a single unit, it
was treated as two separate units (“front” and “back”). The front 18S rDNA
portion used (a) forward primer: 5'-CTG GTT GAT CCT GCC AGT AGT-3';
and (b) reverse primer: 5'-GGT TAG AAC TAG GGC GGT ATC-3'. The back
18S rDNA portion used (c) forward primer: 5'-GAT ACC GCC CTA GTT CTA
ACC-3'; and (d) reverse primer: 5'-TCC TTC CGC AGG TTC ACC-3'. These
primers, a-d respectively, correspond to the base positions (a) 4-24, (b) 1385—
1404, (c) 1385-1404, and (d) 2446-2463, of 18S rDNA for Acyrthosiphon pisum
(Harris), as determined by Kwon et al. (1991).

All PCR products were cloned to contend with potentially contaminating DNA
(from associated fungi, parasitic arthropods, etc.) that might be present in the
hemipteran (“template”) preparations. Cloning used the plasmid and competent
cells supplied in the TA Cloning ® System (Invitrogen, LaJolla, California), and
cloning procedures followed the protocols in the instruction manual. Plasmid
DNA preparations were digested with Eco RI and separated by electrophoresis.
Candidate clones for sequencing were selected based upon appropriate size of the
inserted PCR product. Confirmation of the correct 18S rDNA was determined

34

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Table 1. Base sites used in SET 4 analysis. These most conservative informative sites were retained,
as discussed in the text, after attenuation and polarization of alignment A. Sites numbers are our’s
for alignment A after the initial attenuation (SET 1 analysis). See text for site position and secondary
structure of synonymous rRNA (sensu Kwon et al. 1991). Taxa species are given under methods,
STERN represents the site expression across all treated stemorrhynchan taxa. The full sequences
(>2000 sites) for all taxa are deposited in GenBank, and are available there or from us.

Base site number

l

l

l

l

l

l

l

l

l

1

2

2

4"

4

7

0

l

l

l

2

2

5

6

6

7

7*

5

5

5

9

4

6

5

5

2

2

l

l

2

5

6

Taxon

3

2

6

0

9

2

3

9

8

1

3

4

7

1

5

0

7

3

1

9

COLEO

T

A

G

T

G

A

A

c

A

c

G

G

G

G

G

G

G

G

c

T

STERN

T

G

G

T

G

C

G

c

A

c

G

G

G

G

G

T

G

G

c

C

MEMBR

A

A

G

C

A

A

A

T

A

A

A

G

T

T

T

G

G

G

T

T

CERCO

A

A

G

T

A

A

A

T

A

A

A

G

T

T

G

G

G

G

T

T

CICAD

A

A

A

T

A

A

A

T

G

A

G

G

T

T

G

G

G

A

T

T

DELPH

A

A

G

C

A

A

A

T

A

C

G

A

T

G

T

G

A

A

C

T

MIRID

A

A

A

T

A

A

A

T

G

A

A

A

G

A

T

G

A

G

C

T

a Site 79 is homoplasious, as A, in the dipterans, Aedes and Drosophila (see Carmean et al. 1992).
b Site 454 is homoplasious within several heteropteren lineages in Wheeler et al’s. (1993) data
sequences.

by restriction endonuclease analysis and nucleotide sequencing. Stock cultures of
clones used here are available from BCC and JDS-C at USD A, Albany, California.

Both top and bottom strands of double-stranded DNA were completely se¬
quenced using the materials and protocols supplied with the Sequenase® (version
2.0) Sequencing Kit (U.S. Biochemical, Cleveland, Ohio), and [a 35 S]dATP (Am-
resham, Arlington Heights, Illinois).

Exemplar Taxa Employed. — Sequences from our material are deposited with
GenBank under acc. nos. U06474 to U06481, except for Prokelisia marginata
(Van Duzee) (acc. no U09207). Identifications were made by RJG; voucher spec¬
imens of most of the taxa are maintained at CDFA, Sacramento, California.
Families analyzed and their exemplars are:

ALEYRODIDAE: Pealius kelloggii (Bemis) [CALIFORNIA. SACRAMENTO Co.: Sacramento,
Mar 1993, Prunus lyoni (Eastwood) C. S. Sargent]. APHIDIDAE: Acyrthosiphon pisum (Harris) [18S
rDNA sequence ex Kwon et al. (1991), deposited in GenBank, acc. number X62623]. CERCOPIDAE:
Philaenus spumarius L. [CALIFORNIA. CONTRA COSTA Co.: Pinole, 29 Jun 1993, geranium].
CICADIDAE: Okanagana utahensis Davis [CALIFORNIA. SHASTA Co.: Milford, Jul 1993, Arte¬
misia tridentata Nuttall]. DELPHACIDAE: Prokelisia marginata [CALIFORNIA. CONTRA COSTA
Co.: Richmond, 28 Sep 1993, Spartina foliosa Trin.]. DIASPIDIDAE: Aonidiella aurantii (Maskell)
[CALIFORNIA. SACRAMENTO Co.: Sacramento, 14 Jul 1993, Lauras nobilis L.]. MEMBRACI-
DAE: Spissistilusfestinus (Say) [CALIFORNIA. YOLO Co.: Davis, 20 Sep 1993, alfalfa]. MIRIDAE:
Lygus hesperus Knight [CALIFORNIA. YOLO Co.: Davis, 20 Sep 1993, alfalfa]. PSYLLIDAE: Trioza
eugeniae Froggatt [CALIFORNIA. ALAMEDA Co.: Albany, 7 Apr 1993, Eugenia sp.]. TENEBRI-
ONIDAE: Tenebrio molitor L. [18S rDNA sequence ex Hendriks et al. (1988), deposited in GenBank,
acc. number X07801].

Phylogenetic Analyses. — Initial alignments of nucleotide sequences were achieved
using Gene Works® (version 2.3.1, subprogram: “DNA Alignment”; Intelli-
Genetics, Mountain View, California); final optimal alignments were done by
hand. Because of the length of our nucleotide sequences, we only present those
most conservative sites for Euhemiptera in Table 1; full sequences are deposited
in GenBank and are available there, or from us, upon request. The 18S rDNA of

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 35

many of the hemipteran taxa, especially Stemorrhyncha, contained highly variable
expansion regions. These regions were synonymous to helices 10, E21, 41 and 47
of the secondary structure of synonomous 18S rRNA of A. pisum (Kwon et al.
1991, Campbell et al. 1994), and were largely unalignable (< 70%) at the higher
taxonomic levels studied here. Further, the 18S rDNA of several groups suggests
they have a higher clock-speed base substitution rate, causing unacceptable DNA
homoplasy between major clades. Because the effect of these swamped the more
conservative 18S rDNA regions that were needed to decipher the ancient topology
among major clades, we eliminated their influences through a sequential series of
attenuations.

PAUP (Swofford 1993: vers. 3.1.1), in both “branch and bound” and “ex¬
haustive” search modes, was used for phylogenetic analyses. Gaps and deletions
were scored as missing (in SET 1, see below). Weighting (1:10) of transitions to
transversion did not affect tree topologies in any analyses. The PAUP algorithm
was employed because parsimony, as an optimality criterion, has been demon¬
strated to show the greatest accuracy in converging on a phylogenetic topology
with equal rates of evolution, across the range of numbers of available base sites
(especially the least), for Kimura model of evolution and a 10:1 transition: trans¬
version ratio (Hillis et al. 1994); also see Steel et al. (1993) and Sidow/Stewart
(1993) for further discussion of the parsimony criterion in nucleotide analyses.
Although our taxa initially indicated differential rates of base pair substitutions
among differing lineages (Campbell et al. 1994), the problem was dealt with by
selective removal of ancillary groups during the analyses to eliminate these effects
and increase resolution among retained taxa. Similar analytical procedures were
functionally employed on problematic 18S and 28S rRNA data for metazoans
and increased the resolution of their ancient phylogenetic topology (Christen et
al. 1991, Lafay et al. 1992, Smothers et al. 1994), and also have been employed
in phylogenetic reconstruction using continuous morphometric data that has been
transformed using ordinations (Sorensen 1992).

Of many sets of PAUP analyses that were run, four sets are presented here to
illustrate the effect of alignments, and of sequentially attenuating the homoplasy
encountered in the 18S rRNA gene in order to eliminate all but its most conser¬
vative regions. This homoplasy was usually judged by relatively poor (1) consis¬
tency indexes and (2) bootstrap numbers (but see Hillis & Jull 1993, Felsenstein
& Kishino 1993), and by (3) convergent site expression among only the more
terminal taxa between established sister-clades Stemorrhyncha and Euhemiptera.

Initially, our 18S rDNA extraction of a thrips (.Frankliniella sp.) was considered
for tree rooting; however, it possessed an inordinate number of autapomorphic
nucleotides, which rendered it unsuitable, given the level of 18S rDNA homoplasy
in Hemiptera. We also considered a psocopteran for rooting, but were unable to
amplify the full 18S rRNA gene. Ultimately, we chose an available coleopteran,
because of the temporal (Permian) divergence involved, and because Coleoptera
is a basal clade in the Endopterygota, the sister-group to the hemipteroid lineage
(Hennig 1981, Kukalova-Peck 1991, Carmean et al. 1992). The beetle 18S rDNA
was used in conjunction with that of a psyllid, because Campbell et al. (1994),
and our initial analyses, determined that psyllids were the most basal group in
clade Stemorrhyncha; thus, Psyllidae are the nearest monophyletic out-group for
analyses of Euhemiptera.

36

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

In the first set of analyses (SET 1), all the 18S rDNA sites and all treated taxa
were employed, and generated trees were anchored using the beetle. SET 1 was
divided into two subsets (1A, IB), allowing an estimation of the effect of two
differing alignment orders (A, B) among their taxa. Each subset began with a
different taxon as its initial nucleotide alignment, and aligned the sequentially
varying remaining taxa to the first; this served as a check for potential homology
among sites, as deletions were inferred during alignment. The order of alignment
A (SET 1A) was: delphacid, mirid, cicada, cercopid, membracid, beetle, psyllid,
diaspidid, aphid, aleyrodid; this yielded 2738 (alignment inferred) sites, of which
336 were informative. The order of alignment B (SET IB) was: membracid,
cercopid, cicada, mirid, delphacid, beetle, psyllid, diaspidid, aphid, aleyrodid; this
yielded 2773 (alignment inferred) sites, of which 307 were informative. Differences
in the number of sites between these alignments resulted from ambiguities in
aligning sites within variable helices.

The second set of analyses (SET 2) were also conducted on all treated taxa using
subsets with alignments A and B (SET 2A, SET 2B, respectively). The data from
both these subsets were attenuated, however, so that all inferred site deletions
were removed from each, along with all adjacent sites on both sides, back to
agreement across all taxa. This provided an objective and significantly more
conservative estimate of site homology and essentially eliminated subjectivity in
the interpretation of ambiguously aligned sites. The SET 2A attenuation yielded
1513 sites, of which 110 were informative; that of SET 2B yielded 1494 sites, of
which 100 were informative.

The third analysis set (SET 3) was conducted to eliminate the effect of site
homoplasy induced by the presence of more derived taxa within clade Stemor-
rhyncha, some members of which have greatly accelerated base substitution rates
for the gene (Campbell et al. 1994). In SET 3: the diaspidid, aphid and aleyrodid
were eliminated; the nucleotides were realigned in their absence using the align¬
ment A (most informative sites) taxon order; and the tree was anchored using the
beetle. This yielded 1647 sites, of which 64 were informative. The total SET 3
site number increased over that of either SET 2 subset because deletions present
in the omitted taxa, and their pruning effect, were eliminated. The SET 3 number
of informative sites dropped from either of the SET 2 subsets, however, because
synapomorphies among the omitted stemorrhynchans were also eliminated.

The final analysis set (SET 4) was conducted on the SET 3 taxa, but used the
most severe estimate of conservative sites available within Euhemiptera. The SET
4 analysis was based upon alignment A (most informative sites), but used: (1)
only those sites that could be individually out-group polarized in a Hennigian
sense, and (2) of those, sites showing parallel homoplasy between Stemorrhyncha
and Euhemiptera were excluded. Therefore, only those alignment A sites were
used that were plesiomorphic in both the beetle and psyllid (the stemorrhynchan
basal clade), but which were also nonhomoplasiously apomorphic within Euhem¬
iptera, with respect to their lack of co-occurrence in Aleyrodiformes (diaspidid,
aphid, aleyrodid, sensu Campbell et al. 1994). Sites synapomorphic throughout
Stemorrhyncha, but plesiomorphic throughout Euhemiptera used, were also in¬
cluded to give a measure of the support for clade Stemorrhyncha. Thus, SET 4
employed the 20 most conservative informative sites. The SET 4 topology was
manipulated using MacClade (Maddison & Maddison 1992), to explore its less
optimal alternatives.

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 37

Topology Descriptors Used.—Here, brevity of text description for various tree
topologies favors the use of a slightly modified “Newicks’s 8:45” tree description
standard, which is commonly used in phylogenetics. This format lists network
terminals as relative nested subsets within parenthetical enclosures; for further
definition, see Swofford (1993). We use curved brackets, { }, and italics to offset
the descriptors from the text. For example, {{A, B},{C, {D, £}}} describes the
topology: clade A+B as sister-group to clade C+D+E, and within the latter,
sister-group C to clade D+E. We also may inject bootstrap support numbers (BSS)
in the descriptors, as for example, {{A, B} 85, C} 73, where clade A+B bootstraps
at 85% and clade A+B+C at 73%. We abbreviate the taxa, sometimes including
larger recognized clade names where their internal topology are unimportant in
the given frame of reference, by their capitalized first five letters (e.g., { {MEMBR,
CERCO}, STERN} for {{Membracidae, Cercopidae }, Sternorrhyncha}).

Results: The 18S rDNA Trees

SET 7. — SET 1A, based on 2738 total sites [TS] and 336 informative sites [IS],
yielded a minimum length tree [MLT] (not shown) with a tree length [TL] of 847
and a consistency index [Cl] of 0.58. In that topology: {{STERN} 92, {EUHEM}
60}. Within Sternorrhyncha: {{{APHID, DIASP} 100, ALEYR} 99, PSYLL} 92\
which supports clade Aleyrodiformes (sensu Campbell et al. 1994). Within Eu-
hemiptera: {{AUCHE} 53, MI RID} 60. Within Auchenorrhyncha: {{ CICAD,
CERCO, MEMBR} 96, DELPH} 53; as a trichotomy within Cicadomorpha, with
sister-clade Fulgoromorpha. Thus, SET 1A supports an Auchenorrhyncha clade
but only at BSS 53.

SET IB (based on 2773 TS, 307 IS) yielded a MLT (not shown) with TL 773
with Cl 0.57. The MLT topology for SET IB is similar to that for SET 1A in
that: {{STERN} 68, {EUHEM} 75}; showing lower bootstraps for Stemorrhyn-
cha, but higher for Euhemiptera. Also, within Sternorrhyncha: {{ {APHID, DIASP}
100, ALEYR} 79, PSYLL} 68; showing lower bootstraps for the entire clade and
clade Aleyrodiformes. However, SET IB shows paraphyly for Auchenorrhyncha,
with topology: {{CICAD, CERCO, MEMBR, MIRID} 54, DELPH} 54; where
the heteropteran forms a quadrachotomy at low bootstrap with the cicadomor-
phans, and fulgoromorpha is sister-clade to that grouping.

SET 1 resolves Sternorrhyncha, its internal topology, and Euhemiptera, but
does not resolve the origin of Heteroptera or potential monophyly for Auchen¬
orrhyncha. The low CIs (0.58, 0.57) for SETs 1 indicate high homoplasy levels
in the data.

SET 2. — The same two equally parsimonious MLT topologies, shown in Figs.
1A, IB, were produced by both attenuated SET 2A (based on 1513 TS, 110 IS)
and SET 2B (based on 1494 TS, 100 IS). For SET 2A, these MLT topologies had
TL 232 with Cl 0.59; for SET 2B, they had TL 208 with Cl 0.58.

Both these SETs 2 MLTs show topology: {{STERN} 93, {EUHEM} 97; the
increased euhemipteran bootstrap indicates that the first attenuation of the data
was successful in removing some homoplasy between it and Sternorrhyncha, due,
most probably, to the unique expansion areas of the 18S rDNA in the latter (see
Campbell et al. 1994). The internal stemorrhynchan topology is also preserved
with reasonable bootstraps, as: {{{APHID, DIASP} 99, ALEYR} 84, PSYLL} 93.

The two competing SET 2 MLTs, however, again differ in the placement of
Heteroptera within Euhemiptera, but both indicate polyphyly for Auchenorrhyn-

38

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 71(1)

A

rMEMBR

L CERCO

CICAD

— DELPH

— PSYLL

MIRID

ALEYR
r- DIASP
'—APHID

1 B r- MEMBR

rC

_ CERCO
— CICAD
DELPH

-MIRID

— PSYLL

ALEYR
r- DIASP
1 —APHID

COLEO

COLEO

Figure 1. Two tying minimum length trees (Figures 1A, IB) from PAUP analyses of SETs 2A and
2B. Alignments A (1513 TS, 110 IS) and B (1494 TS, 100 IS) both produced these tying MLTs. For
SET 2A: TL 232, Cl 0.59; for SET 2B: TL 208, Cl 0.58. Branch & Bound bootstrapping for this data
indicates support for clade Euhemiptera (BSS 97) and clade Stemorrhyncha (BSS 93); within Euhem-
iptera: quadrachotomy {MIRID, CICAD, DELPH, {MEMBR, CERCO) 52}; within Stemorrhyncha:
{{{APHID, DIASP} 99, ALEYR) 84, PSYLL } 93. The Fig. 1A MLT indicates a potential origin of
Heteroptera may be associated with cicadomorphans. The Fig. IB MLT indicates clade Fulgoromor-
pha+Heteroptera with sister-clade Cicadomorpha. Both MLTs show internal topology for Stemor¬
rhyncha as per Campbell et al. (1994). Topology intemode lengths are proportionate to number of
anagenic base substitutions present in SET 2A data set (alignment A), which is a function of the
induced groups and their informative sites in the nucleotide matrix.

cha. The first topology indicates: {{{{MEMBR, MIRID), CERCO), CICAD),
DELPH) ; with Heteroptera originating from the more terminal end of an oth¬
erwise paraphyletic Auchenorrhyncha and Cicadomorpha. The second indicates:
{{{MEMBR, CERCO), CICAD), {DELPH, MIRID) }; with monophyly for Ci¬
cadomorpha, polyphyly for Auchenorrhyncha, and clade Fulgoromor-
pha+Heteroptera as sister-group to Cicadomorpha. SET 2 bootstraps for Euhem¬
iptera show the quadrachotomy: { [MEMBR, CERCO) 52, CICAD, DELPH,
MIRID) 97.

SET 2 confirms the topology of Stemorrhyncha. Within Euhemiptera, it does
not resolve the origin of Heteroptera or monophyly of Cicadomorpha, Although
it indicates polyphyly for Auchenorrhyncha. The low SETs 2 CIs (0.58, 0.59)
continue to indicate the presence of high homoplasy levels.

SET 3. — SET 3 (based on 1647 TS, 64 IS), which eliminated all Stemorrhycha
except Psyllidae, produced 945 possible trees; its MLT, with TL 117, and the
next five shortest trees, with TLs 118-120, are shown in Figs. 2A-F. The SET 3
MLT topology (TL 117) for Euhemiptera shows: {{{ CERCO, CICAD), MEMBR),
{DELPH, MIRID)}; indicating monophyly for Cicadomorpha with clade Ful-
goromorphaL Heteroptera as its sister-group, and polyphyly for Auchenorrhyn¬
cha. The second and third shortest SET 3 topologies confirm this, and differ only
in their internal topology within Cicadomorpha, as: {{MEMBR, CICAD), CER¬
CO) at TL 118, and { {MEMBR, CERCO), CICAD) at TL 119. The three to¬
pologies tying for fourth most parsimonious place, at TL 120, all place Heteroptera
at various origin points within (extant) Cicadomorpha (Figs. 2D-F). Thus, the
several most parsimonious SET 3 trees indicate polyphyly for Auchenorrhyncha.

SET 4. — The out-group polarized data of SET 4 (20 IS only), yielded the MLT
in Fig. 3, with TL 29 with Cl 0.72. In this analysis, only the most conservative
informative sites available for inference of euhemipteran topology were used (see

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 39

2 A

HE

MEMBR
CERCO
- CICAD
DELPH

2 B

£

MEMBR
- CICAD

CERCO

DELPH

-STERN

— MIRID

- 1

- STERN

— MIRID

-STERN

— COLEO

(TL 117)

— COLEO

(TL 118)

-COLEO

MEMBR
CERCO
CICAD
DELPH
MIRID

(TL 119)

2 D

j- M

Je

MEMBR
CICAD
-MIRID

L - STERN
COLEO

CERCO
- DELPH

(TL 120)

MEMBR
MIRID
CERCO
CICAD
DELPH
STERN

COLEO (TL 120)

2 F

JE

e

MEMBR
CERCO
-MIRID

L- CICAD
DELPH
STERN

COLEO (TL 120)

Figure 2. MLT (Figure 2A) from SET 3 PAUP analysis, based on 647 TS and 64 IS, yielding TL
117. Figures 2B-F show topologies for second (Figure 2B: TL 118), third (Figure 2C: TL 119) and
fourth (Figures 2D-F: TLs 120) best levels of parsimony. The MLT plus the second and third most
parsimonious topologies indicate clade Fulgoromorpha+Heteroptera with sister-clade Cicadomorpha;
a heteropteran association with Cicadomorpha does not occur until the fourth best parsimony level.

methods discussion for SET 4). The MLT topology for Euhemiptera was
{{{MEMBR, CERCO), CICAD), {DELPH, MIRID) }; again this indicates mono-
phyly for Cicadomorpha, with sister-group clade Fulgoromorpha+Heteroptera,
and polyphyly for Auchenorrhyncha.

Support for Non-monophyly of Auchenorrhyncha.— Given a parsimony crite¬
rion, none of our 18S rDNA analyses indicate monophyly for Auchenorrhyncha.
Instead, Auchenorrhyncha was always indicated to be para- or polyphyletic be¬
cause usually either Heteroptera arises: (1) as a sister-group to Fulgoromorpha,
the two forming a clade that itself assumes a sister relationship to clade Cica¬
domorpha; or (2) from within the (then nonmonophyletic) Cicadomorpha. In fact,
clade Cicadomorpha with sister-group Heteroptera is more parsimonious than
clade Auchenorrhyncha.

In our most conservative and preferred analysis, SET 4, the clades in the MLT
are supported by the following numbers of synapomorphies (our alignment A
numbers for SET 2 sequences, first attenuation), with transitions indicated by *
and transversions by ** (Table 1). Stemorrhyncha: 5 nonhomoplasious unam¬
biguous synapomorphies (sites: 62 [A —> G*], 152 [A —> C**], 153 [A —*■ G*],
1110 [G —> T**], 1269 [T —> C*]). Euhemiptera: 2 nonhomoplasious unambiguous
synapomorphies (sites: 53 [T —> A**], 159 [C —» T*]), plus potentially 2 homo-
plasious ambiguous synapomorphies (sites: 241 [C —> A**] with reversal in Del-
phacidae, 457 [G —► T**] with reversal in Miridae); the latter two ambiguities are
equivocal in support of either Euhemiptera or Cicadomorpha, however; in ad¬
dition, site 79 [G —* A*] is apomorphic for the Euhemiptera, but is homoplasious
with some Diptera (see Table 1, also see Carmean et al. 1992). Cicadomorpha: 2
nonhomoplasious unambiguous synapomorphies (sites: 721 [G —» T**] with in¬
dependent mutation in Miridae [G —* A*], 1251 [C—> T*]); also potentially plus
the two ambiguous sites stated to be equivocal for Euhemiptera. Clade Cercop-
idae+Membracidae: 1 homoplasious unambiguous synapomorphy (site: 263 [G

40

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

STERN

CM CM CD O CD

CO Lfi LO CD

-t- t- t- CM

CO O) O) !7 N

m s in ^ lo

T- CM Tt

*

T- N T- LO
lO CM CM

cm ^ r ■»—

it

't in n
LO CM i-
^ O T-

LO
CM
O O

D- T-

00

CO

CM

CERCO

CO
00 CM
CO CD t-
CO -r- i—

CO

i—

CM

o

-M-

r-

CM

[}t

co co n n r;

CO CD co lo cm

1- CM I s **

MEMBR

CICAD

DELPH

MIRID

Figure 3. MLT produced from the SET 4 data set (20 IS only), where stemorrhynchan homoplasy
was excluded using out-group polarization. Bars on intemodes represent synapomorphies labelled
with their site numbers (Table 1); black = nonhomoplasious and unambiguous site change; gray =
homoplasious (within Euhemiptera) but unambiguous site change; white = homoplasious (within
Euhemiptera) and ambiguous site change. Sites 79 and 454 (white to black gradients with asterisk)
are homoplasious outside this analysis; 79 is homoplasious in dipterans and 454 in some heteropteran
lineages (see Table 1). Sites 241 and 457 are ambiguous site changes, marked by ?, that may occur
either along the euhemipteran ancestral intemode, or alternatively along the cicadomorphan ancestral
intemode. Site 721 is an independent transformation on the cicadomorphan and heteropteran ancestral
intemodes. The MLT supports clade Fulgoromorpha+Heteroptera.

—» A*] parallelism in Miridae). Clade Fulgoromorpha+Heteroptera: 1 nonhom¬
oplasious unambiguous synapomorphy (site: 1117 [G —> A*]) and 2 homoplasious
unambiguous synapomorphies (sites: 454 [G —* A*], homoplasious within het-
eropterans in Wheeler et al’s. (1993) sequences, and 1025 [G —► T**], a parallelism
in Membracidae). Although the single representatives for Fulgoromorpha and
Heteroptera used were thought to preclude informative sites as synapomorphies
for them, Heteroptera showed the mentioned independent mutation of site 721
[G —* A*]. (Synapomorphies for each of Fulgoromorpha and Heteroptera are
available in our subsequent analyses, see footnote 7).

In the SET 4 MLT, clade Fulgoromorpha+Heteroptera precludes Auchenor-
rhyncha monophyly, yet it is based on 1 nonhomoplasious transition synapo¬
morphy (site 1117) and (in “opposition”) 2 homoplasious synapomorphies, a
transition (site 454) showing homoplasy in some heteropteran lineages (Wheeler
et al. 1993), and a transversion (site 1025). Some authors suggest transversion/
transition mutation biases are present in some nucleotide data (e.g., primate
mtDNA), and that a 10:1 weight should be imposed in favor of transversions for
phylogenetic inference (Mishler et al. 1988, Patterson 1989, Michevich & Weller
1990). If so, such weighting could affect MLT generation towards a topology
optimizing transversions over transitions. In fact, even a philosophical preference
towards a transversion bias should tend to negatively affect the relative acceptance

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 41

of a topology where transitions appear to dominate over tranversions on given
cladogram intemodes (e.g., clade Fulgoromorpha+Heteroptera on the SET 4 MLT).

However, 18S rDNA does not appear to show such bias for those secondary
structural portions of the molecule termed “bulges” or “loops” (Vawter & Brown
1993). The transition synapomorphy of clade Fulgoromorpha+Heteroptera oc¬
curs on such a secondary substructure. Our site 1117 (= site 1715 of Kwon et al.
1991) occurs on a “bulge” (Kwon et al. 1991: fig. 3, bulge position of helix 40),
where a transversion bias was not present for 18S rDNA (Vawter & Brown 1993).
Thus, for our 18S rDNA sequences, equal weights for transitions and transversions
are appropriate, so that a prejudice against the SET 4 MLT is unreasonable. 7

Nevertheless, as an alternative to the SET 4 MLT, we explored other, less
parsimonious SET 4 topologies that would permit monophyly for Auchenor-
rhyncha. Using PAUP and the SET 4 data, we tabulated the probability of mono¬
phyly for Auchenorrhyncha and other groups sequentially across all possible TLs
(29-42), as decreasing levels of parsimony (Table 2). For each rising TL level, we
noted the accumulative numbers of trees containing each of 5 possible clades: (a)
Euhemiptera, (b) Cicadomorpha, (c) Cicadomorpha+Heteroptera, (d) Fulgoro¬
morpha+Heteroptera, and (e) Auchenorrhyncha; any internal topology was per¬
mitted for the member taxa of each “clade.” These accumulations were trans¬
formed to probabilities (of existence) for the clades, as their frequency of occurrence
(i.e., the accumulated total number of trees containing a clade at each TL, divided
into the number of trees possible at that TL). The probabilities of clades Cica¬
domorpha+Heteroptera and Fulgoromorpha+Heteroptera, and their total, can
also be taken as a function of probability for non-monophyly for Auchenorrhyn¬
cha, because of conflicting relative association of Heteroptera. In Table 2, clade
Auchenorrhyncha does not exist until the third best parsimony level (TL 31),
where it occurs on only 2 of 23 possible trees (0.09), and that by that level,
competing clades Fulgoromorpha + Heteroptera (0.52) and Cicadomor¬
pha+Heteroptera (0.39) both occur at greater frequencies (2 0.91). Auchenor¬
rhyncha rises to its greatest frequency (0.18) at TL 32, where it remains the least
probable clade; it rises to its greatest occurrence (30 trees of 822 retained and 945
possible) at TL 38, where it ties with competing clade Cicadomorpha+Heteroptera

7 This synapomorphy is supported in additional analyses involving a more extensive sampling of
taxa (Campbell et al, unpublished data), to be published elsewhere: [GenBank accession numbers in
parentheses] Cercopidae-Tomaspinae (U16264), Cicadellidae-Cicadellinae (U15213), Cicadellidae-
Deltocephalinae (U15148), Cixidae (U15215), Dictyopharidae (U15216), Flatidae (U06476), Gerridae
(U15691), Issidae (U15214), Lygaeidae (U15188). Given the fact, in matrix generation of MLTs, that
holding character number constant, and either decreasing average state number or increasing terminal
taxa number, effectively increases the probability of homoplasy, we chose here to increase the total
number of 18S rDNA base pairs analyzed to maximize the discovered synapomorphies. Based on the
distribution of synapomorphies throughout differing regions of the 18S rDNA gene, it may not be
possible to infer accurate phylogenetic conclusions using short segments (i.e., 6-700 base pairs) of the
gene. We have compared our sequences with those of Wheeler at al. (1993) and Carmean et al. (1992)
for site homoplasy. Functionally, “throwing more taxa” at this problem will merely (a) validate, or
negate, the existing synapomorphies among the presented basal topology, (b) supply synapomorphies
for morphologically obvious clades (e.g., Fulgoromorpha), or (c) permit insertion of excluded taxa
(e.g. Coleorhyncha). The Campbell et al. (to be published) analyses, which increase taxa, will verify
non-monophylly for Auchenorrhyncha and discuss mutation rate differences for regions of the 18S
rDNA gene. See note added at end of Literature Cited.

K)

Table 2. Accumulative frequency of selected “clades” across all tree lengths for 945 possible trees from SET 4 data.

Tree length

29

30

31

32

33

34

35

36

37

38

39

40

41

42

Trees generated 3

1

9

23

51

74

109

127

169

244

383

582

700

791

822

Euhemiptera

1

9

23

50

72

99

103

105

105

105

105

105

105

105

(1.00)

(1.00)

(1.00)

(0.98)

(0.97)

(0.91)

(0.81)

(0.62)

(0.43)

(0.27)

(0.18)

(0.15)

(0.13)

(0.13)

Cicadomorpha

1

4

8

10

11

15

23

35

35

35

35

35

35

35

(1.00)

(0.44)

(0.35)

(0.20)

(0.15)

(0.14)

(0.18)

(0.21)

(0.14)

(0.09)

(0.06)

(0.05)

(0.04)

(0.04)

Cicadomorpha+

0

5

12

15

15

22

26

30

30

30

30

30

30

30

Heteroptera b

(0)

(0.56)

(0.52)

(0.29)

(0.20)

(0.20)

(0.20)

(0.18)

(0.12)

(0.08)

(0.05)

(0.04)

(0.04)

(0.04)

Fulgoromorpha+

1

4

9

16

17

17

17

23

46

54

78

78

78

78

Heteroptera

(1.00)

(0.44)

(0.39)

(0.31)

(0.23)

(0.16)

(0.13)

(0.14)

(0.19)

(0.14)

(0.13)

(0.11)

(0.10)

(0.09)

Auchenorrhyncha

0

0

2

9

11

16

18

22

25

30

30

30

30

30

(0)

(0)

(0.09)

(0.18)

(0.15)

(0.15)

(0.14)

(0.13)

(0.10)

(0.08)

(0.05)

(0.04)

(0.04)

(0.04)

3 Retained.

b Any internal topology allowed among member taxa.

THE PAN-PACIFIC ENTOMOLOGIST Vol.

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 43

for fewest tree numbers. Thus, given the conservative data of SET 4, which was
designed to optimally eliminate the more recently derived homoplasious sites
that obfuscate evolutionary topological relationships among the older clades, we
find scant evidence for the possibility of monophyly for Auchenorrhyncha.

Cladistic Implications

Until now, Auchenorrhyncha was generally considered to be monophyletic on
the basis of either molecular data from insufficient subgroups (Wheeler et al.
1993), or morphological traits previously considered to be valid synapomorphies
(but see Hamilton 1981). A recent example of the latter is Carver et al.’s (1991:
464) statement that “The monophyly of the Auchenorrhyncha ... is firmly es¬
tablished by the complex tymbal acoustic system and the aristoid antennal fla¬
gellum characteristic of the group.” Other traits across Auchenorrhyncha have
been considered symplesiomorphies, with the exception of a fused ScP+R vein
apomorphy (Kukalova-Peck 1991: 170).

However, phylogenetic reconstruction using nucleotide sequencing is thought
to be superior to, and definitely more objective than, that based upon morphology
(Felsenstein 1982, 1983, 1988; Crespi 1992; Sorensen 1992). This is because, in
general, nucleotide substitutions are random, non-selective events, as opposed to
trying to determine how to code and weight morphological characters, which are
defacto a result of selection. Morphologically-based phylogenetics is conceptually
plagued by the inherent effects of selection and character correlation; although
these are easily recognizable, they are nearly impossible to handle (see Sorensen
1990, 1992). Use of nucleotides not only renders a portrait that is essentially free
of these problems (Lewontin 1989), but permits character transformation overlays
that allow recognition of morphological homoplasy. If the 18S rDNA phylogeny
derived here is correct, it is evident that the morphological synapomorphies for
Auchenorrhyncha must be convergences that are most probably selection-induced.

Tymbal Systems as Homoplasy. — Although the development of a complex tym¬
bal system for sound production may seem like a strong synapomorphy for Au¬
chenorrhyncha, this mechanism is homoplasious in Hemiptera and clearly is under
strong sexual selection. Tymbal systems not only exist in Cicadomorpha and
Fulgoromorpha, but they also occur in Pentatomomorpha (e.g., Pentatomidae:
Carpocoris ; Chapman 1971), a highly derived and phylogenetically distant clade
(Wheeler et al. 1993), where their position and function appears to be similar to
that within most Auchenorrhyncha. Furthermore, despite many investigations
into tymbal sound production in various Auchenorrhyncha (Ossiannilsson 1949,
Smith & Georghiou 1972, Shaw & Carlson 1979, Mitomi & Okamoto 1984,
Zhang & Chen 1987, Zhang et al. 1988), except for Cicadidae (Pringle 1954, 1957),
precise and convincing physiological mechanisms of their function in leafhoppers
or planthoppers have not yet been published (Claridge 1985, Claridge & de Vrijer
1994) and remain, at best, controversial.

In Ossiannilsson’s (1949: 103-106) discussion of morphology, there are many
significant differences between the fulgoromorphans (Delphacidae [as “Areopi-
dae”], Cixidae, Issidae) and cicadomorphans (Cercopidae, Cicadellidae, Mem-
bracidae) that he examined. Examples of these differences include Fulgoromor-
pha’s lack of (a) a “striated tymbal” (shared with some cicadellids) and (b) a
“pilose surface”; their (c) “enlarged metapostnotum,” (d) “less developed meta-

44

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

postphragma,” (e) “well developed lateral dorsal longitudinal muscles” (except
in brachypterous forms); their (f) “second abdominal tergum” being “devoid of
phragmata in spite of the dorsal longitudinal muscles of the first abdominal seg¬
ment being strongly developed”; and their (g) “second tergum being strongly
vaulted into a convex, shield-like surface with inner strengthening lists,” which
serve as the posterior attachment of the longitudinal muscles from the meta-
postnotum.

Perhaps the best reference to Fulgoromorpha’s tymbal variance is summarized
by Ossiannilsson’s (1949: 104) statement that homology across the Auchenor-
rhyncha for muscle I a dvm } “. . . might be uncertain for only the Fulgoromorpha,
as the conditions of this group are so deviating .It should be evident that
this uncertain homology between fulgoromorphan and cicadomorphan tymbal
systems does not seem adequate to be regarded as a convincing synapomorphy
for these groups, especially in light of the occurrence of an (at least superficially)
similar tymbal mechanism in the Pentatomomorpha. Clearly more detailed tym¬
bal comparisons are needed.

Aristoid Antennae as Homoplasy. — It is easier to accept the reduction to an
aristoid antennae among the auchenorrhynchan groups as homoplasy if one re¬
members that all Pterygota and Thysanura have annulated (or flagellar) antennae
(sensu Schneider 1964: type B; Chapman 1971: type A), as opposed to true
segmented antennae (sensu Schneider 1964: type A; Chapman 1971: type B),
which occur in the apterogote subclasses Collembola and Diplura. In segmented
antennae, each true segment, including the scape, pedicel and each flagellar seg¬
ment has up to five intrinsic muscles connecting its base to the base of the next
distal segment, and these permit intersegmental movement. In annulated anten¬
nae, however, only the scape has such segmental musculature, whereas each fla¬
gellar “segment,” all of which are actually mere annulations, is connected to the
next by membrane only; annulated antennae are moved only by levator/depressor
muscles connecting the anterior tentorial arms to the scape, and flexor/extensor
muscles connecting the scape to the pedicel (Imms 1940). Thus the flagellum of
the Pterogota is a single, functional unit that has already undergone reduction
from true segmentation to mere annulation, and it has undergone many homo-
plasious further reductions across diverse taxa (i.e., larval Holometabola, adult
Mallophaga/Anoplura, adult Brachycera/Cyclorrhapha Diptera, etc.).

Among hemipterans, only those that jump have evolved aristoid flagella. How¬
ever, differing forms of flagellar reduction occur independently at least twice in
Hemiptera (i.e., Peloridiidae and Nepomorpha) besides that noted in Auchen-
orrhyncha. Cicadomorphan and fulgoromorphan convergence towards an aristoid
antenna results, we believe, from selection to: (a) minimize injury; (b) enhance
aerodynamic streamlining; and/or (c) allow acoustic receptions via Johnston’s
organ. Because of its sensory function, selection to avoid or minimize antennal
damage should be an extremely strong force. Antennal injury should be lessened
during the less controlled, head-first landings encountered in jumping. Further,
jumping with large antennae would enhance aerodynamic instability in small,
bullet-like auchenorrhynchans that leap with almost explosive force (K. G. A.
Hamilton, personal communication). In contrast, the more massive bodies of
larger jumpers with long antennae (e.g., orthopteroids) probably minimize anten¬
nal contributions toward instability.

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 45

Aristoid flagella on hemipterans occur only in the presence of tymbal trans¬
missions systems, but not the reverse (e.g., Pentatomomorpha). Thus, aristoid
antennae may also serve as an acoustic reception device, picking up air-transmitted
vibrations and transferring them to Johnston’s organ, a chordotonal organ in the
antennal pedicel. Although many Auchenorrhyncha apparently transmit sound
through the substrate, the acoustic receptors remain largely unknown (Claridge
1985), but Johnston’s organ has been suggested as such a receptor (Howse &
Claridge 1970), and clearly serves such a function in other insects (Chapman
1971).

If the development of the scape+pedicel versus the flagellum are considered,
the antennal systems of cicadomorphans and fulgoromorphans appear only su¬
perficially similar in their respective ultimate development. The fulgoromorphan
pedicel is exceptionally developed (e.g., Hamilton 1981: figs. 18, 19), with nu¬
merous autapomorphic plaque sensilla (e.g.. Baker & Chandrapatya 1993: figs. 1,
2) that vary across the group (Marshall & Lewis 1971). Fulgoromorphan flagellar
annulation is generally extreme, appearing as mere thin rings, except for a rela¬
tively enlarged, bulbous flagellomere 1 (= antennal 3) (e.g., Baker & Chandrapatya
1993: fig. 6), which has an autapomorphic sensory organ (Bourgoin 1985: fig. 2,
“OSBF”) throughout the group.

Supportive evidence for the homoplasious evolution of an aristoid antenna in
fulgoromorphans is provided inadvertently by Megaleurodes megocellata Ham¬
ilton (1990: fig. 34), a fossil from Brazilian Lower Cretaceous deposits (AMNH
type 43608). Hamilton (1990: 96) thought it was a primitive whitefly with ful¬
goromorphan traits, and assigned it to “Aleyrodoidea: Boreoscytidae?”. However,
the traits with which M. megocellata was assigned to Aleyrodidae are either quite
homoplasious in Hemiptera (e.g., divided eye, ocellar position) or symplesio-
morphies (K. G. A. Hamilton, personal communication). Because of its facial ca-
rinae, tegulae and three-segmented tarsi (the latter two symplesiomorphies) we
believe it is a primitive fulgoromorphan that shows non-aristoid antennae that
arise fairly high on the face. Therefore, we tentatively reassign Megaleurodes
megocellata to the fossil superfamily Fulgoridioidea, but with an uncertain family
assignment. It is similar to the Jurassic Fulgoridiidae (sensu Bode 1953) in that
its antennae are multiarticulate (non-aristoid), a diagnostic plesiomorphy for that
(gradistic ?) family (Bode 1953, Hamilton 1990); but the head of Megaleurodes
differs from that of Fulgoridium (Bode 1953: fig. 143) with its ocelli below the
eyes (K. G. A. Hamilton, personal communication). We consider the fossil Ful¬
goridioidea to be an extinct grade to the modem Fulgoroidea, within Fulgoro-
morpha, and to demonstrate the lineage initially had non-aristoid antennae.

In contrast, in many cicadomorphans, the antenna generally has a less developed
scape and pedicel and a less reduced flagellum, where flagellar annulation (“seg¬
mentation”) is still usually quite evident (e.g., Cwikla & Freytag 1983: fig. 4). In
some cicadas, the flagellum is still reasonably developed (e.g, Hamilton 1981: fig.
14), especially in nymphs (e.g., Hamilton 1981: fig. 2), which retain a developed,
definitely “segmented,” but short flagellum. Interestingly, Cicadas do not jump,
and their tympana also serve as acoustic receptors. Nevertheless, some cercopids
have an aristoid antennal flagellum that appears to approach that of Fulgoro-
morpha. These have flagellomeres 2 -n quite annulated and an enlarged flagello¬
mere 1, possibly with a sensory organ that externally appears somewhat similar

46

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

to that of fulgoromorphans. Shcherbakov (1988), however, states that fossil Pro-
cercopidae and Karajassidae, the initial cercopoids and cicadelloids, respectively,
retained a “segmented” antennal flagellum. This would necessarily indicate a more
recent, independent derivation of the cicadomorphan arista than would have to
occur if it was synapomorphic on a postulated monophyletic auchenorrhynchan
ancestral stem.

If our 18S rDNA inferred relationships between Fulgoromorpha and Cicado-
morpha are correct, homoplasy for aristoid flagellar development is required. The
fulgoromorphan-like antennae of cercopids appears necessarily unparsimonious
on any cladogram containing extant taxa, with sister-group Fulgoromorpha and
any internal topology for Cicadomorpha (unpublished data); the early fulgoro¬
morphans present a similar problem. If aristoid antennae were derived only once,
on the euhemipteran ancestral phylogenetic intemode, the character requires at
least two-steps on the 18S rDNA-based topology, with a reversal on the heter-
opterodean ancestral intemode; independent derivation on each of the ancestral
intemodes for cicadomorphans and fulgoromorphans is equally parsimonious.

Fused ScP+R Vein. —Kukalova-Peck, following her own venation terminology
(Kukalova-Peck 1983), which is also used here, states that for Auchenorrhyncha,
ScP- supports R, as a fusion apomorphy (Kukalova-Peck 1991: 170). She notes
that in Heteropterodea, however, ScP- is independent of R, as a symplesiomorphy;
yet she also shows an apomorphic ScP+R fusion in the Coleoptera (Kukalova-
Peck 1991: fig. 6.28E) in the hindwing (the beetle flight wing). Dworakowska
(1988) reviews the venation of Auchenorrhyncha, following Kukalova-Peck’s ter¬
minology, and details many auchenorrhynchan wings, but her excellent study
shows the limitations of homological interpretation of venation. Also see Wootton
(1979) for discussion of problems in determining vein homologies.

Although the auchenorrhynchan fusion of ScP+R seems reasonable as a syn-
apomorphy, we believe that it is a homoplasy. Convergence in venation occurs
commonly in hemipterans (Wootton & Betts 1986), particularly among their early
fossils (Wootton 1981), and is probably related to selection for various flight
dynamics parameters (Betts 1986a, b, c). The auchenorrhynchan ScP+R fusion
probably results from selection for rigidity in the basal region of the wing, coupled
with the developing need for a point or area of flexion, just beyond, near midpoint
of the forewing margin. These modifications of the primary flight wing are required
for camber control during flight in heteropterans (Wootton & Betts 1986; Betts
1986a, b, c). Function-based similarities in wing geometries also appear to have
been derived in more phylogenetically advanced orders, for example Hymenoptera
(see Whitfield & Mason 1994: figs. 3-8). Another function-based homoplasy is
the development of an expansion of the wing’s precostal strip, to form an epi-
pleuron in Auchenorrhyncha and Coleoptera (Kukalova-Peck 1991: 167).

To promote greater flight efficiency, we believe differing wing geometries were
evolved and tested among early hemipterans. This resulted in structural conver¬
gence in response to the selective constraints imposed by physical factors. We
feel such homoplasy can often be recognized by subtle differences among clades,
however. For example, where ScP eventually reaches the forewing margin in
Cicadomorpha, a venation break occurs where component C should merge
smoothly with liberated component ScP, as occurs in Fulgoromorpha. To illustrate
this point, consider the modifications of the three veins of the costal (pronating)

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 47

complex, while bearing in mind the auchenorrhynchan ScP+R fusion. As Pc, CA
(= C+) and CP (= C—), these veins usually form a relatively tight beam-like triad
along the leading edge of the fulgoromorphan forewing (Dworakowska 1988: figs.
3-5 cross-sections). This wing-leading “beam” is undoubtedly for structural re¬
inforcement.

In some groups (e.g., Eurybrachyidae, Flatidae, Lophopidae, Nogodinidae, Ri-
caniidae, Tropiduchidae, some Fulgoridae; Dworakowska 1988), Pc rolls ventrally
to more closely associate with CP (as fused Pc+CP), which leaves CA alone to
form the fore wing’s functional anterior margin. However, CP never exists sepa¬
rately at the wing base. In Fulgoromorpha, when CP posteriorly separates from
CA more distally, CP gives rise to several serial branches along the wing’s anterior
margin. This is what Kukalova-Peck (1991: 170) refers to as a false ‘subcosta’.
In such instances among fulgoromorphans, where this posteriorly moved and
serially branched CP occurs, ScP+R splits distally, and shortly thereafter the
liberated ScP curves to the forewing’s anterior margin to fuse with CP, as ScP+CP
(Dworakowska 1988: figs. 29, 37c, 41, 67); meanwhile, the abandoned R com¬
ponent continues distally to the wing margin, also to split as RA and RP (and
usually each again). In contrast, in Cicadomorpha, where CP remains nearer the
anterior margin of the forewing throughout its course, this C/ScP abutment occurs
as an unfused association (Dworakowska 1988: figs. 94, 97).

Clearly structural selection is involved in this difference because the cicado-
morphan situation promotes flexibility at that point along the wing margin. The
homoplasious coleopteran ScP+R fusion allows hind(flight)wing folding under
their elytra, with the appropriate articulation. It may also be possible that the
auchenorrhynchan ScP+R fusion merely reflects a strengthening of the front-
basal or proximal area of the wing, enabling CP to travel distally to its ultimate
fusion/abutment with the ultimately liberated ScP, allowing the nodal flexion
point. If so, it should not be surprising that in some auchenorrhynchans, proximal
fusions of ScP and R with M also occur, permitting even greater stiffening, as
either ScP+R+MA (Dworakowska 1988: fig. 42), or, particularly among fossils,
ScP+R+M (?) (Hamilton 1990: figs. 6, 41, 42, 58, also apparently 31, 33, 65,
69, 74, 75).

In some Fulgoromorpha, the ScP+C fusion point marks the distad border of
tegminization (e.g., Hamilton 1990: fig. 52), or an apparent “pterostigma” in some
fossils (e.g., Hamilton 1990: figs. 46A, 55, 56, 58, 75, 80). In Cicadomorpha, the
C/ScP abutment break marks a quite primitive line of flexion (Hamilton 1990:
fig. 31, “Cicadoprosbolidae”; Dworakowska 1988: figs. 92, 93, 95). It is the an¬
terior of the flexion line that permits camber change during the wing beat (Wootton
& Betts 1986), and as such is under strong selection pressures.

Within clades Fulgoromorpha and Cicadomorpha, many other venation as¬
sociations or fusions change, at least in part, sometimes quite notably. For in¬
stance, the free base of Sc in Cercopoidea and Cicadoidea (Shcherbakov 1981:
66), or Pc+C+Sc+R amalgamation in some cicadas (Carver et al. 1991: fig.
30.4f). We believe that these differences between cicadomorphans and fulgoro¬
morphans serve to: (a) cloud the potential questions of homology; (b) demonstrate
the “dancing,” but functionally related, fusion of the axial unit-radial complex
veins (sensu Dworakowska 1988) among auchenorrhynchans; and (c) illustrate
the apparent need of fusion in that region of the membranous wing of these highly

48

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

active insects, to achieve rigidity among the more basal components of these
veins.

In the other hemipteran clades, selection for a convergent ScP+R fusion may
have been alleviated by non-active habits or differential wing evolution. Ster-
norrhynchans are smaller, often with “passive” flight. Coleorhynchan forewing
venation is often quite thickened and pronounced (Kukalova-Peck 1991: fig. 6.25 J;
Popov & Shcherbakov 1991: figs. 9, 10, 12, 22, 23, 35). Among the more derived
Heteroptera, the wing may be quite sclerotized proximally, with a developed
cuneus and costal fracture, while among the basal heteropteran Enicocephalo-
morpha, which have relatively membranous wings, it is the forewing venation
that is thickened.

Morphological Synapomorphies Supporting the 18S rDNA Tree. —The under¬
standing of “homopteran” phylogenetic topology has always been plagued by an
abundance of character homoplasy within and among groups, and the dearth of
convincing morphological synapomorphies indicating the relationships among
the major clades; the latter appears to be an artifact of limited local perspective
(sensu Sorensen 1992). The 18S rDNA topology here cannot “correct” these
problems; it can merely illustrate those few nonhomoplasious synapomorphies
that appropriately structure the topology of the corresponding morphological tree.
We disagree with methods employed elsewhere (e.g., Wheeler et al. 1993), wherein
combinations of molecular and morphological traits are used in the same analyses
to increase phylogenetic resolution. We find such character amalgamations to be
philosophically and pragmatically untenable. We consider a combinable-com-
ponent approach (i.e., Bremer 1990, Lanyon 1993) among various competing
topologies that are based on differing dataset types, as appropriate to define to¬
pological reliability, if required. We have avoided a separate, comparative mor¬
phological analysis here, however, because we concur with Felsenstein (1988), at
least in this case, that morphological characters for phylogenetic inference are
inherently problematic. For example, we believe that a meaningful, morpholog¬
ically-based phylogenetic analysis of hemipterans must, at the very least, reflect
an apriori understanding of their historical homoplasies, as well as their coding/
scoring consequences, and must appropriately include all fossil taxa.

The morphological synapomorphies that support the 18S rDNA-based topology
follow, as developments (gains), unless otherwise noted. Clade Sternorrhyncha—
(a) a stemorrhynchan-type filter chamber (Evans 1963: type A); see Fig. 3 and
Campbell et al. (1994) for 18S rDNA synapomorphies. Clade Euhemiptera—{ a)
a vannus (Wootton & Betts 1986); (b) pronounced separation of costal and sub¬
costal basivenale (Kukalova-Peck & Brauckmann 1992); (c) loss of ScA+ vein
(Kukalova-Peck & Brauckmann 1992). Clade Cicadomorpha —(a) a cicadomor-
phan-type filter chamber (Evans 1963: type B); (b) a ledge overhanging the antennal
insertion (Hamilton 1981; K. G. A. Hamilton, personal communication); (c) the
lorum with a wide connection to hypopharynx and a very narrow connection to
the gena (Hamilton 1981; K. G. A. Hamilton, personal communication); and (d)
a spiral-fold or -lobed wing-coupling system (D’Urso & Ippolito 1994: type A),
modified from the stemorrhynchan system wherein one or more spiral hooks
occur instead (D’Urso & Ippolito 1994: 223). Clade Fulgoromor-
pha+Heteropterodea—(a ) slight reduction of the lorum (Hamilton 1981), as in¬
termediate step to Heteropterodea (K. G. A. Hamilton, personal communication);

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 49

(b) apical fusion of forewing veins 1A and 2A (Wootton & Betts 1986); (c) a long
and longitudinally-directed forewing vein CuA (Wootton & Betts 1986); ques¬
tionably (e) often strong microspines, as accessory microsculpture, on the vein
opposite the fold of the wing-coupling apparatus (D’Urso & Ippolito 1994: 223);
and (d), of uncertain polarity, lack of a hindwing ambient vein; also, although
polarities are uncertain, we suspect that several alimentary canal modifications
shared by Fulgoromorpha, Coleorhyncha and Heteroptera (Goodchild 1966) rep¬
resent plesiomorphies for a gut that lacks any filter chamber type—these include
a ‘pylorus’, a sac-like rectum, reduced rectal glands, and a midgut-hindgut junction
situated posteriorly in the body cavity. Clade Fulgoromorpha— (a) specialized
facial carina (Hamilton 1981); (b) a collar-like pronotum (Hamilton 1990); (c)
placate sensilla on the pedicel (Baker & Chandrapatya 1993); (d) a specialized
sensory organ on the base of flagellomere 1 (Bourgoin 1985); (e) a rolled, but
never spiral, folded wing-coupling system (D’Urso & Ippolito 1994: type B), with
(f) strong accessory microsculpture. Clade Heteropterodea (= Coleorhyn¬
cha + Heteroptera)—(a) a gula, or the beginning of its ventral fusion in Coleo¬
rhyncha (Hamilton 1981: fig. 23); (b) a distinctive triangular mandibular lever
(Hamilton 1981; K. G. A. Hamilton, personal communication); (c) a non-aristoid
reduction of antennae to 3 or 4 (secondarily 5) segments (Schlee 1969, Emel’yanov
1987, Wheeler et al. 1993); (d) capture of the trachea of forewing vein 1A by
CuA2 and its invasion of the remigium (Wootton 1965, 1986), despite Wootton’s
(1979) summary of unreliability of tracheal capture for vein homology; (e) wings
capable of being folded flat (overlapping) over the body (Wheeler et al. 1993); (f)
ground plan for the abdominal segments (Schlee 1969); (g) structure of the anal
cone (Schlee 1969); and (h) development of the sclerites at the base of the aedeagus
(Schlee 1969); see Wheeler et al. (1993) for 18S rDNA synapomorphies. Clade
Coleorhyncha — see Popov & Shcherbakov (1991: 233) for synapomorphies. Clade
Heteroptera —see Wheeler et al. (1993) or Hennig (1981) for numerous synapo¬
morphies.

Paleontological Evidence

Under the section on cladistic implications, we considered some fossil evidence
for character homoplasy. Here, we estimate the concordance of fossil lineages
with the 18S rDNA topology.

Prior to 1980, the relationships among hemipteran fossils were confused by
differing philosophical camps that often made interpretations despite a lack of
important character information. In a review article, Wootton (1981: 331-332)
states: “Within the Permian, Hemiptera radiated spectacularly, leaving behind a
bewildering array of fossils, many of them just wings. Convergence is widespread,
and interpretation difficult and conflicting. . . . Auchenorrhyncha occur in pro¬
fusion and confusion in the L. and U. Permian . . .”; he cites as an example:
“Prosbolidae may be primitive Cicadoidea, and Scytinopteridae may be Cerco-
poidea, but both these families have been conflictingly defined” (e.g., Evans 1956,
1964, vs Rohdendorf et al. 1961, Bekker-Migdisova in Rohdendorf 1962). Hennig
(1981: 273) aptly summarizes: “The differences of opinion do not inspire me with
much confidence in the decisions of specialists who have assigned the Permian
and other fossils to various subgroups of * Auchenorrhyncha.” There was no
apparent rigorous cladistic methodology for assignments and homology. Usually,

50

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 71(1)

K

Cz

R

CO
CD
O

c
cc

§

o
.c

I-,

co

CD

1

ca

"O
CD

S

3

CO

2

O. ?,

I

Cicadomorphan
lineage

- aaammmm

m Karajassidae

— Procercopidae

Prosbolidae

Dysmorphoptilidae

Prosbolopseidae

— Hylicellidae

Palaeontinoidea

Perdborioidea

Ignotalidae

Fulgoromorphan lineage

•/

Coleoscytoidea

Surijokoeixidae

Fulgoridiidae

Hoploridiinae
Karabapiinae ?

3 v

Progonocimicinae
Cicadocorinae

T

—Ingruidae

7 .

^ m “ mm

?

I ^ :

— Scytinopteridae

Scytinopteroidea

llpsviciidae
■i— Serpenivenidae
Paraknightiidae
Stenoviciidae

Cicadelloidea

Cercopoidea

Cicadoidea

Achilidae

Cixidae

Peloridiidae

Heteroptera

Heteropteran lineage

Figure 4. Paleontological synopsis of (selected) taxa from euhemipteran lineages, largely following
Shcherbakov (1984, 1988) and Popov & Shcherbakov (1988, 1991) with insertion of Fulgoridiidae
(Bode 1953, Hamilton 1990). Abbreviations for geological times are standard; gray boxes demarcate
clade lineages; question marks (small and large) signify derivations implied as tenative in the literature.
Shcherbakov (1984) places Prosbolopseidae and Ingruidae in superfamily Prosboloidea.

early hemipterans were known only from forewing tegmina; body and head im¬
pressions, sometimes distorted, usually are unknown until the Jurassic (e.g., Bode
1953, Hamilton 1990). However, despite this reliance on tegmina, only Evans
(1964) attempted to define early fossil auchenorrhynchan superfamilies by wing
venation.

More recently, Shcherbakov (1981, 1982), following Emel’yanov (1977), and
Dworakowska (1988), following Kukalova-Peck (1983), have treated the diag¬
nostic venation of extant auchenorrhynchan families. Since then, reassessments
of older phylogenetic relationships, based on group diagnostics but not necessarily
apomorphies, have been made for both the ancestral hemipteroid lineage (e.g.,
Kukalova-Peck & Brauckmann 1992), and for earlier hemipterans themselves
(e.g., Shcherbakov 1984,1988; Popov & Shcherbakov 1988,1991). Figure 4 shows
a current paleontological synopsis of euhemipteran lines.

These assessments suggest that the extant (monophyletic) Cicadomorpha (Cly-
peata sensu Shcherbakov) and Heteropterodea were derived from the Permian
Prosboloidea PVJ 3 ] of the polyphyletic Cicadomorpha. Reputedly, the modem
Cicadomorpha lineage evolved from an ancestor in the prosboloidean Prosbolidae

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 51

[P 2 ], along a lineage that involved Hylicellidae [T 3 -K2] giving rise to: (a) Cica-
doidea [T 3 -R]; (b) Procercopidae [Ji-K 2 ], that begot Cercopoidea [Ji-R]; and (c)
Karajassidae [J 2 _ 3 ], that begot Cicadelloidea [J 2 -R] (Shcherbakov 1988). A second
prosbolid lineage begot Dysmorphoptilidae [P 2 ] (Shcherbakov 1984). A prosbol-
opseid Prosbolopseinae lineage gave rise to: (a) Palaeontinoidea [P 2 -Ki]; and (b)
Pereborioidea [P 2 -T 3 ], the latter probably deriving Ignotalidae [P 2 ] (Shcherbakov
1984, 1988).

The Heteropterodea reputedly arose from a prosbolopseid Ingruidae [P 2 ] an¬
cestor. The Coleorhyncha lineage began when ingruids begot Progonocimicinae
[P 2 -K 2 ], that begot Cicadocorinae [Ji-KJ and Karabasiinae [Ji-K 2 ], the latter of
which begot Hoploridiinae [KJ and Peloridiidae [K?-R] (Popov & Shcherbakov
1991). The Heteroptera lineage reputedly arose when ingruids begot the Scytin-
opteroidae, the most primitive of which, Scytinopteridae [P 2 -T 3 ], begot: (a) the
Serpenivenidae [P 2 -T 3 ] and their probable descendents, Stenoviciidae [P 2 -T 3 ] and
Paraknightiidae [T 3 ]; and later, (b) Ipsviciidae [J^] (Shcherbakov 1984).

The origin of the Fulgoromorpha lineage is yet unclear. However, Shcherbakov
(1984) suggests it arose from Archescytinoidea, independently of Cicadomorpha,
towards the end of the early Permian. Assessment of Fulgoromorpha’s Permian
ancestors, reputedly Surijokocixidae [P 2 -Ji] and Coleoscytoidea [P u2 ], is more
tentative, and modem fulgoromorphan groups, such as Cixidae [K r R] and Achil-
idae [K,-R], do not appear until the Cretaceous (Shcherbakov 1988), after the
intervening presence of Fulgoridiidae [J] in the Jurassic (Bode 1953, Hamilton
1990, but see Wilson et al. 1994).

Thus, the paleontologically supported origin of Fulgoromorpha remains the
most unsettling of the three major euhemipteran clades. Tracing early fulgoro-
morphans before the Jurassic is problematic because only tegmina occur then,
but most fulgoromorphan apomorphies are head characters. The paleontological
evidence, therefore, does not support clade Auchenorrhyncha, because of the
polyphyletic nature of Cicadomorpha (sensu Shcherbakov). Presently, it would
seem to most closely support the slightly less parsimonious 18S rDNA topologies
that indicate clade modem Cicadomorpha+Heteroptera. In our opinion, however,
the nucleotide-based topology is superior to very nebulous indications of origin
for Fulgoromorpha that are revealed by fossils.

Eco-evolution of Hemipterans and Cladogenesis

What selective driving forces were responsible for the major cladogenic events
that shaped the 18S rDNA topology of hemipterans? We believe that the diver¬
gence, establishment and success of major evolutionary lineages (as clades) re¬
quires the presence, recognition and exploitation of existing niches. At best, re¬
strictive niches should hamper the evolutionary diversification of their exploitive
tive lineages. New niches (“neoniches”) that develop after the establishment of
previously existing and non-competing clades, would permit multiple entry points
for would-be competing invaders from multiple, existing clades. Such homopla-
sious invasions of any neoniche should require its delineation among the poly¬
phyletic neocompetitors if all are to survive as neo(sub)clades of their respective
parental clades. In time, each neoclade should genetically and morphologically
differentiate from its parental clade, both before (cladogenic) and during (anagenic)
its radiation in the neoniche.

52

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Resultant convergence among the polyphyletic neoniche invaders would be
dictated by niche-required morphology and function or other underlaying bio¬
logical constraints (Wake & Larson 1987, Wake 1991). Neoniche radiations should
be recognizable by the phylogenetic distributions of their taxa among parental
clades whose basal section taxa have differing niche habitations. The eco-evolu-
tionary constraints on such a scenario are the relative chronological developments
of niches versus clades, the existence and degree of preadaptation or adaptive
constraints (Moran 1988, 1990; Wake 1991), and potentially overlaying and in¬
hibiting biogeographic demarcations.

The Hemiptera illustrate these tenets, and their early cladogenesis overlays the
evolution of vascularization within plants. Clade Stemorrhyncha has intercellular
stylet-penetration of plants. Its most basal group, Psyllidae (Campbell et al. 1994),
ingest from a variety of vascular and non-vascular tissues (Ullman & McLean
1988a, b). The Psyllidae’s more derived sister-clade, Aleyrodiformes (Aphidoi-
dea+Coccoidea+Aleyrodoidea, sensu Campbell et al. 1994), ingests predomi¬
nantly when their stylet tips are within phloem sieve elements (Backus 1988,
Janssen et al. 1989). In contrast, within clade Euhemiptera, Cicadomorpha and
Fulgoromorpha have /n/ra cellular stylet-penetration, with less precision than ster-
norrhynchans (Backus 1988). Clade Cicadomorpha initially evolved to feed on
xylem (Cercopidae, Cicadidae, Cicadellidae: Cidadellinae), but has radiated to
phloem (Membracidae, Cicadellidae: Deltocephalinae) and parenchyma (Cica¬
dellidae: Typhlocybinae) as neoniches, presumably after the development of these
plant tissues.

Both Stemorrhyncha and Cicadomorpha have developed varying types of filter
chambers that are presumably used for osmoregulating profuse amounts of in¬
gested hypotonic plant fluids. The stemorrhynchan filter (Evans 1963: type A) is
simple and anteriorly expanded; the cicadomorphan filter (Evans 1963: type B)
is complex and posteriorly expanded in association with the Malpighian tubules
(Pesson 1944, Goodchild 1966). The relatively simple stemorrhychan filter was
evolved by the appearance of the psyllids, who feed on various tissues, and was
retained (probably parsimoniously) in their phloem feeding sister-clade Aleyro¬
diformes. Interestingly, psyllids are the only Stemorrhyncha that have retained
all four Malpighian tubules; Aleyrodiformes have a reduced number or none (some
aphids). The complexity of the cicadomorphan filter was probably required for
xylem feeding, because that food source is very dilute; it also was retained (again,
probably parsimoniously) among the cicadomorphan neoniche invaders (i.e.,
Membracidae, Cicadellidae: Deltocephalinae). All euhemipterans have retained
all four Malpighian tubules.

It seems probable that early fulgoromorphans initially evolved to feed on roots
and fungal hyphae, which exist in subterranean/semisubterranean (duff) niches,
much as many of their immatures do now (Wilson et al. 1994). This selection
probably happened because Stemorrhyncha and early Cicadomorpha (i.e., Ci¬
cadidae, Cercopidae, Cicadellidae: Cicadellinae), respectively, already had occu¬
pied intracellular and intercellular/xylem feeding niches, (before their secondary
radiations onto later neoniches). Later, with the advent of phloem, fulgoromor¬
phans probably moved readily into that neoniche and radiated. The Fulgoro¬
morpha, lacking the filter chambers of the coexisting clades, probably found fine
roots and fungal hyphae had relatively nutritious cells that are easily attacked; as

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 53

a food source, both these and phloem are less dilute than liquids from xylem. As
a result, fulgoromorphans did not require development of an extraordinarily en¬
larged feeding pump, the associated, enlarged clypeal housing, or the specialized
gut filter, that cicadomorphans did to handle the increased fluid load necessary
for xylem feeding.

As cladogenesis of hemipterans progressed, and earlier (“homopteran”) clades
dominated both intra- and intercellular niches in developing vascular plant sys¬
tems, their roots and soil fungi, the coleorhynchans appeared; their surviving
relictual group, peloridiids, ended up on mosses, a nonvascular plant resource
that was unoccupied by the other hemipteran clades. Probably because that niche
is not diverse, coleorhynchans did not flourish, expand and radiate as did the
stemorrhynchans, cicadomorphans and fulgoromorphans. However, their begin¬
ning gular development (Hamilton 1981: fig. 23), or rather that of their immediate
ancestor in common with the heteropterans, began a change toward a prognathous
rostrum and its liberating evolutionary potential.

In contrast to the Coleorhyncha, their sister-group, Heteroptera, evolved an
alternative strategy, predation, which required the major and radical morpholog¬
ical shifts witnessed in the Enicocephalomorpha (Grimaldi et al. 1993). Once the
predatory phena was accomplished, however, it opened vast new niches and
environs for suctoral feeding on animalian body fluids, which up until then only
mandibulate predators exploited. Predation as primary feeding strategy was ex¬
ploited by most early heteropteran clades (Carver et al. 1991), and cladogenic
radiation (Fig. 5) occurred in both terrestrial (Enicocephalomorpha, Dipsocoro-
morpha, Cimicomorpha), and aquatic/semiaquatic environs (Gerromorpha, Neo-
morpha, Leptopodomorpha). Although some groups among the more derived
heteropteran clades reverted secondarily to phytophagy, they feed on parenchyma,
seeds and pollen (Carver et al. 1991), which are largely unexploited by the “ho¬
mopteran” clades. Only the Pentatomomorpha, a terminal heteropteran clade
(Fig. 5) shows a major reversion to phytophagy. Wheeler et al. (1993) discuss the
phylogenetic topology of Heteroptera, and Carver et al. (1991) discuss their bi¬
ology.

Our 18S rDNA findings, in conjunction with other evidence for placement of
the Coleorhyncha (Schlee 1969: 23, Popov & Shcherbakov 1991: 233, Wheeler
et al. 1993: 131-132), suggests the preceding order of hemipteran cladogenesis.
Available evidence indicates the major clades diverged by the late Permian, and
scant synapomorphies linking these clades suggest rapid divergence of morpho¬
logical form occurred. Frequent homoplasy within these developing clades prob¬
ably resulted from evolutionary constraints (Wake & Larson 1987, Wake 1991).
In conjunction with a relatively steady speed base substitution clock, the relatively
few 18S rDNA synapomorphies shown among these clades (Fig. 3) functionally
also indicates a relatively short time was involved during the cladogenesis. A
similar 28S rRNA topology has been found for sponges, with deep radiations
among clades that are separated by short intemodes (Lafay et al. 1992).

Thus, a saltational and punctuated equilibrium mode of evolution appears to
be involved among the basal hemipteran clades, and we suspect this may have
resulted from sudden and dramatic selection pressures during the Permian, prob¬
ably following one or more catastrophic truncation events. Ecomorphotypic di¬
versity among every existing major group of vascular plants declined dramatically

54

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

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— CLYPEORRHYNCHA

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- Cimicomorpha

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Figure 5 . Phylogenetic relationships of proposed hemipteran suborders and existing (heteropter-
odean) infraorders. Horizontals depict the three basal clade suborders (capitals; Clypeorrhyncha =
extant Cicadomorpha; Archaeorrhyncha = Fulgoromorpha) and the more derived infraorders (lower
case; Peloridiomorpha = Coleorhyncha). Verticals depict the clade names (sensu Schuh 1979; lower
case) and the proposed suborder Prosorrhyncha (capitals; = Heteropterodea, sensu Schuh 1979, as
Coleorrhy ncha+Heteroptera).

during the Permian (Shear 1991: 288), but rose again among the new angiosperms
during the Cretaceous. This temporally changing aspect of plant diversity parallels
the initiation of the major hemipteran clades (Permian) and their later internal
radiation (late Jurassic/Cretaceous) into modem groups.

Implications for Suborder Nomenclature

If our 18S rDNA-based topologies are correct, the paraphyly of Auchenor-
rhyncha requires its abandonment as a cladistic subordinal taxon of Hemiptera.
Instead, recognition of four major hemipteran clades (stemorrhynchans, extant
cicadomorphans, fulgoromorphans, heteropterodeans) as suborders is clearly ap¬
propriate (Fig. 5). We rely on the 18S rDNA synapomorphies of Wheeler et al.
(1993), the morphological synapomorphies of Schlee (1969), and the fossil lineage
assessment of Popov & Shcherbakov (1991: 233, as Coleorhyncha Ingruidae
—* Scytinopteroidea —» Heteroptera) for placement of the Coleorhyncha as sister-
clade to Heteroptera 8 . Despite anyone’s lingering uncertainty concerning the rel¬
ative phylogenetic topology among the major clades, there can be no doubt of
their individual monophyly. Thus, demarcation of Hemiptera into these four
major clades, as suborders, is a conservative treatment that preserves their mor¬
phological and ecological delineation.

Three new suborder names are proposed here, however, because several po¬
tential obfuscations confuse the application of the currently available names. First,
there is a polyphyletic, paleontological use (e.g., Shcherbakov 1984) of Cicado¬
morpha, that differs from the one that is monophyletic covering extant taxa only
(e.g., Carver et al. 1991). Second, there are varying definitions of Heteroptera,
which may (e.g., Carver et al. 1991) or may not (e.g., Henry & Froeschner 1988)

8 Recent molecular evidence based on 18S rDNA sequences (ex Wheeler et al. 1993) shows resolute
synapomorphic sites supporting Coleorhyncha+Heteroptera monophylly; to be discussed elsewhere
(Campbell et al., unpublished data).

1995 SORENSEN ET AL.: NON-MONOPHYLY OF AUCHENORRHYNCHA 55

include Coleorhyncha, versus Heteropterodea (e.g., Schuh 1979, Wheeler et al.
1993) or its alternative, initial spelling Heteropteroidea (Schlee 1969). Third, a
problem exists regarding the implied relative hierarchical status of Cicadomorpha
and Fulgoromorpha in contrast to heteropteran infraorders, which also end in
suffix “-morpha” (e.g., Schuh 1979).

Standardizing on suffix “-rrhyncha” to denote suborder, we retain Stemor-
rhyncha, and propose as hemipteran suborders: (a) Clypeorrhyncha [Gr. “shield-
nose”], for the monophyletic extant cicadomorphan taxa, (b) Archaeorrhyncha
[Gr. “ancient-nose”], for Fulgoromorpha, and (c) Prosorrhyncha [Gr. “front-” or
“forward-nose”], for clade Coleorhyncha+Heteroptera. We believe these names
provide a much needed alleviation of confusion over the boundaries, hierarchical
status and monophyly of these groups. Their application toward that end is feasible
because the ICZN code does not require priority-basis recognition of subordinal
names. In view of our 18S rDNA findings, the clade name Neohemiptera is also
proposed for the clade Fulgoromorpha+Heteropterodea in Schuh’s (1979) system
(our clade Archaeorrhyncha+Prosorrhyncha).

It is appropriate, under this system, to refer to Coleorhyncha as Peloridiomor-
pha, indicating its infraordinal level within suborder Prosorrhyncha. Continued
use of Coleorhyncha would imply its subordinal status, and necessarily that of
Heteroptera, negating Prosorrhyncha. In contrast, use of Heteroptera can imply
a greater clade division within suborder Prosorrhyncha (i.e., Hemiptera: Prosor¬
rhyncha: Heteroptera), as the sister-group to Peloridiomorpha. Continued use of
Fulgoromorpha and Cicadomorpha, however, would confuse their infra- and
subordinal status. Moreover, use of Cicadomorpha confuses its paleontological
versus extant taxonomic meaning; therefore, any such use should be in a non-
cladistic fashion only, to indicate the extinct, polyphyletic Mesozoic taxa that
may be relatives of the modem, monophyletic Clypeorrhyncha, but that lack all
the latter’s defining synapomorphies.

The logic for continuation of “-morpha” suffixed infraorders, and proposed
adoption of “-rrhyncha” suffixed suborders, for Hemiptera is independent of, but
related to, another question that should be asked. Because Hemiptera is mono¬
phyletic, and heteropterists generally use Heteroptera for “their group,” perhaps
it is time to recognize and address a common, often expressed resentment by
many “homopterists,” for whatever rationale, towards incorporation of those
groups under the name Hemiptera. Unfortunately, Fabricius’ (1775) neutral or¬
dinal name, Ryngota, later modified to Rhyngota (Fabricius 1803) and then Rhyn-
chota (Burmeister 1835), the latter championed by Hamilton (1981, 1983) and
others (e.g., Dworakowska 1988), has been largely ignored for hemipterans. Adop¬
tion of Rhynchota may be appropriate as an admittedly political, but pragmatic,
attempt at appeasing and unifying all “hemipterists” under one ordinal banner.

Acknowledgment

We thank E. Backus (University of Missouri), R. Denno (University of Mary¬
land), R. Foottit and K. G. A. Hamilton (Canada Agriculture, Ottawa), D. Hendrix
(USDA, Phoenix, Arizona), C. Schaefer (University of Connecticut), D. Schlee
(Staatliches Museum fur Naturkunde, Stuttgart, Germany), and T. Wood (Uni¬
versity of Delaware) for helpful discussions. Robert V. Dowell served as editor,
and three anonymous reviewers’ comments were addressed and incorporated.

56

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Vol. 71(1)

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Note added in final galley. The homoplasy (in literature) of sites 79 (dipterans, ex Carmean et
al. 1992) and 454 (various heteropteran lineages, ex Wheeler et al. 1993) was discovered after
acceptance of this manuscript, and was addressed in initial galley, along with insertion of
footnotes 7 (p. 41) and 8 (p. 54). We have since tested the effect of removal of these sites on
generation of the most parsimonious topology for the modified SET 4 matrix. The absence of 454,
leaving only 19 nucleotides, created six MLTs (TL 28, Cl 0.714) rather that the single SET 4 MLT.
The additional absence of 79, leaving 18 nucleotides, produced the identical six topologies (TL
27, Cl 0.704). These are:

(A) { { { { { CICAD , MIRID }, CERCO }, MEMBR }, DELPH }, STERN}

(B) { { { { { CICAD , MIRID }, MEMBR }, CERCO }, DELPH }, STERN }

(C) { { { { CICAD , MIRID }, { MEMBR , CERCO } }, DELPH }, STERN}

(D) { { { { {MEMBR , MIRID }, CERCO }, CICAD }, DELPH }, STERN}

(E) { { { {{ CICAD , CERCO }, MEMBR }, MIRID }, DELPH }, STERN }

(F) { { { { MEMBR , CERCO }, CICAD }, { DELPH , MIRID } } , STERN }

These MLTs all negate clade Auchenorrhyncha. MLT F is identical with the original SET 4
MLT, espousing clade Neohemiptera. MLT E places Heteroptera as sister clade to clade
Clypeorrhyncha. MLTs A-C negate clade Clypeorrhyncha, placing the heteropteran variously
among its members. The 50% majority rule consensus tree, with compatible groupings, from
these MLTs is the same as MLT C, as:

{{ {{ CICAD , MIRID ) 50, { MEMBR , CERCO } 33 } 83, DELPH ) 100, STERN }

However, our further analyses (see footnote 7) using additional taxa (Campbell et al.,
unpublished data), to be published elsewhere, together with significant morphological
synapomorphies that we do not consider to be selection-induced homoplasies, indicate the
monophylly of Clypeorrhyncha. Thus, our suborder proposal remains unaffected.

PAN-PACIFIC ENTOMOLOGIST
71(1): 61-63, (1995)

Scientific Note

AQUATIC MACROINVERTEBRATE RESPONSE TO
SHORT-TERM HABITAT LOSS IN EXPERIMENTAL

POOLS IN THAILAND

Biotic interactions can cause community structures to change temporally so
that new communities in recently disturbed habitats differ from established ones
in similar undisturbed habitats (Sousa, W. P. 1979. Ecology, 60: 1225-1239). In
this study, I contrasted aquatic macroinvertebrate communities in experimental
pools that dried temporarily and were then reflooded to those in similar habitats
that remained flooded.

This study was conducted using facilities at Chiang Mai University in northern
Thailand. The conditions in natural rain-filled pools were simulated using 10
cement tanks, each 80 cm in diameter, that were flooded by rainfall in September
1990. To provide sediments for benthic invertebrates, I added 0.5 liter of soil to
each tank. Tanks were paired spatially so that both tanks in each pair received
similar amounts of shading and organic matter from falling tree leaves. In most
cases, much of the water column in tanks eventually became filled with leaves.
From September through December 1991, rainfall kept experimental pools flood¬
ed and aquatic invertebrate communities developed naturally within them.

With the onset of Thailand’s winter dry season in December, the pools began
to dry. When water depths in tank pairs had declined to approximately 2 cm, I
randomly selected one member of each pair to be refilled to a depth of 4 cm by
adding 10 liters of tap water per tank; water was left standing for 24 h prior to
introduction to allow chlorine to dissipate. Water in all of the tanks continued to
evaporate, and the unfilled tanks in each of the five pairs dried completely during
late January. An examination of the dry leaves and sediments in these tanks
revealed no live aquatic invertebrates. These tanks were allowed to remain dry
for 48 h.

I then refilled these disturbed tanks to a depth of 4 cm by adding 20 liters of
water per tank. Concurrently, 10 liters of water was added to the non-dried tank
of each pair. I continued to add equal amounts of water to paired tanks, as needed,
to maintain depths of at least 2 cm; in mid-March, all tanks were allowed to dry.
Thus, in this experiment, identical volumes of water were added to paired tanks
but one half of each pair was disturbed by drying for two days in January whereas
the other retained water from September through March.

In early February, 10 days after January refloodings of dried tanks, macroin¬
vertebrates in each of the five tank pairs were sampled. A 10-cm by 6-cm net
(0.1-mm mesh) was swept across a randomly selected transect spanning each
tank’s 80-cm diameter; the distal edge of the net was scraped along the bottom
so that benthic invertebrates were collected. This technique had the desirable
feature of not being destructive to the habitats but probably under-sampled benthic
and fast-swimming organisms. Thus, for the sample collected at the experiment’s
end in mid-March, I vigorously stirred the water and sediments for 1 min and

62

THE PAN-PACIFIC ENTOMOLOGIST

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T able 1. Numbers of macroinvertebrates collected from experimental tanks that had been disturbed
by drying and reflooding in January 1991 compared to numbers in paired habitats that did not dry
(undisturbed). The February sweep-net samples were collected 10 days after disturbed habitats were
reflooded. For March samples, collected six weeks after refloodings, water and sediments were stirred
vigorously before sweep netting to increase capture efficiency for benthic organisms.

Taxa

February samples

March samples

Disturbed habitats Undisturbed habitats

(number per sweep [SE]) (number per sweep [SE])

Disturbed habitats
(number per sweep
[SE])

Undisturbed habitats
(number per sweep [SE])

Ephemeroptera

Baetidae

6(2)

4(2)

23 (32)

15 (21)

Diptera

Culicidae

59 (14)

6 (5) a

35(11)

l(0) a

Chironomidae

12(6)

7(1)

92 (45)

76 (6)

Ephydridae

8(2)

3(1)

<1

<1

Ostracoda

3(2)

179 (113) a

116 (116)

163 (69)

Numbers differed significantly (paired Mest; P < 0.05) between treatments.

swept the net through the slurry, selecting transects as above. The numbers of
macroinvertebrates collected per treatment were contrasted using paired /-tests.

In February samples (Table 1), numbers of seed shrimp (Ostracoda) in the
disturbed habitats were < 2% of those in undisturbed habitats (3 ± 2 ostracods/
sweep vs. 179 ± 113 ostracods/sweep; paired /-test, P < 0.01). Ostracod im-
matures and adults are noted for their ability to tolerate drought if sediments
remain humid (Wiggins, G. B., R. J. Mackay & I. M. Smith. 1980. Archiv f.
Hydrobiol. Supple., 58: 97-206), so their reductions from January dryings suggests
the disturbance from drought was severe. However, numbers of Culex quinque-
fasciatus Say mosquito larvae (Diptera: Culicidae) were 10 times greater in habitats
that had dried in January and were reflooded for only 10 days than in habitats
that had retained water since September (59 ± 14 larvae/sweep {1 SE} vs. 6 ±
5 larvae/sweep; paired /-test, P < 0.01). In addition, analyses (paired /-tests, P
> 0.05) failed to detect density differences between disturbed and undisturbed
habitats for the other common invertebrates such as midge larvae (Diptera: Chi-
ronomidae) (12 ± 6 larvae/sweep vs. 7 ± 1 larvae/sweep), brine fly larvae (Diptera:
Ephydridae) (8 ± 2 larvae/sweep vs. 3 ± 1 larvae/sweep), and mayfly nymphs
(Ephemeroptera: Baetidae) (6 ± 2 nymphs/sweep vs. 4 ± 2 nymphs/sweep).
Clearly, rates of recolonization and development by these insect species were
rapid. I occasionally saw predators such as dragonfly nymphs (Odonata: Libel-
lulidae) and backswimmer adults (Hemiptera: Notonectidae) in undisturbed tanks
but these organisms were rare and were not collected in sweep samples.

In March, samples (Table 1), collected six weeks after January refloodings,
mosquito larvae were still abundant in the habitats that dried in January, and
significantly more larvae were collected there than in habitats that had not dried
(35 ±11 larvae/sweep vs. 1 ± 0 larva/sweep; paired /-test, P < 0.01). By March,
ostracod numbers in the habitats that dried in January had rebounded so that
numbers were no longer significantly different in disturbed vs. undisturbed hab¬
itats (116 ± 116 ostracods/sweep vs. 163 ± 69 ostracods/sweep; P > 0.05).

1995

SCIENTIFIC NOTE

63

Although the capture efficiency for mosquitoes and ostracods appeared to be
similar for the two sampling variations used in February and March, the stirring
of the sediments prior to sweep netting clearly increased the capture rates of
benthic midges and mayflies in March. I collected 92 ± 45 midge larvae/sample
in disturbed habitats, and 76 ± 6 larvae/sample in undisturbed ones. For mayflies,
23 ± 32nymphs/sample were collected in disturbed habitats vs. 15 ± 21 nymphs/
sample in undisturbed habitats. However, as in the February sample, midge and
mayfly numbers during March did not differ significantly between treatments (P
> 0.05). Brine fly larvae were rare during March.

Although disturbance from drying and reflooding habitats is known to benefit
Aedes spp. and other mosquitoes that have desiccation resistant eggs (Wiggins et
al. 1980), the temporary drawdowns in this study also increased densities of Culex
mosquitoes, which do not have desiccation resistant eggs. The greater numbers
of mosquito larvae in the drought disturbed habitats may have been related to
differences in water chemistry between treatments, which may have influenced
oviposition rates or larval survivals. Water pH was lower in disturbed habitats
than in undisturbed habitats (8.1 ± 0.4 vs. 8.5 ± 0.2, respectively; P < 0.05,
paired Mest). The water in the tanks that dried was in all cases also visibly darker
brown than in corresponding tanks that had remained flooded, suggesting greater
concentrations of humic materials. Although shallow, organic-rich habitats with
few predators are considered to be prime habitats for mosquito larvae (Laird, M.
1988. The natural history of larval mosquito habitats. Academic Press, New
York), this axiom applied only to habitats that temporarily became dry and not
to habitats that remained flooded.

Aside from the strong responses to drying by mosquitoes, the remaining mac¬
roin vertebrates showed little response to the disturbance. Keys were not available
to determine species compositions of the immature insects (except mosquitoes),
so the failure to detect response at the community level may be in part a product
of low taxonomic resolution. However, all common species occurred in both
treatments. Alternatively, a combination of rapid rates of recolonization and
growth in the warm tropical conditions may have limited the impact of disturbance
in these pools. Although January dryings appeared to kill all invertebrates in the
disturbed habitats, the fast-maturing insects present in the undisturbed habitats
during January probably also disappeared shortly thereafter via emergence. Sub¬
sequent recolonization of both habitat types was rapid, and colonizers (except for
mosquitoes) failed to differentiate between disturbed and undisturbed habitats.
Thus, disturbance may be less important to community development in habitats
dominated by fast-growing immature insects than in habitats dominated by other
types of organisms (e.g., Power, M. A. & A. J. Stewart. 1987. Amer. Midi. Nat¬
uralist, 117: 333-345).

Acknowledgment. — \ appreciated the cooperation in this study of the Depart¬
ment of Entomology at Chiang Mai University, Thailand and editorial comments
on an earlier draft of this paper by Vincent H. Resh.

Darold P. Batzer, 218 Wellman Hall, Department of Entomological Sciences,
University of California, Berkeley, California 94720.

PAN-PACIFIC ENTOMOLOGIST
71(1): 64-65, (1995)

Scientific Note

LALAPA LUSA PATE (HYMENOPTERA: TIPHIIDAE):
NEW LOCALITIES AND NEW FLORAL
ASSOCIATIONS IN THE PACIFIC NORTHWEST

Lalapa lusa Pate (Hymenoptera: Tiphiidae) is a distinctive wasp and the sole
North American representative of the subfamily Anthoboscinae. As such, it has
attracted the attention of aculeate Hymenoptera workers. Lalapa lusa is known
from Idaho, Washington, Oregon and California (Krombein, K. V. 1979. Cat.
Hymen. Amer. N of Mex., 2: 1268) where it occurs in arid and semiarid regions.
Yet, it remains rare in collections and its biology is unknown.

The only previous Idaho record was a single female collected at Hollister, on
21 Aug 1930, which was designated as the holotype (Pate, V. S. L. 1947. J. N.Y.
Entomol. Soc., 55: 115-145). There were two previously known collections of L.
lusa from Washington: at Whiskey Dick Canyon, (M. Wasbauer, personal com¬
munication), and at Burke, which came from the M. T. James Collection, De¬
partment of Entomology, Washington State University.

We collected twelve additional specimens of L. lusa from Idaho and Washington
(see records). Collections were made by sweeping low vegetation, the blossoms
of rabbitbrush, Chrysothamnus nauseosus (Pallas) Britton (Asteraceae), and Can¬
ada thistle, Cirsium arvense (L.) Scopoli (Asteraceae). Specimens were also ob¬
tained from flowers of white sweet clover, Melilotus alba Desrousseaux (Fabaceae),
and from yellow pan traps.

All four floral associations for L. lusa are new. Lalapa lusa was previously
known wild buckwheat flowers, Eriogonum sp. (Polygonaceae), in Riverside Co.,
California, and feeding on the exudate of Disholcaspis sp. galls (Hymenoptera:
Cynipidae) on oak, Quercus sp. (Fagaceae) (M. Wasbauer, personal communi¬
cation).

Lalapa lusa are 6-7 mm long, mostly matte black with a red apex of the
abdomen. The body is largely covered with long, white to tan setae that are
particularly dense on the apical abdominal segments. These characters allow dis¬
crimination of L. lusa from most other tiphiids in the field. This is important
because it was found sharing inflorescences of Canada thistle and white sweet
clover with a far more abundant Paratiphia sp. (prob. neomexicana Cameron)
(Hymenoptera: Tiphiidae). Under the microscope Lalapa lusa can be distin¬
guished from other tiphiids by examining the middle and hind tibiae which are
flattened and bear several rows of short, thick, blunt, peg-like tubercles. The wasps
are active from mid summer to early fall. Pan trap collections indicate that they
spend a good deal of time flying low over the ground, as would be typical for a
fossorial wasp. Thus, pan traps or flight intercept traps may be the best means of
sampling for L. lusa. Subsequent observations in the area may then reveal bio¬
logical secrets of another fascinating wasp and yield data important to our un¬
derstanding of the Tiphioidea.

Records.— IDAHO. NEZ PERCE Co.: Hatwai Crk, 8 km (5 mi) E of Lewiston, 31 Jul 1984, W. J.

1995

SCIENTIFIC NOTE

65

Turner, Chrysothamnus nauseosus (Pallas) Britton (Rabbitbrush, Asteraceae) (1); Hell’s Gate State
Park, 6.4 km (4 mi) E of Lewiston, 14 Jul 1982, T. D. Miller, Cirsium arvense (L.) Scopoli (Canada
thistle, Asteraceae) (1); same loc., but 28 Jul 1982, J. B. Johnson, sweeping low vegetation, (1); same,
but 14 Jul 1983, Melilotus alba Desrousseaux flowers (white sweet clover, Fabaceae) (2); same, but
22 Aug/6 Sep 1984, T. D. Miller, yellow pan trap (3); same, but 10/20 Aug 1985 (2). OWYHEE Co.:
Murphy, 18 Jul 1982, J. B. Johnson, sweeping low vegetation (1). TWIN FALLS Co.: Hollister, 21
Aug 1930 (holotype). WASHINGTON. BENTON Co.: 8 km (5 mi) N of Richmond, 2 Oct 1982, J.
B. Johnson, sweeping low vegetation (1). GRANT Co.: Burke, 9 Aug 1950, E. Klostermeyer, sweeping
Salsola kali L. (Russian thistle, Chenopodiaceae). KITTITAS Co.: Whiskey Dick Cyn, 12.8 km (8
mi) N of Vantage.

Acknowledgment. —Published with the approval of the director of the Idaho
Agricultural Experiment Station, as Research Paper 93733.

James B. Johnson 1 , Terry D. Miller 2 , William J. Turner 3 , 1 Department of Plant,
Soil and Entomological Sciences, University of Idaho, Moscow, Idaho 83844-
2339; 2 Department of Entomology, Washington State University, Pullman, Wash¬
ington 99164-6432; 3 Department of Entomology, Washington State University,
Pullman, Washington 99164-6432.

PAN-PACIFIC ENTOMOLOGIST
71(1): 65-66, (1995)

Scientific Note

NEW RECORDS OF TRICHOSTERESIS FOERSTER FROM

THE WESTERN UNITED STATES
(HYMENOPTERA: MEGASPILIDAE)

Only two species of Trichosteresis Foerster are recorded from North America—
T. floridana Ashmead from Jacksonville, Florida, and T. vitripennis Whittaker
from Chilliwack, British Columbia (Muesebeck, C. F. W. 1979. Catalog of Hy-
menoptera of North America: 1191). Their hosts are not known, but European
species have been reared from syrphid pupae. However Dessart (Dessart, P. 1974.
Ann. Soc. Entomol. Fr., (N.S.) 10:395-448) believes Trichosteresis is monotypic,
and all other species, are synonyms of T. glabra (Boheman).

In 1993,1 found T. vitripennis in two widely-separated locations in California,
suggesting that it occurs throughout the state. In April, I collected a female on
the roof of my car that had just come through a car wash in the City of San
Bernardino (see records). In June, I swept two females from the foliage of Quercus
agrifolia Nee near the North Oakland Sports Center in Oakland. Determinations
were made using a generic key to world Ceraphronoidea (Alekseyev, V. N. 1978.
Entom. Rev., 57: 449-453) and the species description (Whittaker, O. 1930. Proc.
Entom. Soc. Wash., 32: 72-73); no comparisons with the types were made. These
discoveries caused me to reexamine the material in the Essig Museum, where I
found four additional Trichosteresis specimens. One was a T. vitripennis female,
which I had swept from Medicago sativa L. at U.C. Berkeley’s experiment station
in Albany. The other three were females that did not match the descriptions of
either T. floridana or T. vitripennis’, these were collected at the Needle Rocks at
the north end of Pyramid Lake, Nevada (collector unknown).

66

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

Trichosteresis is easily distinguished from other megaspilids by its forewing
characteristics (lacking a marginal fringe and the disc mostly bare or with micro¬
scopic hairs). The three species from North America also have the radial vein
shorter than the breadth of the pterostigma. The mesonotum of T. vitripennis has
a complete and deeply impressed longitudinal median line, and two anterior
longitudinal furrows between the median line and notauli; in T. floridanus the
median line is incomplete posteriorly and the two longitudinal furrows absent.
The species from Nevada closely resembles T. vitripennis, but its first funicular
segment is about the same length as the pedicel; in T. vitripennis, this segment is
1.5-2 times longer than the pedicel.

All seven specimens are deposited in the collection at the Laboratory of Bio¬
logical Control in Albany, part of the Essig Museum at the University of California
at Berkeley.

Records. —Trichosteresis vitripennis: CALIFORNIA. ALAMEDA Co.: Oakland, 3 and 10 Jun 1993,
R. Zuparko, Quercus agrifolia Nee, 2 females; Albany, 3 Oct 1992, R. Zuparko, Medicago sativa L.,
1 female. SAN BERNARDINO Co.: San Bernardino, 12 Apr 1993, R. Zuparko, 1 female.

Trichosteresis sp.: NEVADA. WASHOE Co.: Needle Rocks at N end of Pyramid Lake, 15 Sep
1983.

Robert L. Zuparko, Laboratory of Biological Control, University of California,
Berkeley, 1050 San Pablo Avenue, Albany, California 94706.

PAN-PACIFIC ENTOMOLOGIST
71(1): 66-68, (1995)

Scientific Note

INITIATION OF MATING ACTIVITY AT THE TREE
CANOPY LEVEL AMONG OVERWINTERING
MONARCH BUTTERFLIES IN CALIFORNIA

Overwintering monarch butterflies, Danaus plexippus (L.) (Danaidae, Lepi-
doptera) congregate west of the Rocky Mountains in clusters, ranging from a few
hundred to several thousand individuals, in certain groves along the California
coastline. This aggregation behavior, the result of migration to escape the rigors
of winter, is believed to lessen bird predation (Fadem, C. M. & A. Shapiro. 1979.
Pan-Pacif Entomol., 55: 309-310) and concentrates the sexes in a locale that
increases their chances of mating in the spring. Mating activity at a wintering
grove may occur sporadically throughout the winter, but begins in earnest by early
or mid-February and lasts approximately two weeks. Females usually mate with
several males before their spring dispersal to oviposition sites (Hill, H. F., A. M.
Wenner & P. H. Wells. 1976. Amer. Mid. Nat., 95: 10-19). The males capture
females in flight (Hill et al. 1976) or “nudge” them toward the ground (Pliske, T.
E. 1975. Ann. Ent. Soc. Amer., 68: 143-151) before mating. Similar behavior has
been observed in the laboratory (Rothschild, M. 1978. Antenna, 2: 38-39) and
in summer populations (Zalucki, M. P. 1982. J. Aust. Ent. Soc., 21: 241-246).

1995

SCIENTIFIC NOTE

67

Table 1. The average number of canopy and ground butterfly pairs recorded at two-h intervals
(08:00 h to 14:00 h) on 6 separate days in February, 1993. The mean and SE are presented for each
observational period.

Time interval

08:00 h

10:00 h

12:00 h

14:00 h

Canopy attempts

Male-male

Male-female

4.3 ± 1.9

1.2 ± 0.6

12.0 ± 2.2

5.3 ± 0.7

6.2 ± 1.1

3.5 ± 0.6

1.4 ± 0.6

0.8 ± 0.4

Ground pairs

Male-male

Male-female

1.2 ± 0.6

1.2 ± 0.7

2.2 ± 0.7

5.5 ± 0.7

1.2 ± 1.4

3.3 ± 0.8

0.2 ± 0.4

1.6 ± 0.9

During February, 1993, at a winter site in Pismo Beach North State Park, San
Luis Obispo County, California, (35°07'46" latitude; 120°37'53" longitude), I ob¬
served, using a spotting scope (20 x 45, Zoom Bushnell Spacemaster) and bin¬
oculars (10 x 50 Bushnell), mating activity occurring at the canopy level of large
blue gum, (Eucalyptus globulus Labillardiere) and Monterey cypress, (Cupressus
macrocarp a Gordon) trees. Males captured potential mates sunning on the foliage
within butterfly clusters and/or on the foliage of neighboring trees. The male
would fly above a butterfly (either a female or another male) that was resting on
the foliage with outstretched wings and pounce and grasp the thorax of the in¬
dividual with its legs. The pair frequently displayed rapid wing fluttering and other
interactions typical of copulating pairs (Pliske 1975). If male-female paired, the
struggling butterflies, after 3 to 10 sec, would slowly fall from the foliage to the
ground and complete or abandon their mating activity. On two occasions, I
observed a male capture and successfully couple with a female at the canopy level.
Both matings occurred on the flat and shelf-like foliage of Monterey cypress. If
two males, the interplay between them lasted < 5 sec, but was occasionally longer,
especially toward the end of the overwintering season. In such cases, the pair fell
from the canopy foliage and separated either before, or shortly after, landing on
the ground.

I documented the initial and latter phase of mating activity by recording the
number of canopy and ground butterfly pairs (male/female & male/male) at two-
h intervals, starting at 08:00 h and ending when mating activity ceased (14:00 h).
At the beginning of each interval, the number of ground pairs was counted beneath
each cluster tree, before recording the number of canopy mating attempts observed
during a thirty min period. At the end of thirty min, the number of paired
butterflies on the ground was again recorded. This procedure was repeated on 6
separate days in February. The average number of canopy and ground pairing
attempts for each two-h interval showed a similar pattern of mating activity at
the foliage level and on the ground (Table 1). Pairing attempts began slowly in
the morning, reached a peak at 10:00 h and slowly declined as daytime temper¬
atures cooled. There were more male/male than male/female encounters at the
canopy level, indicating that D. plexippus seek mates visually during the early
stages of the mating sequences, resulting in many missed pairings. This relation¬
ship was exactly opposite on the ground, however, where more male/female than
male/male couples were observed. Once physical contact of courtship is initiated,

68

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

the males are able to discriminate between the sexes (via visual or short distance
chemical communication) resulting in longer interplay and frequently to a suc¬
cessful union.

I believe that the initiation of mating sequences on the canopy is common
among overwintering monarch butterflies and that it has been overlooked by
earlier investigators. Once observed, it can be recognized easily; I examined and
noticed this mating activity on a kodachrome slide I took in the winter of 1990—
1991 and recently, in a picture of Mexican monarch butterflies on roosting trees
published with a article in Natural History (Larsen, T. 1993. Nat. His., (6): 30-
39). The capture of mates in flight, at least for California overwintering monarch
butterfly populations, may not be as frequent as those initiated at the canopy
level. I observed only one in-flight capture of a female by a male during many
hours of field observations. This single event was observed when the female slowed
her flight while trying to land on foliage, and was then captured by a male. The
capture of stationary “mates” concentrated in a small area (foliage of roosting
trees), after months of overwintering, saves time and energy, and provides max¬
imum opportunities for mating.

Acknowledgment. — I thank Dennis Frey, Harry Kaya and Aryan Roest for their
critical review and comments and Christopher Nagano for asking the question
“where” mating was occurring.

Kingston L. H. Leong, Department of Biological Sciences, California Polytechnic
State University, San Luis Obispo, California 93407.

PAN-PACIFIC ENTOMOLOGIST
71(1): 68-71, (1995)

Scientific Note

OBSERVATIONS OF THE FORAGING PATTERNS OF
ANDRENA ( DIANDRENA) BLENNOSPERMATIS THORP
(HYMENOPTERA: ANDRENIDAE)

Pollinator foraging movements can determine pollen transfer among flowers
and thus may affect pollen and gene flow within and among plant populations
(Handel, S. N. 1983. pp. 163-211. In Real, L. (ed.). Pollination biology. Academic
Press Inc.). From a landscape perspective, pollinator foraging patterns form a
spatial link among available floral resources that is bounded by the particular
species’ flight and floral preferences. Foraging studies that emphasize the latter
can also help identify the spatial requirements of insect pollinators. Therefore,
quantification of pollinator foraging patterns can yield information pertinent to
floral ecology and evolution as well as to landscape utilization by insect pollinators.
Unfortunately, many insect pollinator foraging patterns are not well documented,
and that is especially true for solitary bee species.

1995

SCIENTIFIC NOTE

69

Figure 1. Schematic diagram of Blennosperma nanum nanum patches observed. The approximate
shapes of patches, and distances between patches are as indicated. The approximate sizes of the white,
orange, and yellow patches are 54 m 2 , 560 m 2 , and 960 m 2 , respectively.

We studied the foraging patterns of the native, solitary bee Andrena (.Diandrena)
blennospermatis Thorp, which is oligolectic on Blennosperma nanum nanum
(Hook.) Blake, a vernal pool plant (Thorp, R. W. 1969. Univ. Calif. Publ. En-
tomol., 52: 1-146). Specifically, we sought to determine whether individual fe¬
males of A. blennospermatis forage between discrete patches of B. n. nanum. Our
primary purpose was to evaluate the spatial utilization of discrete floral patches
by female A. blennospermatis during one flight season. Consequently, in this study,
we are interested in the spatial, rather than temporal, patterns of female A. blen¬
nospermatis foraging.

We conducted this study at Jepson Prairie Preserve, near Dixon, Solano Co.,
California from 6-18 Mar 1993. This period encompassed the peak of the adult
flight season of this bee in 1993. To observe interpatch foraging, we marked and
subsequently observed marked female bees in three separate patches of B. n.
nanum (Fig. 1) on each of nine nonconsecutive days (March 6-8, 10-11, 13-14,
16, 18) between 10:00-13:00 h. However, the period of time we spent marking
and observing each day varied to some degree, depending upon weather conditions
and flight activity. Except for the first date, one person marked and observed bees

70

THE PAN-PACIFIC ENTOMOLOGIST

Yol. 71(1)

in all patches on each day. On the first date, a total of six people simultaneously
marked and observed bees, two per floral patch. The number of bees marked per
patch per date varied (1-11 bees) yielding a total of 64 marked bees.

We marked female bees by placing a dot of enamel paint on the thorax using
a plastic dental toothpick. Each floral patch was assigned a unique color: white,
yellow, or orange. Female bees netted within a floral patch were marked with that
patch’s color and immediately released. To assess the extent of interpatch foraging
by A blennospermatis females, we recorded observations of foraging females in
which the female’s color was different from the assigned patch color. Because we
were concerned with the spatial patterns of floral utilization, rather than the
temporal aspects of those foraging patterns, we kept each patch color constant
throughout the study. This system of marking, however, did not allow us to
distinguish individuals marked the same color unless they were sighted simul¬
taneously. Voucher specimens are deposited in the Bohart Museum, University
of California, Davis.

Our observations indicate that limited interpatch foraging by female A. blen¬
nospermatis occurs. Of 28 females marked in the white patch, only 2 (7%) were
observed foraging simultaneously in the orange patch (Fig. 1). Of 25 females
marked in the orange patch, only 1 (4%) was observed foraging in the white patch.
None of the 11 females marked in the yellow patch were observed foraging in the
other two patches. These observations suggest that individual females occasionally
forage between B. n. nanum patches 25 m apart (Fig. 1), but rarely forage, if at
all, between patches 80-100 m apart. In contrast, we commonly observed intra¬
patch foraging by females that we were able to visually follow directly after mark¬
ing. We cannot determine whether these instances of interpatch foraging represent
movements within a single foraging bout, within a single day, or between days.

It is unclear how the floral patches (Fig. 1) are spatially related to the nest sites
of the marked A blennospermatis females. Although there were several areas near
the white and orange patches that contained scattered nests of A blennospermatis,
Andrena ( Tylandrena ) sp. and other Andrena spp., we did not identify the indi¬
vidual nests of the marked females. However, we did identify the nests of two A.
blennospermatis females whom we later individually marked. We observed one
bee foraging in the orange patch that was approximately 50 m away from her
nest. We observed the other female foraging at B. n. nanum patches 25 m or
closer to her nest.

Our observations of limited interpatch foraging and common intrapatch for¬
aging by A. blennospermatis females are consistent with other studies of andrenid
bee foraging behavior. These studies (Danforth, B. N. 1989. J. Kansas Entomol.
Soc., 62: 59-79; Thorp 1969, 1990. pp. 109-122. In Ikeda, D. H. and R. A.
Schlising (eds.). Vernal pool plants—their habitat and biology. Studies from the
Herbarium No. 8, California State University, Chico.) suggest that the foraging
areas of several andrenid bee species are spatially very limited. Thorp (1990)
found that at Jepson Prairie Preserve, most females of Andrena (Hesper andrena)
limnanthis exhibited limited foraging areas and were observed 10 m or closer to
the original marking site. Our observations suggest that A. blennospermatis females
tend to forage within a particular B. n. nanum patch. Consequently, it is likely
that females largely transfer pollen within a B. n . nanum patch rather than between
patches (Fig. 1). Because A blennospermatis females are one of the most common

1995

SCIENTIFIC NOTE

71

visitors to B. n. nanum flowers (Thorp 1969, 1990), they may have the potential
to strongly influence pollen flow within B. n. nanum patches.

Acknowledgment. — We thank K. Schick, J. Schick, D. Carmean, S. Heydon, C.
Hey don, and J. Barthell for assistance.

Joan M. Leong, Robert P. Randolph, 1 and Robbin W. Thorp, Department of
Entomology and Ecology Graduate Group, University of California, Davis, Cali¬
fornia 95616 ; 1 Current address: 310 S. Orange Ave. #33 Lodi, California 95240.

PAN-PACIFIC ENTOMOLOGIST
71(1): 71-74, (1995)

Scientific Note

LONG-TERM CHANGES IN OBSCURA GROUP
DROSOPHILA SPECIES COMPOSITION AT
MATHER, CALIFORNIA 1

Since the 1940s, Dobzhansky and his collaborators have collected obscura group
Drosophila species from Mather, California, located at 1375 m on the western
slope of the Sierra Nevada. Mather’s Transition Zone association and moderate
climate have made it one of the most heavily-collected areas in the world for
Drosophila. Fifty years of accumulated data give us the rare opportunity to study
long-term changes in Drosophila species’ relative abundances. Such studies can
also identify effects of climatic changes on species frequencies. This study docu¬
ments evolution in obscura group Drosophila species composition at Mather,
shows that the changes are associated with climate, and provides a baseline for
future investigations.

The genetics of the D. obscura group have been studied extensively, but their
ecology is largely unknown. The ranges of the four native California species vary
latitudinally and altitudinally. In zones of geographic overlap, Drosophila pseu-
doobscura Frolova and D. azteca Sturtevant & Dobzhansky are more frequent in
warmer and drier areas and at lower altitudes (Dobzhansky, T. & J. Powell. 1975.
pp. 537-587. In R. King (ed.). Invertebrates of genetic interest. Plenum Press,
New York.). Drosophila persimilis Dobzhansky & Epling and D. miranda Dob¬
zhansky predominate at higher elevations and northern latitudes. Based on their
zoogeography, D. azteca and D. pseudoobscura are perceived as the more dry/hot
adapted of the four species.

Dobzhansky (1973. Evolution, 27: 565-575) noted an increase in the frequency
of D. persimilis relative to D. pseudoobscura at Mather. Figure 1A shows this
trend, supplemented with data from later collections by the persons mentioned
in the acknowledgment. However, such relative abundances can be deceptive
when the rest of the species group is ignored. Figure IB shows the frequencies of

1 Author’s page charges were partially offset by a grant from the C. P. Alexander Fund, PCES.

(azteca)/(total obscura group) (per or mir)/(total obscura

72

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71(1)

A.

1940 1950 1960 1970 1980 1990 2000

Collection

B.

1970 1975 1980 1985 1990 1995

Collection

C.

1970 1975 1980 1985 1990 1995

Collection

1995

SCIENTIFIC NOTE

73

Table 1. Multiple regression equation of arcsine transformed species frequency with cm rainfall
and year:month collection (e.g., June 1974 = 74.5).

Species

Intercept

Rainfall

Year: month

r 2

n

p

D. pseudoobscura

-13.56

-0.91

0.20

0.85

7

0.021

D. azteca

-4.60

-0.05

0.08

0.68

12

0.006

D. persimilis and D. miranda relative to the frequencies of all obscura group
species for the last twenty years of collections. Except for one anomalous year,
their relative frequencies remained constant. However, D. azteca increased in
frequency dramatically (see Fig. 1C), and D. pseudoobscura's frequency dropped
from 54% in 1974 to 2% in 1993.

Temperature data for Mather are not available, but I obtained rainfall measures
for the 1973-1993 period from the National Climatic Data Center. Multiple
regressions of D. pseudoobscura and D. azteca frequencies on collection date and
cm rainfall for the preceding month were significant (see Table 1). The frequencies
of both species regressed positive to collection date and negative to rainfall, but
the different coefficient magnitudes caused the opposite trends observed. The
negative regressions to rainfall corroborate the claim that these species prefer drier
environments.

Although rainfall partially explains these species’ relative frequencies, the as¬
sociation with collection date suggests an unknown secular trend. The simplest
explanation is that D. azteca is replacing D. pseudoobscura, but there are many
alternative hypotheses. Is there something gradually accumulating or being de¬
pleted in the environment causing the changes in frequencies? Do these changes
reflect differences in the intrinsic potential for these species to increase in numbers?
Many questions remain unanswered.

The processes occurring at Mather can be better understood with density studies.
Without an estimate of the number of flies present each year, we cannot say
whether any species are increasing or declining in absolute abundance. Absolute
numbers available for previous collections at Mather are unrevealing due to dif¬
ferent collecting methods. Further, previous studies at Mather have shown that
the densities of these species vary considerably, even at the same time of year
over different years (Taylor, C. & J. Powell. 1983. pp. 29-59. In Ashbumer, M.,
H. Carson & J. Thompson (eds.). The genetics and biology of Drosophila (Yol.
3). Academic Press, New York). Future studies should combine relative species
abundances with density measurements to ascertain how the observed relative
trends relate to changes in population sizes.

Acknowledgment. — Financial support was provided by a Genetics Training Grant
from the Department of Health and Human Services, a Grant-in-Aid of Research

Figure 1. Relative frequencies of Drosophila species collected at Mather. (A) shows the percentage
of D. persimilis flies relative to the total number of D. pseudoobscura plus D. persimilis flies caught.
(B) shows the percentage of D. persimilis and D. miranda flies relative to the total number of obscura
group flies captured. (C) shows the percentage of D. azteca flies relative to the total number of obscura
group flies collected.

74

THE PAN-PACIFIC ENTOMOLOGIST

Vol. 71 ( 1 )

from Sigma Xi, and a Hinds Fund grant from the University of Chicago. J. Coyne,
J. Kelly, M. Wayne, and T. Wootton provided comments on the manuscript, and
A. Bronikowski provided statistical help. Thanks to F. Mestres, A. Prevosti, C.
Taylor, and especially, J. Powell for providing me with data from their collections
at Mather and to the Carnegie Institute of Washington for allowing the use of
their Mather facility for Drosophila collections.

Mohamed A. Noor, Department of Ecology and Evolution, University of Chi¬
cago, 1101 East 57th Street, Chicago, Illinois 60637.

New Journal Submission Address,

New Laboratory Building:

Plant Pest Diagnostics Center

Effective 1 Jan 1995, the following address change should be noted for
all new submissions to The Pan-Pacific Entomologist:

Dr. John T. Sorensen

Editor - Pan-Pacific Entomologist

California Dept, of Food & Agriculture,

Plant Pest Diagnostic Center,

3294 Meadowview Road,

Sacramento, California 95832-1448

All correspondence to the PCES Treasurer or Secretary, including all
financial inquires, should continue to be addressed to their California
Academy of Sciences addresses. Correspondence directed to the Associate
Editor, Dr. Robert V. Dowell, should be addressed to him at: CDFA,
Pest Detection/Emergency Projects, 1220 "N" Street, Sacramento, CA 95814.

This address change is caused by the movement of CDFA's Insect
Taxonomy Laboratory to a newly constructed biology laboratory building,
the Plant Pest Diagnostics Center (PPDC). The new facility is in southern
Sacramento at the CDFA meadowview operations complex, which it shares
with the department's Chemistry Laboratories, greenhouses and facilities
for emergency projects and biological control.

The new 53,000 sq ft PPDC building houses separate laboratories for
Insect Biosystematics, Botany, Seeds, Plant Pathology and Nematology.
The Insect Biosystematics section has a 1.5 million specimen, compactor-
based insect collection, a nucleotide laboratory and a critical point drying
facility. Additionally, all PPDC laboratories share a photographic
darkroom, scanning and transmission electron microscope facilities and
a 25,000 volume, compactor-based library. The PPDC has a staff of 46,
including 22 scientists. Its insect biosystematists are: Fred Andrews,
Karen Corwin, Tom Eichlin, Eric Fisher, Ray Gill, Alan Hardy, Terry
Seeno, Ron Somerby, and John Sorensen.

PAN-PACIFIC ENTOMOLOGIST
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Literature Cited. — Format examples are:

Anderson, T. W. 1984. An introduction to multivariate statistical analysis (2nd ed). John Wiley & Sons, New York.

Blackman, R. L., P. A. Brown & V. F. Eastop. 1987. Problems in pest aphid taxonomy: can chromosomes plus morphometries
provide some answers? pp. 233-238. In Holman, J., J. Pelikan, A. G. F. Dixon & L. Weismann (eds.). Population structure, genetics
and taxonomy of aphids and Thysanoptera. Proc. international symposium held at Smolenice Czechoslovakia, Sept. 9-14, 1985.
SPB Academic Publishing, The Hague, The Netherlands.

Ferrari, J. A. & K. S. Rai. 1989. Phenotypic correlates of genome size variation in Aedes albopictus. Evolution, 42: 895-899.
Sorensen, J. T. (in press). Three new species of Essigella (Homoptera: Aphididae). Pan-Pacif. Entomol.

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Volume 71

THE PAN-PACIFIC ENTOMOLOGIST
January 1995

Number 1

Contents

LINSLEY, E. G. & J. CHEMSAK—Obituary: Celeste Green, scientific illustrator, 1913-1994_ 1

GUILBERT, E., M. BAYLAC & J. NAJT—Canopy arthropod diversity in a New Caledonian

primary forest sampled by fogging_ 3

PUNZO, F.—Feeding and prey preparation in the solpugid, Eremorhax magnus Hancock

(Solpugida: Eremobatidae)_ 13

CROSLAND, M. W. J.—Nest and colony structure in the primitive ant, Harpegnathos Venator

(Smith) (Hymenoptera: Formicidae)__ 18

HORTON, D. R. & T. M. LEWIS —Tethered flight characteristics of male and female pear
psylla (Homoptera: Psyllidae): comparison of pre-reproductive and reproductive
insects. 24

SORENSEN, J. T„ B. C. CAMPBELL, R. J. GILL & J. D. STEFFEN-CAMPBELL-Non-
monophyly of Auchenorrhyncha (“Homoptera”), based upon 18S rDNA phylogeny: eco-
eco-evolutionary and cladistic implications within pre-Heteropterodea Hemiptera (s.l.)

and a proposal for new monophyletic suborders.... 31

SCIENTIFIC NOTES

BATZER, D. P.—Aquatic macroinvertebrate response to short-term habitat loss in experi¬
mental pools in Thailand__ 61

JOHNSON, J. B„ T. D. MILLER & W. J. TURNER— Lalapa lusa Pate (Hymenoptera: Ti-

phiidae): new localities and new floral associations in the Pacific Northwest. 64

ZUPARKO, R. L.—New records of Trichosteresis Foerster from the western United States

(Hymenoptera: Megaspilidae). 65

LEONG, K. L. H.—Initiation of mating activity at the tree canopy level among overwintering

monarch butterflies in California_ 66

LEONG, J. M., R. P. RANDOLPH & R. W. THORP—Observations of the foraging patterns

of Andrena ( Diandrena ) blennospermatis Thorp (Hymenoptera: Andrenidae)_ 68

NOOR, M. A. — Long-term changes in obscura group Drosophila species composition at Mather,

California. 71

Announcement: new journal submission address, new laboratory building: Plant Pest Diag¬
nostics Center. 74