Occasional papers of the California Academy of Sciences

OCCASIONAL PAPERS

OF THE

California Academy of Sciences

No. 57, 13 pages, 13 figures.

June 30, 1966

Descriptions of the Larva and Pupa of

Necydalis cavipennis LeConte

and the

Pupa of Ortholeptura insignis (Fall)

(Coleoptera : Cerambycidae)

By

Hugh B. Leech

California Academy of Sciences

P*/!arino Dioloiiinal Laboratory

L_ I f. r^ A R Y

WOODS HOLE, MASS.

SAN FRANCISCO

PUBLISHED BY THE ACADEMY
1966

OCCASIONAL PAPERS

OF THE

CALIFORNIA ACADEMY OF SCIENCES

No. 57, 13 pages, 13 figures. June 30, 1966

Descriptions of the Larva and Pupa of

Necydalis cavipennis LeConte

and the

Pupa of Ortholeptura insignis (Fall)

(Coleoptera : Cerambycidae)

By

Hugh B. Leech

California Academy of Sciences

Introduction

On the basis of adult morphology the tribe Necydalini is currently in-
cluded in the subfamily Lepturinae. The genus Necydalis is well developed
in Asia, much less so in Europe; Gressitt (1961) gives a key to sixteen spe-
cies, one of which, A. major Linnaeus, occurs also in Europe. In the Nearc-
tic fauna we have Necydalis with six species and two subspecies, A. mellita
(Say) being from southeastern Canada and the northeastern United States, the
rest from the Pacific Coast eastward to the Rocky Mountains; and Ulochaetes,
monotypic, from the Pacific Coast (Linsley, 1940).

Our genera do not reach the nootropics, but the stronghold of the tribe
is actually Chile, with some 35 species in three genera; some kinds have
long elytra. Two other genera occur in Brazil, one having Rhathymoscelis
haldemani Thomson described from Mexico and recorded from Guatemala.

2 CALIFORNIA ACADEMY OF SCIENCES (Occ. Papers

The nearctic species of ISecydalis, with their long legs and elytra so
short as to expose the wings, are strongly suggestive of ichneumonid wasps.
The large, hairy, black and testaceous ilochaetes leoninus Le Conte is well
named the bumblebee longhorn; see Linsley, 1961, p. 40.

When the immature stages are examined, immediately there are problems
in classification. Craighead (1923) gave the first descriptions of larvae, with
a key to separate I . leoninus and three of the six nearctic species of Secy-
dalis, and epitomized the pupa of ( . leoninus in three lines. He remarked,
"The larvae of this tribe show a strong and undoubted relationship to the As-
eminae. This is illustrated in the tendency (in some species) of the dorsal
margins of the epicranium to be slightly fused and in the short, robust, trian-
gular mandible. In Ilochaetes it is shown by the velvety asperate pronotum
and ampullae, and the two lateral impressions marking off the ambulatory am-
pullae, caused by splitting of the strong muscles from the posterior cuneal
notch. The legs are weaker than in other Lepturinae and jointed as in the As-
eminae." Duffy (1953) gave fuller descriptions of the larva and pupa of Ilo-
chaetes. Of the former he wrote, "It is only with difficulty that this larva can
be retained in the LEPTURINAE, possessing as it does many affinities to-
wards the ASEMINAE, such as the non-tuberculate, asperate ampullae, the
asperate pronotum and the protuberant gular sutures."; of the latter, "The
pupa of this species, although not at all typical of the LEPTURINAE, does
not show any marked affinities toward those of the ASEMINAE as is the case
in the larval stage." The pupa of \ecydalis is described for the first time in
the following paper, and it fits Duffy's key to the Lepturinae even less well
than does that of Ulochaetes.

If the immature stages of the south American genera and species prove
not to fit well into either the Lepturinae or the Aseminae as now classified,
it is possible that the adults should be restudied. In his 1960 monograph on
the immature stages of Neotropical timber beetles Duffy recorded of Necyda-
lini, "Unfortunately no neotropical material of this tribe was available."
However, he was able to quote a number of host records from the literature,
so this matter may be near solution. The ancient type of distribution, aber-
rant appearance of the adults, and discordant characters of the larvae and
pupae may suggest a higher than tribal standing for the group, if supporting
characters are found in the adults.

The Larva of Necydalis cavipennis

Craighead gave a rather short description of the larva oi ISecydalis cav-
ipennis, with figures of certain parts. A fuller description is offered here,
and attention is drawn to discrepancies between his findings and mine.

In 1953 there appeared the first of Duffy's very fine regional works, "A
monograph of the immature stages of British and imported timber beetles (Cer-

No. 57) LEECH: LARVA AND PUPA OF COLEOPTERA 3

ambycidae)." The only example of the Necydalini included is V. leoninus, a
nearctic species occasionally imported into Britain in timber. In his key to
the subfamilies of cerambycid larvae he wrote (p. 66, footnote 1), "The gen-
us Ulochaetes, possessing as it does many affinities toward the ASEMINAE,
can only with difficulty be included in the LEPTURINAE as only the first
character given in the key is applicable (see also p. 146)."

The larva of A', cavipennis on the other hand agrees well with his char-
acters for the Lepturinae in the key to subfamilies except for the first one!
The posterior emargination of the head is neither deep nor very shallow, though
closer to the shallow or asemine type. In his key to the genera of Lepturinae
known from Britain, it will trace to couplet 8 with all characters in agreement,
but will run to the typical lepturines Leptura and Strangalia rather than to
the necydaline Ulochaetes.

Craighead included Necydalis in his treatment of the Lepturinae (loc.
cit., p. 82), but in his own key to the subfamilies (p. 26) the larva traces to
Aseminae, because in couplet 2 the choices are restricted to the fusion or
separation of the epicranial halves behind the front (fig. 3). Thus one is not
greatly surprised to find him state, in his discussion of the subfamily Asem-
inae, "In fact the Necydalini could be as well placed with the Aseminae as
in the true Lepturinae."

Hardy and Preece (1927, p. 64) and Linsley (1940, p. 275) have given
notes on the hosts and habits of the larva of A. cavipennis. My specimens
were found in the damp, rotting heartwood of a log of tanbark oak, Lithocar-
pus densiflorus at Mill Valley, Marin County, California, 26 May, 1957- These
and other rearings were published by me in 1959, page 43. Mature larvae were
taken from their pupal cells, as were pupae with associated last larval skins;
adults were reared, and subsequently examined by Dr. John Chemsak, who
confirmed my identification.

Mature larva (figs. 1, 2). Length 26 to 30 mm., maximum width at pro-
thorax 6 mm. Form subcylindrical, depth of abdomen greater than its width
(compare figs. 1 and 2), tapering slightly to fifth abdominal segment. Head
(figs. 3, 4) about three-quarters as wide as prothorax, transverse, rather thick,
nearly twice as wide as deep; one pair of ocelli, inconspicuous, laterad of an-
tennae, lens rounded; six small setae present on the narrow epistoma. Anten-
nae three-segmented, with large fleshy basal membrane (figs. 5,6) into which
first segment is commonly retracted; segment two slightly shorter, narrower
and more tapering than one, with an inconspicuous short conical supplement-
ary apical process (fig. 5); third segment small, less than twice as long as
process of second, and bearing three apical setae; when not retracted, anten-
nae (less basal membrane) are as long as maxillary palpi. Mandible short, tri-
angular, stout, cutting edge obliquely truncate and not toothed dorsally near
its base; outer side a little rugose basally, with transverse median arcuate

CALIFORNIA ACADEMY OF SCIENCES

(Occ. Papers

Figures 1-2- Larva of Necydalis cavipennis, dorsal and lateral views respec-
tively. Length, 28 mm.

Figures 3-4. Larva of Necydalis cavipennis, dorsal and ventral views of head.
(From Craighead).

No. 57) LEECH: LARVA AND PUPA OF COLEOPTERA 5

carina, slightly sinuate, beginning at base of cutting edge; a single hair arises
from near top of each rugose area; in outline, mandible closely resembles that
of Homaesthesis emarginatus (Say); a prionine,as figured by Craighead (1923,
pi. L fig- 10)- Labrum with numerous setae along front margin and onto adja-
cent dorsal surface, one longer seta laterally near each hind angle on the med-
ian, more strongly sclerotized area, and a transverse line of smaller ones near
base.

Hypos toma slightly narrower than long, with about fifteen well separated
setae in inner anterior half; sutures nearly straight, ferruginous. Gulaone-fifth
longer than wide, half as wide as hypostoma, narrowest anteriorly; sutures
slightly, irregularly raised, ferruginous. Maxillary palpi rather short and broad;
first segment two-thirds as long as wide, third shorter than second and slight-
ly tapered; lacinia broad, fleshy, rounded apically, densely setose. Labial
palpi separated by twice their own width.

Prothorax weakly arcuate dorsally, nearly twice as broad as long, weak-
ly sclerotized, with a transverse vaguely ferruginous band behind front mar-
gin. Pronotum seven-ninths as long as it is wide between lateral furrows,
which are distinct in basal half; surface of lateral furrows and front margin
dull, finely velvety with tiny golden spicules (see best when surface is dry
and lighted from an angle); darkened band behind front margin shining, longi-
tudinally rugose, sparsely setose across anterior darkened band. Proeustem-
um, presternum laterally in part, and sternellum transversely across middle,
velvety spiculate with scattered setae (fig. 6); eusterna of meso-and meta-
thoracic segments dull, sparsely velvety spiculate, their sternella shining,
with irregular bead-like tubercles and a transverse median furrow. Mid-meta-
notum with small patch of tubercles, comparable to those of abdominal am-
pullae; in some cases a few tubercles are found on mid mesonotum. Legs ra-
ther small and weak, nearly as long as gula; unguiculus straight, stout, with
basal seta on inner side.

Abdomen with dorsal ampullae closely set with bead-like tubercles, ar-
ranged in definite transverse rows only on first segment; ampulla of first seg-
ment with a broad median longitudinal impression, segments two to five with
progressively narrower and shallower impressions, ampulla of segment six not
impressed; fine golden spicules on sides of and in transverse median line a-
cross ampullae. Tenth abdominal tergum simple at apex; anus terminal. Am-
pullae on first seven abdominal sterna, the ampullae progressively narrower
and more rounded, first four each with a median transverse impression, all
with bead-like tubercles. Each ventral ampulla encircled by an area of tiny
golden spicules.

Remarks. The larvae described above will trace to A. cavipennis in
Craighead's key to the species (1923, p. 83), but differ from parts of the de-

CALIFORNIA ACADEMY OF SCIENCES

(Occ. Papers

scription on page 84, and from figures on plate XXII as follows:

1. The second antennal segment is appreciably shorter than the first
(fig. 6), not twice as long, as it was described by Craighead.

2. The front margin of the pronotum is dull, velvety spiculate (Craig-
head wrote/'Pronotum anteriorly glabrous, posteriorly rugose;..."). The mid-
metanotum has a patch of bead-like tubercles, not mentioned by Craighead;
this area is comparable to an abdominal ampulla and doubtless functions in
the same manner. There are similar areas on the meso-and metasterna, also
not mentioned by Craighead.

ANTENNAL RING

PPLEMENTARY
OCESS

Figures 5-6. Larva of Necydalis cai'ipennis. Figure 5 shows the interrupted
antennal ring, the partially contracted large basal membrane, and antennal segments
2 and 3- This is the view usually seen. Figure 6 shows the basal membrane fully ex-
tended, segment 1 extruded, segment 2 a little retracted andtwisted in relation to fig-
ure 5.

No. 57)

LEECH: LARVA AND PUPA OF COLEOPTERA

Figures 7-8- Prostemum of larva of Necydalis cavipennis. Figure 7 shows ex-
tensive velvety-spiculate area on the presternum, with small smooth spots, and the
setae on both the presternum and eustemum. Figure 8 shows presternum as figured by
Craighead.

3. Craighead's figure 9, plate XXII, shows a ventral view of the pro-
sternum. The legend draws attention to the triangular, finely pubescent euster-
num, which is differentiated in his drawing (fig. 8 of the present paper). How-
ever, in my material the presternum is in large part equally densely spiculate,
as are also the epipleura (fig. 7). More significantly, the distribution of large
setae on the presternum of my specimens differ considerably from that figured
by Craighead, and he does not show any arising on the eustemum.

4. Craighead's figure 10 on plate XXII illustrates the dorsal ampulla of
the third abdominal segment, with tubercles occupying a median transverse
band; his figure shows the band of tubercles to be five-eighths the width of
the ampulla. In my specimens the band extends completely across the ampulla,
from margin to margin.

Since Craighead's description was based on a larva from California,
from the same host plant as mine, it presumably was A', cavipennis. The dif-
ferences noted may have resulted in part from the artist's interpretations, in
part from a greater variation within the species than has been evident in my
material.

It should be mentioned that there is confusion in some of the legends
for Craighead's plate XI. The second sentence, starting "Note that the dor-
sal...," of the legend for figure 2, actually pertains to figure L Similarly, the
second sentence of the legend for figure 4 applies rather to figure 3.

The Pupa of Necydalis cavipennis

The pupa of a species of Necydalis has not been described before. In
Duffy's key to pupae of the subfamilies of Cerambycidae {loc. cit. pp. 86-88),
that of A. cavipennis traces to couplet 3 because the head has spines, the pro-
thorax has no lateral tubercles, and the prostemum projects beyond the coxae
as a "T"-shaped process. His couplet 3 is as follows:

8 CALIFORNIA ACADEMY OF SCIENCES (^ Occ. Papers

'3. Ninth abdominal segment either with a horizontal spine (fig.
65) or with excurved or parallel urogomphi (fig. 83). Tarsi
each bearingone or a pair of setae (fig. 65)- Hind tibiae with
long, apical, tuberculate spurs (fig. 76). Labrum transverse,
rectangular (fig. 65). Functional spiracles absent on sixth
and seventh abdominal segments. [Femora always with apical
setae (fig. 65). Head triangular and usually rather elongate.
Clypeus usually with a deep impression and a row of setae
across base (fig. 653 3. LEPTURINAE, ^ p. 88

Ninth abdominal segment usually simple but sometimes with

strongly incurved urogomphi (figs. Ill, 248). Tarsi nearly
always without setae, but if setose (Monochamus) then an-
tennae coiled. Hind tibiae never with long, apical, tubercu-
late spurs. Labrum seldom transverse, but if so never rec-
tangular; usually triangular or cordate (fig. 286). Functional
spiracles present on sixth or seventh abdominal segments
(fig. 193). ...4."

"^' The genus Ulochaetes can only with difficulty be included in the LEPTURINAE
as only the first two characters given in the key are applicable (see also p. 145)-"

The second choice leads via couplet 4 to the Aseminae, Cerambycinae,
and Lamiinae.

The pupa of A. cavipennis agrees with only certain of the definitions
in the first part of couplet 3. Taking the points as they are given: The ninth
abdominal segment has a pair of excurved urogomphi. The tarsi lack setae.
The hind tibiae (as well as the front and middle tibiae) have each a pair of
rather short apical spurs, only slightly tuberculate. The labrum is virtually
square, not transverse. There are functional spiracles on both the sixth and
seventh abdominal segment. The femora have no apical setae. The head is
triangular and rather elongate. The clypeus has no deep impression nor a
row of setae across the base. Thus the pupa doesn't fit even as well as that
of JJ. leoninus, the only necydaline considered by Duffy; yet neither is it in
agreement with much of the second part of couplet 3.

In Duffy's key to the Lepturinae (loc. cit.. p. 88-89) it traces best to
couplet 6, which contains the North American Ulochaetes leoninus (occasion-
ally introduced into Britain in timber) in the first choice, and the British Lep-
tura and Strangalia in the second. The pupa of N. cavipennis agrees better
with that of Ulochaetes, but each spine on the abdominal tergites bears a sub-
basal (not subapical)seta, which thus closely resembles the larval unguiculus.
The tarsi lack setae, the tibial spurs are short, the femora are without setae,
and the hind legs have the tarsi shorter than the tibiae.

No. 57)

LEECH: LARVA AND PUPA OF COLEOPTERA

Figures 9-10. Male pupa of Necydalis cavipennis, dorsal and ventral views re-
spectively. Length, 22 mm.

Pupa (figs. 9, 10). Length 15 to 24 mm., width up to 7mm. Head elong-
ate, triangular, with faint transverse rugae; vertex visible from above, with
four longer spines, one at each corner of an approximate quadrangle, and two
or three irregularly placed smaller spines nearby; anteriorly, with a group of
from two to six small spines of several sizes and irregular placement oppo-
site base of each antenna; clypeus without setae. Antennae arcuate, extend-
ing to bases of hind coxae thence curved anteriorly for two segments, termin-
ating adjacent to apices of hind tibiae. Eyes large but not prominent, not se-
tose. Mandibles with a group of tiny setae on a small prominence at outer
apical three-fifths; apex a sharp cone, angled slightly inward. Labrum almost
square, slightly wider than long, apical half with median longitudinal impres-
sion, appearing almost bilobate; sometimes with a few tiny setae near sides
of basal section, which may be slightly tumid medially.

10 CALIFORNIA ACADEMY OF SCIENCES (Occ. Papers

Pronotum tumid, broadly pyriform or oviform, slightly wider than long,
widest just before middle, apex five-sevenths as wide as base; anterior an-
gles small but distinct, hind angles not apparent, base broadly rounded; tumid
area nearly circular, broadest anteriorly, extending from just before basal five-
sevenths to apical two-sevenths; median line apparent, especially on pos-
terior declivity of tumidity where sides of "valley" formed by it are trans-
versely rugose; a patch of spines on each side of median line, starting at top
of tumidity and extending more than half way to base of pronotum, each spine
with a subbasal seta. Scutellum with a few minute setae. Metanotum with a
few very small seta-bearing spines grouped on each side of median line slight-
ly behind middle.

Abdomen with terga one to eight each having a scattering of small seta-
bearing spines in an irregular group on each side of median line, those on
terga one and two slightly behind middle, others nearer apices of terga. Eighth
and ninth terga produced posteriorly in male but not in female pupa. Tenth
tergum short, terminating in a pair of horizontal urogomphi, their apices curved
outward, hooked, and strongly chitinized; urogomphi of male almost three
times as long as dorsal length of tenth tergum, those of female less elongate.
Sterna glabrous. Tenth sternum of male projecting behind eighth as a rec-
tangular protuberance (fig. 10), twice as broad as long, tuberculate on each
side at middle, divided on median line posteriorly and slightly bilobed; in fe-
male pupa sternum ten is represented by two small subcontiguous rounded
bumps. Pleura glabrous. Legs glabrous; hind femora reaching to middle of
third abdominal segment. Functional spiracles on first seven abdominal seg-
ments; peritreme oval, thin, not raised above general level of cuticle.

The Pupa of Ortholeptura insignis (Fall)

This is a typical lepturine pupa, tracing readily toLepturinae in Duffy's
key, and agreeing on all points. In his key to the British genera of the sub-
family it runs to Leptura. Craighead described, but did not figure, the larva
and pupa of the closely related O. valida LeConte; his description of the pupa
is short and that of 0. insignis (which has not been characterized or illustra-
ted before) answers his description equally well.

Fall (1907, p. 251) described 0. insignis as from "California, Monterey
(Fuchs and Fenyes)." Before me are two pupae, one shown in the accompany-
ing photographs (figs. 11, 12, 13); the other contains a beetle so nearly ready
to emerge as to make identification simple. They are from the collection of
the late F. E. Blaisdell, Sr., but the original label, "Monterey, June 30/01"
is in the writing of Carl Fuchs. It is thus possible that they were taken at
the same time as the original Fuchs material Fall had before him in 1907-

No. 57)

LEECH: LARVA AND PUPA OF COLEOPTERA

11

Figures 11-13- Female pupa of Ortholeptura insignis, dorsal, ventral, and la-
teral views. Length 25 mm.

Pupa (figs. 11, 12. 13). Length 22 to 25 mm., width 8 to 9mm. Head
with faint transverse rugae across front, and across vertex behind antenna!
bases; vertex barely visible in dorsal view of pupa; vertex with irregular group
of ten or twelve stout setae on each prominence (one on each side of median
line, midway between it and eyes), several setae in depression between prom-
inences and antennal bases; five or six strong setae and one or two smaller
ones on a protuberance above base of each antenna; clypeus with transverse
arcuate row of six stout setae. Antennae glabrous, extending to base of sec-
ond abdominal segment, curved, ending near apex of middle tibiae. Eyes bare.
Mandibles with single seta at middle of outer face. Labrum nearly rectangu-
lar, a little more than twice as broad as long, glabrous.

P ronotum quadrate, margined laterally, a little wider than long, hind
angles rounded; a few spines laterally at mid-point and near base. Front mar-
gin impressed at middle between two transve'rse protuberances which project
backward (in the example at hand the area behind the protuberances is lun-
ately depressed, but this is probably the result of damage after it was col-
lected); protuberances impressed across their bases, each with eight or ten
stout setae apically and a few more on summit ofpronotum. There is a deeply
impressed "V" with its point at middle of base of pronotum, its ends at mid-
dle, half way between middle of disk and sides, and bounding a broadly dia-
mond-shaped transversely striated area which has several setae arising from

12 CALIFORNIA ACADEMY OF SCIENCES (Occ. Papers

small tubercles; a line of about eight setae on a crested tumidity on each
side of point of above mentioned "V." Scutellum rugose laterally near base,
apical part tumid with group of about ten setae on each side of middle. Meta-
notum transversely rugose along mid-line, which has a tumidity on each side,
preapically, tumidities each armed with twenty to twenty-five stout setae.

Abdomen with terga one to six each with paired tumidities, each tumid-
tumidity having a posterior regular and an anterior less regular line of papil-
lae, each papilla bearing a stout apical spinose seta; seventh tergum narrow,
with sides converging posteriorly, rounded apically; eight tergum only half as
long as seventh, each with a scattering of setae; ninth tergum short, termina-
ting in a pair of horizontally excurved urogomphi which are hooked and strong-
ly sclerotized apically. Sterna three to six each with a few small setae about
halfway between mid-line and sides, seventh and eighth with setae more api-
cal, fewer; ninth sternum with ten or twelve stronger setae on each side; tenth
sternum with one or two small setae on the paired tubercles (female pupa).
Pleura each with oneortwo seta-bearing papillae on a raised area. Legs with
row of small setae near apex on outer face of each femur; hind tibiae each
with paired small blunt apical spurs; tarsi a trifle shorter than tibiae, each
tarsus with single seta near apex; hind femora reaching to middle of fourth
abdominal segment. Functional spiracles present on first five abdominal seg-
ments; peritreme broadly oval , thin, barely raised above general level of cuticle.

Acknowledgments

John Chemsak of the University of California, Berkeley, was so kind
as to verify my identification of l\ ecydalis cavipennis. To Maurice Giles of
the California Academy of Sciences I am indebted for the photographic prints
here used, from my original negatives, and for copies of certain figures from
Craighead's paper of 1923-

LITERATURE CITED

Craighead, e. C

1923. North American cerambycid larvae. A classification and the biology of
North American cerambycid larvae. Ottawa, Canada Department of
Agriculture, Bulletin no. 27, New Series, Technical (Entomological
Bulletin no. 23). 239 pp., 8 figs, in text, pis. I-XLIV.

DUFFY, E. A. J.

1953- A monograph of the immature stages of British and imported timber beet-
les (Cerambycidae). London, British Museum (Natural History). Pp.
viii+ 350, frontispiece, 292 figs., pis. I-VIII.
I960. A monograph of the immature stages of neotropical timber beetles (Cer-
ambycidae). London, British Museum (Natural History). Pp.viii+327,
frontispiece, 176 figs., pis. I-XII.

No. 57) LEECH: LARVA AND PUPA OF COLEOPTERA 13

Fall, H. C., and T. D. A. Cockerell

1907- The Coleoptera of New Mexico. Transactions of the American Entomo-
logical Society, vol. 33, no. 2 & 3, pp- 145-272-
Gressitt, J. L.

1951. Longicom beetles of China. Longicornia, vol. 2, [8+] 667 pp., 22 pls.
with facing pp. of explanations.

Hardy, G. A., and W. H. A. Preece

1927. Additional notes on some Cerambycidae (Col.) from Vancouver Island,
B.C. Pan-Pacific Entomologist, vol.4, no. 2, pp. 61-67.
Leech, H. B.

1959. Notes on a few species of Pacific Coast Cerambycidae. The Coleop-
terists' Bulletin, vol. 13, no. 2, pp. 42-46.
Linsley, E. G.

1940. A revision of the North American Necydalini (Coleoptera, Cerambycidae).
Annals of the Entomological Society of America, vol. 33, no. 2, pp.
269-281.
1961. The Cerambycidae of North America. PartL Introduction. University of
California Publications in Entomology, vol. 18, [4+] 135 pp., incl.
35 pis.; 16 figs, in text.

MBL WHOI LIBRARY

H ITFV J