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Paciric

INloRTH

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FOREST AND RANGE
EXPERIMENT STATION

_- USDA FOREST SERVICE RESEARCH NOTE |

PNW-294 March 1977

MORPHOLOGY OF THE INTERNAL REPRODUCTIVE ORGANS IN RELATION TO
THE SEX PHEROMONE GLANDS OF THE SPEAR—MARKED BLACK MOTH

W FOREST AND RANGE
PERIMENT STATION

SEP 12 1977
WON LIBRARY COPY

by

Richard A. Werner, Research Entomologist

ABSTRACT

The morphology of the male and female internal
reproductive organs of Rheumaptera hastata (L.) is de-
scribed and illustrated. A new type of sex pheromone-
producing gland was found in adult females. Unlike those
of other Lepidoptera whose glands are modified interseg-
mental membranes, the paired glands of this geometrid moth
are internal in structure and function. The opening of
the common duct from the paired glands is in the posterior
region of the vagina, and the sex pheromone is released by
pulsation of the terminal abdominal segments.

KEYWORDS: Rheumaptera hastata, reproductive organs
t (insect), morphology, attractants.

Introduction

The morphology of the internal reproductive system of the spear-marked

black moth, Rhewnaptera hastata (L.), has not been previously reported, though

McGuffin (1973) described the external genitalia. The information presented in
1 this paper resulted from a study on the role of sex pheromones in mating behavior

of R. hastata (Werner 1977). Sex pheromone glands were found in the terminal
abdominal segments of female moths and this prompted an investigation on the
morphology of the reproductive organs in order to positively describe the loca-
tion of the glands.

OREST SERVICE - U.S. DEPARTMENT OF AGRICULTURE - PORTLAND, OREGON

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i

Materials and Methods

Unmated adults of R. hastata were reared from field-collected pupae. Moths
were anesthetized with carbon dioxide, wings and legs excised, and abdominal
scales removed with adhesive tape (Fatzinger 1970). The insect was then dis-
sected in Bouin's fluid and the exposed reproductive organs stained with fast
green. Measurements were made on 10 moths of each sex using an ocular micrometer.

Results and Discussion

The male reproductive system of R. hastata (fig. 1) is basically similar to
that of other Lepidoptera in that the testes (T) are paired and enclosed in a
single large spherical scrotum about 1.45 mm in diameter. The reddish-brown,
thin-membranous scrotum is located dorsally between the third and fourth abdomi-
nal segments. The testes of newly emerged adults were filled with live sperm
which suggests that male moths are sexually mature when they emerge from the

pupa.

Paired vasa deferentia (VD), about 5-7 mm in length, arise from the ventral
side of the testes and extend to the ductus ejaculatorius duplex (DED). Two
seminal vesicles (SV) appear in each vas deferens about 1 mm distal from the
testes. A second pair of seminal vesicles known as the accessory seminal vesicles
(ASV) are located at the junction of the vasa deferentia and ductus ejaculatorius
duplex. Live sperm were also found in the seminal vesicles which serve as a
storage area for sperm.

The ductus ejaculatorius duplex is located dorsally, and the paired organs
are fused posteriorly to form the single ductus ejaculatorius simplex (DES).
Each duplex is about 3 mm long and 0.5 mm in diameter. At the anterior end,
each duplex narrows to form an accessory gland (AG). The vas deferens enters
each duplex near the anterior end. The accessory glands are 7.5 to 8.0 mm long
and were found to contain a white substance. These glands, which secrete the
seminal fluid, appear united but are merely connected by tracheal tissue. The
ductus ejaculatorius simplex is about 22-25 mm long and in R. hastata consists
of two distinct segments: the anterior primary segment (PS) and the posterior
cuticular segment (CS). According to Callahan (1958), the simplex of Heltothts
zea, is composed of two morphological areas as was found in R. hastata. But
Outram (1970) describes seven morphological divisions in Choristoneura fumtferana;
whereas, Norris (1932) found four divisions in Ephestia kilhniella and Khalifa
(1950) reported six divisions in Gallerta mellonella. Fatzinger (1970) also
reports two morphological divisions in Dtoryectria abtetella. The cuticular
segment is differentiated into the ejaculatory bulb (EB) which functions in
forming the spermatophore in most Lepidoptera including R. hastata. Spermatophore
precursor substances were found in the primary segment of unmated males. The
posterior end of the ductus ejaculatorius simplex terminates in the aedeagus
(AE). McGuffin (1973) described the aedeagus as a stout structure containing
three cornuti with the possibility that the cornuti are deciduous.

The female reproductive system (fig. 2) is similar to other ditrysian
Lepidoptera in that the bursa copulatrix (BC) is connected to the common oviduct
(OVC) by a seminal duct (DS). The ostium bursae (OB) opens externally midventral
in the intersegmental cuticula of the seventh and eighth sternite and the ovipore
(OP) and rectum (RE) on the ninth sternite.

EB

cs
NE Figure 2.--Reproductive organs of
Ca female R. hastata. AG, accessory
: gland; BC, bursa copulatrix; DS,
seminal duct; DSP, spermatheca
Figure 1.--Reproductive organs of male duct; O, ovariole; OB, ostium
R. hastata. AE, aedeagus; AG, acces- bursae; OO, odcyte; OP, ovipore;
sory gland; EB, ejaculatory bulb; OV, Ovipositor; OVC, common oviduct;
CS, cuticular segment of ductus RAG, reservoir of accessory gland;
ejaculatorius simplex; DED, ductus RE, rectum; SG, spermathecal gland;
ejaculatorius duplex; DES, ductus S, signum; SP, spermatheca; SPG,
ejaculatorius simplex; SV, seminal sex pheromone gland; TF, terminal
vesicle; T, testis; VD, vas deferens; filament; V, vagina. Ovarioles
ASV, accessory seminal vesicles; of left ovary are not shown.

PS, primary segment.

The system contains paired ovaries, each ovary consisting of 4 polytrophic
ovarioles (0) and each arising from a. separate terminal filament (TF). The :
ovarioles of newly emerged, unmated females are longer (8-9 mm long) than the
abdomen but are folded and extend from the seventh to the second abdominal
segment.

Each ovariole of newly emerged females contains from 15 to 25 oocytes (00) ,
with the mature oocytes located at the proximal end where the ovarioles are
connected by the short lateral oviducts to the common oviduct. The latter (2-3 ¢;
mm long) is connected at the anterior end to the lateral oviducts and has two
ducts leading into it before it terminates posteriorly in the vagina (V).

The first of the four ducts is the seminal duct (DS) which connects the
bursa copulatrix to the common oviduct. The seminal duct is 1.0-1.5 mm long and
opens into the common oviduct immediately posterior to the junction of the
lateral oviducts.

The bursa copulatrix of R. hastata is a large brownish, muscular organ
which was found to contain a spermatophore in mated females. In unmated females,
the bursa copulatrix appears smaller and flattened. A heavily sclerotized
Signum (S) is located in the center of the bursa. The signun is somewhat oblong,
0.5 mm long, rigid with sharp spines.

The spermatophore is inserted through the sclerotized ostium bursae (OB),
which is an external opening located midventrally in the intersegmental cuticula
of the seventh and eighth abdominal sternites. The morphology of the spermatophore
will not be described in this paper.

The spermathecal duct (DSP) (1.0-1.5 mm long) connects the spermatheca
(SP) and spermathecal gland (SG) to the common oviduct opposite the seminal duct.
Live sperm were found in the seminal duct, spermathecal duct, and spermatheca of
mated females which indicates the latter functions to store sperm. Callahan and
Cascio (1963) first described the movement of sperm from‘the spermatophore in
the bursa copulatrix, through the seminal duct, across the common oviduct, and
up the spermathecal duct to the spermatheca.

Posterior to the opening of the spermathecal duct, the common oviduct opens
into the vagina. A pair of accessory gland reservoirs (RAG) (1.5-1.8 mm long)
are situated posterior to the spermatheca and bursa copulatrix and connect by a
common duct to the dorsum of the anterior region of the vagina. Each accessory
gland reservoir constricts anteriorly into an accessory gland (AG) (4.0-5.0 mm
long). A pinkish secretion was found in the accessory gland reservoirs.

Rk. hastata females have an additional pair of internal glands which open
via a common duct into the dorsum of the posterior region of the vagina. These
are the sex pheromone glands (SPG) and were found through bioassay to produce
the female sex pheromone during courtship behavior. Previous reports indicate
that all sex pheromone glands have external openings somewhere on the terminal
region of the abdomen (Urbahn 1913, Gotz 1951, Jefferson et al. 1968, Percy and
Weatherston 1971). The sex pheromone glands of R. hastata open in the vagina,

and the sex pheromone is released by a pulsating action of the terminal abdominal ;
segments. Urbahn (1913) described similar internal glands in several species of i
Arctiidae and an external opening between the eighth and ninth abdominal tergite. i

Posterior to the sex pheromone gland, the vagina opens into a telescopic
Ovipositor (OV), which has an ovipore for egg laying and for the dispersal of !
sex pheromone and accessory gland secretions. The ovipore is located on the ;

fused ninth and tenth abdominal segment ventral to the anus.

Literature Cited

Callahan, P. S.
1958. Serial morphology as a technique for determination of
reproductive patterns in the corn earworm, Heliothis zea (Boddie).
Ann. Entomol. Soc. Am. 51:415-428.

Galtahan,, P. S., and TI.’ Cascio.
1963. Histology of the reproductive tracts and transmission of
sperm in the corn earworm, Heliothis zea (Boddie). Ann. Entomol.
Soc. Am. 56:535-556.

Fatzinger, C. W.
1970. Morphology of the reproductive organs Dioryctria abietella
(Lepidoptera: Pyralidae (Phycitinae)). Ann. Entomol. Soc. Am.
63:1257-1261.

Gotz, V. B.
1951. Die Sexualdufstoffe an Lepidoptera. Experientia 7:406-418.

Jefferson, R. N., H. H. Shorey, and R. E. Rubin.
1968. Sex pheromones of noctuid moths. 16. The morphology of the
female sex pheromone glands of eight species. Ann. Entomol. Soc.
Am. 61:861-865.

Khalifa, A.
1950. Spermatophore production in Galleria mellonella L. (Lepidoptera).
R. Entomol. Soc. London (A) 25:32-42.

McGuffin, W. C.
1973. The Rhewnaptera of North America (Lepidoptera: Geometridae) .,
Can. Entomol. 105:383-398.

Norris.) M. 1d.
1932. Contributions toward the study of insect fertility. 1. The
structure and operation of the reproductive organs of the genera
Ephestta and Plodia (Lepidoptera, Phycitidae). Proc. Zool. Soc.
Lond. (Part 3) 7595-611.

Outram, I.
1970. Morphology and histology of the reproductive system of the
male spruce budworm, Chortstoneura fumntferana. Can. Entomol.
102:404-414.

Percy, J., and J. Weatherston.
1971. Studies of physiologically active arthropod secretions. 9.
Morphology and histology of the sex pheromone producing glands of
some female Lepidoptera. Can. Entomol. 103:1733-1739.

Urbahn, E.
1913. Abdominale duft Organe bei weiblichen Schmetterlingen. Jena
Z. Naturwiss. 50:277-358.

Werner, R. A.
1977. Behavioral responses of the spear-marked black moth, Rhewnaptera
hastata, to a female-produced sex pheromone. Ann. Entomol. Soc.
Am. 70:84-86.

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