Proc. Indian Acad. Sci. (Anim. Sci.), Vol. 92. Number 4.July 1983.pp. 333-342. © Printed in India. Wing microsculpturing ill the small house cockroach, Supella longipalpa (Dictyoptera, Blattidae) M L ROONWAL and N SRATHORE Desert Regional Station. Zoological Survey of India. Paota B Road. Jodhpur 342 006. India MS received 23 February 1983 Abstrad. Elytra and wings of Supella longipalpa (Fabricius) show sexual dimorphism in size. being well developed in males and less so in females. The following eight types of microsculpturing elements (including hairs) occur on both the upper and lower surfaces. 2 varying in size (0.5-100 ~m) and density (a few to IOOO{mm ): Pimpules, papilllae, rods. microsetae, hairs (setae or macrotrichia of authors). polygons. parallel ridgesand an irregular reticulum. The nomenclature adopted is mainly based on termites wherethese structures have been studied in great detail. Comparison is made with the lsoptera, Embioptera and Zoraptera. The biological and ecological con'sequences of microsculpturing are discussed. Keywords. Wing microsculpturing; cockroach; Supel/a longipalpa. 1. Introduction In recent years, several kinds of cuticular microsculpturings (in addition to hairs) have been found on the wings of a number of lower insect orders. The most remarkable in this respect are the termites (lsoptera) in which at least sevendifferent types of discrete sculpturings have been recorded, varying greatly in shape, sizeand density. They range in size from ca. 0.5 - 23pm, in shape from thin rods to finger-likeor thorny papillae, tubercles, arrowheads, pimpules and micrasters (with 1-8arms), and in density from about 300 - 13000j mm2 (RoonwaI1977, 1981,and in press a,b); Roonwalet a11967­ 1979, vide the references). In Embioptera (Roonwal and Rathore (in press» three types of short to long 'hair-like' structures have been found, viz. macroscimitars, macrotrichia and microtrichia, with moderate to fairly high densities. In Zoraptera only short and long hairs are present (Roonwal in press b). Since these orders are dose to the cockroaches or Blattoidea (termites and cockroaches are believed to have arisen from a common Protoblattoid stock), and since no such structures appear to have been described in cockroaches so far except hairs (Miall and Denny 1886; Rehn 1951; Richards and Davies 1977; Chapman 1973; Bell and Adiyodi 1982),it was considered desirable to study wing microsculpturing in cockroaches. Lefeuvre (1969) mentions some sensillae on fore and hind wings of Blaberus craniifer. In this paper microsculpturing in the commonly available small house cockroach, Supella longipalpa (Fabricius) (family Blattidae*, subfamily Pseudomopinae, tribe Supellini), is described. • The classification of Rehn (1951) is followed. In another system. Supella is assigned to the family Blatellidae. 333 334 M L Roonwal and NS Rathore 2. Material and methods Samples of Supella longipalpa were obtained from kitchens at Jodhpur. It is fairly widespread in India and has also been reported from Punjab (Sandhu and Sohi 1981). Both elytra and wings were studied in glycerine mounts. which. as in termites. gave better definition of microsculpturing than permanent Canada balsam mounts. Densities were determined from camera lucida drawings. Nearly identical microsculpturing occurs on the upper and lower wing surfaces; the dorsal surface is described here. 3. Results 3.1. General Elytra and wings show sexual dimorphism, being well-developed in males (figure I) and less so in females (figure 2). On the basis of microsculpturing, each structure is divisible into several regions (vide infra). 3.2. Types ofmicrostructures The eight types of microstructures found in Supella longipalpa are described below. 3.2 (i) Pimpules: Minute, rounded or papillate, glassy, refractile structures occurring 2 on the membrane in considerable density (ca. 1000/ mm ); diameter 1.5 - 2.5 ut«. 3.2 (ii) Papillae: Small, thorny structures without a basal head (cf rnicrosetae). Size 0.5 pm x 2 um. Rare Cu. M. R. Cu. M. R. Sc. C. Figure 1. Supella longipalpa, male. A. left elytron B. left wmg. to show venation (nomenclature based on Rehn 1951). (A. anals: C. costa; Cu. cubitus; f. fold. M. media; R, radius; Sc. subcostal. Wing microsculpturing in S. longipalpa 335 Cu. 3mm "----A.--.... Cu. M. R. SC. C. f B Figure 2. Supella longipalpa, female. A. Left clytron B. left wing. to show venation (nomenclature based on Rehn 195\). Abbreviations as in figure I. 3.2 (iii) Rods: Small, thin or thick, rod-like bodies; substraight, cresentic or V­ 2 shaped. Length 10-15 utxv; density 310/mm • Usually thinner on veins than on membrane. 3.2 (iv) Microsetae: Short, thick, stubby, nail-like structures, with a broad, rounded basal head and a short, sharply pointed shaft. Length 7-14 pm; density 3oo-400! mm". 3.2(v) Hairs (setae) : Hair-like structures with a basal rounded platelet and a longish, pointed shaft. Length 35-100 um. Few and scattered. 3.2 (vi) Polygons: A pattern of adjacent polygonal areas enclosed by fine lines. Usually with 5 sides, sometimes subrectangular. Polygons 5-9pm wide, 26-33pm long. 3.2 (vii) Parallel lines: A pattern of fine parallel lines, 8-17 pm apart. 3.2 (viii) Reticulum: An irregular, indefinable reticulum of fine iines (probably ridges). 3.3. Microsculpturing in males 3.3a. Elytra: Length II mm, maximum width 3 mm. surface divisible into 4 regions (figure 3): 3.3a(i) region no. I (figure 4 A. B): A small region at the base. Densely covered all over 2 with minute pimpules (diameter 1.5 - 2.5 utt»; density ca looO'mm ). 3.3a(ii) region no. 2 (figure 4 C. D): A longish region at the anterior margin. Covered 336 M L Roon.....al and N S Rathore Fiaure 3. Supella longipalpa. Outlines of left elytra and wings, to show regions of different types of microsculpturing; region Nos. 1-4 in elytra and 1-3in wings. A, B. Male elytron and wing, C, D. Female elytron and wing. ,." .~ ;,.. ,."'.""".... ,.,.~ pen. ,. ,."• "... '" • /J\ "" ,. .. ~ ... ,. ,. r ; ,. ,. -. ,. ... ": "'''',.:-: :."... : "'", to" .. .. ",."',,: ,. :/' :: :..".. : .. to ." flo .. ::,.",. ,. .,. ~ ,. ... :->: "',,' ,."'A Figure4. Supella longipalpa, male elytron. Views of dorsal surface from regions I and 2, 10 show microsculpturing A. From region No, l. B. Same. a part more magnified C. From region No. 2. D. same. a part more magnified (h. hairs; p, papillae; pg, polygons; pm, pimpules). Wing microsculpturing in S. longipalpa 337 with three types of structures: (i) All over with a pattern of adjacent polygons, (5-9 pm X 26-33 pm); (ii) a few scattered hairs (80-100 pm long) on veins; and (iii) a few minute (0.5 pm X 2 pm), thorny papillae scattered on membrane. 3.3a(iii) region no. 3 (figure 5 A. B): A small region in the middle. Covered with three types of structures: (i) A pattern of adjacent polygons as in region No.2; present all over except on the veins; (ii) thin, substraight, cresentic or V-shaped rods (length 10­ 15pm, density ca. 310/ mm'') on the main veins, usually ab~ent on the branches; and (iii) short, thick, nail-like microsetae scattered all over membrane among the polygons; 2 length 7-14 pm, density ca. 350/mm • 3.3a(iv) region no. 4 (figure 5 C. D) : The rest of the surface. Covered all over with a 2 pattern of polygons and microsetae (density ca. 300/mm ) as in region No.2, but without any rods. In addition, a few hairs also present here and there, and an irregular reticulum on the veins. , If pg. r.-r ms, /-, r (' rocurn 40 um A.C B,D Ficure 5. Supella longipalpa, male elytron. Views of dorsal surface from regions 3 and 4, to show microsculpturing A. from region No.3. B. same. a pan more magnified C. from region No.4. D. same. a pan more magnified. (h. hairs; ir.• irregular reticulum; ms, microsetae; pg, polygons; r, rods). 338 M L Roonwal and N S Rathore 3.3b. Wings: Length 9.5 rnm. maximum width 6.5 mm. Divisible into 3 regions: 3.3b (i) region no. I (figure 6 A): A longish region along the entire anterior margin. Covered with an irregular reticulum of fine lines. and a few hairs and microsetae. 3.3b (ii) region no. 2 (figure 6 B): A short, triangular region at the distal end. Covered .---.-.............._---------------- ?E ~ ..---------.--~- --!"~.-- .-.....--.--...-.........- ------ -......--.-- 1"""'----------.----- -- l:!:------- ----_.p.r. ~ ----- ......... .--- -- ------ --...---- - -- 1----- --_.- ~ 1_----- ~. ~h~ - ~~-.:---= - ~ ~ ~-rr__y -'"'- - '8 lOOf,UTI A,8,C c Figure 6. Supella longipalpa, male wing. Views of dorsal surface from regions 1·3. to show microsculpturing A. from region No. I. B. from region No.2. C. from region No.3. D. same. a part more magnified. (h. hairs; ir, irregular reticulum; ms, microsetae: p.r, parallel ridges; r, rods). Wing microsculpturing in S. longipalpa 339 with a pattern of fine, parallel lines (8-17 Jlm apart) on membrane. an irregular reticulum on veins and a few microsetae and hairs. 3.3b (iii) region no. 3 (figure 6 C. D): The-rest of the wing forms region 3. Covered with 2 3 types of structures: (i)Thin rods all over (length 10-15Jlm, density-ca. 320/mm ); (ii) microsetae in dense patches (length 3-9Jlm, density in patches 370/ rnrn''); and (iii) a few scattered hairs.. 3.4 Microsculpturing in females 3.4a Elytra: Length 8 mm, maximum width 3.2 mm. Surface divisible into 4 regions. Nos. 1-4. which are nearly similar in position and extent to those in males. The micro­ sculpturing found here is also similar and need not be described separately. 3.4b. Wings: Length 7.5 mm, maximumwidth 3.3 mm. Surface divisible into 3 regions similar to those in males, and microsculpturing is also similar. 4. Discussion 4.1 Types ofmicrosculpturing elements Eight types (including hairs) of microsculpturing elements have been found on the elytra and wing surfaces of Supe/la longipalpa.