. Annales de la Société entomologique de Belgique. Insects; Entomology. 197. indistinctly ti'ilobed (g^ , h, Fig. 7), the two latéral lobes being very small ; ail thèse evaginations or pouches are directed posteriorly. The lip of the médian lobe is invaginated (y, c, Fig. 7) ou ils ventral face, forming a laterally-compressed tube extending ante- riorly wilhiti the lobe; this tube subsequeutly becomes the ectodermal porliou of the ejaculatory duct (ejd, d, Fig. 7). AU thèse pouches, after the third moult (fourth instar) are much lengthened, and the two latéral lobes of the dorsal evagination b
. Annales de la Société entomologique de Belgique. Insects; Entomology. 197. indistinctly ti'ilobed (g^ , h, Fig. 7), the two latéral lobes being very small ; ail thèse evaginations or pouches are directed posteriorly. The lip of the médian lobe is invaginated (y, c, Fig. 7) ou ils ventral face, forming a laterally-compressed tube extending ante- riorly wilhiti the lobe; this tube subsequeutly becomes the ectodermal porliou of the ejaculatory duct (ejd, d, Fig. 7). AU thèse pouches, after the third moult (fourth instar) are much lengthened, and the two latéral lobes of the dorsal evagination become constricted off from the mé- dian lobe, so that altogether five pouches are now easily discerned. The inlegument around the genilal area is also puckered into a ridge (z, Fig. 7). After the fourth moult (fiflb inslar) ail thèse pouches are furlher enlarged and lengthened ; the invagination of the distal part of the médian lobe on its ventral face to •' X form the ejaculatory duct is distinctly visible, and extends inwards and anteriorly as a large diameter tube till it meets and fuses with the mesodermic portion of the duct, which at an earlier stage is a tliick mass of cells with a very small lumen. Transverse vertical sections through the anterior part of,' the ninth segment of a nymph of the fifth instar, just before moul- ting, are shown in Fig. 8 a being the most posterior and d the most anlerior section. Thèse sections pass through the génital area and pouches. After the fifth and last moult (to adult) the dorsal médian lobe appears as the adult pénis {g''- , Fig. 9) the two latéral dorsal lobes as the third gonapophyses ( g'^ ), and the two ventral pouches as the first gonapophyses ( g(* ). The raised integuraent (r, Fig. 7) around the génital area forme in the adult the narrow, latéral, terminal plates (IX, tp) belonging to, butseparated by a membraneous area from the ninth segment. If the abdomen of â nymph just ready to moult is boiled in pot
Size: 1698px × 1472px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookd, booksubjectentomology, booksubjectinsects
