Morphology And Ultrastructure Of The Peach Fruit Moth Carposina Sasakii Matsumura (Lepidoptera: Carposinidae)

The peach fruit moth, Carposina sasakii Matsumura(Lepidoptera: Carposinidae), is one of the serious pests of orchards in the eastern Asia, with the larvae boring in the fruits of various important fruit trees, frequently causing significant damage. Its host plants include several economically important fruits, such as Prunus persicae, P. armeniaca, Crataegus pinnatifida, Malus domestica, Pyrus spp., Zizyphus jujuba, Z. spinosus, and Punica granatum. Previous studies on C. sasakii mainly focused on its life cycle and integrated control, the morphology has not been well studied. In this thesis, the morphology of the adults, egg, larva and pupa in C. sasakii were investigated using light microscopy and scanning and transmission electron microscopy, in order to provide morphological basis for some behaviors. The wing shape of the C. sasakii on the different host plants was analysised using geometric morphometrics, to provide morphological basis for its morphological diferentitaion. The main results are as follows:1. Morphology of the adults: The antennae are filiform. The mouthparts are in the siphoning type, and the paired three-segmented labial palps of the female are longer than those of the male. There are 7–9 clusters of erect scales on the fore wing, obliquely. We found the epiphysis on the forelegs, medial spurs and apical spurs on the midlegs and hindlegs. Numerous sensilla are present on the mouthparts, antennae and genitalia.The mouthparts consist of a striking coilable proboscis formed from two galeae of the maxillae, a pair of developed labial palps, and other degenerate parts. The three-segmented labial palps display distinct sexual dimorphism between the sexes, much longer in the female than in the male. The mouthparts aslo bear seven types of sensilla, i.e. sensilla campaniformia, s. trichodea, s. styloconica, s. basiconica, s. squamiformia, s. chaetica and flattened sensilla.The surface of antennae has irregular reticular pattern, except the smooth base of the scape and pedicel. Eight types of sensilla are found on the antennae: hair plate sensilla, sensilla styloconica, s. auricillica, s. coeloconica, s. chaetica, s. basiconica, s. squamiformia and s. trichodea. The basal scape and the pedicel only possess hair plate sensilla and sensilla squamiformia. The terminal flagellum carries all sensilla types, except the hair plate sensilla.The compound eyes are composed of numerous ommatidia, each of which consists of a convex cornea, a crystalline cone, nine retinula cells, two primary pigment cells, and six secondary pigment cells. The rhabdom is formed by the rhabdomeres from eight retinula cells and runs to the basal lamina. The 9th retinula cell only lies on the basal lamina.Four types of scales are found on the wing. Type I is flatted and broad, forms forked branch. The scales are abundant and widespread on the bottom of the wing. Type II is slender than type I, does not form forked branch. The scales are the fewest and are distributed near the wing margin. Type III are also flatted and broad, covered on scales I. A few of type III are clustered and oblique on the wing, and referred to as “scale tufts”. Type IV is the longest and forked, and distributed on the wing margin. A few of type III are cluster and oblique at the base and middle in the wing.In the female, a pair of π-shaped signa is found on the middle of the oval corpus bursae. The ostium bursa is found on the venter of lamella antevaginalis. The papillae anales are oval and valvular structures, and have many sensilla chaetica on their surface.In the male, the tegumen is very large and turban-shaped. The interior valvae have many setae, and have strong and long tooth. Cornuti are found on the distal end of vesica. The gnathos arms are long and upward. The top of uncus have many long setae. Saccus is conical.Geometric morphometric analysis of wing shape on different host plants: In comparison with other host plants, the procustues distance of C. sasakii is the farthest on Pyrus spp. The result is in accordance with that of canonical variance analysis. On the comparision trials of the centroid sizes on wing shape, C. sasakii are smaller on Pyrus spp. and Z. jujuba, and are larger on P. armeniaca and M. domestica.2. Ultrastucture of the eggshell: The eggs of C. sasakii are oval, with the micropyles located at the top of the egg. The micropyles are usually four in number. Lotus-like decoration with 6–8 disc floriation lobules and 2–3 circles of Y-shaped processes are around the micropyles. The granular processes and spiracles are located on the lateral side of eggs.3. Ultrastucture of the larva: The types and numbers of sensilla on the larval antennae and mouthparts of C. sasakii and C. coreana are very similar. The first segment of the antenna is devoid of sensilla. The second segment possesses two sensilla chaetica and three sensilla basiconica. The terminal segment carries distally one sensillum styloconicum and three sensilla basiconica. Six types of sensilla are found on the mouthparts: sensilla chaetica, s. styloconica, s. digitiformia, s. basiconica, s. placodea and epipharyngeal sensilla. C. sasakii has three pairs of epipharyngeal sensilla, and C. coreana has two pairs of epipharyngeal sensilla.There are ten pairs of setae on the prothorax of mature larvae: prothoracic setae, dorsal setae, lateral setae, subdorsal setae, and subventral setae. There are no prothoracic setae, and three pairs of lateral setae and one pair of subventral setae on the mesothorax. The remaining setae on the mesothorax are similar to those of prothorax. The setae on the metathorax are similar to those on the mesothorax. There are two pairs of dorsal setae, subdorsal setae and subventral setae respectively, and three pairs of lateral setae on the first abdominal segment(A1). The setae on A2 are similar to the setae on A1, but three pairs of subventral setae. The setae on A3 to A6 are similar to the setae on A1 and A2, but four pairs of subventral setae. There are two pairs of dorsal setae, subdorsal setae, lateral setae and subventral setae on A7, respectively. Two pairs of dorsal setae, subdorsal setae, three pairs of lateral setae and one pair of subventral setae are found on A8. Two pairs of dorsal setae, one pair of subdural setae, lateral setae and subventral setae are found on A9. Only two pairs of dorsal setae and subdorsal setae are on the anal plate.The crochets of the mature larvae are in a uniordinal circle. There are 15–21 crochets on each abdominal proleg from A3 to A6, and 9–13 crochets on A11. The crochets of the first instar are only 4 in number.4. Morphology of the pupa: The pupa of C. sasakii is obtect, glabrous and orange yellow. Its head includes the red compound eyes, antennae, labrum, mandibles, maxillary palps, proboscis, labial palps. The wing-pad of fore wing reaches the 4th abdominal segment. The pupal abdomen consists of ten segments, the last three of which are always fused together. There is a spiracle on both sides of A1 to A8. In male pupae the genital groove occurs midventrally on A9, and in female genital grooves are usually found midventrally on A8 and A9 and confluent longitudinal crack. The anus is situated on A10. No cremaster was found.Through morphological comparisons of sensilla on the larval antennae and mouthparts of C. sasakii and C. coreana, we concluded that there is no strict correspondence between larval sensilla and host range in Carposinidae. The wing shape analysis of C. sasakii on the different host plants indicates that the genetic divergence of C. sasakii is the greatest on Pyrus spp. compared with other host races.