Some aspects of the biology of the lemon butterfly Papilio demodocus Esper. (Lepidoptera; Papilionidae) and its preference to three citrus cultivars

Abstract

The lemon butterfly Papilio demodocus Esper (Lepidoptera : Papilionidae) also known as, citrus butterfly and orange dog butterfly is a major pest of citrus trees and nurseries in the Sudan. Field surveys were conducted during the course of this study at the nursery and the Shambat Farm of the University of Khartoum while the labrotary experiments were conducted at the Entomology laboratory of the Department of Crop Protection of the Faculty of Agriculture, University of Khartoum. The study aimed to investigate the biology and morphology of the lemon buttterfly reared on leaves of lemon plant, and to determine the degree of preference of the lemon butterfly to different citrus cultivars. The development of the immature stages were followed under laboratory conditions, (20-28°C and R.H. 44-63%). Egg incubation period lasted for 4 to 5 days (average 4.2 ± 0.42). Larval duration lasted for 17 to 19 days with an average of 17.7 ± 0.42 days. Pupal period ranged from 8 to 9 days with an average of 8.2 ± 0.42 days. The whole life cycle lasted for 29 to 32 days averaging 30.2 ± 1.032 days. The egg is small round in shape, pale yellow but turns to dark brown before hatching ; it shows a red mark on the top . The colour of the first three larval instars ranged from black to dark brown and from greenish to bright green for 4th and 5th instars respectively. The adult is quite large in shape, dark brown with numerous pale yellow green spots; the forewings are long and narrow, cream with green longitudinal median wedges. Both sexes are alike but the female is larger than the male in the size . The results showed that, in the nurseries, the larvae of the lemon butterfly preferred lemon to orange and the latter to grapefruit.