The Bionomics of predatory butterfly, apefly (Spalgis epius) (Lepidoptera: Lycaenidae) on mealybug, Paracoccus marginatus (Hemiptera: Pseudococcidae) in cocoa

Apefly, Spalgis epius (Westwood) (Lepidoptera: Lycaenidae) is a small aphytophagous butterfly and their larvae feeds on the insects of Pseudococcidae, Hemiptera. In the present study, development of immature stages and life cycle of this predatory butterfly was observed on mealybugs, Paracoccus marginatus (Williams and Granara de Willink) (Hemiptera: Pseudococcidae) in cocoa under the laboratory conditions. The morphometry results indicated that the diameter of the egg was 0.52 ± 0.06 mm and the they were collected and kept in the laboratory at 25-30°C and 40-80% Relative Humidity. The eggs were greenish blue in colour and disk shaped, sculptured and both the top and bottom compacted with micropylar despair in the top and hatched in 4.16 ± 0.29 days. It undergoes four larval instars and the total larval period lasts 13.1 ± 0.12 days. The upper surface of the larval body was fully developed with wax coating. The duration of the pre pupal stage was 3.00 ± 0.17 days. The mold on the hard dorsal side of the pupa resembled on the face of a monkey structure. The prepupal larva shrunk and turned toward dull black colour of the surface of body. The pupal period was recorded as 10.00 ± 0.04 days. The total duration from egg to adult emergence was noticed as 30.30 ± 0.33 days. In adults, the patch is bigger in females than that in the males. The knowledge of development and life cycle of S. epius on factitious/natural hosts on various crops is advantageous to develop and standardize the mass culturing techniques for exploration of this potential species for predation of mealybugs.

Inter- and intraspecific interactions in two mealybug predators Spalgis epius and Cryptolaemus montrouzieri in the presence and absence of prey

Spalgis epius and Cryptolaemus montrouzieri are the two potential predators of different species of mealybugs. However, the mode of their interactions is not known to use these predators together in the field. Hence, we investigated on the possible interactions i.e., cannibalism, intraguild predation (IGP) and competition between the predators in the presence and absence of prey Planococcus citri. In the presence of prey, no cannibalism and predation were observed in both S. epius and C. montrouzieri larvae. A pair of S. epius larvae consumed significantly more number of mealybugs than one S. epius/C. montrouzieri larva or a pair of C. montrouzieri larvae. The predation of S. epius larva by C. montrouzieri larva was significantly more than the predation of C. montrouzieri by S. epius. Conspecific and interspecific egg predation was absent both in S. epius and C. montrouzieri. Cannibalism in C. montrouzieri was more than that in S. epius. The study indicated that C. montrouzieri larvae can be used as an additive along with voracious S. epius larvae under abundant prey population. IGP was asymmetric between the two predators in the absence of prey. Both S. epius and C. montrouzieri larvae can maintain a stable coexistence when prey is abundantly available, however, in the complete absence of prey C. montrouzieri may dominate the guild. This study provides an insight into the possible complex inter- and intraspecific predatory phenomena in the field to use these two predators in the biological control of mealybugs.