Epilachna chrysomelina (Fabricius)
{Also known as Henosepilachna elaterii (Rossi)}
Taxonomic placing: Insecta, Holometabola, Coleoptera, Coccinellidae.
Common name: Melon ladybird beetle, twelve-spotted melon beetle.
Geographical distribution: Southern Europe, Africa, Middle East, India, Afghanistan, Azerbaijan and Turkmenistan. CIE Distribution Maps of Plant Pests Map ## 409, updated 1992.
Morphology: Adults 7-9 mm long, red-brown, dorsum with short hairs, each elytron with 6 black points. Larva yellow-green, about 8-11 mm long, the dorsum covered with several longitudinal rows of branched setae.
Host plants: Various cucurbits (Cucurbitaceae), like melons, water melons, snake melons and gourds.
Life history: The pest usually raises 4-5 annual generations. In spring adults emerge from dormancy and begin to lay several hundred eggs/female on the undersides of host leaves. The larvae feed and pupate there; those of the autumnal generation then enter dormancy. The adults feed on the same hosts, sometimes aggregating in hundreds on the plants. Temperatures of 25-32°C and high humilities are optimal for the pests, which can disperse by flying.
Economic importance: Most injury caused by this pest is to young melons, cucumbers and pumpkins. Entire seedlings can be consumed, and partially damaged plants may rot afterwards. Additional damage is due to the transmission of squash mosaic virus by the beetle, a disease manifested by misshapen fruits, leaf blistering, yellowing and distortions.
Management
Cultural control: Removal of cucurbit plant residues after harvesting, autumn plowing, and crop rotation.
Plant resistance: “Snake cucumber”, Cucumis melo var. flexuosus (L.) Naudin, a long, slender fruit, was preferred by E. chrysomelina over other cucurbits. The pest was relatively less fecund on cucumber, suggesting options for resistance breeding.
Chemical control: In the past various organophosphates and carbamates successfully controlled the pest. Treating the fourth instar pest larvae with Pyrethroids, Neem or “Neudosan”, a compound consisting of potassium salts of fatty acids, significantly shortened the lives of emerging adults and reduced their fecundity.
Biological control: Endemic Egyptian Entomopathogenic nematodes killed 65-85% of the pest’s larvae.
References
Abdel‐Moniem, A.S.H. and Gesraha, M.A. 2001. Evaluation of certain entomopathogenic nematodes against the melon ladybird, Epilachna chrysomelina F. (Coleoptera: Coccinellidae). Archives of Phytopathology and Plant Protection 34: 327-336.
Abdel-Moniem, A.S.H., Gomaa, A.A., Dimetry, N.Z., Wetzel, T. and Volkmar, C. 2004. Laboratory evaluation of certain natural compounds against the melon ladybird beetle, Epilachna chrysomelina F. attacking cucurbit plants. Archives of Phytopathology and Plant Protection 37: 71-81.
Akandeh, M. and Shishehbor, P. 2011. Life history traits of melon ladybeetle, Epilachna chrysomelina (Col.: Coccinellidae), on four host plant species. Journal of Entomological Society of Iran 31: 17-27.
El-Abdin, A.M.Z. and Siragelnour, B.G. 1991. Biological aspects, food preference and chemical control of the cucurbit beetle, Henosepilachna elaterii (Rossi)(Coleoptera; Coccinellidae). Arab Journal of Plant Protection 9: 103-110.
Cohen, S. and Nitzani, F.E. 1963.Identity of viruses affecting cucurbits in Israel. Phytopathology 53: 193-196.
Melamed, V., 1956: Contributions to the biology of Epilachna chrysomclina in Israel. Ktavim 7: 83-95.
Wool, D. and van Emden, H. F. 1981. Influence of temperature, photoperiod and host-plant on the bionomics of the melon ladybird Epilachna chrysomelina (F.) (Coleoptera: Coccinellidae). Zeitschrift für Angewandte Entomologie 91: 256-262.