Life Cycle and Demography of Phytophagous Ladybird Beetle Henosepilachna vigintioctopunctata Fabricius (Coleoptera: Coccinellidae) on Different Host Plants

Abstract

Phytophagous lady beetle Henosepilachna vigintioctopunctata Fabricius is a serious pest of solanaceous crops, such as eggplants and potatoes. The beetles distributes from sub temperate of Asia to the tropics of Indonesia. The beetle feeds on several species of agricultural plants as well as wild solanaceous plants. Their life cycle has been known in a certain species of plant, however none comparing both their life cycle and demography on different host plants. It has been well known that the species of insect responds physiologically different to the different of food plants. This research aimed to study the respons of H. vigintioctopunctata to the different of given food plants of S. torvum, S. nigrum, S. melongena, and Brugmansia suaveolens. Life cycle, demography, life table, and survivorship curve of the beetle were studied. Results showed that the longest time in life-cycle of H. vigintioctopunctata fed with S.nigrum (93,8 days, male and 104,1 days, female), respectively. The shortest time in life-cycle of H.vigintioctopunctata fed with S.melongena (16,5 days,male and 16,9 days, female), respectively. Highest number of eggs per egg mass occurred in H. vigintioctopunctata fed by S. nigrum (26,20 eggs per egg mass) and the lowest number occurred ini beetle fed by B. suaveolens (19,80 eggs per egg mass). Statistic demography of H.vigintioctopunctata showed that the highest value of gross reproductive rate was in S. torvum (5,5 individu) and the lowest value was in B. suaveolens (0,3 individu). The highest value of net reproductive Rrate was in S. torvum (2,11) and the lowest value was in B.suaveolens (0,02). The shortest of generation time was in S. melongena (5,9 days) and the longest of generation time was in S.nigrum (29,33 days). The higher value of intrinsic growth rate were in S.torvum (0,04) and S.nigrum (0,04), respectively and the lower value were in S. melongena (0,01) and B.suaveolens (0,01), respectively. Life-table analysis showed that the highest value of life expectation of egg and larval stages found on treatment with foliage of S. torvum. The highest value of mortality was found on S. nigrum (32,86%) and the lowest was found in S. melongena (16,67%). Based on value of its life-table, the most suitable host for development of H. vigintioctopunctata were S. torvum and S. nigrum. Survivorship curve of H. vigintioctopunctata showed that the highest number of mortality occurred in egg and larval stage.