A Study of the Effect of Spatial Distribution on Mortality of the Immatures, and Associated Predators of the Phytophagous Lady Beetle, Epilachna vigintioctomaculata (Coleoptera : Coccinellidae)

We investigated the effect of spatial distribution pattern on the immature of Epilachna vigintioctomaculata, employing two distinctly different spatial distribution patterns (clumped and uniform), and examined the associated predator fauna in an experimental study site in the field. Mortality was higher in the uniform distribution as compared to the clumped one in 1992 and 1993. The dominant predators were spiders, ants, and other predators were Coccinellids, bugs and mantis. Predator numbers showed a decrease with a decrease in prey population. Egg mass sizes varied widely with an average of ca. 27. Since prey distribution was the major difference between the two fields, and predation was the major mortality factor, predation probably acted with varying intensities on the different spatial distribution patterns.