BIOLOGY OF THE BLACK LEAFHOPPER, Ricania speculum Walker on PATOLA (Luffa cylindrica (L) Roem)

Abstract

Eggs of black leafhopper, Ricania speculum Walker, were laid in batches on the nether surface of patola leaves (Luffa cylindrica (L) Roem) and were commonly covered with white mealy secretions. Incubation period of eggs on both detached and undetached leaves lasted 17 days. Total development period ranged from 40-71 days for males and 37-73 days for females when reared on detached leaves, and 41-61 days for males and 40-61 days for females on undetached leaves. There were 5 nymphal instars. The male to female ratio was 1:1.32 for those reared on detached leaves and 1:1.82 on undetached leaves. Of the 5 alternate hosts tested, ampalaya (Momordica charantia L.) sustained the insects for the longest period, i.e., until the 4th instar. An unidentified species of spider preyed on both the nymphs and adults.