Population dynamics, varietal reactions, and microbial control of different species of mango leafhoppers

High population of both nymphs and adults of Idioscopus clypealis was observed only during the flowering period of mango, which was the last week of February for nymphs, first week of May for adult because it breed only on inflorescence. However, the population of I. niveosparsus had three peaks for nymphs, first week of September, second week of March and the last week of April and two peaks for adults, one at the last week of September and another at last week of May, depending on the flowering and the new flushings, due to its successful breeding both in flowers and new terminal shoots. The third species B. nigrobilineata had two nymphal and adult population peaks, in May and September for nymphs and at last week of June and third week of October for adults, depending on the flushing periods due to its reproductive success only on young but matured leaves. The number of I. clypealis was always highest in Carabao variety than on Pico, Pahutan, and Kathmitha (Indian mango), while in Kathmitha variety the number of B. nigrobilineata was always highest among the four varieties. I. niveosparsus were present in high numbers in the Kathmitha variety except in February to April. In these three months its population was observed to be highest on Carabao variety. Three species of spiders, a lady bird beetle and a praying manthis fed on the nymphs of the three species of mango leafhoppers. Light trapping was more effective during dark nights. I. clypealis, I. niveosparsus were positively photropic while B. nigrobilineata was negatively phototropic. I. niveosparsus attracted to the trap more than I. clypealis in the nights with moon. All the fungal isolates: two strains of Metarhizium anisopliae (Metch.) Sorokin FM3 and FM6 and one strain of Beauveria bassiana (Bals.) Fb9, were pathogenic to all the three species of mango leafhoppers within nylon cages, causing 100 percent mortality in 12 days after treatment. The percent reduction of B. nigrobilineata nymphs were highest than the other two species of MLH at 7, and 14 days after treatment in comparison with untreated, while there was no species specific reduction occurred in the field trials against adults. The FM3 strains of M. anisopliae had quicker, better action and controlled both adults and nymphs of MLH