Leafy greens are produced for the fresh market or processed for canned or frozen greens. Grasshoppers are important insect pests of leafy greens and destroy the crop as well as contaminate the final product and substantially reduce the market value.
This study was conducted to evaluate four insecticides, (Diflubenzuron (Dimilin), azadarachtin (Neemix 4.5), Beauveria bassiana GHA (Mycotrol) and esfenvalerate (Asena)) at four different temperatures (10ºC, 15ºC, 25ºC, and 35ºC).
The differential grasshopper Melanoplus differentialis (Thomas) (Orthoptera: Acrididae) was used in the study. Each third instar was starved for 24 hours and provided with a collard (Brassica acephala) leaf treated with specific insecticide and kept in the environmental growth chambers providing light period (14:10) and specific temperature. After 48 hours leaves were replaced with untreated ones.
Esfenvalerate showed highest activity as determined by insect mortality followed by diflubenzuron, Beauvaria bassiana GHA, and azadarachtin respectively. Diflubenzuron showed mortality associated with molting deformities. Higher temperatures resulted in higher mortality except for esfenvalerate, which was not affected, by temperature.
Species 1: Orthoptera Acrididae Melanoplus differentialis (differential grasshopper)
Species 2: Brassica acephala (collard)
Keywords: mortality, temperature
The ESA 2001 Annual Meeting - 2001: An Entomological Odyssey of ESA