Effects of Feeding on Different Host Plants on Susceptibility Variation to Insecticides in the Progeny of Brontispa longissima
The sensitivity to 3 insecticides of the laboratory populations of coconut leaf beetle,Brontispa longissima,feeding on different host plants was tested with bioassay.The results showed that the susceptibility of the test populations to acetamiprid could be arranged in order by the plants that the larvae fed on:Fishtail palm leaf Bottle palm leaf Royal palm leaf Coconut leaf;the susceptibility to β-cypermethrin:Fishtail palm leaf Bottle palm leaf Coconut leaf Royal palm leaf;the susceptibility to avermectin:Bottle palm leaf Coconut leaf Royal palm leaf Fishtail palm leaf.The maximal susceptibility difference to avermectin was 14.18 times,but to β-cypermethrin and acetamiprid was only 3.47 times and 2.54 times,respectively.It proved that the rearing on different host plants could cause by the susceptibility changes to insecticides of Brontispa longissima.