Changes in the haemocytes of Agrotis ipsilon larvae (Lepidoptera: Noctuidae) in relation to dimilin and Bacillus thuringiensis infections

摘要

Five types of haemocytes are observed in the fourth larval in star of the black cutworm, Agrotis ipsilon: prohaemocytes (PRs), plasmatocytes (PLs), granulocytes (GRs), spherule cells (SPs) and adipohaemocytes (ADs). Infection of A. ipsilon fourth larval instar with Bacillus thuringiensis and dimilin resulted in a reduction of the total haemocyte count. Changes in the differential haemocyte population during bacterial and dimilin infections have been assessed. The PRs% decreased significantly while SPs, PLs, and GRs% increased significantly after the application of the two insecticides at 12 and 24 h. Ultrastructural alternations and malformations have been observed in "circulating haemocytes of A ipsilon larvae treated with dimilin and B. thuringiensis.