Susceptibility to insecticides in the Q biotype of Bemisia tabaci is correlated with bacterial symbiont densities.

Abstract

BACKGROUND:

The presence of symbiotic microorganisms may influence an insect's ability to tolerate natural and artificial stress agents such as insecticides. The authors have previously shown that Rickettsia in the B biotype of the whitefly Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) increases this insect's susceptibility to several insecticidal compounds. This communication reports a comparison of the susceptibilities of three isofemale strains of the Q biotype of B. tabaci harbouring different bacterial complements to major insecticides from different chemical groups: one strain harboured only Arsenophonus, one harboured Rickettsia and Arsenophonus and one harboured Arsenophonus and Wolbachia.

RESULTS:

The presence of different symbiont combinations in the three strains had a significant influence on their susceptibility to most of the insecticides tested. Thiamethoxam, imidacloprid, pyriproxyfen and spiromesifen had a significant influence on strains that had the double infections Rickettsia-Arsenophonus and Wolbachia-Arsenophonus, which also carried higher amounts of symbionts as assessed by quantitative real-time PCR. No significant differences in mortality rates were observed when the tested strains were treated with diafenthiuron.

CONCLUSION:

The results suggest a correlation between the presence of high bacterial densities in B. tabaci and the insect's ability to detoxify toxic compounds such as insecticides.

• Authors: Murad Ghanim, Svetlana Kontsedalov
• Journal: Pest management science (Pest Manag Sci) Vol. 65 Issue 9 Pg. 939-42 (Sep 2009) ISSN: 1526-4998 [Electronic] England
• PMID: 19479746 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, Non-P.H.S.)
• Copyright: Copyright 2009 Society of Chemical Industry.

Chemical References

• Insecticides

Topics

• Animals
• Female
• Gram-Negative Bacteria (genetics, physiology)
• Hemiptera (drug effects, microbiology, physiology)
• Insecticides (pharmacology)
• Symbiosis