Characterizing the molecular changes underlying clothianidin response in the colorado potato beetle Leptinotarsa decemlineata

Leptinotarsa decemlineata (Say), also known as Colorado potato beetle, is a pest that can cause substantial harm to potato plant leaves. This insect is responsible for significant losses within the potato industry. Over the years, several insecticides have been used to control this insect even though resistance to these compounds develop. Many studies have been conducted regarding the molecular response of L. decemlineata when confronted with Chlorantraniliprol, imidacloprid, and spinosad, but the same cannot be said for the insecticide clothianidin. This study aims to better understand the molecular basis of clothianidin response in this insect. To reach this goal, multiple targets relevant to insecticides response were quantified by qRT-PCR in L. decemlineata exposed to clothianidin. Targets included various transcripts coding for cytochrome P450s, glutathione-S-transferases and cuticle proteins. Results showed no significant change for expression of transcripts coding for cuticle proteins. On the other hand, two transcripts coding for select glutathione-S-transferases showed over-expression greater than 2-fold in insects treated with clothianidin versus control insects. Transcripts coding for select cytochrome P450s also exhibited modulation including over-expression of four out of the six targets investigated such as CYP4g15 (8.6-fold), CYP4c1 (5.6-fold), CYP6a13 (12.7-fold) and CYP9e2 (4.2-fold). Overall, these results highlight the variation of targets relevant to insecticides response in L. decemlineata exposed to clothianidin and generate molecular leads that warrant further investigation in this insect pest.