Effect of <i>Tagetes minuta</i> oil on larval morphology of <i>Plutella xylostella</i> through scanning electron microscopy and mechanism of action by enzyme assay

Abstract

The larvae of Plutella xylostella treated with Tagetes minuta oil were processed for SEM and detoxification enzyme activities. In treated larvae, reduction in the length of the setae (15.93 ± 3.46 to 30.59 ± 3.35 µm) was observed as compared to untreated setae. The cuticular setae were clubbed, swollen, and shaft of the hair was broken after 72 h of treatment and then hair socket was fragmented the bloated setae. Similarly, the larval cuticle, thoracic and abdominal legs after treatment were also presented. Higher concentration of T. minuta oil significantly inhibited the GST and AChE activity in P. xylostella.