Electroantennogram responses of Plutella xylostella (L.), to sex pheromone components and host plant volatile semiochemicals

Abstract

The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae), is a notorious insect pest of cruciferous crops worldwide. Attract‐and‐kill strategies to manage the DBM based on insect pheromone and plant volatile semiochemicals have been explored and partially applied in the field. However, little is known about whether the attractant effects of insect pheromone and host plant volatile semiochemicals on insects are affected by insect age or volatile concentrations. Therefore, we examined the electroantennogram (EAG) responses of both DBM males and females varying in age and body size to a range of concentrations of seven host plant volatiles and two main female sex pheromone components. Our results showed that DBM age had no influence on EAG responses to trans‐2‐Hexenal, trans‐2‐Hexenol, Heptanal, cis‐3‐Hexen‐1‐ol and Z11‐16:Ald and significantly influenced the EAG responses to Z11‐16:Ac and three isothiocyanates. Age and sex had interaction effects on EAG responses of DBMs to some tested semiochemicals. DBM females had significantly stronger responses than males to all tested plant volatiles, and values were enhanced with increasing concentrations. Moreover, the degree of enhancement of EAG responses in females was larger than that in males for trans‐2‐Hexenal, trans‐2‐Hexenol, cis‐3‐Hexen‐1‐ol, 2‐Phenylethyl isothiocyanate and Methyl isothiocyanate treatments. Body size seemed to have no influence on EAG responses. Our results might provide a theoretical basis for optimizing attract‐and‐kill strategies for insect pests.

Pheromone antagonism in Plu tella xylostella (Linnaeus) by sex pheromones of two sympatric noctuid moths

“…4 Previous research showed that both males and females of P. xylostella can detect a broad range of plant volatiles, but only males respond to female sex pheromone components. 25 Taken together with our results, it is reasonable to speculate two olfactory mechanisms for the cross-species inhibition. The first is that the olfactory receptors in male P. xylostella antennae that respond to the three heterospecific pheromone components are also broadly tuned to a range of moth pheromone components.…”

Electrophysiological and Behavioral Responses of Plutella xylostella (Lepidoptera: Plutellidae) to Volatiles from a Non-host Plant, Geranium, Pelargonium × hortorum (Geraniaceae)

“…The sensitivity of DBM females to the five active compounds or two blends was assessed through the EAG method as described by Wu et al with slight modifications . Blend-1 was a mixture of equal amounts of the five bioactive compounds, and blend-2 was a five-component mixture (1:5:3:4:3) that mimics the volatile bouquet from geranium.…”

“…The sensitivity of DBM females to the five active compounds or two blends was assessed through the EAG method as described by Wu et al with slight modifications. 30 Blend-1 was a mixture of equal amounts of the five bioactive compounds, and blend-2 was a five-component mixture (1:5:3:4:3) that mimics the volatile bouquet from geranium. Each test chemical at three concentrations (1, 10, and 100 μg/μL) was applied to a single antennal preparation and tested from low to high concentrations, with 10 μL of paraffin oil as a control.…”

Expression Profiles and Binding Properties of the Chemosensory Protein PxylCSP11 from the Diamondback Moth, Plutella xylostella (Lepidoptera: Plutellidae)

“…It is common that electroantennogram (EAG) responses to sex pheromone components are stronger in males than in females but weaker to host volatiles. In P. xylostella , the response of males to sex pheromone constituents is higher than to host plant odorants, but females have a higher EAG response to plant odorants than to sex pheromones ( Palaniswamy et al 1986 , Pivnick et al 1994 , Wu et al 2020 ). Therefore, it is reasonable to speculate that Pxyl CSP11 may be sensitive to the sex pheromone besides plant volatiles in the olfactory communication.…”