HOST PLANT INFLUENCES ON SEX PHEROMONES BEHAVIOUR OF PHYTOPHAGOUS INSECTS

SUBMITTED TO SUBMITTED BY

DR. J. SATHYANARAYANA MD. ABDUL MALIK

PROFFESOR RAM/ 16-36

DEPARTMENT OF ENTOMOLOGY M.SC. I YEAR

CONTENTSTitle

Introduction

Mechanisms of host plant influences on sex pheromones

Pheromone production and release

Larval sequestration of plant chemicals

Adult acquisition of plant compounds

Insect responses to sex pheromone

Reproductive strategy involving host plant and sex pheromones

conclusion

references

Introduction Sex pheromones :

It is a chemical signal emitted by an organism for sexual purposes or that elicits any sexual response in a member of the opposite sex of the same species.

How host plant influences on sex pheromones……?

Influences of host

Pheromone Insect behavioural

signaller responses

Pheromone production and releaseEffect of host plant material on pheromone production

acquisition of bioactive chemicals

Plant released Kairomone stimulate pheromone production in

◦Acting on nervous system

◦Hormonal system

Larval sequestration of plant chemicals

Larvae aquire plant chemical while feeding on host plantoUse it for sexual communication in adult stage

(Hindenlang and Wichman, )

Same studies are carried out and proven correct in case of◦Nymphalid Butterflies

◦Arctiid moths

Adult acquisition of plant compounds

PyrollizidineAlkaloid

Sex Pheromone

Arctiid moth

Insect responses to sex pheromoneHost odour enhances the attraction responses to male pheromones.

In Diptera such effects have been demonstrated in Tephritidae and Drosophilidae.

For example the combination of host fruit odour and male pheromones is more attractive to female papaya fruit flies.

Sex attraction responses of males to female pheromone may also be directly influenced by stimuli from host plant

For example male corn moths are trapped in greater numbers when pheromone trap are placed near silking corn plants

Reproductive strategy involving host plant and sex pheromonesMales of phytophagous insects most likely releases pheromones attractive to females from host plants to optimize sexual encounter rates and mating oppurtunities .

Males of many species focus their mate searching in areas of female activity including host plants where female may oviposit,

Another possible strategy of males calling from plants is the advertising of resources to females .

Host plant influences on female pheromone bhevaiour may be strategy by females to maximize reproduction.

Females of some species uses cues from host plants suitable for oviposition to regulate the reproductive function.

Females postpone sexual attraction until suitable host is available.

conclusion

Sexual communication in a diverse array of phytophagous insects is evidently strongly influenced by host plant chemistry.

Well documented examples are found in several families of Coleoptera,Lepidoptera and Diptera.

The effects of host plants on sex pheromone behaviour are varied and reflect different stratigies in females and males.

Host odour enhancement of sex attraction of great importance in the development of pheromone based lures.

ReferencesLandolt, P.J. and Phillips, T.W. 1997. Host plant influences on sex pheromones behaviour of phytophagus insects. Annual review of Entomology 42: 371-91.