Effect of Trichosanthes anguina L. flower surface wax chemicals as short-range attractants and oviposition stimulants in Diaphania indica (Saunders) (Lepidoptera: Crambidae)

Abstract

Larvae of Diaphania indica (Saunders) (Lepidoptera: Crambidae) feed on flowers of Trichosanthes anguina L., and reduce crop production. Therefore, we have tried to find whether flower surface wax chemicals (alkanes and free fatty acids) of three T. anguina cultivars [MNSR-1 (MNS), Baruipur Long (BAR), and Polo No. 1 (POLO)] could act as short-range attractants and oviposition stimulants in females of D. indica. One mg flower surface wax of these cultivars acted as attractants in short Y-tube olfactometer bioassays and stimulated oviposition in females. A synthetic blend of nonadecane, pentacosane, and palmitoleic acid, a synthetic blend of pentacosane and palmitoleic acid, and a synthetic blend of pentacosane and oleic acid in amounts comparable to those present in 1 mg flower surface wax of MNS, BAR, and POLO cultivars, respectively, served as short-range attractants and oviposition stimulants in D. indica. Females exhibited equal egg-laying behavior towards these three synthetic blends when these blends were tested against one another, and hence, these blends could be used as lures in developing baits for traps in pest management strategies.

Keywords:

• Trichosanthes anguina
• flower surface wax
• long-chain alkanes
• free fatty acids
• Diaphania indica
• olfactometer bioassay
• oviposition assay

Acknowledgements

We are thankful to anonymous reviewers for many helpful suggestions of earlier versions of the manuscript. We thank Dr. M. Alma Solis, Research Entomologist, SEL, USDA, Smithsonian Institution, Washington for authenticating the insect.

Authors’ contributions

RD and AB designed experiments; RD and SHM performed bioassays; RD did chemical analyses; RD and AB analyzed data; RD made Figs; AB wrote the manuscript. All authors edited the manuscript and approved the final version of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The authors confirm that the data supporting the findings of this study are available within the article and its supplementary material.

Additional information

Funding

The financial assistance from the Govt. of India as UGC-Senior Research Fellowship [F.No. 16-6(DEC. 2017)/2018(NET/CSIR)] to Rahul Debnath is gratefully acknowledged. We are thankful to DST PURSE Phase-II for providing necessary instrumental facilities.