Identification of sex pheromone produced by female sweetpotato weevil,Cylas formicarius elegantulus (Summers)

Abstract

A sex pheromone of the sweetpotato weevil,Cylas formicarius elegantulus (Summers), was obtained from collections of volatiles from virgin females, and pheromone was isolated by means of liquid and gas chromatography. The purification procedure was monitored by quantitative laboratory and field bioassays and the compound was identified as (Z)-3-dodecen-1-ol (E)-2-butenoate by means of spectroscopic and microchemical methods. Synthesis, followed by laboratory and field bioassays, showed that the biological activity of the synthetic material was qualitatively and quantitatively indistinguishable from that of the purified natural product.

Synthesis of (3Z)-Dodecenyl-(E)-2-butenoate, the Pheromone of Sweet Potato Weevil

“…Its production and storage are strongly hampered [1] by the weevil, Cylas formicarius elegantulus which is a serious insect pest prevalent in India. The virgin female weevils secrete [2] (3Z)-dodecenyl (E)-2-butenoate (9) as the pheromone. Some other agriculturally important insects viz.…”

“…In addition, these C 12 -esters also constitute [5] synthetic attractants for the Reticulitermes termites. Our interest for the field control of the weevil has led to a novel preparation of 9, whose synthesis has already been described [2,[6][7][8]. Amongst these, Heath et al [2] have used the potential carcinogenic compounds like HMPA and ethylene oxide in their synthesis.…”

“…Our interest for the field control of the weevil has led to a novel preparation of 9, whose synthesis has already been described [2,[6][7][8]. Amongst these, Heath et al [2] have used the potential carcinogenic compounds like HMPA and ethylene oxide in their synthesis. The Wittig-based synthesis by a Chinese group [6] has been published with no technical detail.…”

“…The best result was obtained by refluxing its solution in THF-HOAc-H 2 O. Upon reduction of the resultant aldehyde 8a with NaBH 4 , the known [5,6,11] alcohol 8b was obtained. Acylation with cro-tonyl chloride via a conventional procedure [7,8] gave the title pheromone 9 whose properties (IR, NMR, BP) were in agreement with those reported previously.…”

“…Acylation with cro-tonyl chloride via a conventional procedure [7,8] gave the title pheromone 9 whose properties (IR, NMR, BP) were in agreement with those reported previously. [7,8,11].…”