Uncommon C18 Conjugated Dienes Define the Sex Pheromone System of Thelosia camina (Lepidoptera: Apatelodidae), a Pest of Yerba Mate

TL;DR

Researchers identified the sex pheromone of Thelosia camina, a pest of yerba mate, to develop sustainable pest control methods.

Contribution

The study identifies specific conjugated C18 dienes as key pheromone components for T. camina.

Findings

Three major pheromone components were identified and synthesized.

Field tests showed that the pheromone blend and individual acetate attracted male moths effectively.

The findings support pheromone-based pest management for yerba mate.

Abstract

The yerba mate tree Ilex paraguariensis is widely
consumed in South America, and the limited recommendation for pesticide
use highlights the need for alternative pest-management strategies. Thelosia camina is an important defoliator whose damage
severely reduces yields. This study investigated the sex-pheromone
system of T. camina as a basis for pheromone-mediated
control. Female pheromone glands were extracted and analyzed by gas
chromatography-electroantennographic detection, revealing nine antennally
active compounds. Structural elucidation identified three major components
(13Z,15Z)-octadeca-13,15-dienal
(4), (13Z,15Z)-octadeca-13,15-dien-1-ol
(5) and (13Z,15Z)-octadeca-13,15-dien-1-yl
acetate (9). Remaining components were stereoisomers
and related monoenes consistent with the same double-bond system.
All isomers were synthesized, field bioassays showed that both the
ternary blend (4,5 and 9) and
the acetate (9) alone attracted males at levels significantly
higher than controls. These results confirm conjugated C18 dienes
as key pheromone components of T. camina and provide
a foundation for pheromone-based, sustainable management in yerba
mate cultivation.

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