There is some interesting new research out on the Asian Fruit Fly, Drosophila suzukii.
The short version: This sort of fruit fly ruins fruit crops because it prefers to, and is able to, lay its eggs on harder, firmer, unrotten, and, essentially, ripe fruit, thus ruining it. Regular fruit flies focus on rotten fruit such as groundfall.
The Asian fruit fly manages this because of slightly different fruit detection mechanisms, though some of the details of this are not yet known. In the future, it is hoped that the exact chemical used by this fly to find its target ripe fruit can be reproduced and used in the manufacture of a bait, to reduce crop damage.
The paper is:
Evolution of multiple sensory systems drives novel egg-laying behavior in the fruit pest Drosophila suzukii, Marianthi Karageorgi, Lasse B. Bräcker, Sébastien Lebreton, Caroline Minervino, Matthieu Cavey, K.P. Siju, Ilona C. Grunwald Kadow, Nicolas Gompel & Benjamin Prud’homme. Current Biology, 9 March 2017.
From the press release:
The Asian fruit fly Drosophila suzukii reached Europe and the US about a decade ago. This invasive species ravages fruit crops, including strawberries and cherries, and there is currently no effective means of staving it off. Unlike other drosophilae, which lay eggs on rotting fruits, D. suzukii chooses ripe fruits, thereby accelerating their decomposition. Researchers from the Developmental Biology Institute of Marseille (CNRS / AMU) and LMU Munich recently discovered that D. suzukii has developed greater sensitivity to the smell and taste of ripe fruit, in comparison to fermented fruit, and the ability to lay eggs in relatively firm fruit. By selectively inactivating the fly’s neurons and olfactory receptors, they demonstrated that the smell of fresh fruit enhanced D. suzukii egg laying. The scientists are now trying to identify the molecule or molecules that elicit this response. This would then make it possible to develop bait or design molecules that could inhibit egg laying. The results of their work also offer insight into how instinctive behaviors like egg laying are altered in the course of evolution.
And yet some foolish politicians (I'm looking at you, former half-term governor) have laughed at and belittled studies of fruit flies and sex because, well, they just have no clue.