Sugar sensation and mechanosensation in the egg-laying preference shift of Drosophila suzukii

Abstract

The agricultural pest Drosophila suzukii differs from most other Drosophila species in that it lays eggs in ripe, rather than overripe, fruit. Previously, we showed that changes in bitter taste sensation accompanied this adaptation (Dweck et al., 2021). Here, we show that D. suzukii has also undergone a variety of changes in sweet taste sensation. D. suzukii has a weaker preference than Drosophila melanogaster for laying eggs on substrates containing all three primary fruit sugars: sucrose, fructose, and glucose. Major subsets of D. suzukii taste sensilla have lost electrophysiological responses to sugars. Expression of several key sugar receptor genes is reduced in the taste organs of D. suzukii. By contrast, certain mechanosensory channel genes, including no mechanoreceptor potential C, are expressed at higher levels in the taste organs of D. suzukii, which has a higher preference for stiff substrates. Finally, we find that D. suzukii responds differently from D. melanogaster to combinations of sweet and mechanosensory cues. Thus, the two species differ in sweet sensation, mechanosensation, and their integration, which are all likely to contribute to the differences in their egg-laying preferences in nature.

Jasmonic acid and salicylic acid induced defensive response in wine grapes against Drosophila suzukii (Diptera: Drosophilidae)

“…A large, serrated ovipositor is present on abdominal tip of D. suzukii females, which is pierced into the soft ripening fruit. The eggs are laid inside the fruit and the developing maggots consume the fruits and make them vulnerable to microbial infection [ 1 , 38 , 39 ]. In choice and no choice assays, our results showed that SA application on a fly diet resulted in reduced oviposition by D. suzukii in a dose-dependent manner.…”

“…Though, SWD females are least attracted to unripe fruits, they possess a nasty ovipositor to lacerate the immature or unripe fruits. Further, it has been reported that life history traits, fecundity, insecticide tolerance, etc., depend on sucrose concentrations in fruits [ 39 ]. The total soluble sugars influence the oviposition behavior of SWD.…”

“…The total soluble sugars influence the oviposition behavior of SWD. More eggs are laid on fruits with higher sugar content and the larval growth is faster on the fruits with high sugar levels [ 18 , 39 , 44 ]. Further research to quantify the total sugars from different wine grape varieties is needed to understand the effects of °Brix and penetration pressure [ 16 ].…”

DrosophilaHCN mediates gustatory homeostasis by preserving sensillar transepithelial potential in sweet environments

“…We showed that ectopic expression of Ih in bGRNs also upheld SP and the activity of the neighboring sGRNs, underscoring the independent capability of HCN in SP preservation. Despite such an option available, the preference for sGRNs over bGRNs in HCN-mediated taste homeostasis implies that Drosophila melanogaster may have ecologically adapted to the high sweetness 52 prevalent in their feeding niche, such as overripe or fermented fruits 53 . It would be interesting to investigate whether and how respective niches of various insect species differentiate the HCN expression pattern in sensory receptor neurons for ecological adaptation.…”

Odor-regulated oviposition behavior in an ecological specialist

“…Studies in D. melanogaster and other drosophilids have revealed that oviposition decisions are complex, multisensory-dependent behaviors 35 , 52 , 55 , 56 , guided both by substrate properties and the recent experience of animals 57 ; moreover, the choice of egg-laying site is often assay-dependent (e.g., 58 , 59 ). Using several types of behavioral assays, we have confirmed the importance of noni for D. sechellia for egg-laying rate and site selection.…”