The sex pheromone heptacosane enhances the mating competitiveness of sterile Aedes aegypti males

Abstract

Background Aedes aegypti is a vector that transmits various viral diseases, including dengue and Zika. The radiation-based sterile insect technique (SIT) has a limited effect on mosquito control because of the difficulty in irradiating males without reducing their mating competitiveness. In this study, the insect sex pheromone heptacosane was applied to Ae. aegypti males to investigate whether it could enhance the mating competitiveness of irradiated males. Methods Heptacosane was smeared on the abdomens of Ae. aegypti males that were allowed to mate with untreated virgin females. The insemination rate was used to assess the attractiveness of heptacosane-treated males to females. The pupae were irradiated with different doses of X-rays and γ-rays, and the emergence, survival time, egg number, and hatch rate were detected to find the optimal dose of X-ray and γ-ray radiation. The males irradiated at the optimal dose were smeared with heptacosane, released in different ratios with untreated males, and mated with females. The effect of heptacosane on the mating competitiveness of irradiated mosquitoes was then evaluated by the hatch rate, induced sterility, and mating competitiveness index. Results Applying heptacosane to Ae. aegypti males significantly increased the insemination rate of females by 20%. Pupal radiation did not affect egg number but significantly reduced survival time and hatch rate. The emergence of the pupae was not affected by X-ray radiation but was affected by γ-ray radiation. Pupae exposed to 60 Gy X-rays and 40 Gy γ-rays were selected for subsequent experiments. After 60 Gy X-ray irradiation or 40 Gy γ-ray irradiation, the average hatch rate was less than 0.1%, and the average survival time was more than 15 days. Moreover, at the same release ratio, the hatch rate of the irradiated group perfumed with heptacosane was lower than that of the group without heptacosane. Conversely, the male sterility and male mating competitiveness index were significantly increased due to the use of heptacosane. Conclusions The sex pheromone heptacosane enhanced the interaction between Ae. aegypti males and females. Perfuming males irradiated by X-rays or γ-rays with heptacosane led to a significant increase in mating competitiveness. This study provided a new idea for improving the application effect of SIT. Graphical Abstract

Phylogeny not mimicry drives chemical variation in tropical aposematic butterflies

“…Even though many individual compounds are shared between species, we found chemical blends to be highly species-specific, a feature that may be indicative of evolution primarily for mate recognition (Gomez-Diaz & Benton, 2013; Symonds & Elgar, 2008; Wyatt, 2014). This is further supported by the fact that many of the shared compounds detected in this study function as pheromones in other insects (Yang et al ., 2017; Funaro et al ., 2018; Wang et al ., 2023). This includes octadecanal, which is used by H. melpomene in female mate choice (Byers et al, 2020), and is found in varying concentrations across four Heliconiini and three Ithomiini species.…”

Oviposition site selection in mosquitoes : the role of conspecific larvae, heterospecific larvae and microbes

“…aegypti and Anopheles spp. have been shown to mate in swarms of flying males, often consisting of a few to many thousands of mosquitoes (Oliva et al, 2014;Wang et al, 2021Wang et al, , 2023.…”

“…Mosquitoes use both auditory (Feugere et al, 2021(Feugere et al, , 2022 and may or may not use chemical cues to attract both sexes to mate in a swarm (Fawaz et al, 2014;Mozuraitis et al, 2020;Poda et al, 2022;Wang et al, 2021Wang et al, , 2023. Both sexes are sensitive to auditory cues and swarm in the air to mate (Feugere et al, 2021;Su et al, 2018).…”

“…In addition, the chemical cues have been proposed in Anopheles mosquitoes e.g., Anopheles gambiae and Anopheles coluzzii exhibit swarming behaviour at specific times of the day (Mozuraitis et al, 2020;Wang et al, 2021Wang et al, , 2023. This behaviour is circadic and regulated by clock genes, entrained by light and temperature, which in turn regulate the expression of the desaturase gene desat1 regulating the production of heptacosane and induce mating activity (Wang et al, 2021).…”

Correction: The sex pheromone heptacosane enhances the mating competitiveness of sterile Aedes aegypti males

“…Following publication of the original article [ 1 ], two errors came to the attention of the authors: Mao Zhang had not been indicated as a co-first author, and in the Funding declaration, the funding number of the National Natural Science Foundation of China had been incorrectly detailed as ‘8210082025’ instead of ‘82102432’, the correct number.…”