Mating harassment may boost the effectiveness of the sterile insect technique for Aedes mosquitoes

Abstract

The sterile insect technique is based on the overflooding of a target population with released sterile males inducing sterility in the wild female population. It has proven to be effective against several insect pest species of agricultural and veterinary importance and is under development for Aedes mosquitoes. Here, we show that the release of sterile males at high sterile male to wild female ratios may also impact the target female population through mating harassment. Under laboratory conditions, male to female ratios above 50 to 1 reduce the longevity of female Aedes mosquitoes by reducing their feeding success. Under controlled conditions, blood uptake of females from an artificial host or from a mouse and biting rates on humans are also reduced. Finally, in a field trial conducted in a 1.17 ha area in China, the female biting rate is reduced by 80%, concurrent to a reduction of female mosquito density of 40% due to the swarming of males around humans attempting to mate with the female mosquitoes. This suggests that the sterile insect technique does not only suppress mosquito vector populations through the induction of sterility, but may also reduce disease transmission due to increased female mortality and lower host contact.

Mark–Release–Recapture (MRR) of Sterile Male Aedes albopictus (Skuse) in Sri Lanka: Field Performance of Sterile Males and Estimation of the Wild Mosquito Population Density

“…An estimation of the size of the wild mosquito population is necessary for the determination of the appropriate quantity of sterile males to be released for controlling the population effectively, which should be at least more than 10 times higher than that of the natural population size to see a quick suppression [19,31,55]. The current study showed a wild mosquito population density ranging from 95 to 232 males/ha (mean 163 males/ha), which shows a high density of wild mosquitoes.…”

“…The current study showed a wild mosquito population density ranging from 95 to 232 males/ha (mean 163 males/ha), which shows a high density of wild mosquitoes. Considering the results of this study and other studies [19,31,55], release rates of more than 163 males/ha can be considered for future trials in Sri Lanka. The significant difference in wild male population sizes between the first and second release series could be attributed to several factors.…”

“…Based on the results of this study, as well as other studies on SIT for the control of Aedes mosquitoes [19,31,55], a release rate of more than 1630 sterile males/ha once a week with a 255.1 ± 44.6 m distance between two sterile male release points should be considered for future SIT trials in Sri Lanka. The data generated in this study on the distance between release sites, release frequency, and density will be useful for designing future Ae.…”

Gonadal Transcriptomic Analysis Reveals Novel Sex-Related Genes in Bactrocera dorsalis

“…B. dorsalis is a significant pest, with a global distribution and rapid reproduction, and it causes substantial damage to fruit and vegetable production [ 36 ]. Recently, the SIT has been applied to the control of pests such as Aedes aegypti and Ceratitis capitata [ 37 , 38 ]. The successful application of the SIT is based on the elucidation of the reproductive developmental rules and the identification of reproduction-related or sex-related genes, especially the gonad-specific genes.…”