The Possible Role of Microorganisms in Mosquito Mass Rearing

Abstract

In Europe, one of the most significant mosquitoes of public health importance is Aedes albopictus (Skuse), an allochthonous species of Asian origin. One of the most promising control methods against Aedes albopictus is the sterile insect technique (SIT), which consists of mass rearing the target species, separation of males from females, and male exposure to sterilizing ionizing radiation. Once released in the environment, the sterile males are expected to search for wild females to mate with. If mating occurs, no offspring is produced. The quality of sterile males is a crucial aspect in SIT programs in order to optimize effectiveness and limit production costs. The integration of probiotic microorganisms in larval and adult mosquito diets could enhance the quality parameters of the released sterile males. In this review, we attempt to give the most representative picture of the present knowledge on the relationships between gut microbiota of mosquitoes and the natural or artificial larval diet. Furthermore, the possible use of probiotic microorganisms for mosquito larvae rearing is explored. Based on the limited amount of data found in the literature, we hypothesize that a better understanding of the interaction between mosquitoes and their microbiota may bring significant improvements in mosquito mass rearing for SIT purposes.

Aedes albopictus microbiota: Differences between wild and mass-reared immatures do not suggest negative impacts from a diet based on black soldier fly larvae and fish food

“…Such differences point to a certain, though apparently weak, acquisition of bacterial components from the rearing diet to immature stages as shown by the lab-reared mosquitoes’ microbiota profile. The occurrence of only a few bacterial taxa shared between mosquitoes and the diet suggests that the mosquitoes internal body environment allows the survival of only a few bacteria, as also noted by previous studies on Aedes [ 15 , 21 , 43 , 44 ].…”

“…However, producing sterile males of high quality (i.e., competitive with wild ones) while limiting production costs, remains challenging [ 12 , 13 ]. For this purpose, the role of microbiota in developing more efficient mass-rearing aimed at SIT application has recently received increasing attention [ 14 , 15 ].…”

“…A promising research line could be the development of novel diets, such as those containing probiotics supplements, to improve larval survival, adult longevity, dispersal ability or sexual performance [ 15 ]. However, the role of the diet and the development of new media to improve current SIT methodologies is still largely overlooked [ 26 – 28 ], especially regarding the effects of such diets on mosquito microbiota.…”

Sterility ofCydia pomonellaby X ray irradiation as an alternative to gamma radiation for the sterile insect technique

“…However, it is very important to perform other studies before field application of X-ray, including mating competitions in field cage, proportion of sterile males vs fertile females (laboratory and field studies), experiments of releasing sterile males at a reduced scale and monitor the percentage of fruit infestation. Currently, we are investigating the mechanisms of loss of mating competitiveness of irradiated codling moths and attempting to improve competitiveness via a series of rearing and acclimation studies, such as using insects that have gone through diapause (Dyck, 2010), or integration of probiotic microorganisms in the diet of larvae, which has been proved to be effective in Aedes albopictus (Chersoni et al ., 2021).…”