Growth and development of two predator species fed a diet of genetically engineered mosquitoes

Genetically engineered mosquitoes (GEMs) with gene drives have been developed for malaria control but remain untested in natural environments. Upon release, GEMs are expected to modify or replace wild-type counterparts, potentially uniquely interacting with nontarget organisms (NTOs). Concerns exist over possible negative effects on NTOs and broader ecological harm. Predators consuming GEMs represent a group that interacts closely with these modified mosquitoes.

Here, we examine the effect of GEM and wild-type Anopheles coluzzii diets on the growth of two predator species: the aquatic mosquitofish (Gambusia affinis) and the terrestrial bold jumping spider (Phidippus audax). Gambusia affinis was fed lyophilized gravid mosquitoes, and growth was measured using length and mass. Phidippus audax was fed live semi-gravid mosquitoes, with growth tracked via eye size, body size, and mass.

No adverse effects were found in either predator species fed GEM diets. Gambusia affinis showed no significant growth differences between diet groups. However, P. audax that were fed GEMs consumed more mosquitoes, grew larger, and matured faster.

Differences in predator growth rate suggest that GEMs' nutritional content is similar to that of wild-type mosquitoes, but that they may be more vulnerable to predation. Further research is needed to explore whether GEM visual or behavioral traits increase their susceptibility to predators.