Which characteristic is NOT typical of adult mosquitoes?

Adult mosquitoes are characterized by several distinctive features, and their anatomy is well-adapted for their feeding habits and habitat. One of these key features is the presence of a proboscis, which is a long, tubular mouthpart that allows them to pierce the skin of their hosts to feed on blood. Having a proboscis is typical of adult mosquitoes, as it is crucial for their reproductive behavior and survival.

In contrast, the marked absence of a proboscis would deviate significantly from the standard characteristics of mosquitoes. This means that the option regarding the absence of a proboscis stands out as atypical, making it the correct answer to the question about which characteristic is not typical of adult mosquitoes.