The main idea is to assess treatment success by looking at the life stages you’re actually trying to control in the breeding sites. If your treatment targets larvae and pupae, then post-treatment inspections are most informative when you count how many larvae and pupae remain. Seeing few or no immature mosquitoes in the water indicates the habitat has been effectively suppressing production, and fewer adults will emerge as a result. Adult counts aren’t as reliable for evaluating a larvicidal or habitat-management treatment because adults can fly in from untreated areas or from elsewhere and may linger even after larvae are reduced. Egg counts can be variable and don’t always reflect current survival in the treated habitat, since eggs might have been laid before treatment or in multiple sites. Simply identifying water sources doesn’t measure treatment success either, since it’s the presence or absence of the immature stages within those sources that directly shows whether the intervention is working.