Behavior and physiology of a <i>Lygus hesperus</i> (Hemiptera: Miridae) <i>aaNAT</i> knockout strain diverges little from the wild type

Manipulation of genes involved in regulating pigmentation can create externally visible markers of successful gene editing. However, such engineered mutations can have secondary impacts on key traits that are undesirable, especially if the mutants are expected to compete with wild-type (WT) individuals, such as might occur with a genetic sterile insect technique. Here, we tested for negative impacts in Lygus hesperus Knight from the knockout of aralkylamine N-acetyltransferase (aaNAT), needed to convert dopamine to N-acetyldopamine (NADA) sclerotin. Knockdown of this gene was previously shown to produce entirely black versions of this significant crop pest. Here, we compared knockout (KO) and WT strains across numerous behavioral and physiological traits. In most regards, the 2 strains were quite similar, with adults exhibiting equivalent locomotor activity, sperm production, mating activity, and susceptibility to heat, desiccation, and predation. However, some differences were observed with the aaNAT KO strain relative to the WT strain; eggs were more likely to hatch, nymphs had higher rates of survival to adulthood, adults lived longer, females produced fewer eggs, and males had a higher rate of mating success. Overall, the results suggest the aaNAT KO is a suitable marker that may facilitate rapid screening of gene edits and the development of population suppression systems.