Infection, Choice Behavior, and Cross-Infectivity of the Sculpted Damsel Bug, Nabis roseipennis, Offered the Tarnished Plant Bug, Lygus lineolaris, Infected with Entomopathogenic Nematodes

The tarnished plant bug, <i>Lygus lineolaris</i> Palisot de Beauvois (Hemiptera: Miridae), is an economically important pest of row crops worldwide. Ten isolates of entomopathogenic nematodes (EPNs) (Rhabditida: Steinernematidae and Heterorhabditidae) were evaluated against the third instar nymphal stage of the tarnished plant bug and its generalist predator, the sculpted damsel bug, <i>Nabis roseipennis</i> Reuter (Hemiptera: Nabidae), one of the most abundant and commonly encountered damsel bugs in cotton and soybean agroecoscapes across the Southeastern United States. The objectives of these experiments were to assess the infectivity of entomopathogenic nematodes (EPN) by direct topical exposure against the sculpted damsel bug and tarnished plant bug, whether the predator prey choice is affected by EPN infection, and if feeding on EPN-infected tarnished plant bug (TPB) prey items could result in cross-infection of the predator. Mortality rates at a concentration of 200 infective juveniles (IJs)/mL significantly differed among isolates and insect species, ranging from 30% to 93% for tarnished plant bugs and from 6% to 38% for sculpted damsels, respectively. The third instars of <i>L. lineolaris</i> were more susceptible to the ten nematode isolates than <i>N. roseipennis</i>. Higher pathogenicity on the tarnished plant bug and a low mortality potential make strains HbHP88, HbVS, Sc17c+e, and SfSN the most promising candidates for the biological control of <i>L. lineolaris</i> under lab and greenhouse conditions while preserving beneficial predators of the Southeastern United States.