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In the last two decades, bed bugs (Cimex lectularius L. and Cimex hemipterus F.) have become perennial and difficult to control indoor pests. Current pest control options are severely constrained by high prevalence of insecticide resistance and availability and relatively high costs of alternative interventions. Among various measures to counter the drawbacks of insecticide resistance include efforts to diversify the modes of action of insecticides with residual applications of combinations of insecticides, which include a juvenile hormone analog (JHA). JHAs, such as hydroprene and methoprene, have a desirable safety profile and are effective against a variety of indoor pests. We evaluated the potential of hydroprene and methoprene to be incorporated into an ingestible bait, with dose-response studies on fifth-instar male and female bed bugs. Females were more susceptible than males to both JHAs, and methoprene was more effective by ingestion than hydroprene at inducing both lethal and sublethal effects. Ingestion of ≥10 µg/ml blood of either JHA by last instar nymphs reduced oviposition; untreated females that mated with males exposed to high concentrations of either JHA also exhibited lower oviposition. We suggest that methoprene could be incorporated into integrated pest management programs in liquid baits and residual sprays in combination with other active ingredients., (© The Author(s) 2020. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Baits are a preferred method of urban pest management. Baits enable more targeted insecticide applications with a fraction of the active ingredient used in residual sprays. Bait translocation by foragers, and consequent secondary kill of nonforagers, enhances bait effectiveness in social insects, and in other group-living species like German cockroaches (Blattella germanica L.). We investigated the potential for secondary kill in bed bugs (Cimex lectularius L.), another gregarious species, using a liquid bait. We first investigated whether blood-fed adults enhance nymph survivorship within aggregations by increasing the local relative humidity (RH) and providing fecal nutrients. Higher RH (50% and 95%) resulted in greater survivorship of first instars compared with 0% RH. Therefore, in subsequent experiments, we controlled RH to decouple its effect on nymph survivorship from effects of fecal nutrients. The presence of fed or unfed adults did not increase unfed first instar survivorship, suggesting that if nymphs ingested feces, its nutritional benefits were minimal. Nymph survivorship was unaffected by the presence of adult males fed fipronil or clothianidin, suggesting that unlike in cockroaches, highly effective insecticides might not be effective as secondary kill toxicants in bed bugs. To directly compare secondary kill in first-instar bed bugs and B. germanica, we exposed both to insecticide-laden adult B. germanica feces. Whereas first-instar B. germanica died in the presence of insecticide-laden feces, bed bugs did not. We, therefore, conclude that secondary kill with neuroactive insecticides will likely not be a significant factor in bed bug population suppression., (© The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.)

Background: The global prevalence of Cimex lectularius infestations has challenged current intervention efforts, as pyrethroid resistance has become ubiquitous, availability of labeled insecticides for bed bugs is limited, and non-chemical treatment options, such as heat, are often unaffordable. We evaluated representative insecticides toward the goal of developing a novel, ingestible liquid bait for hematophagous arthropods., Results: LC 50 values were estimated for adult males and first instar nymphs of an insecticide-susceptible strain for abamectin, clothianidin, fipronil and indoxacarb, after ingestion from an artificial feeder. LD 50 values were calculated based on the ingested blood volume. Ingested abamectin, clothianidin and fipronil caused rapid mortality in both life stages. Fipronil was ∼43-fold more effective by ingestion than by topical application. Indoxacarb and its bioactive metabolite decarbomethoxylated JW062 (DCJW) were ineffective at causing bed bug mortality even at concentrations as high as 1000 ng mL -1 blood., Conclusions: Fipronil, clothianidin and abamectin have potential for being incorporated into a liquid bait for bed bug control; indoxacarb and DCJW were not effective. Bed bugs are a good candidate for an ingestible liquid bait because systemic formulations generally require less active ingredient than residual sprays, they remain contained and more effectively target hematophagous arthropods. © 2016 Society of Chemical Industry., (© 2016 Society of Chemical Industry.)