Methyl salicylate (MeSA) is an herbivore-induced plant volatile (HIPV) known to attract the natural enemies of herbivores in agro-ecosystems; however, whether this attraction leads to an increase in natural enemy functioning, i.e., predation, remains largely unknown. Here, we monitored for 2 years (2011–2012) the response of herbivores and natural enemies to MeSA lures (PredaLure) by using sticky and pitfall traps in cranberry bogs. In addition, European corn borer, Ostrinia nubilalis, egg masses were used to determine whether natural enemy attraction to MeSA leads to higher predation. In both years, MeSA increased adult hoverfly captures on sticky traps and augmented predation of O. nubilalis eggs. However, MeSA also attracted more phytophagous thrips and, in 2012, more plant bugs (Miridae) to sticky traps. Furthermore, we used surveillance cameras to record the identity of natural enemies attracted to MeSA and measure their predation rate. Video recordings showed that MeSA lures increase visitation by adult lady beetles, adult hoverflies, and predatory mites to sentinel eggs, and predation of these eggs doubled compared to no-lure controls. Our data indicate that MeSA lures increase predator attraction, resulting in increased predation; thus, we provide evidence that attraction to HIPVs can increase natural enemy functioning in an agro-ecosystem.

The cranberry weevil, Anthonomus musculus Say (Coleoptera: Curculionidae), is a key (univoltine) pest of highbush blueberries in the northeast United States. To date, however, no trapping system has been developed to successfully monitor this pest. In 2012–2014, studies were conducted in commercial highbush blueberry farms in New Jersey to 1) evaluate the efficacy of various commercially available traps, designed for other weevil species (e.g., pepper weevil, plum curculio, boll weevil, red palm weevil, and black vine weevil), in capturing A. musculus adults; 2) test whether the relative location of traps within the blueberry canopy affects adult captures and 3) determine the effects of different colored (yellow, white, green, red, blue, brown, and black) sticky traps on weevil captures. For a comparison with existing techniques, we also monitored the number of overwintered adult weevils on blueberry bushes using beat sheet sampling. Of all traps and colors tested, the most A. musculus adults were caught on yellow sticky traps and more adults were captured when these traps were placed at the bottom half of the blueberry canopy, i.e., 0.5–1.0 m above ground. Most weevils were caught on colored traps late in the season (i.e., during bloom), which corresponds mostly to the second (summer) adult generation. Thus, number of overwintered adults caught on traps did not correlate with those on bushes. Although our study identified traps that can be used to capture A. musculus adults, these traps alone (i.e., without semiochemicals) have so far limited applicability for monitoring overwintered adult weevils in highbush blueberries.

Laboratory and extended laboratory bioassays were conducted to determine the residual toxicities of various insecticides against two key pests of cranberries, Sparganothis sulfureana and Choristoneura parallela (Lepidoptera: Tortricidae), and their non-target effects on the predatory Orius insidiosus (Hemiptera: Anthocoridae). The effects of nine insecticides with different modes of action on S. sulfureana and Ch. parallela eggs, larvae, and adults were tested in the laboratory, while the efficacy of a post-bloom application on larval mortality and mass of these pests and on adult O. insidiosus was evaluated in extended laboratory experiments. The organophosphate chlorpyrifos and the spinosyn spinetoram provided long-lasting (seven-day) control against all stages of both pests. The growth regulator methoxyfenozide and the diamides chlorantraniliprole and cyantraniliprole had strong (1–7 days) larvicidal, particularly on young larvae, and growth inhibitory activity, but only the diamides were adulticidal. Among neonicotinoids, acetamiprid had stronger ovicidal and adulticidal activity than thiamethoxam, showing within-insecticide class differences in toxicities; however, both were weak on larvae. Lethality of novaluron and indoxacarb was inconsistent, varying depending on species and stage. Chlorpyrifos was most toxic to O. insidiosus. These results show species- and stage-specific toxicities, and greater compatibility with biological control, of the newer reduced-risk classes of insecticides than older chemistries.