Evaluation of Attractants for Monitoring Drosophila suzukii (Diptera: Drosophilidae)

Abstract

Drosophila suzukii Matsumura is an economically important pest of soft and small fruit crops. Unlike other drosophilid flies, D. suzukii is capable of infesting ripe and partially ripe fruit, which poses a significant pest management challenge, as there is no tolerance for infested or damaged fruit in the marketplace. As a result, producers in many regions rely on calendar-scheduled insecticide applications for D. suzukii management. In order to develop an integrated pest management approach, better tools for monitoring adult fly populations are needed. Over two growing seasons in southern Ontario, we evaluated three commercial (Pherocon SWD dual-lure, Suzukii Trap, and Scentry Lure) and two homemade baits (apple cider vinegar and yeast + sugar water) for their ability to capture D. suzukii in raspberry and highbush blueberry fields. In general, commercial attractants captured D. suzukii earlier in the growing season and in greater numbers, with fewer nontarget captures, compared with homemade baits. Scentry Lure tended to perform better than other attractants, capturing D. suzukii earlier and in larger numbers during peak harvest. Pherocon SWD dual-lure was highly specific to D. suzukii. The combination of Scentry Lure with Suzukii Trap had possible synergistic effects, as numbers of D. suzukii captured to the combined treatment were more than additive. Using commercial attractants improves D. suzukii monitoring and will allow growers to improve the timing of insecticide applications with D. suzukii activity in the field.

Trapping system comparisons for and factors affecting populations of Drosophila suzukii and Zaprionus indianus in winter‐grown strawberry

“…However, winter morphotypes were more common in D. suzukii populations in northern Florida where winter temperatures are cooler. Even though D. suzukii are continually present throughout the Florida winter, maximum captures were approximately 1.5 flies per trap per day, which are low compared with peak D. suzukii captures in other susceptible crops during late summer in temperate regions; for example, North Carolina, 93 flies; Ontario, 31 flies; Oregon, 55 flies per trap per day . Captures varied by trapping system but also by week, corroborating previous results that widely variable winter temperatures over a few days (e.g.…”

“…Even though few data are available on relating trap counts to total D. suzukii populations in a field or infestation rates in fruit, trapping systems and new formulations of attractants that consistently have greater D. suzukii captures and fewer non‐targets should be used in future research focused on defining an action threshold using trap count data . In previous comparative studies, the synthetic lure has generally been the most effective commercial attractant tested . In this study, the synthetic lure and commercial systems were comparable, except that the commercial system caught more female D. suzukii and only 10% of the Nitidulidae, the primary non‐target taxa, compared with the synthetic lure system.…”

“…Studies have shown that red or black traps and traps with an expanded entry area, a larger surface area for liquid attractants and increased headspace improved capture rates . Apple cider vinegar is an easy‐to‐use attractant, but it is relatively inefficient at capturing D. suzukii compared with homemade yeast‐sugar and yeast‐flour mixtures or commercially available, synthetic lures . Some synthetic pouch lures [e.g.…”

“…Pherocon SWD dual‐lure (Trécé Inc., Adair, OK, USA) and Scentry Lure (Scentry Biologicals, Billings, MO, USA)] are based on a four‐compound blend, but they vary in efficiency at capturing D. suzukii . Pherocon SWD dual‐lure captured few D. suzukii , but also fewer non‐targets, enabling rapid identification of D. suzukii , whereas Scentry Lure captured many D. suzukii , but also many non‐targets, particularly other Drosophilidae . Liquid attractants [Suzukii Trap (Bioibérica, S.A.U., Barcelona, Spain), DroskiDrink and Dros'Attract (Biobest®, Westerlo, Belgium)], typically based on mixtures of alcohols and fruit juices or extracts, also vary in their effectiveness at capturing D. suzukii .…”

“…Pherocon SWD dual‐lure captured few D. suzukii , but also fewer non‐targets, enabling rapid identification of D. suzukii , whereas Scentry Lure captured many D. suzukii , but also many non‐targets, particularly other Drosophilidae . Liquid attractants [Suzukii Trap (Bioibérica, S.A.U., Barcelona, Spain), DroskiDrink and Dros'Attract (Biobest®, Westerlo, Belgium)], typically based on mixtures of alcohols and fruit juices or extracts, also vary in their effectiveness at capturing D. suzukii . In one study, the combination of Scentry Lure and Suzukii Trap caught more D. suzukii than the additive amount of either product alone, suggesting a synergistic effect .…”