Male lures and the detection of tephritid fruit flies: assessing the relationships between lure amount and release rate and trap captures of invasive pest species

Authors: SHELLY, TODD - Animal And Plant Health Inspection Service (APHIS); Cloonan, Kevin

Submitted to: Crop Protection
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/31/2023
Publication Date: 11/3/2023
Citation: Shelly, T.E., Cloonan, K.R. 2023. Male lures and the detection of tephritid fruit flies: assessing the relationships between lure amount and release rate and trap captures of invasive pest species. Crop Protection. 176.Article 106504. https://doi.org/10.1016/j.cropro.2023.106504.
DOI: https://doi.org/10.1016/j.cropro.2023.106504

Interpretive Summary: Invasive fruit flies feed on commercial fruit and vegetable products worldwide and pose a serious threat to U.S. agriculture through quarantine restrictions and direct feeding damage. Early detection of invasive fruit flies is an important first step of control and eradication programs, and regulatory agencies in the U.S. monitor adult flies with a combination of food-baits and male lures. These male attractants include trimedlure, methyl eugenol, and cue-lure. The effectiveness of these male attractants has been researched extensively, but no synthesis of the impact of lure age and weathering on attraction has been compiled up to this point. Therefore, researchers from the USDA-ARS (Miami, Florida), and the USDA-APHIS (Waimanalo, Hawaii) reviewed the available literature on the effects of aging, or weathering, on lures baited with trimedlure, methyl eugenol, and cue-lure to summarize the impacts of weathering on the attraction of these male lures to fruit flies. We found that large variation exists in the data, and we recommend that more research efforts are made to better characterize the relationship between lure emission and attractiveness to fruit flies. This information will benefit regulatory agencies in their implementation and design of fruit fly monitoring programs with trimedlure, methyl eugenol, and cue-lure.

Technical Abstract: Invasive tephritid fruit flies pose an enormous threat to commercial fruit and vegetable production worldwide as females oviposit in, and hatched larvae then consume, a broad range of commercially important crops. Early detection is critical to successful control and eradication, and fruit fly-free countries or regions generally maintain extensive trapping networks to identify incipient infestations. These networks rely heavily on male lures, which are natural or synthetic sex-specific attractants, the most important being trimedlure (attractive to males of certain Ceratitis spp.), methyl eugenol (attractive to males of certain Bactrocera spp.), and cue-lure/raspberry ketone (attractive to males of certain Bactrocera spp. and Zeugodacus spp.). The efficacy of male lures in trapping tephritids has been the subject of considerable research, but the results are scattered, and no synthesis has (to our knowledge) been presented. The objective of this review was to summarize data on the change in the attractiveness of male lure/dispenser combinations over the course of their aging (weathering) in the field. We highlighted studies that related temporal variation in trap captures with associated changes in the residual content and release rate of the male lure. Where possible, we identified the effective longevity of male lures based on statistical comparisons of captures between weathered and fresh lures and then estimated the residual content and release rate of the weathered lures that were associated with the onset of significantly reduced attractiveness. Large variation in these parameters was evident even among studies examining the same initial dose and dispenser type, and we encourage additional work to better characterize the relationship between lure emission and trap effectiveness.