Capture of Bactrocera fruit flies (Diptera: Tephritidae) in traps baited with liquid versus solid formulations of male lures Todd E. Shelly a, ⁎, Rick Kurashima a , Jon Nishimoto a , A. Diaz b , J. Leathers c , M. War c , D. Joseph b a USDA-APHIS, 41-650 Ahiki St., Waimanalo, HI 96795, USA b California Department of Food and Agriculture, 935 E. Discovery Lane, Anaheim, CA 92801, USA c California Department of Food and Agriculture, 3802 Constitution Ave., Los Alamitos, CA 90720, USA abstract article info Article history: Received 26 May 2011 Revised 20 July 2011 Accepted 21 July 2011 Available online 29 July 2011 Keywords: Bactrocera dorsalis Bactrocera cucurbitae Detection Invasive pests Trapping Bactrocera dorsalis (Hendel) and B. cucurbitae (Coquillett) (Diptera: Tephritidae) are important agricultural pests of the Pacific region. Detection and control of these species rely largely on traps baited with male- specific attractants (parapheromones), namely methyl eugenol for B. dorsalis and cue lure for B. cucurbitae. Presently, these lures (plus naled, an insecticide) are applied in liquid form, although this procedure is time- consuming, and naled as well as methyl eugenol may pose human health risks. Recently, a solid formulation (termed a wafer) has been developed that contains both male lures (plus DDVP, an insecticide), and here we present data from field tests in California and Hawaii that compare the effectiveness of liquid versus solid formulations of the lures in capturing marked, released males of these two Bactrocera species. For both species and in both California and Hawaii, traps baited with the solid formulation of the male lure captured similar or significantly more released flies than the liquid formulation for both fresh and aged baits. Traps in Hawaii also captured wild (unmarked) males of both B. dorsalis and B. cucurbitae, and the results obtained for wild flies were similar to those recorded for released flies for both species. Collectively, the results presented suggest that the solid dispenser of the male lures constitutes a reliable substitute for the liquid formulation in detecting incipient Bactrocera outbreaks. © Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society, 2011. Published by Elsevier B.V. All rights reserved. Introduction The genus Bactrocera (Diptera: Tephritidae) contains ≈ 500 described species, most of which are endemic to Southeast Asia and South Pacific Islands (Drew and Hancock, 2000). Approximately 70 polyphagous Bactrocera attack fruit and vegetable crops and are a serious impediment to agriculture (Clarke et al., 2005; White and Elson-Harris, 1992). Although most species in the genus have limited geographic distributions, several species are invasive, and among these, the oriental fruit fly, B. dorsalis (Hendel), and the melon fly, B. cucurbitae (Coquillett), pose serious threats to agriculture owing to their broad host ranges. Females of both species oviposit in well over 100 different plant species, with B. dorsalis infesting such commer- cially important crops as mango (Mangifera indica L.), papaya (Carica papaya L.), sweet orange (Citrus sinensis (L.) Osbeck), and common guava (Psidium guajava L.) and B. cucurbitae infesting zucchini (Cucurbita pepo L.), pumpkin (C. maxima Duchesne), honeydew, Cucumis melo L. and watermelon, Citrullus lanatus (Thunb.) among others (White and Elson-Harris, 1992). Many countries operate continuous trapping programs to detect incipient infestations of invasive Bactrocera. Males of many Bactrocera species respond to particular chemicals termed male lures or parapheromones (Cunningham, 1989), and these have been incorpo- rated in surveillance programs worldwide (Gonzalez and Troncoso, 2007). Among lure-responding species, males of a given species are attracted to either methyl eugenol (ME) or raspberry ketone (RK) (or its synthetic acetyl-analog, cue lure [CL]) but not both (Drew, 1974; Drew and Hooper, 1981). Accordingly, surveillance programs typically operate both ME- and CL-baited traps. In southern California, for example, five traps of each lure type are maintained per 2.6 km 2 (1 mile 2 ) over an area of ≈6400 km 2 (2500 miles 2 ), yielding 12,500 traps per lure type over the entire sampling area (IPRFFSP, 2006). At present, in both California and Florida, ME and CL are applied as liquids to cotton wicks positioned inside traps. Moreover, the insecticide naled is usually added (also in liquid form) to the lures before application to the cotton wicks. Thus, the current procedure involves considerable handling time for measuring and applying the liquids as well as potential health risks resulting from accidental contact or ingestion of the insecticide. In addition, data derived from rodents suggest that ME itself may be carcinogenic, as subjects administered high doses showed increased incidence of liver cancer and mortality (National Toxicology Program, 2000). This result does not necessarily Journal of Asia-Pacific Entomology 14 (2011) 463–467 ⁎ Corresponding author. E-mail address: todd.e.shelly@aphis.usda.gov (T.E. Shelly). 1226-8615/$ – see front matter © Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society, 2011. Published by Elsevier B.V. All rights reserved. doi:10.1016/j.aspen.2011.07.006 Contents lists available at ScienceDirect Journal of Asia-Pacific Entomology journal homepage: www.elsevier.com/locate/jape