Mark-release-recapture of males of Bactrocera cucurbitae and B. dorsalis (Diptera: Tephritidae) in two residential areas of Honolulu

Todd E. Shelly,James Edu 한국응용곤충학회 2010 Journal of Asia-Pacific Entomology Vol.13 No.2

This paper describes a mark-release-recapture study involving males of two economically important tephritid fruit flies (Diptera: Tephritidae), Bactrocera cucurbitae (Coquillett) and B. dorsalis (Hendel),conducted over a 2-year period in Honolulu, Hawaii. In each of two residential neighborhoods, we placed two traps, one baited with cue lure and the other with methyl eugenol (male attractants for B. cucurbitae and B. dorsalis, respectively), in a single tree. Dyed, mature males from recently established laboratory colonies were released 100 or 500 m from the traps along the four compass directions in both winter and summer seasons. In each neighborhood, a total of 5,600 flight-able males of each species were released 100 m from the traps (14 dates×4 directions×100 males/release) and 56,000 flight-able males of each species were released 500 m from the traps (14 dates×4 directions×1,000 males/release). Within each study area, the number of males trapped did not vary significantly with direction or season for either species for either the 100- or 500-m releases. Significantly higher numbers of B. dorsalis males were captured than B. cucurbitae males for both the 100-m (16 versus 8 males/release) and 500-m (7 versus 2 males/release) releases (average values computed over both study areas). Also, following their release, B. dorsalis males were, in general, trapped more quickly than B. cucurbitae males. Given the strong attractancy of methyl eugenol, trap captures for B. dorsalis were lower than expected, and possible explanations are discussed.

Zingerone and themating success and field attraction ofmalemelon flies (Diptera: Tephritidae)

Todd E. Shelly 한국응용곤충학회 2017 Journal of Asia-Pacific Entomology Vol.20 No.1

Males ofmany Dacina (Diptera: Tephritidae: Dacini) fruit fly species are attracted to either methyl eugenol (ME) or cue lure (CL) or its natural analogue raspberry ketone (RK). Recently, the compound zingerone (ZG) has also been shown to attract males of both ME- and CL/RK-responding Bactrocera species, and in the Queensland fruit fly, B. tryoni (Froggatt), males that fed on ZG had a mating advantage over non-fed males. The objective of this study was to determine whether ZG similarly enhanced mating success of CL/RK responding males of the melon fly, Zeugodacus cucurbitae (Coquillett) and to assess the relative attractiveness of CL and ZG to Z. cucurbitae males in the field. ZG was provided in 5 different formulations, including that used in the aforementioned work on B. tryoni.Mating trials were conducted in walk-in field cages containing potted plants, and in all cases 80 ZGfed (treated) males competedwith 80 control (non-fed)males formatings with 80 females. Contrary to B. tryoni, ZG did not confer a mating advantage to Z. cucurbitae males: the numbers of matings procured by treated and control males did not differ significantly for any of the 5 ZG formulations tested. A mark-release-recapture study showed that CL-baited traps significantly more Z. cucurbitae males than ZG-baited traps,whichwere, however, more attractive than control traps lacking any lure.

Capture of melon flies, Zeugodacus cucurbitae (Diptera: Tephritidae), in a food-baited Multilure trap: Influence of distance, diet, and sex

Todd E. Shelly,Nicholas C. Manoukis 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

Many countries operate trapping programs to detect invasions of pestiferous fruit fly species (Diptera:Tephritidae). Surveillance relies heavily on traps baited with male lures, which, while highly attractive, havelimited effectiveness, because (i) they are sex-specific and (ii) males of some species do not respond to the lurescurrently in use. For these reasons, detection programs also include food-baited traps that are neither sex- norspecies-specific. Compared to male lure-baited traps, however, few studies have measured the attractiveness offood-based traps. The present study describes a mark-release-recapture study conducted in a fruit orchard inHawaii that measured the attractiveness of a liquid protein hydrolysate-based (torula yeast/borax slurry) trap toadults of the melon fly Zeugodacus cucurbitae (Coquillett). Multiple release points were used at varying distancesfrom a single, central trap to generate estimates of distance-dependent capture probabilities. The potential influencesof sex and pre-release diet on capture probability were also examined. Flies were released at 14 d of ageand were maintained on one of four dietary regimes that offered a protein hydrolysate-rich diet for varyingintervals (i.e., 0, 3, 7, or 14 d, respectively). Recapture rates were similar between the sexes and over both sexesand all diets averaged 3.6%, 3.2%, and 0.6% for release distances of 10, 25, and 50 m, respectively. Pre-releasediet had a significant effect on recapture probability for releases at 10 and 25 m: flies fed sugar only or proteinhydrolysate-rich diet for only 3 d were captured more frequently than flies that had longer access to yeast extractprior to release.

Capture of Bactrocera fruit flies (Diptera: Tephritidae) in traps baited with liquid versus solid formulations of male lures

Todd E. Shelly,Rick Kurashima,Jon Nishimoto,A. Diaz,J. Leathers,D. Joseph,M. War 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.4

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 malespecific 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 timeconsuming,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

Additional measurements of distance-dependent capture probabilities for released males of Bactrocera cucurbitae and B. dorsalis (Diptera: Tephritidae) in Honolulu

Todd E. Shelly,Jon Nishimoto 한국응용곤충학회 2011 Journal of Asia-Pacific Entomology Vol.14 No.3

This paper describes a mark-release-recapture study involving males of two economically important fruit flies (Diptera: Tephritidae), Bactrocera cucurbitae (Coquillett) and B. dorsalis (Hendel), conducted in Honolulu,Hawaii. In each of three residential neighborhoods in Honolulu, we placed two traps, one baited with cue lure and the other with methyl eugenol (male attractants for B. cucurbitae and B. dorsalis, respectively), in a single tree. For both species, dyed, mature males from recently established laboratory colonies were released 25, 50,100, and 200 m from the traps along the four compass directions, and for B. dorsalis releases were also made 300 m from the traps. For both B. cucurbitae and B. dorsalis, the proportion of males captured varied significantly among study areas and among release distances. Averaged over the 3 sites, the percentage of released males captured varied from 14% for releases at 25 mto 0.5% for releases at 200 mfor B. cucurbitae and from 21% for releases at 25 m to 3% for releases at 300 m for B. dorsalis. In general, the capture rates of B. cucurbitae males were similar between California and Hawaii, whereas the captures rates of B. dorsalis males were significantly higher in California than Hawaii for all releases distances tested. Distance-dependent capture rates were used to estimate detection sensitivities for the two species under a trapping regime utilizing 5 cue lure- and 5 methyl eugenol-baited traps per 2.59 km^2 (as currently employed in California) and then compare these sensitivities between California and Hawaii.

Male lures and male mating competitiveness in a genetic sexing strain of the melon fly (Diptera: Tephritidae)

Todd E. Shelly 한국응용곤충학회 2019 Journal of Asia-Pacific Entomology Vol.22 No.2

The Sterile Insect Technique (SIT) has been used to suppress or eradicate populations of the melon fly, Zeugodacus cucurbitae (Coquillett), a pest of various fruits and vegetables throughout Asia, Africa, and South Pacific Islands. The success of the SIT depends largely on the ability of released, sterile males to compete successfully with wild males for copulations with wild females. Unfortunately, both the sterilization process (via gamma irradiation) and artificial selection under mass-rearing conditions generally reduce the biological competence, including the mating competitiveness, of the released males. However, previous data on Z. cucurbitae show that irradiation has minimal adverse effects and prolonged mass-rearing may or may not result in decreased mating ability. The present study first confirms that neither irradiation nor mass-rearing had deleterious effects on male mating ability of males from a pupal-color, genetic sexing strain (termed T1). Then, the influence of male lures (cue-lure and its natural analogue raspberry ketone) on the mating success of sterile T1 males was measured as a potential pre-release procedure to improve the effectiveness of SIT. Feeding on cue-lure enhanced male mating success, but the effect was short-lived (1 d but not 3 d post-feeding). Feeding on raspberry ketone boosted mating success over a longer time, i.e., at least 5 d but not 10 d post-feeding. However, mixing raspberry ketone into the adult diet had no detectable effect on male mating performance. The implications of these results for SIT against Z. cucurbitae are discussed.

Raspberry ketone-supplemented diet has no effect on fitness parameters or lure responsiveness in male melon flies, Zeugodacus cucurbitae (Diptera: Tephritidae)

Thomas J. Fezza,Todd E. Shelly 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.4

The male annihilation technique (MAT) and sterile insect technique (SIT) are often used to control pestiferous tephritid fruit flies (Diptera: Tephritidae). MAT involves the deployment of traps containing a male attractant and insecticide with the goal of drastically reducing male abundance and ultimately eliminating the entire population. SIT, which involves the mass production, sterilization, and release of the target species, may also be implemented to achieve final extirpation. Generally, simultaneous implementation of MAT and SIT is counterproductive, because the presence of large numbers of male-specific traps in the environment (MAT) would greatly reduce the number of sterile males available for copulating with wild females (SIT). However, studies on the Queensland fruit fly, Bactrocera tryoni (Froggatt), indicate that concurrent use of MAT and SIT may be feasible. Sexually mature males of B. tryoni are attracted to the raspberry ketone and its synthetic analogue cuelure. Males of B. tryoni fed raspberry-ketone-supplemented diet when newly emerged showed lower attraction to cue-lure baited traps than control males. In addition, newly emerged males provided this diet displayed accelerated sexual maturation, which would allow the early release of sterile males and reduce pre-release holding costs. Here, we examined whether the addition of raspberry ketone to the adult diet of male melon flies, Zeugodacus cucurbitae (Coquillett), produced effects similar to those observed for B. tryoni. Despite using similar methods, no significant effect of raspberry ketone-supplemented diet on time to sexual maturity, survival, mating competitiveness, or attraction to cue-lure baited traps in mass-reared Z. cucurbitae males.

Comparative rearing parameters for bisexual and genetic sexing strains of Zeugodacus cucurbitae and Bactrocera dorsalis (Diptera: Tephritidae) on an artificial diet

Thomas J. Fezza,Scott M. Geib,Todd E. Shelly 한국응용곤충학회 2018 Journal of Asia-Pacific Entomology Vol.21 No.1

The Sterile Insect Technique (SIT) is an important component of area wide programs to control invading orestablished populations of pestiferous tephritids. The SIT involves the production, sterilization, and release oflarge numbers of the target species, with the goal of obtaining sterile male x wild female matings, which yieldinfertile eggs. A major advance in SIT involved sex-linked, genetic manipulations that allowed the productionand release of male-only strains (also termed genetic sexing strains, GSS). The use of GSS avoids matings betweensterile males and females, which may divert males from seeking and mating with wild females, and studiesshow that male-only releases result in greater suppression of wild populations than standard bisexual releases(i.e., those including both males and females). GSS based on sex-linked pupal color exist for Zeugodacus cucurbitae(Coquillett) and Bactrocera dorsalis (Hendel), two important agricultural pest species, but their rearingcharacteristics have not been documented in detail. The goal of the present study was to compare the pupal colorsexing and bisexual strains for each of these species with respect to important rearing parameters, including eggproduction and eclosion of larvae from eggs (egg hatch), pupal recovery, and weight, emergence rate, and flightability. In both species, most of these parameters were significantly greater for the bisexual strain than the GSS,and, for a given number of eggs, the production of flight-capable adults was approximately 2 times greater in thebisexual strains of both species. The potential usefulness of GSS in SIT against Z. cucurbitae and B. dorsalis isassessed based on these findings.

Attraction of feral Bactrocera dorsalis males (Diptera: Tephritidae) to natural versus commercial sources of methyl eugenol

Tan Keng-Hong,Wee Suk-Ling,Nishida Ritsuo,Shelly Todd E. 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.4

Males of Bactrocera dorsalis (Hendel) are strongly attracted to methyl eugenol (ME), which occurs in over 450 plant species. Given this powerful attraction, ME is commonly used in surveillance and eradication programs against this invasive agricultural pest. Preliminary observations revealed that B. dorsalis males visited MEbearing flowers of the fruit fly orchid (FFO) Bulbophyllum cheiri subsp. cheiri even when these occurred near traps baited with far greater quantities of ME. Based on this evidence, we undertook field experiments to assess the attraction of feral B. dorsalis males to FFO flowers relative to commercial sources of ME. At the edge of a secondary forest, an FFO flower was placed midway between two ME sources located 20 m apart, and attracted flies were collected over an entire day. When the ME sources were unenclosed (not in traps), the relative attractiveness of FFO flowers to B. dorsalis males varied with the amount of ME placed nearby. The FFO flower (i) attracted a similar proportion of males when 1 g ME was placed at the flanking sites but (ii) captured signifi cantly smaller proportions when the nearby sites had 6 or 10 g commercial ME sources. Similar tests with the commercial sources enclosed in traps showed that (i) 6 g ME sources in Steiner traps attracted significantly more B. dorsalis males than FFO flowers but (ii) 10 g sources in Clear traps (1 L buckets with 4 entrance holes) did not outperform the FFO flowers, presumably owing to limited dispersion of volatiles from the trap. Implications of these results for surveillance programs are discussed.