Does Male Sexual Experience Influence Female Mate Choice and Reproduction in the Melon Fly (Diptera: Tephritidae)?

The mating experience of male insects can have significant effects on female fitness, particularly if prior copulations deplete stores of sperm and/or accessory gland products. Females of several tephritid fruit fly species appear to incur a cost - in terms of reduced longevity or reproductive success – by mating with non-virgin over virgin males. Despite these fitness costs, however, females do not always discriminate among males having different sexual experience. The present study had two objectives. First, mating trials were performed to determine whether virgin females of the melon fly Zeugodacus cucurbitae (Coquillett) discriminated between virgin and non-virgin (thrice-mated) males in selecting a mate. Second, survivorship, egg production and egg hatch rate were measured for females mated to virgin or non-virgin males to assess the impact, if any, of male mating experience on female lifespan and reproduction. Results showed that females did not discriminate among males based on their sexual experience and that female survival and reproduction were unaffected by male mating experience. These findings are compared with results obtained for other tephritid species

Capture of Mediterranean Fruit Flies and Melon Flies (Diptera: Tephritidae) in Food-Baited Traps in Hawaii

Food-based attractants are an important component of tephritid fruit fly detection programs, because they are general baits that are neither sex- nor species-specific. Two widely used food baits are enzymatic hydrolyzed torula yeast, which is presented as an aqueous solution that also serves to catch insects (wet trap), and a synthetic lure that combines ammomonium acetate, putrescine, and trimethylamine and may be presented with or without a water-based catch system. Recently, the liquid attractant CeraTrap, which is an enzymatic hydrolyzed animal protein, has been shown to be equally or more effective than traditional protein baits in capturing species of Anastrepha. The present study compares capture of wild Mediterranean fruit flies, Ceratitis capitata (Wiedemann), and melon flies, Zeugodacus cucurbitae (Coquillett) in traps baited with torula yeast or CeraTrap. In addition, one sampling interval compared the catch of C. capitata in wet traps baited with torula yeast, a synthetic food lure, or CeraTrap. CeraTrap was generally more effective in capturing both sexes of C. capitata than the other food baits, while torula yeast resulted in higher captures of Z. cucurbitae than CeraTrap. Results are compared with other trapping studies of tephritids involving food-based attractants

Capturing Males of Pestiferous Fruit Flies (Diptera: Tephritidae): Is the Combination of Triple-Lure Wafers and Insecticidal Strips as Effective as Standard Treatments?

The detection of invasive tephritid fruit fly pests relies primarily on traps baited with male-specific lures. Three different male lures are typically used, and accordingly three sets of traps are deployed: those baited with liquid methyl eugenol (ME) or liquid cue lure (CL) for different Bactrocera species and those baited with plug-bearing trimedlure (TML) for Ceratitis species. The liquid lures contain the insecticide naled, whereas the trimedlure plugs contain no toxicant. Preparing the liquid solutions and servicing three types of traps requires consid- erable labor, and handling naled (and possibly ME) introduces potential health risks. The purpose of this study was to compare the effectiveness of Jackson traps baited with a solid dispenser (wafer) containing all three male lures plus a separate insecticidal (DDVP; 2, 2-dichlorovinyl dimethyl phosphate) strip with Jackson traps baited with the standard male lure/toxicant combinations. Trapping was conducted during two 12-week periods in a coffee field on Oahu, Hawaii. The effectiveness of the wafer-baited traps varied among different species. Catch of Bactrocera dorsalis (Hendel) males was similar between wafer-baited and liquid ME-baited traps for both sampling periods. Conversely, traps baited with the standard TML plug captured significantly more Ceratitis capitata (Wiedemann) males than the wafer-baited traps in both sampling periods. The relative effectiveness of the two trap treatments varied between sampling periods for Bactrocera cucurbitae (Coquillett) males. Based on these results, the triple-lure wafer plus separate kill strip does not, at present, appear to be a viable substitute for the male lure/toxicant combinations currently in use

Trapping Male Melon Flies, Zeugodacus cucurbitae (Coquillett) (Diptera: Tephritidae), Using Mixtures of Zingerone and Cue-Lure in the Field

The males of many fruit flies (Diptera: Tephritidae) are strongly attracted to, and feed upon, a few natural compounds (and their synthetic analogs; commonly referred to as “lures”). Zingerone is a lure that has garnered recent attention for its use as an attractant for ecological surveys and pest management of select fruit flies. We investigated the attraction of male melon flies, Zeugodacus cucurbitae (Coquillett), to zingerone and mixtures of zingerone and cue-lure (the typical lure for this species) at a commercial farm on Oahu, Hawaii. Our findings indicate that zingerone and mixtures of zingerone and cue-lure are less attractive than cue-lure alone to male melon flies in the field, and the number of captured flies is positively and linearly correlated to the quantity of cue-lure in traps

Pre-Release Consumption of Methyl Eugenol Increases the Mating Competitiveness of Sterile Males of the Oriental Fruit Fly, Bactrocera dorsalis, in Large Field Enclosures

The sterile insect technique may be implemented to control populations of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), when environmental concerns preclude widespread use of chemical attractants or toxicants. The goal of the present study was to evaluate whether the mating competitiveness of sterile B. dorsalis males could be increased via pre-release feeding on methyl eugenol. Males of the oriental fruit fly are strongly attracted to this plant-borne compound, which they ingest and use in the synthesis of the sex pheromone. Previous studies conducted in the laboratory and small field-cages have shown that males given methyl eugenol produce a more attractive pheromone for females and have a higher mating success rate than males denied methyl eugenol. Here, levels of egg sterility were compared following the release of wild-like flies and either methyl eugenol-fed (treated) or methyl eugenol-deprived (control) sterile males in large field enclosures at four over flooding ratios ranging from 5:1 to 60:1 (sterile: wild-like males). Treated sterile males were fed methyl eugenol for 1–4 h (depending on the over flooding ratio tested) 3 d prior to release. Eggs were dissected from introduced fruits (apples), incubated in the laboratory, and scored for hatch rate. The effect of methyl eugenol was most pronounced at lower over flooding ratios. At the 5:1 and 10:1 over flooding ratios, the level of egg sterility observed for treated, sterile males was significantly greater than that observed for control, sterile males. In addition, the incidence of egg sterility reported for treated sterile males at these lower over flooding ratios was similar to that noted for treated or control sterile males at the 30:1 or 60:1 over flooding ratios. This latter result, in particular, suggests that pre-release feeding on methyl eugenol allows for a reduction in the number of sterile flies that are produced and released, thus increasing the cost-effectiveness of the sterile insect technique

Plant chemicals and the sexual behavior of male tephritid fruit flies

Plant compounds affect insects in many different ways. In addition to being a food source, plants also contain secondary metabolites that may have positive and negative impacts on insects. The influence of these compounds on sexual behavior, in particular, has been the focus of many recent studies. Here, we review the existing literature on the effects of plant compounds on the sexual behavior of tephritid fruit fly males. We put special focus on polyphagous species whose males congregate in leks, where females exert strong mate selection. We first summarize the main findings related to plant compounds that increase male signaling behavior and attraction of females and consequently increase mating frequency, a phenomenon that has been recorded mainly for species of Anastrepha and Ceratitis. In other tephritid species, males are attracted to phenylpropanoids produced by plants (such as methyl eugenol or raspberry ketone) that, upon encounter, are consumed and sequestered by males. These compounds, or metabolic derivatives, which normally have negligible nutritional value, are included in the pheromone and also confer advantages in a sexual context: enhanced female attraction and improved male mating success. These phenomena have been reported for several Bactrocera species as well as for Zeugodacus cucurbitae. Because many tephritid species are serious pests, the effect of plant compounds on male behavior has been explored for potential incorporation into control strategies such as the sterile insect technique (SIT). We conclude noting several factors, such as age and nutrition during larval and adult stage, that modulate the effect of plant compounds on male mating behavior as well as some prominent gaps that preclude a thorough understanding of the plant-mediated enhancement of male sexual performance and hence limit our ability to effectively utilize phytochemicals in pest control strategies.Instituto de GenéticaFil: Segura, Diego Fernando. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Belliard, Silvina A. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera, María Teresa. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Bachmann, Guillermo Enrique. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ruiz, María Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; ArgentinaFil: Jofre-Barud, Flavia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fernández, Patricia. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lopez, M. Liza. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria San Juan; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Shelly, Todd E. United States Department of Agriculture. Animal and Plant Health Inspection Service; Estados Unido

Mate choice confers direct benefits to females of Anastrepha fraterculus (Diptera: Tephritidae)

Exposure to plant compounds and analogues of juvenile hormone (JH) increase male mating success in several species of tephritid fruit flies. Most of these species exhibit a lek mating system, characterized by active female choice. Although the pattern of enhanced male mating success is evident, few studies have investigated what benefits, if any, females gain via choice of exposed males in the lek mating system. In the South American fruit fly, Anastrepha fraterculus, females mate preferentially with males that were exposed to volatiles released by guava fruit or treated with methoprene (a JH analogue). Here, we tested the hypothesis that female choice confers direct fitness benefits in terms of fecundity and fertility. We first carried out mate choice experiments presenting females with males treated and non-treated with guava volatiles or, alternatively, treated and non-treated with methoprene. After we confirmed female preference for treated males, we compared the fecundity and fertility between females mated with treated males and non-treated ones. We found that A. fraterculus females that mated with males exposed to guava volatiles showed higher fecundity than females mated to non-exposed males. On the other hand, females that mated methoprene-treated males showed no evidence of direct benefits. Our findings represent the first evidence of a direct benefit associated to female preference for males that were exposed to host fruit odors in tephritid fruit flies. Differences between the two treatments are discussed in evolutionary and pest management terms.Fil: Bachmann, Guillermo Enrique. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo.; ArgentinaFil: Devescovi, Francisco. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo.; ArgentinaFil: Nussenbaum, Ana Laura. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo.; ArgentinaFil: Milla, Fabian Horacio. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo.; ArgentinaFil: Shelly, Todd E.. Animal and Plant Health Inspection Service; Estados UnidosFil: Cladera, Jorge Luis. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo.; ArgentinaFil: Fernandez, Patricia Carina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires Norte. Estación Experimental Agropecuaria Delta del Paraná; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Vera, María Teresa. Universidad Nacional de Tucumán. Facultad de Agronomía y Zootecnia; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Segura, Diego Fernando. Instituto Nacional de Tecnologia Agropecuaria. Centro de Investigacion En Ciencias Veterinarias y Agronomicas. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo | Consejo Nacional de Investigaciones Cientificas y Tecnicas. Oficina de Coordinacion Administrativa Pque. Centenario. Instituto de Agrobiotecnologia y Biologia Molecular. Grupo Vinculado Instituto de Genetica "ewald A. Favret" Al Iabimo.; Argentin

Effects of Raspberry Ketone on the Mating Success of Male Melon Flies (Diptera: Tephritidae)

Laboratory tests were conducted to determine whether feeding on raspberry ketone affected the mating success of male melon flies, Bactrocera cucurbitae (Coquillett). The effect of this chemical was time-dependent. Males exposed to raspberry ketone obtained a disproportionately small number of matings when tested on the day of exposure but a disproportionately large number of matings when tested 1 d after exposure. The chemical had no detectable effect on mating frequency in tests conducted 3 d or 7 d after feeding by the treated males. Males exposed to raspberry ketone were less likely to be captured in traps than unexposed males. These results are compared with similar studies on other tephritids