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

A New Eye Mutant, apricot, of the Oriental Fruit Fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), and its Mating Preference

Genetic crossing experiments of the apricot eye (ap) mutant, discovered in a recently introduced laboratory colony of Bactrocera dorsalis (Hendel), demonstrated that it was inherited as an autosomal recessive gene. Mating preference tests showed that both apricot eye females and wild-type females preferred to male with males of their own strains. However, only wild-type males were highly successful in mating with both types of females

Sexual communication in the oriental fruit fly, Dacus dorsalis Hendel (Diptera: Tephritidae)

Typescript.Thesis (Ph. D.)--University of Hawaii at Manoa, 1988.Includes bibliographical references.Microfiche.xii, 126 leaves, bound ill. 29 cmResults of the research on sexual communication in the Oriental fruit fly, Dacus dorsalis were reported in three chapters: 1) description and details of its sexual behavior, 2) determination of the significance of sexual signals for attracting members of the opposite sex and in successful mating, and 3) identification of the behavioral characteristics which make males attractive and successful in mating with females. Three major components in the sexual behavior included: 1) signal emission through male wing-fanning followed by the arrival of females; 2) courtship behavior involving male wing-fanning followed by attempted copulations; and 3) copulation. Further tests also showed that females that had mated once neither were attracted to males nor accepted Subsequent matings as readily as virgin females. By modifying either the male's ability in emitting sexual signals, i.e. modification of wing fanning, or the various sensory receptors in the females, i.e. the eyes for visual signals, the aristae for acoustic stimuli, and the antennae for olfactory cues, it was possible to investigate the separate modalities of sexual communication during the 1) attraction phase (i.e. the bringing together of the two sexes over a distance of about 50 cm), and the 2) courtship phase (i.e. signal emission at close range of about 6 cm). The wing fanning in males was found to play a significant role in the production of signals for the attraction of and mating with females. Experiments conducted in the females showed that acoustic as well as olfactory signals were crucial in attracting females to wing-fanning males, but only olfactory stimuli were important for mating acceptance of the females. Differential sexual success among males and female choice played an important role in the complex mating system in this species. Sexual success in males was measured in terms of ability to attract and mate with females. For the most part, both qualities could be found in the same male. It was also found that sexually successful males had the capability of signaling for a longer duration, and had the top rank in male-male aggressive interactions more frequently than other males. Thus, intermale competition could possibly be another component of sexual selection operating in this species. The results of this study provide baseline information that will be important for the development of more effective control and/or eradication methods for D. dorsalis as well as other related species

Sexual Selection in a Tropical Fruit Fly: Role of a Plant Derived Chemical in Mate Choice

The specific mechanisms by which selective pressures affect individuals are often difficult to resolve. In tephritid fruit flies, males respond strongly and positively to certain plant derived chemicals. Sexual selection by female choice has been hypothesized as the mechanism driving this behaviour in certain species, as females preferentially mate with males that have fed on these chemicals. This hypothesis is, to date, based on studies of only very few species and its generality is largely untested. We tested the hypothesis on different spatial scales (small cage and seminatural field-cage) using the monophagous fruit fly, Bactrocera cacuminata. This species is known to respond to methyl eugenol (ME), a chemical found in many plant species and one upon which previous studies have focused. Contrary to expectation, no obvious female choice was apparent in selecting ME-fed males over unfed males as measured by the number of matings achieved over time, copulation duration, or time of copulation initiation. However, the number of matings achieved by ME-fed males was significantly greater than unfed males 16 and 32 days after exposure to ME in small cages (but not in a field-cage). This delayed advantage suggests that ME may not influence the pheromone system of B. cacuminata but may have other consequences, acting on some other fitness consequence (e.g., enhancement of physiology or survival) of male exposure to these chemicals. We discuss the ecological and evolutionary implications of our findings to explore alternate hypotheses to explain the patterns of response of dacine fruit flies to specific plant-derived chemicals

Erratum: Influence of local and regional sources on the observed variability in the concentration levels of fine and coarse atmospheric aerosol water-soluble species in Athens (Environmental Monitoring and Assessment)

Close-range courtship behaviours are a critical element of a species’ biology but, if rapid, can often be overlooked. Beyond male chemical and audio calling, close-range courtship interactions leading to copulation in the Queensland fruit fly Bactrocera tryoni are unknown; this may be due to a true absence or because they have been overlooked and not previously investigated.We sought to resolve the close-range courtship sequence of B. tryoni and construct an ethogram of identified behaviours. Close-range video recordings of B. tryoni courtship were taken during the dusk mating window and an ethogram constructed by combining all observed behaviours which led to successful copulation and unsuccessful copulation. While the previously well-recognised male wing fanning behaviour was documented, a number of other behaviours were identified for the first time in B. tryoni courtship, including female ovipositor extension, and both male and female synchronous supination, face-to-face contact, and fore- and hind leg interactions. Analyses showed that the total duration of male synchronous supination, but not the number of occurrences, differed significantly between successful and unsuccessful males. Male foreleg interaction with the female abdomen was significantly different in both total duration and total number of occurrences between successful and unsuccessful males. The results reinforce data obtained from other Bactrocera species of simplified courtship sequences in these flies in comparison with other tephritid genera, but nevertheless courtship is more complex than previously recognised