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Buenos Aires, Argentina

Abraham S.,Catedra de Terapeutica Vegetal | Abraham S.,CONICET | Goane L.,Seccion Zoologia Agricola | Goane L.,CONICET | And 5 more authors.
Entomologia Experimentalis et Applicata | Year: 2011

The occurrence of female remating has been widely reported in insects and the frequency at which it occurs and the factors driving females' remating behavior have been shown to be both species specific and variable within species. Herein, we studied the remating behavior of females from a well established laboratory colony and a wild population of the South American fruit fly, Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae), under laboratory conditions. Latency to first mating (number of days from the onset of the experiment until the first copula) was shorter for remating females than for females that did not remate. Two-day fecundity was higher for females that did remate than for monogamous females. Egg hatch was sustained after remating and was not affected by the number of times the female mated. However, when females willing to remate were prevented from doing so, percent egg hatch showed a significant drop. These results and the fact that remating occurred more often in more fecund females than in less fecund ones suggest that remating may be a response to sperm depletion. Remating frequency was similar in laboratory and wild flies, but 2-day fecundity was higher for laboratory than for wild females of similar mating status. Also, the length of the refractory period (time between first and second copulation) was longer for wild than for laboratory females. Differences between strains could be the result of artificial selection. Results are discussed from a theoretical and applied perspective in the context of direct benefits to females. © 2011 The Authors. Entomologia Experimentalis et Applicata © 2011 The Netherlands Entomological Society.

Schutze M.K.,Cooperative Research Center for National Plant Biosecurity | Schutze M.K.,Queensland University of Technology | Jessup A.,International Atomic Energy Agency | Jessup A.,Australian Department of Primary Industries and Fisheries | And 7 more authors.
Journal of Economic Entomology | Year: 2013

Bactrocera dorsalis (Hendel), Bactrocera papayae Drew & Hancock, Bactrocera philippinensis Drew & Hancock, and Bactrocera carambolae Drew & Hancock are pest members within the B. dorsalis species complex of tropical fruit flies. The species status of these taxa is unclear and this confounds quarantine, pest management, and general research. Mating studies carried out under uniform experimental conditions are required as part of resolving their species limits. These four taxa were collected from the wild and established as laboratory cultures for which we subsequently determined levels of prezygotic compatibility, assessed by field cage mating trials for all pair-wise combinations. We demonstrate random mating among all pair-wise combinations involving B. dorsalis, B. papayae, and B. philippinensis. B. carambolae was relatively incompatible with each of these species as evidenced by nonrandom mating for all crosses. Reasons for incompatibility involving B. carambolae remain unclear; however, we observed differences in the location of couples in the field cage for some comparisons. Alongside other factors such as pheromone composition or other courtship signals, this may lead to reduced interspecific mating compatibility with B. carambolae. These data add to evidence that B. dorsalis, B. papayae, and B. philippinensis represent the same biological species, while B. carambolae remains sufficiently different to maintain its current taxonomic identity. This poses significant implications for this group's systematics, impacting on pest management, and international trade. © 2013 Entomological Society of America.

Devescovi F.,Instituto Nacional de Tecnologia Agropecuaria | Abraham S.,Laboratory Of Investigaciones Ecoetologicas Demoscas Of La Fruta Y Sus Enemigos Naturales Liemen | Roriz A.K.P.,Federal University of Bahia | Nolazco N.,Laboratorios Of Sanidad Vegetal Senasa | And 8 more authors.
Entomologia Experimentalis et Applicata | Year: 2014

The Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) cryptic species complex is currently composed of seven taxonomically recognized morphotypes. Both, pre- and post-zygotic isolation has been documented among four of these morphotypes, revealing that in fact they appear to be distinct biological entities. In order to progress in the full delimitation of species within the complex, we examined reproductive isolation between a Colombian population of the Andean morphotype and populations belonging to four other morphotypes spanning from Mexico to Argentina. Flies from the Andean morphotype exhibited strong pre-zygoticmating isolation through temporal partitioning of mating activity. Post-zygotic isolation was observed for crosses of males of all morphotypes and Andeanmorphotype females, yetmost of the F1 hybrid? 9 F1 hybrid?self-crosses showed normal levels of fertility, a finding suggesting a nuclear-cytoplasmic interaction according to previous studies. Overall, the Andean morphotype within the complex also appears to be a distinct biological entity. We discuss the implications of these findings for the understanding of speciation mechanisms in the Neotropical genus Anastrepha. © 2014 The Netherlands Entomological Society.

Abraham S.,Laboratorio Of Investigaciones Ecoetologicas Of Moscas Of La Fruta Y Sus Enemigos Naturales | Abraham S.,CONICET | Rull J.,Institute Ecologia | Mendoza M.,Catedra de Terapeutica Vegetal | And 9 more authors.
Bulletin of Entomological Research | Year: 2014

The South American fruit fly, Anastrepha fraterculus, is a complex of cryptic species composed of at least seven morphotypes. Some of them, such as the Peruvian and Brazilian 1 morphotypes (which include Argentinean populations), exhibit strong pre-copulatory isolation, yet it is possible to obtain heterotypic crosses when forcing copulation of adults under laboratory conditions. The cross involving Peruvian males and Argentinean females produces F1 offspring with reduced viability in terms of egg hatch. This low hatchability could be caused by a reduced amount of sperm transferred to and stored by females mated with heterotypic males, which in turn could affect their post-copulatory behaviour. To test these hypotheses, we investigated sperm transfer and female mating and remating behaviour for homotypic and heterotypic crosses between adults of two morphotypes (Brazilian 1 [Argentina] and Peruvian [Peru]) of the A. fraterculus cryptic species complex. As reported before, Argentinean males and females mated earlier in the day than the other three mating combinations. Peruvian females engaged in shorter copulation times than Argentinean females. Peruvian females tended to store smaller quantities of sperm than Argentinean females, and almost a half of the crosses involving Argentinean males and Peruvian females were unsuccessful (no sperm transfer). However, there was no evidence that the cross between Peruvian males and Argentinean females resulted in storage of a critically small amount of sperm (posing risk of sperm shortage). Argentinean females were more willing to remate than Peruvian females, irrespective of male morphotype, but latency to remating was not affected by male or female morphotype. This study shows that mating behaviour differs between some of the A. fraterculus complex morphotypes, with female but not male morphotype determining female likelihood to remate. Copyright © 2013 Cambridge University Press.

Rull J.,Institute Ecologia | Abraham S.,Catedra de Terapeutica Vegetal | Abraham S.,CONICET | Kovaleski A.,Embrapa Uva e Vinho | And 9 more authors.
Bulletin of Entomological Research | Year: 2012

As a prerequisite for area-wide application of the sterile insect technique in an area encompassing northern Argentina and southern Brazil, prezygotic and postzygotic reproductive compatibility among three geographically distant populations in the area was tested. In field cages, sexually mature adults of each population were found to be sexually compatible, mating duration was not affected by fly origin and there was no clear evidence of spatial partition of mating location. In the laboratory, homotypic and heterotypic crosses for all possible combinations displayed similar levels of fertility and yielded F1 adults without distortion of the sex ratio. Finally, F1 hybrid and parental adults produced equally viable F2 eggs. Put together, our results and those from earlier studies suggest that a large area, ranging from Buenos Aires to the surroundings of São Paulo, could be managed using a single A. fraterculus mass-reared strain. At the northern margin of this area, two A. fraterculus morphotypes appear to coexist in sympatry. We delineate future research to further delimit the distribution of the aff1 morphotype (Argentina-southern Brazil) and to gain insight into evolutionary patterns producing divergence and radiation of tropical fruit fly species. © 2012 Cambridge University Press.

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