Seccion Zoologia Agricola

San Miguel de Tucumán, Argentina

Seccion Zoologia Agricola

San Miguel de Tucumán, Argentina
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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.


Abraham S.,Seccion Zoologia Agricola | Abraham S.,CONICET | Cladera J.,Instituto Nacional de Tecnologia Agropecuaria | Goane L.,Seccion Zoologia Agricola | And 3 more authors.
Journal of Insect Physiology | Year: 2012

In the context of the sterile insect technique (SIT), mass-rearing and male irradiation are imperative. Post-teneral treatments such as the addition of protein in adult's male diet and male hormonal treatment are used to improve sexual performance and to accelerate sexual maturation. In this work we investigated the effect of male accessory glands products (AGPs) on female receptivity of the South American fruit fly Anastrepha fraterculus (Wiedemann), and the effect of strain rearing history, male irradiation, male diet and hormonal treatment on AGPs. Injections of aqueous extracts of male accessory glands into the abdomen of females reduced their receptivity. The AGPs from laboratory males were more effective in inhibiting female receptivity, compared to AGPs from wild males, irrespective of females' origin. The AGPs from fertile males were more effective than AGPs from sterile males. The AGPs from protein-fed males were more effective than AGPs from sugar-fed males. Finally, the AGPs of males treated with juvenile hormone were less effective in inhibiting female receptivity than AGPs of untreated males. We conclude that inhibition of sexual receptivity of A. fraterculus mated females is mediated by products in male accessory gland's and the way that these products act vary widely according to the effect of extrinsic factors. We discuss the results in the perspective of the SIT application for A. fraterculus. © 2011 Elsevier Ltd.


Abraham S.,Seccion Zoologia Agricola | Abraham S.,CONICET | Goane L.,Seccion Zoologia Agricola | Goane L.,CONICET | And 3 more authors.
Journal of Insect Physiology | Year: 2011

Male physiological condition can affect his ability to modulate female sexual receptivity. Thus, studying this aspect can have biological and practical implications. Here, we examine how male nutritional status affected the amount of sperm stored, remating rate and refractory period of the tephritid fruit fly Anastrepha fraterculus (Wiedemann) females. Both wild and laboratory flies were evaluated. We also examine female sperm storage patterns. Experiments were carried out by manipulating male adult diet and exposing these males to virgin females. Females mated with differently treated males were either dissected to count the amount of sperm stored or exposed to virgin males to determine remating rate and the length of the refractory period. We found that male nutritional status affected the amount of the sperm stored and the renewal of sexual receptivity in wild flies. For laboratory flies, male nutritional status affected the length of the refractory period but not the amount of sperm stored by females. In addition, we report that the ventral receptacle is not an important organ of sperm storage in this species. We conclude that male nutritional condition influences the ability to modulate female sexual receptivity, possibly through a combination of the quantity and quality of the ejaculate. From an applied perspective, providing males with an enriched diet will likely result in increased efficacy of the sterile insect technique. © 2011 Elsevier Ltd.


Cazado L.E.,Seccion Zoologia Agricola | Cazado L.E.,CONICET | Murua M.G.,Seccion Zoologia Agricola | Murua M.G.,CONICET | And 6 more authors.
Florida Entomologist | Year: 2013

Rhyssomatus subtilis, the black soybean weevil, has emerged as a major pest of soybean [Glycine max (L.) Merr. (Fabales: Fabaceae)] in northwestern Argentina during the last 3 yr. This species was detected in 30 localities of Salta, Santiago del Estero and Tucumán provinces comprising a total area of about 541,000 ha. This species was observed for the first time developing on dry bean [Phaseolus vulgaris L. (Fabales: Fabaceae)] crops and feeding on 3 unrelated weeds [Conyza bonariensis (L.) Cronquist (Asterales: Asteraceae), Brassica campestris (L.) Metzg. (Brassicales: Brassicaceae) and Sphaeralcea bonariensis (Cav.) Griseb (Malvales: Malvaceae)]. The damage produced by R. subtilis in dry bean crops is similar to that produced in soybean crops. The results obtained suggest that as of 2012, R. subtilis has greatly expanded its distribution since its first detection in 2006 and produces major direct and indirect damage in soybean and dry bean crops in northwestern Argentina.


Unbehend M.,Max Planck Institute for Chemical Ecology | Hanniger S.,Max Planck Institute for Chemical Ecology | Vasquez G.M.,North Carolina State University | Juarez M.L.,Seccion Zoologia Agricola | And 7 more authors.
PLoS ONE | Year: 2014

The corn- and rice-strains of Spodoptera frugiperda exhibit several genetic and behavioral differences and appear to be undergoing ecological speciation in sympatry. Previous studies reported conflicting results when investigating male attraction to pheromone lures in different regions, but this could have been due to inter-strain and/or geographic differences. Therefore, we investigated whether corn- and rice-strain males differed in their response to different synthetic pheromone blends in different regions in North America, the Caribbean and South America. All trapped males were straintyped by two strain-specific mitochondrial DNA markers. In the first experiment, we found a nearly similar response of cornand rice-strain males to two different 4-component blends, resembling the corn- and rice-strain female blend we previously described from females in Florida. This response showed some geographic variation in fields in Canada, North Carolina, Florida, Puerto Rico, and South America (Peru, Argentina). In dose-response experiments with the critical secondary sex pheromone component (Z)-7-dodecenyl acetate (Z7-12:OAc), we found some strain-specific differences in male attraction. While the response to Z7-12:OAc varied geographically in the corn-strain, rice-strain males showed almost no variation. We also found that the minor compound (Z)-11-hexadecenyl acetate (Z11-16:OAc) did not increase attraction of both strains in Florida and of corn-strain males in Peru. In a fourth experiment, where we added the stereo-isomer of the critical sex pheromone component, (E)-7-dodecenyl acetate, to the major pheromone component (Z)-9-tetradecenyl acetate (Z9- 14:OAc), we found that this compound was attractive to males in North Carolina, but not to males in Peru. Overall, our results suggest that both strains show rather geographic than strain-specific differences in their response to pheromone lures, and that regional sexual communication differences might cause geographic differentiation between populations. © 2014 Unbehend et al.


De Leon J.H.,U.S. Department of Agriculture | Setamou M.,Texas A&M University-Kingsville | Gastaminza G.A.,Seccion Zoologia Agricola | Buenahora J.,Instituto Nacional Of Investigacion Agropecuaria Inia | And 4 more authors.
Annals of the Entomological Society of America | Year: 2011

A phylogeographic analysis inferred from the partial mitochondrial cytochrome oxidase subunit I gene (433 bp) was performed with 22 populations of Diaphorina citri Kuwayama collected in the Americas and one in the Pacific. Eight populations from four countries in South America, 14 from four countries in North America, and one from Hawaii were analyzed. Twenty-three haplotypes (hp) were identified and they fell into two groups: hp1-8 were identified in South America (group 1) and hp9-23 were identified in North America and Hawaii (group 2). Hp1 and nine were present in the highest frequencies within each population and within their group, 81 and 85% for group 1 and group 2, respectively. A diagnostic nucleotide at position 48 was identified that allowed for the discrimination of the two groups; in addition, no haplotypes were shared between the two groups. An analysis of molecular variance uncovered significant genetic structure (Φ CT = 0.733; P < 0.001) between the two groups of the Americas. Two haplotype networks (ParsimonySplits and Statistical Parsimony) discriminated the two groups and both networks identified hp1 and nine as the predicted ancestral or founding haplotypes within their respective group. The data suggest that two separate introductions or founding events of D. citri occurred in the Americas, one in South America and one in North America. Furthermore, North America and Hawaii appear to share a similar source of invasion. These data may be important to the development of biological control programs against D. citri in the Americas.


Juarez M.L.,National University of Tucuman | Juarez M.L.,CONICET | Schofl G.,Leibniz Institute for Natural Product Research and Infection Biology | Vera M.T.,National University of Tucuman | And 9 more authors.
Entomologia Experimentalis et Applicata | Year: 2014

Determining which factors contribute to the formation and maintenance of genetic divergence to evaluate their relative importance as a cause of biological differentiation is among the major challenges in evolutionary biology. In Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) two host strains have been recognized in the 1980s: the corn-strain prefers maize, sorghum, and cotton, whereas the rice-strain prefers rice and wild grasses. However, it is not clear to what extent these so-called 'strains', which have also been called 'host races' or even 'sibling species', are really associated with host plants. Due to the indeterminate evolutionary status, we will use the term 'host forms' (sensu Funk). Here, we characterized populations collected from maize, rice, and wild grasses from three countries in South America. Using two mitochondrial cytochrome oxidase I (mtCOI) markers and 10 polymorphisms in the triose phosphate isomerase (Tpi) gene, we found various patterns of host association. Two hundred twenty-seven nuclear amplified fragment length polymorphisms (AFLPs) markers revealed significant genetic differentiation among populations, which was generally correlated to the host from which the larvae were collected. Using a multivariate discriminant analysis and a Bayesian clustering approach, we found that individuals could be grouped into 2-5 genetically distinct clusters, depending on the method. Together, our results indicate that although host-associated differentiation is present in this species, it does not account for all observable genetic variation and other factors must be maintaining genetic differentiation between these forms. Therefore, the term 'host strains' should be abandoned and 'host forms' should be used instead for S. frugiperda. © 2014 The Netherlands Entomological Society.


Vera M.T.,Seccion Zoologia Agricola | Vera M.T.,CONICET | Ruiz M.J.,Seccion Zoologia Agricola | Ruiz M.J.,CONICET | And 9 more authors.
Journal of Applied Entomology | Year: 2013

Although exposure to plants has been shown to influence sexual behaviour in a number of phytophagous insect species, a relatively small number of fruit flies have been investigated in that respect. Here, we evaluated the effect of exposure to the pulp of guava and mango and to essential oils emanating from glands in the flavedo area of lemons on the mating success of Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae) males. We also evaluated different durations of exposure and the need for physical contact with the fruit. Results showed that exposure to guava increased the mating success of both wild and laboratory males relative to non-exposed males. In addition, exposed wild flies copulated earlier than non-exposed males. Physical contact with the fruit or ingestion of compounds was not a prerequisite for this phenomenon to occur, since just the exposure to volatiles resulted in a significant enhancement in mating success. Exposure to mango did not affect male sexual performance. In contrast, exposure to lemon for 1day decreased mating success of males relative to unexposed males, whereas exposure for longer periods seemed to eliminate this effect resulting in comparable mating success rates between treated and untreated males. These results provide a better understanding of the sexual behaviour of this species and may also find application for its control. © 2010 Blackwell Verlag, GmbH.


PubMed | Seccion Zoologia Agricola
Type: Journal Article | Journal: Journal of insect physiology | Year: 2011

In the context of the sterile insect technique (SIT), mass-rearing and male irradiation are imperative. Post-teneral treatments such as the addition of protein in adults male diet and male hormonal treatment are used to improve sexual performance and to accelerate sexual maturation. In this work we investigated the effect of male accessory glands products (AGPs) on female receptivity of the South American fruit fly Anastrepha fraterculus (Wiedemann), and the effect of strain rearing history, male irradiation, male diet and hormonal treatment on AGPs. Injections of aqueous extracts of male accessory glands into the abdomen of females reduced their receptivity. The AGPs from laboratory males were more effective in inhibiting female receptivity, compared to AGPs from wild males, irrespective of females origin. The AGPs from fertile males were more effective than AGPs from sterile males. The AGPs from protein-fed males were more effective than AGPs from sugar-fed males. Finally, the AGPs of males treated with juvenile hormone were less effective in inhibiting female receptivity than AGPs of untreated males. We conclude that inhibition of sexual receptivity of A. fraterculus mated females is mediated by products in male accessory glands and the way that these products act vary widely according to the effect of extrinsic factors. We discuss the results in the perspective of the SIT application for A. fraterculus.


PubMed | Seccion Zoologia Agricola
Type: Journal Article | Journal: Journal of insect physiology | Year: 2011

Male physiological condition can affect his ability to modulate female sexual receptivity. Thus, studying this aspect can have biological and practical implications. Here, we examine how male nutritional status affected the amount of sperm stored, remating rate and refractory period of the tephritid fruit fly Anastrepha fraterculus (Wiedemann) females. Both wild and laboratory flies were evaluated. We also examine female sperm storage patterns. Experiments were carried out by manipulating male adult diet and exposing these males to virgin females. Females mated with differently treated males were either dissected to count the amount of sperm stored or exposed to virgin males to determine remating rate and the length of the refractory period. We found that male nutritional status affected the amount of the sperm stored and the renewal of sexual receptivity in wild flies. For laboratory flies, male nutritional status affected the length of the refractory period but not the amount of sperm stored by females. In addition, we report that the ventral receptacle is not an important organ of sperm storage in this species. We conclude that male nutritional condition influences the ability to modulate female sexual receptivity, possibly through a combination of the quantity and quality of the ejaculate. From an applied perspective, providing males with an enriched diet will likely result in increased efficacy of the sterile insect technique.

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