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Norrbom A.L.,U.S. Department of Agriculture | Alvarado N.N.,Servicio Nacional de Sanidad Agraria del Peru | Colque F.,Servicio Nacional de Sanidad Agropecuaria e Inocuidad Alimentaria | Landa E.Y.,National University San Antonio Abad del Cusco | And 8 more authors.

The nuclear ribosomal internal transcribed spacer 1 (ITS1) was sequenced for Anastrepha fraterculus (Wiedemann, 1830) originating from 85 collections from the northern and central Andean countries of South America including Argentina (Tucumán), Bolivia, Perú, Ecuador, Colombia, and Venezuela. The ITS1 regions of additional specimens (17 collections) from Central America (México, Guatemala, Costa Rica, and Panamá), Brazil, Caribbean Colombia, and coastal Venezuela were sequenced and together with published sequences (Paraguay) provided context for interpretation. A total of six ITS1 sequence variants were recognized in the Andean region comprising four groups. Type I predominates in the southernmost range of A. fraterculus. Type II predominates in its northernmost range. In the central and northern Andes, the geographic distributions overlap and interdigitate with a strong elevational effect. A discussion of relationships between observed ITS1 types and morphometric types is included. © Bruce D. Sutton et al. Source

Adasme-Carreno F.,University of Talca | Munoz-Gutierrez C.,University of Talca | Salinas-Cornejo J.,University of Talca | Ramirez C.C.,University of Talca | Ramirez C.C.,Millennium Nucleus Center in Molecular Ecology and Evolutionary Applications in the Agroecosystems
Computers and Electronics in Agriculture

This article introduces A2EPG, a new software application capable of automatically analyse signals derived from the electrical penetration graphs (EPG), a technique widely used to monitoring the plant probing behaviour of hemipterean insects. EPG records contain different well-known waveform patterns that are associated to specific behavioural activities inside the plant tissues, which are usually manually labelled in the present. A2EPG incorporates search engines for five EPG waveforms (Np, C, pd, G and E1) and provides output information indicating the time spans of each recognised waveform, which can be easily confirmed or manipulated by an expert user, reducing the overall time devoted to the analysis of EPG data. The application will be useful for researchers aimed to study the probing behaviour of piercing/sucking mouth parts, particularly aphids. The effectiveness of A2EPG was studied in EPG records obtained from individuals of two aphid species, exhibiting a substantial recognition efficacy for most of the considered waveforms. In general, A2EPG constitutes a useful tool for a rapid evaluation of EPG data over currently available software in the field. © 2015 Elsevier B.V. Source

Zepeda-Paulo F.,University of Talca | Zepeda-Paulo F.,Austral University of Chile | Lavandero B.,University of Talca | Lavandero B.,Millennium Nucleus Center in Molecular Ecology and Evolutionary Applications in the Agroecosystems | And 6 more authors.
Ecology and Evolution

Host recognition and use in female parasitoids strongly relies on host fidelity, a plastic behavior which can significantly restrict the host preferences of parasitoids, thus reducing the gene flow between parasitoid populations attacking different insect hosts. However, the effect of migrant males on the genetic differentiation of populations has been frequently ignored in parasitoids, despite its known impact on gene flow between populations. Hence, we studied the extent of gene flow mediated by female and male parasitoids by assessing sibship relationships among parasitoids within and between populations, and its impact on geographic and host-associated differentiation in the aphid parasitoid Aphidius ervi. We report evidences of a high gene flow among parasitoid populations on different aphid hosts and geographic locations. The high gene flow among parasitoid populations was found to be largely male mediated, suggested by significant differences in the distribution of full-sib and paternal half-sib dyads of parasitoid populations. © 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd. Source

Tapia D.H.,University of Valparaiso | Silva A.X.,Austral University of Chile | Ballesteros G.I.,University of Talca | Ballesteros G.I.,Millennium Nucleus Center in Molecular Ecology and Evolutionary Applications in the Agroecosystems | And 5 more authors.
Animal Behaviour

Insects are able to learn from experience acquired in their natal habitat, thereby obtaining adaptive advantages. However, the acquisition of new information could involve defects in retrieving previously learned information (i.e. forgetting), a process known as retroactive interference, which diminishes learning capacities. In this study, we evaluated the learning capacity and the impact of retroactive interference during host searching by ecological specialist and generalist phytophagous insects. We examined whether the generalist aphid, Myzus persicae s. str., and the tobacco-specialized subspecies, Myzus persicae nicotianae differ in (1) learning capacity, or (2) retroactive interference during host selection, and (3) whether the learning-associated foraging gene (. for) is differentially expressed. Differences in learning capacity and retroactive interference were assessed in bioassays using rearing hosts and alternative hosts followed by choices between or transferences to rearing or alternative hosts. During the pre-alighting phase of host searching, the generalist aphid showed attraction to the alternative host after 12. h of experience, while the specialist showed no attraction to the alternative host regardless of the amount of time on the plant. The retroactive interference experiments showed that when aphids were exposed to an alternative host for different periods, odour attraction to the rearing host persisted in the generalist after 72. h of experience on the alternative host, whereas in the specialist the attraction to the rearing host was lost after 12. h of experience on the alternative host. During the post-alighting phase of host searching, both taxa performed better on their rearing hosts, but in the specialist aphid, a short period on the alternative host reversed this behaviour. In addition, the specialist showed lower levels of gene for expression, which could be associated with the differences in learning performance. Herein we present further evidence of differences in learning capacities between a specialist and a generalist aphid, which may influence the process of host searching and evolution of ecological specialization. © 2015 The Association for the Study of Animal Behaviour. Source

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