Geographic distribution of sex chromosome polymorphism in Anastrepha fraterculus sp. 1 from Argentina

Background Anastrepha fraterculus is recognized as a quarantine pest in several American countries. This fruit fly species is native to the American continent and distributed throughout tropical and subtropical regions. It has been reported as a complex of cryptic species, and at least eight morphotypes have been described. Only one entity of this complex, formerly named Anastrepha fraterculus sp. 1, is present in Argentina. Previous cytogenetic studies on this morphotype described the presence of sex chromosome variation identified by chromosomal size and staining patterns. In this work, we expanded the cytological study of this morphotype by analyzing laboratory strains and wild populations to provide information about the frequency and geographic distribution of these sex chromosome variants. We analyzed the mitotic metaphases of individuals from four laboratory strains and five wild populations from the main fruit-producing areas of Argentina, including the northwest (Tucumán and La Rioja), northeast (Entre Ríos and Misiones), and center (Buenos Aires) of the country. Results In wild samples, we observed a high frequency of X1X1 (0.94) and X1Y5 (0.93) karyomorphs, whereas X1X2 and X1Y6 were exclusively found at a low frequency in Buenos Aires (0.07 and 0.13, respectively), Entre Ríos (0.16 and 0.14, respectively) and Tucumán (0.03 and 0.04, respectively). X2X2 and X2Y5 karyomorphs were not found in wild populations but were detected at a low frequency in laboratory strains. In fact, karyomorph frequencies differed between wild populations and laboratory strains. No significant differences among A. fraterculus wild populations were evidenced in either karyotypic or chromosomal frequencies. However, a significant correlation was observed between Y5 chromosomal frequency and latitude. Conclusions We discuss the importance of cytogenetics to understand the possible route of invasion and dispersion of this pest in Argentina and the evolutionary forces acting under laboratory conditions, possibly driving changes in the chromosomal frequencies. Our findings provide deep and integral genetic knowledge of this species, which has become of relevance to the characterization and selection of valuable A. fraterculus sp. 1 strains for mass rearing production and SIT implementation.Fil: Giardini, Maria Cecilia. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética "Ewald A. Favret"; Argentina.Fil: Nieves, Mariela. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología. Grupo de Investigación en Biología Evolutiva; Argentina.Fil: Scannapieco, Alejandra Carla. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Insectos de Importancia Económica; Argentina.Fil: Conte, Claudia Alejandra. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética "Ewald A. Favret"; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina.Fil: Milla, Fabian Horacio. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Genética de Insectos de Importancia Económica; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina.Fil: Schapovaloff, Maria Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Montecarlo; Argentina.Fil: Frissolo, Maria Soledad. Programa Nacional de Control y Erradicación de Moscas de los Frutos (PROCEM). Subprograma La Rioja; ArgentinaFil: Remis, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Cladera, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética. Laboratorio de Insectos de Importancia Agronómica; Argentina.Fil: Lanzavecchia, Silvia Beatriz. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Genética; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina.Fil: Nieves, Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Giardini, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Scannapieco, Alejandra Carla. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Conte, Claudia Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Milla, Fabian Horacio. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Schapovaloff, Maria Elena. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Remis, Maria Isabel. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Departamento de Ecología, Genética y Evolución; ArgentinaFil: Cladera, Jorge Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Agrobiotecnología y Biología Molecular; Argentina.Fil: Cladera, Jorge Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lanzavecchia, Silvia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Susceptibility of Gyropsylla spegazziniana (Lizer & Trelles) (Hemiptera: Psyllidae) to Beauveria bassiana (Bals.) Vuill.

Gyropsylla spegazziniana is one of the most prominent pest insects of yerba mate culture in all production regions in Brazil, Argentina and Paraguay. Natural enemies have been recorded on G. spegazziniana nymphs and adults, including the Zoophthora radicans entomopathogenic fungus. Since there are no reports of Beauveria bassiana, the aim of this study was to register its pathogenicity with respect to this insect in a laboratory setting. Yerba mate branches were kept in glass flasks with water and we infested each leaf with 20 newly-emerged nymphs. We prepared three replicates per treatment. We sprayed conidia suspensions (1 × 109 conidia/mL) onto the branches, which we transferred to cages and kept in an acclimatized room (26 ± 1°C, 70 ± 10% of relative humidity (R.H.) with a photophase of 14 hours). We evaluated insect mortality daily, and after five days we observed a high level of pathogenicity due to the presence of the fungus, that could be visually observed on the cadaver. The total mortality varied from 25 to 70% (respectively for Unioeste 4 and CG 716) and the confirmed mortality was 30% for Unioeste 52, revealing the fungus' potential. However, more studies are necessary in order to evaluate the strains of this fungus, as well as other species

Caracterização e atividade de isolados de fungos entomopatogênicos sobre a “ampola da erva-mate” Gyropsylla spegazziniana (Lizer & Trelles) (Hemiptera: Psyllidae)

Paraguay tea is a native crop of southern Brazil and is also socioeconomically important in Paraguay and Argentina. One of the main pests of this crop is Gyropsylla spegazziniana (Hemiptera: Psyllidae). As there are no registered insecticides for this pest in Brazil, the use of entomopathogenic fungi is an alternative method for its control. This study aimed to evaluate and characterize isolates of the entomopathogenic fungi Beauveria spp., Metarhizium anisopliae, Isaria spp. and Lecanicillium spp. on G. spegazziniana. For this purpose, 5th instar nymphs were transferred to Paraguay tea seedlings, followed by spraying of conidial suspensions (1 × 109 conidia mL-1) and then placing the seedlings in polyvinyl chloride (PVC) cages and maintaining them in a temperature-controlled room (26 ± 1°C, 12h00 photophase, 60 ± 10% R.H.). Insect mortality was evaluated daily for 10 days, and the selected isolates were characterized according to their vegetative growth, conidial production in synthetic culture medium and rice and insecticidal activity as well as through molecular analyses, including sequencing the rDNA-ITS region and RAPD analysis. The genus Beauveria spp. was the most efficient, particularly the Unioeste 44 isolate, which caused the greatest total mortality of G. spegazziniana (81.7%) and showed among the highest conidial production levels on rice, indicating a significant potential to be used in an integrated management program for this pest. Molecular analysis of the rDNA-ITS region allowed the isolates to be identified as B. bassiana and B. brongniartii, and RAPD markers were found to be associated with virulence.A erva-mate (Ilex paraguariensis St. Hil.) é uma cultura nativa do Sul do Brasil, tendo grande importância socioeconômica também para o Paraguai e Argentina. Uma das principais pragas da cultura é a Gyropsylla spegazziniana (Hemiptera: Psyllidae), e pelo fato de não existirem inseticidas registrados para essa praga no Brasil, o uso de fungos entomopatogênicos pode ser uma alternativa para o seu controle. O objetivo desse trabalho foi caracterizar isolados dos fungos entomopatogênicos Beauveria spp., Metarhizium anisopliae, Isaria spp. e Lecanicillium spp. sobre G. spegazziniana. Para tal, ninfas de 5o ínstar foram transferidas para mudas de erva-mate, seguido da pulverização das suspensões de conídios (1 × 109 conídios mL-1), e então as mudas foram acondicionadas em gaiolas de PVC (cloreto de polivinila), e mantidas em sala climatizada (26 ± 1°C; 12h00 de fotofase e U.R. 60 ± 10%). A mortalidade dos insetos foi avaliada diariamente, por 10 dias, e os isolados selecionados foram comparados entre si por meio do crescimento vegetativo, produção de conídios em meio sintético e em arroz, atividade inseticida e análises moleculares, utilizando-se o sequenciamento da região rDNA-ITS e marcadores RAPD. O gênero Beauveria spp. foi o mais eficiente, em especial o isolado Unioeste 44 que apresentou a maior mortalidade total sobre G. spegazziniana (81.7%) e uma das maiores produções de conídios em arroz, mostrando potencial significativo para ser usado em programas de manejo integrado da praga. As análises moleculares da região rDNA-ITS possibilitaram a identificação dos isolados como B. bassiana e B. brongniartii e os marcadores RAPD foram associados à virulência