First record of Rachiplusia nu (Lepidoptera: Noctuidae) as host of the egg parasitoid Trichogramma bruni (Hymenoptera: Trichogrammatidae).

Autoria: QUERINO [i.e. SILVA], R. B. Q. da. RANYSE BARBOSA QUERINO DA SILVA

Ocorrência de doenças causadas por molicutes e por vírus em milho nas províncias de Tucumán e de Córdoba na Argentina.

A incidência de doenças causadas por molicutes e por vírus foi avaliada em lavouras de milho (Zea mays) nas Províncias de Tucumán e de Córdoba, na Argentina, em fevereiro de 2000. Na Província de Tucumán verificou-se que 44% das lavouras apresentaram altos níveis de incidência de plantas com sintomas de enfezamentos causados por molicutes (50 a 100%), em altitudes variando de 300 a 2.000 m. A presença de fitoplasma e de espiroplasma foi confirmada em amostras de folhas de plantas com sintomas de enfezamentos, através dos testes de PCR e de ?Western blotting?. Constatou-se, porém, que a eficiência desses testes para detecção destes patógenos, quando os sintomas apresentados pelas plantas eram muito acentuados, foi da ordem de 70%, e de apenas 30% quando os sintomas eram menos acentuados. Na localidade Jesus Maria, foram encontradas plantas apresentando acentuado nanismo, folhas estreitas e com deformações. Dentre quatro amostras destas plantas, submetidas a testes de PCR, em duas foi detectada a presença de fitoplasma, possivelmente d istinto do ?Maize Bushy Stunt Phytoplasma?. A cigarrinha Dalbulus maidis, inseto vetor dos molicutes, foi encontrada apenas em Tucumán, estando ausente em Córdoba. O Mal de Rio Cuarto virus foi detectado em seis lavouras em Córdoba, e em três em Tucumán. A cigarrinha Delphacodes kuscheli foi detectada em todas as lavouras em Córdoba, e em apenas três lavouras em Tucumán. O Maize dwarf mosaic virus foi detectado em cerca de 60% das lavouras amostradas nas duas Províncias e o Maize rayado fino virus em apenas uma localidade em Tucumán

Characterization of the Earwig, Doru lineare, as a Predator of Larvae of the Fall Armyworm, Spodoptera frugiperda: A Functional Response Study

Spodoptera frugiperda Smith (Lepidoptera: Noctuidae) is considered as the most important pest of maize in almost all tropical America. In Argentina, the earwig Doru lineare Eschscholtz (Dermaptera: Forficulidae) has been observed preying on S. frugiperda egg masses in corn crops, but no data about its potential role as a biocontrol agent of this pest have been provided. The predation efficiency of D. lineare on newly emerged S. frugiperda larva was evaluated through a laboratory functional response study. D. lineare showed type II functional response to S. frugiperda larval density, and disc equation estimations of searching efficiency and handling time were (a) = 0.374 and (t) = 182.9 s, respectively. Earwig satiation occurred at 39.4 S. frugiperda larvae

Abundance and Species Richness of Leafhoppers and Planthoppers (Hemiptera: Cicadellidae and Delphacidae) in Brazilian Maize Crops

Fil: De Oliveira, Charles Martins. Embrapa Cerrados. Planaltina. Brasília/DF; BrazilFil: De Oliveira, Elizabeth. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Prazeres De Souza, Isabel Regina. Embrapa Milho e Sorgo. Sete Lagoas/MG; BrazilFil: Alves, Elcio. DuPont do Brazil S.A. DivisÆo Pioneer Sementes. Itumbiara/GO; BrazilFil: Dolezal, William. Pioneer Hi-Bred International. Itumbiara/GO; BrazilFil: Paradell, Susana Liria. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Marino de Remes Lenicov, Ana María. División Entomología. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; ArgentinaFil: Frizzas, Marina Regina. Universidade de Brasília. Departamento de Zoologia. Instituto de Ciências Biológicas. Brasília/DF; Brazi

Natural Distribution of Parasitoids of Larvae of the Fall Armyworm, Spodoptera frugiperda, in Argentina

To develop a better understanding of the natural distribution of the fall armyworm, Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), and to update the knowledge of the incidence of its complex of parasitoids. S. frugiperda, samplings in whorl-stage corn were carried out in provinces of Argentina from 1999 to 2003. S. frugiperda larvae were collected from corn in localities of the provinces of Tucumán, Salta, Jujuy, Santiago del Estero, La Rioja, Córdoba, San Luis, Chaco and Misiones. In each locality 30 corn plants were sampled and only larvae located in those plants were collected. The parasitoids that emerged from S. frugiperda larvae were identified and counted. The abundance of the parasitoids and the parasitism rate were estimated. The S. frugiperda parasitoids collected were Campoletis grioti (Blanchard) (Hymenoptera: Ichneumonidae), Chelonus insularis (Cresson) (Hymenoptera: Braconidae), Archytas marmoratus (Townsend) (Diptera Tachinidae) and/or A. incertus (Macquart), Ophion sp. (Hymenoptera: Ichneumonidae), Euplectrus platyhypenae Howard (Hymenoptera: Eulophidae), and Incamyia chilensis (Aldrich) (Diptera Tachinidae). C. grioti was the most abundant and frequent during the five-year survey. Similar diversity of parasitoids was obtained in all the provinces, with the exception of I. chilensis and E. platyhypenae that were recovered only in the province of Salta. In the Northwestern region, in Tucumán, C. grioti and species of Archytas were the most abundant and frequent parasitoids. On the contrary, in Salta and Jujuy Ch. insularis was the parasitoid most abundant and frequently recovered. The parasitism rate obtained in Tucumán, Salta and Jujuy provinces were 21.96%, 17.87% and 6.63% respectively with an average of 18.93%. These results demonstrate that hymenopteran and dipteran parasitoids of S. frugiperda occurred differentially throughout the Argentinian provinces and played an important role on the natural control of the S. frugiperda larval population

Invasiveness, biology, ecology, and management of the fall armyworm, Spodoptera frugiperda.

First online

Delfácidos asociados al cultivo de maíz en la República Argentina (Insecta - Homoptera - Delphacidae)

Se han identificado once especies de Homoptera Delphacidae asociadas al cultivo de maíz en la República Argentina. Los insectos mencionados en esta contribución fueron obtenidos, en parte, desde muestreos periódicos realizados durante cuatro años sobre cultivos de maíz en la localidad de Sampacho, Río Cuarto, Córdoba, o se han recibido para su estudio desde distintas instituciones relacionadas con el quehacer fitosanitario de la Argentina. El material estudiado ha posibilitado la realización de una lista de los delfácidos asociados al maíz en la que se aporta además, información sobre aspectos taxonómicos, bionómicos y biogeográficos. Esta contribución incluye una clave para la identificación de todas las especies encontradas en este cultivo

Egg parasitoids of the corn leafhopper, Dalbulus maidis, in the southernmost area of its distribution range

Egg parasitoids of the corn leafhopper, Dalbulus maidis (DeLong and Wolcott) (Hemiptera: Cicadellidae), were surveyed exposing sentinel eggs of the leafhopper along a latitudinal transect of 600 km in Argentina, the southernmost area of its distribution range. Four parasitoid species were obtained: the mymarids Anagrus breviphragma Soyka (Hymenoptera: Mymaridae), Anagrus flaveolus Waterhouse, and Polynema sp., and the trichogrammatid Pseudoligosita longifrangiata (Viggiani) (Hymenoptera: Trichogrammatidae). The low parasitism rate, low species richness, and high proportion of generalist egg parasitoids were quite clear in the southern distribution limit of the vector, in contrast to regions where corn crops are available all year round and there are continuous and overlapping generations of the pest. Further studies need to be done in order to determine the native host of the above egg parasitoids, the seasonal abundance, and the possible occurrence of other species affecting D. maidis populations in the studied area