-Trichogramma pretiosum Riley and the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae are effi cient biological control agents and are thought to be used jointly. In here, we investigated if these entomopathogens could have any side-effects on T. pretiosum. Therefore, 1 x 8 cards containing sterilized eggs of Anagasta kuehniella (Zeller) that were sprayed with 0.2 ml of B. bassiana or M. anisopliae (1.0 × 10 9 conidia/ml) were offered to a T. pretiosum female for 24h (30 cards/fungus = 30 replicates). Afterwards, females were isolated in glass tubes. The control group was sprayed with sterile distillated water + Tween 80 (0.01%). In addition, 60 cards with sterilized eggs of A. kuehniella were submitted to parasitism by females of T. pretiosum for 24h. Of these cards, 30 were sprayed with B. bassiana or M. anisopliae and 30 with distillated water + Tween 80 (0.01%), and observed daily until parasitoid emergence. Metarhizium anisopliae decreased parasitoid emergence and caused confi rmed mortality. Therefore, fi eld and semi-fi eld experiments should be conducted for a fi nal assessment of the side-effects of these entomopathogens on Trichogramma as a ways to develop a control strategy in which both can be used.
Knowledge about interactions among biological control agents, used in sequence or simultaneously, may help to increase their efficiency, or in the case of conservation biological control, to avoid the impairment of efficiency. The aim of this study was to evaluate the interaction between two isolates of Beauveria bassiana (Bals.) Vuill. (Hypocreales) (Unioeste 47 and Unioeste 57) and Trichogramma pretiosum Riley (Hymenoptera: Trichogrammatidae), varying the timing of sprays of the fungus. Isolates were sprayed at 109 conidia ml−1 upon cards (1 × 5 cm; i.e., 2 × 105 conidia mm−2) with eggs of Anagasta kuehniella Zeller (Lepidoptera: Pyralidae) and the control group was sprayed with sterile distilled water with Tween® 80 (0.01%). First, the percentage of parasitized eggs was assessed in a choice test: females of T. pretiosum were confined with two cards, one of them treated with either of the fungus isolates, the other a water‐treated control. Second, parasitism was compared on cards sprayed at various time intervals pre‐ vs. post‐parasitism: the number of parasitized eggs was assessed, as well as the parasitoid's emergence percentage, egg‐adult period, offspring sex ratio, and the longevity of parasitizing females. Trichogramma pretiosum preferred to parasitize control eggs (65 and 72%) and parasitization of the treated eggs did not differ between fungus isolates: 35% (Unioeste 47) vs. 28% (Unioeste 57). Spraying before or after parasitizing did not affect the number of parasitized eggs, nor offspring sex ratio; however, both treatments affected the percentage of emerged adults, egg‐adult period, and longevity. These findings suggested that isolates did not interfere in the longevity of parasitizing females. When the fungus was sprayed on the various development stages of the parasitoid within the host egg, or when it was offered to the parasitoid at different times after spraying, differences in adults' longevity, parasitism, emergency period from egg to adult, and sex ratio were observed. Beauveria bassiana may be used in conjunction with this parasitoid in a program of pest control.
Nymphs and adults of the lace bug (Hemiptera: Tingidae) have been found in cassava crops (Manihot esculenta) in Mato Grosso do Sul State, Brazil. The insects were collected in the field and taken to the laboratory where they were identified based on some morphological traits of the species Vatiga manihotae (Drake) and V. illudens (Drake), which are first reported in the aforementioned state.
Este trabalho registra a ocorrência de Aleurothrixus aepim Goeldi em plantas de mandioca na região Oeste do Paraná, Brasil. A espécie foi primeiramente encontrada em fevereiro de 2009, em área experimental da Universidade Estadual do Oeste do Paraná (UNIOESTE), em folhas de mandioca da variedade fécula branca. Os exemplares foram coletados recolhendo-se folhas infestadas com ninfas de mosca-branca, caracterizadas por apresentar corpo recoberto por filamentos cerosos de coloração branca. O material foi preservado em etanol a 70%, em frascos de vidro, e foram enviados para identificação. Novos surtos foram registrados no início de 2010 e 2011 em diferentes propriedades rurais localizadas no município de Marechal Cândido Rondon. Entretanto, a causa precisa da ocorrência de A. aepim nessa região não está totalmente clara. Nas demais regiões produtoras do Estado, esta espécie ainda não foi detectada.
The beetle M. fryanus causes serious damage to cassava in Brazil. However, due to the subterranean behavior of the larvae and the recent appearance of this pest in cassava, little is known about the main behavioral characteristics and damage caused to this crop. The main aim of this study is to demonstrate the variation of starch production in the roots of M. esculenta as a result of the intensity of damage caused by M. fryanus. The study was carried out in a commercial cassava farm in Paraná, Brazil. The proposed scale for damage was: (1) No apparent root damage; (2) roots with scrapings; (3) roots with scraping across the cortex; (4) damaged roots and galleries; (5) roots with galleries and presentation of rot. The parameters evaluated were the damage caused by M. fryanus in roots and starch content, estimated by using a hydrostatic scale, starch extracted by cassava processing, and the starch reduction percentage in damaged roots, assessed by using the hydrostatic scale (SC) and processing methods (SCP). It was observed that there was manifestation of damage in approximately 60% of the roots collected directly from the ground, with levels representing loss of starch produced by the plant. Decreases in the productive parameters, such as starch content, were measured according to the increase of the proposed damage levels in the two cassava cultivation cycles, with a starch reduction rate higher than 20% when the roots suffered the most severe damage.
ResumoAs cigarrinha-das-pastagens são consideradas as mais importantes pragas em pastagens tropicais. Os danos ocasionados por estes insetos diminuem a produção das pastagens. O objetivo deste trabalho foi estudar a flutuação populacional de Notozulia entreriana, no período de junho de 2007 a junho de 2008, e a correlação com os fatores meteorológicos/ambientais (precipitação pluviométrica, temperatura, radiação solar diária e altura da pastagem). Para tanto, amostraram-se três áreas de pastagem no município de Marechal Cândido Rondon-PR. Foram realizadas amostragens de adultos e ninfas. Também se determinaram quais as espécies de cigarrinhas-das-pastagens (Hemiptera: Cercopidae) ocorrem na região oeste do Estado do Paraná. A flutuação populacional de N. entreriana apresentou quatro picos durante o período favorável de desenvolvimento -primavera/verão. A radiação solar diária apresentou maior correlação com a dinâmica populacional. Por outro lado, precipitação pluviométrica, temperatura e altura da pastagem apresentaram pouca correlação com a dinâmica populacional. A espécie que ocorreu com maior abundância foi N. entreriana, representando 88,4% do total de insetos coletados na região oeste do Paraná. Palavras-chave: Cercopídeos, radiação solar diária, dinâmica populacional, Cynodon dactylon. Rhynchospora sp AbstractThe spittlebugs are considered the most important pests in tropical pastures. The damages caused by these insects decrease the production of pastures. The objective this work was to study the population dynamics of Notozulia entreriana, from June 2007 to June 2008, and the correlation with meteorological and environmental factors (rainfall, temperature, daily solar radiation and pasture height). Therefore, sampled were made in three areas of grassland in the municipality of Marechal Cândido Rondon-PR. Sampling of adults and nymphs was made. Also we determined which species of spittlebugs (Hemiptera: Cercopidae) occur in the western region of Paraná State. The population fluctuation of N. entreriana showed four peaks during the period of favorable development -spring / summer. The daily solar radiation had a higher correlation with the population. Rainfall, temperature and pasture height had little correlation with the population dynamics. The species that occurred with greater abundance was N. entreriana, representing 88.4% of the total insects collected in western of Paraná State.
RESUMO: O estudo teve por objetivo adequar o ínstar do hospedeiro Ascia monuste orseis ao parasitismo de Cotesia glomerata e avaliar o desempenho do parasitoide. Foram oferecidas às fêmeas de C. glomerata lagartas de 2o, 3o, 4o e 5o ínstares de A. monuste orseis , permitindo-se o parasitismo por duas horas. Subsequentemente, acompanhou-se o desenvolvimento das lagartas que foram alimentadas com seções foliares de couve-manteiga. Foram avaliados: a duração de cada ínstar das lagartas, o peso da pupa com quatro dias de idade e a porcentagem de lagartas parasitadas e de mortalidade. Em relação ao parasitoide, foram avaliados: porcentagem de parasitismo; número de parasitoide por hospedeiro; porcentagem de emergência; razão sexual; peso médio da pupa; número de parasitoide por lagarta; período ovo-pupa (POP); período pupal (PP); período ovo-adulto (POA). Os resultados indicaram que o segundo ínstar do hospedeiro A. monuste oreseis é o mais apropriado para o parasitismo de C. glomerata por proporcionar maior porcentagem de parasitismo e maior número de descendentes por hospedeiro.
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