Infection by the microsporidium of Clado Nosema/Vairimorpha in pupal parasitoids.

The sugarcane borer, Diatraea saccharalis is one of the hosts more used for parasitoid pupal multiplication in Brazil. The parasitoids pupal of Trichospilus diatraeae and Palmistichus elaeisis are generalist natural enemies with potential to suppress populations of diverse families of lepidopteran pests. The success in the utilization of these natural enemies in the field is directly related to the capacity of search of the host, this capacity might be affected by the presence of the pathogens. In this context, the aim of this essay was to detect the presence of intracellular parasites of Phylum Microsporidia. These pathogens may cause morphological and behavioral alterations. The presence of infection was verified by microscopy and was confirmed by amplification of region small subunit (SSU) of ribosomal RNA using universal primers for microsporidia of Nosema sp. The purified PCR products were submitted to sequencing, and the sequences that had been obtained were edited and aligned with the sequences in a Genbank database. In this way, it was possible to verify the presence of intracellular parasites in T. diatraeae, P. elaeisis and D. saccharalis pertaining to Clade Nosema/Vairimorpha. However, this is the first one report about detection of the microsporidia in the parasitoids T. diatraeae and P. elaeisis.

Thermal requirements, development and number of generations of Duponchelia fovealis (Zeller) (Lepidoptera: Crambidae).

In this study, the effect of temperature on the growth of the European pepper moth, Duponchelia fovealis (Zeller), was assessed at five constant temperatures (18, 21, 24, 27 and 30 °C). The European pepper moth was observed to complete its developmental stages (from egg to adult) at all the temperatures evaluated. From the results, it was evident that temperature affected the rate and development time of all the growth stages, to a significant degree. The length in time of the embryonic, larval, pupal and total (egg-adult) stages was observed to drop as the temperature rose from 18 to 24 °C, but remained constant between 27 and 30 °C. The developmental time in the pre-pupal stage dropped between 18 and 30 °C. The European pepper moth takes 454 degree-days to complete development at 11.7 °C temperature threshold. The D. fovealis survival was thus inversely proportional to temperature over range of 18 to 30 °C. On assessing the number of annual generations for the five largest strawberry-producing municipalities in Espírito Santo State, an average of 5.5 generations per year was estimated. This is a first report of temperature on D. fovealis development.

Functional response of Telenomus remus Nixon(Hymenoptera, Scelionidae) to Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) eggs: effect of female age / Resposta funcional de Telenomus remus Nixon (Hymenoptera, Scelionidae) sobre ovos de Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae): efeito da idade da fêmea

Functional response of Telenomus remus Nixon (Hymenoptera, Scelionidae) to Spodoptera frugiperda (J. E. Smith) (Lepidoptera, Noctuidae) eggs: effect of female age. Functional response of 24-h and 48-h-old Telenomus remus adults was studied on Spodoptera frugiperda eggs. The study was carried out in climatic chamber regulated at 25 ± 1°C, 70 ± 10 percent RH and 12:12h (L: D). Females of T. remus were honey fed and individualized in glass vials along with 25, 50, 75, 100, 150, 200, 250 or 300 eggs of S. frugiperda for 24 h. Complete randomized design with ten replications was adopted. The parameters evaluated to construct the functional response curve were daily average parasitism, searching rate and oviposition time. It was observed that the higher the egg density, the higher the parasitism for 24-h and 48-h-old females although there was a tendency of parasitism stabilization at 150-egg density. The results showed a type II functional response curve for both 24-h and 48-h-old female.

A resposta funcional de fêmeas de Telenomus remus com 24 h e 48 h de idade foi observada em ovos de Spodoptera frugiperda. O experimento foi conduzido em câmara climatizada regulada a 25 ± 1°C, 70 ± 10 por cento UR e fotofase de 12h. As fêmeas de T. remus foram alimentadas com mel e mantidas individualmente por 24h em tubos de vidro que continham 25, 50, 75, 100, 150, 200, 250 ou 300 ovos de S. frugiperda. Foi adotado o delineamento experimental inteiramente casualizado com 10 repetições. Os parâmetros avaliados para a construção da curva de resposta funcional foram o parasitismo médio diário, a taxa de busca e o tempo de oviposição. Foi observado que com o aumento da densidade de ovos também cresce o parasitismo em fêmeas com 24 h e 48 h de idade e que há uma tendência de estabilização do parasitismo na densidade de 150 ovos/fêmea. Os resultados mostraram uma curva de resposta funcional do tipo II para fêmeas de T. remus com 24 h e 48 h de idade.

[Performance of trichogrammatids as biocontrol agents of Pseudoplusia includens Walker (Lepidoptera: Noctuidae)]. / Desempenho de tricogramatídeos como potenciais agentes de controle de Pseudoplusia includens Walker (Lepidoptera: Noctuidae).

This research aimed to point out the most suitable trichogrammatid strains to control the soybean looper Pseudoplusia includes Walker. Biological parameters and parasitism ratio of 11 Trichogramma pretiosum Riley, one Trichogramma atopovirilia Oatman & Platner and one Trichogrammatoidea annulata De Santis strains reared on P. includens eggs were evaluated. Among all tested strains/species, T. pretiosum strain RV, collected in Rio Verde, GO, had the fastest development cycle and the highest percentage of parasitism of P. includens eggs. There was no difference in the parasitism and in the number of parasitoid emerged per egg among the tested parasitoid species and strains. Accordingly to the cluster analysis, T. pretiosum strain RV reared on P. includens eggs had the best performance. Considering the higher parasitism rate, shorter biological cycle, higher survival and sex ratio, T. pretiosum strain RV is the most appropriated to be used in field releases aiming at P. includens control.

Desempenho de tricogramatídeos como potenciais agentes de controle de Pseudoplusia includens Walker (Lepidoptera: Noctuidae) / Performance of trichogrammatids as biocontrol agents of Pseudoplusia includens Walker (Lepidoptera: Noctuidae)

Este estudo objetivou selecionar as linhagens de tricogramatídeos mais adequadas ao controle da lagarta falsa-medideira, Pseudoplusia includens Walker. Foram avaliados os parâmetros biológicos e a taxa de parasitismo de 11 linhagens de Trichogramma pretiosum Riley, uma linhagem de Trichogramma atopovirilia Oatman & Platner e uma linhagem de Trichogrammatoidea annulata De Santis, criadas em ovos de P. includens. Entre as espécies/linhagens avaliadas, a linhagem T. pretiosum RV, coletada em Rio Verde, GO, apresentou o ciclo de desenvolvimento mais rápido e a maior porcentagem de parasitismo em ovos de P. includens. Não houve diferença no parasitismo e no número de parasitóides emergidos por ovo entre as espécies e linhagens de parasitóides avaliadas. De acordo com a análise de agrupamento (cluster analysis), a linhagem RV criada em ovos de P. includens teve o melhor desempenho. Apresentou maior taxa de parasitismo, menor duração do ciclo biológico, alta sobrevivência e predominância de fêmeas, sendo a mais indicada a ser utilizada em liberações de campo visando ao controle de P. includens.

This research aimed to point out the most suitable trichogrammatid strains to control the soybean looper Pseudoplusia includes Walker. Biological parameters and parasitism ratio of 11 Trichogramma pretiosum Riley, one Trichogramma atopovirilia Oatman & Platner and one Trichogrammatoidea annulata De Santis strains reared on P. includens eggs were evaluated. Among all tested strains/species, T. pretiosum strain RV, collected in Rio Verde, GO, had the fastest development cycle and the highest percentage of parasitism of P. includens eggs. There was no difference in the parasitism and in the number of parasitoid emerged per egg among the tested parasitoid species and strains. Accordingly to the cluster analysis, T. pretiosum strain RV reared on P. includens eggs had the best performance. Considering the higher parasitism rate, shorter biological cycle, higher survival and sex ratio, T. pretiosum strain RV is the most appropriated to be used in field releases aiming at P. includens control.