Ulysses Rodrigues Vianna

Biological characteristics of Trichogramma pretiosum and Trichogramma acacioi (Hym.: Trichogrammatidae), parasitoids of the avocado defoliator Nipteria panacea (Lep.: Geometridae), on eggs of Anagasta kuehniella (Lep.: Pyralidae)

The objective of this investigation was to study Trichogramma pretiosum and T. acacioi (Hymenoptera: Trichogrammatidae), parasitoids of the avocado defoliator Nipteria panacea (Lepidoptera: Geometridae) on the eggs of the alternative host Anagasta kuehniella (Lepidoptera: Pyralidae) aiming to use them for biological control of this pest in avocado orchards. The cubic model presented better adjustment for duration of the life cycle of T. pretiosum and T. acacioi with the host A. kuehniella which shows that development rate of these species increases with temperature within the range tested. The number of individuals of both Trichogramma species emerged per egg from this host was higher than one. The quadratic model was significant for viability of T. pretiosum and T. acacioi. This parameter was more affected by extreme temperatures and higher emergence rates of adults of both parasitoids species occurred at temperatures of 20, 25 and 30°C.

Thermal requirements of Trichogramma pretiosum and T. acacioi (Hym.: Trichogrammatidae), parasitoids of the avocado defoliator Nipteria panacea (Lep.: Geometridae), in eggs of two alternative hosts

O objetivo desta pesquisa foi estudar as exigencias termicas de Trichogramma pretiosum e T. acacioi (Hymenoptera: Trichogrammatidae), parasitoides de Nipteria panacea (Lepidoptera: Geometridae), em ovos dos hospedeiros alternativos Anagasta kuehniella (Lepidoptera: Pyralidae) e Sitotroga cerealella (Lepidoptera: Gelechiidae) visando utilizar estes inimigos naturais em programas de controle biologico desta praga em pomares de abacate. T. pretiosum apresentou temperaturas base (Tb) de 10.70 e 10.75°C e constantes termicas (K) de 151.83 e 160.04 graus-dia, sendo estes valores de 10.67 e 10.46°C e 158.50 e 155.46 graus-dia para T. acacioi em ovos de A. kuehniella e S. cerealella, respectivamente.

Desempenho de Trichogramma pratissolii Querino & Zucchi (Hymenoptera, Trichogrammatidae) em ovos de Anagasta kuehniella (Zeller) (Lepidoptera, Pyralidae) sob efeito de Bacillus thuringiensis Berliner

This work was carried out to detect at laboratory the possible side-effects provoked by Bacillus thuringiensis (Bt) strains on egg parasitoid Thichogramma pratissolii and its progeny. Six strains of Bt E-3, E-10, E-15, E-16, E-19, E-20 and Bt kurstaki were assayed in honey drop to stimulate the feeding of the parasitoids in each treatment (1:1) and pure honey as check treatment and offered simultaneously displays with eggs of the host alternative Anagasta kuehniella. The experiment was maintained in a climatized chamber at 25 ± 1oC, RH 70 ± 10% and photofase of 14hours. The survival, daily parasitism, accumulated parasitism and total parasitism and also the progenys emergence and sexual ratio were analyzed. Bt isolates did not affect parasitism, sexual ratio and longevity, but some of them (E-3, E-10, E-16 e E-20) affected parasitoid progeny. In field conditions this could imply in more parasitoid liberations to the expected results. Otherwise, parasitism acceleration verified in all treatments suggest that when T. pratissolii adults pass on some extern pressure (stress) they parasitize as soon as possible to assure progeny survival. The interaction Bt + T. pratissolii may increase the parasitoid preformance in the field, mainly when a rapid decrease of pest population is desirable.

Características biológicas de linhagens de Trichogramma pretiosum, criados em ovos de Sitotroga cerealella e Anagasta kuehniella

The biological characteristics of five lineages of T. pretiosum Riley (Hym.: Trichogrammatidae), collected from tomato crops, and reared in A. kuehniella (Zeller) and S. cerealella (Olivier) eggs were evaluated. The parasitism rate of the lineages, varied from 56,1 to 68.6%, when the host was A. kuehniella, being higher than for S. cerealella. The viability of all lineages, when reared in S. cerealella eggs, was superior to 90%; however, only those lineages reared in S. cerealella eggs and collected in Afonso Claudio and Venda Nova dos Imigrantes (Espirito Santo State, Brazil) were significantly higher than those reared on A. kuehniella. The longevity of the offspring submitted to the parasitism, was higher in all the lineages reared in A. kuehniella eggs. All five lineages can be mass reared using both hosts. However, considering the parasitism rate and the quality of the progeny, the host A. kuehniella seems to be superior than S. cerealella

Parasitism Capacity of Trichogramma pretiosum and Trichogramma acacioi (Hym.: Trichogrammatidae) on eggs of Sitotroga cerealella (Lep.: Gelechiidae)

The objective of this work was to evaluate the parasitism capacity of Trichogramma pretiosum Riley and T. acacioi Brun, Moraes and Soares (Hymenoptera: Trichogrammatidae) in eggs of the alternative host Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae) aiming to use both species in biological control programs of Nipteria panacea Tierry-Mieg (Lepidoptera: Geometridae). The parasitism rhythm and total parasitism of these parasitoid species were affected by the temperature with higher values during the first 24 h of their life. Parasitism period was longer for T. pretiosum and T. acacioi at the lowest temperature.

Seletividade de inseticidas, recomendados para cucurbitáceas para Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) em condições de laboratório

Selectivity of pesticides used in cucurbits to Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae) The cucurbit borers Diaphania spp. are major cucurbit pests, causing losses of up to 100% in production. Biological control with the parasitoid Trichogramma is an alternative for reducing the use of insecticides. The objective of this study was to evaluate the selectivity of the active ingredients abamectin, chlorfenapyr and thiacloprid to Trichogramma atopovirilia Oatman & Platner (Hymenoptera: Trichogrammatidae). For this purpose, 20 newly emerged females of T. atopovirilla were confined individually in glass tubes (2.5 cm diameter x 8.5 cm in length), with 30 eggs of Diaphania hyalinata (Linnaeus) (Lepidoptera: Pyralidae) glued on a small cardboard strip that was previously immersed for five seconds in chemical solution. The active ingredients abamectin, chlorfenapyr and thiacloprid did not af fect the T. atopovirilia parasitism. However, chlorfenapyr reduced larval emergence. Abamectin and thiacloprid can be therefore recommended for the Integrated Pest Management, as they proved to be the most selective to T. atopovirilia in D. hyalinata eggs.

Capacidade de parasitismo de Trichogramma exiguum Pinto & Platner, 1978 (Hymenoptera: Trichogrammatidae) em ovos de Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae) em diferentes temperaturas

The parasitism capacity of Trichogramma exiguum Pinto & Platner, 1978 (Hymenoptera: Trichogrammatidae) on eggs of Plutella xylostella (L., 1758) (Lepidoptera: Plutellidae) was studied, under temperatures of 18, 20, 22, 25, 28, 30 and 32°C aiming at evaluating the number of days with parasitism, cumulated parasitism, total number of eggs parasited per female and their longevity. Parasitism during the first 24 hours ranged from 1.5 to 11.7 eggs of P. xylostella per T. exiguum female in the range of 18 to 32°C. Cumulated egg parasitism of P. xylostella by T. exiguum reached 80% after 10, 7, 8, 5, 5, 4 and 5 days at 18, 20, 22, 25, 28, 30 and 32°C. Higher parasitism rates were recorded at 25, 30 and 32°C while longevity of T. exiguum females varied from 4.2 to 7.4 days under temperatures of 18 to 32°C.

INFLUÊNCIA DA DENSIDADE DE OVOS DE Spodoptera frugiperda EM ALGUNS ASPECTOS BIOLÓGICOS DE TRÊS ESPÉCIES DE Trichogramma

O objetivo do presente trabalho foi determinar as isotermas de sorcao das espigas de milho para diversas condicoes de temperatura e umidade relativa do ar e ajustar diferentes modelos matematicos aos dados experimentais. Para obtencao do teor de agua de equilibrio higroscopico das espigas de milho foi utilizado o metodo estatico, em câmaras com temperatura controlada, contendo no seu interior dessecadores com solucoes salinas saturadas. A temperatura variou entre 10 e 50°C e a umidade relativa entre 0,11 e 0,84 (decimal). As amostras foram pesadas periodicamente, sendo o equilibrio higroscopio alcancado quando a variacao da massa das amostras foi igual ou inferior a 0,01 g. Os modelos matematicos recomendados pela ASAE foram ajustados as dados experimentais. Para a avaliacao do grau de ajuste de cada modelo considerou-se a magnitude do coeficiente de determinacao ajustado, erros medio relativo e estimado, e a verificacao do comportamento da distribuicao dos residuos. Conclui-se que a higroscopicidade da espiga de milho segue a mesma tendencia da maioria dos produtos agricolas e que os modelos de Chung-Pfost Modificado, Halsey Modificado e Oswin Modificado representam adequadamente o fenomeno.

É POSSÍVEL À ASSOCIAÇÃO PODISUS NIGRISPINUS E ESPÉCIES DE TRICHOGRAMMA EM UM PROGRAMA DE CONTROLE BIOLÓGICO EM FLORESTAS

Tem-se buscado alternativas para o controle de pragas no setor florestal. Uma possibilidade e a utilizacao do controle biologico com predadores e parasitoides. O objetivo deste trabalho foi avaliar o parasitismo de diferentes especies de Trichogramma em ovos de P. nigrispinus. Foram colados em retângulos de cartolina azul celeste 15 ovos, de P. nigrispinus, com um dia de idade. Foram utilizados ovos de uma mesma postura em cada tratamento. As cartelas contendo os ovos do predador foram expostas ao parasitismo de femeas de cinco especies de Trichogramma por 24 horas. Como testemunha, foram utilizados ovos de P. nigrispinus que nao foi submetido a presenca do parasitoide. Nao houve emergencia de adultos do parasitoide oriundos desses ovos e a viabilidade nao foi afetada por nenhuma das cinco especies utilizadas. O predador P. nigrispinus e o parasitoide Trichogramma podem ser utilizados em programas de controle biologico.

O EMBRIÃO DE THYRINTEINA ARNOBIA (LEPIDOPTERA: GEOMETRIDAE) PODE PRODUZIR PROTEÇÃO AO PARASITISMO DE ESPÉCIES DE TRICHOGRAMMA?

Lepidopteros desfolhadores causam danos a plantios de Eucalyptus. Uma alternativa de controle e o uso de Trichogramma, que embora tenha sido relatado parasitando varias especies em eucalipto, nao se encontra casos de parasitismo em T. arnobia. O objetivo deste trabalho foi avaliar o parasitismo de Trichogramma pratissolii Querino & Zucchi (Hymenoptera: Trichogrammatidae) em ovos inviaveis de T. arnobia. Ovos inviaveis de T. arnobia foram colados em retângulos de cartolina azul celeste, e expostos ao parasitismo de T. pratissolii por 24 horas. Apos esse periodo observou-se mortalidade 100% dos individuos, sendo que os ovos nao apresentaram parasitismo.