COLD STORAGE OF TRICHOGRAMMA PRETIOSUM RILEY (HYMENOPTERA: TRICHOGRAMMATIDAE)

The objective of this work was to evaluate the effect of storage at low temperature of Trichogramma pretiosum pupae in eggs of Sitotroga cerealella on the emergence and reproduction rates of the parasitoid. The trials were conducted in a climatic chamber at 5, 8 and 10 degree C, 70% R.H., constant scotophase, with 10 treatments: 4, 6, 8, 10, 12, 14, 16, 18, 20 days of storage and a control not kept in storage, all in 10 replicates. A total of 1,000 eggs containing pupae were distributed in glass tubes (10 x 3 cm), 100 of which were kept at 25 degree C, 70% RH and 14 h photophase (control), while the remaining ones were stored. After each storage period 100 eggs were transferred to 25 degree C and the emergence and reproductive capacity were observed. The T. pretiosum emergence rate was not affected by the storage time at 3 temperatures (Tukey P less than or equal to 0.05) and the lowest emergence rates were 85.6%, 84.5% and 77.6%, respectively for parasitoid storage at 5, 8 and 10 degree C. The reproductive capacity of T. pretiosum was not affected after the exposure periods in the temperatures evaluated. This result will aid in the planning of mass production, package and transport of T. pretiosum to the place of release.Original Abstract: Avaliou-se o efeito do armazenamento em baixa tempera tura de pupas de Trichogrammapretiosum, em ovos de Sitotroga cerealella, sobre a emergencia e a viabilidade reprodutiva do parasitoide. Os testes foram conduzidos em camara climatica a 5, 8 e 10 degree C, 70% UR, escotofase constante, com 10 tratamentos (testemunha, 4,6,8,10,12,14,16,18 e 20 dias de armazenamento) e 10 repeticoes. Foram distribuidos 1.000 ovos contendo pupas em tubos de ensaio (10 x 3 cm), 100 foram mantidos a 25 degree C, 70% UR e 14 horas de fotofase (testemunha) e os demais armazenados. Apos cada periodo de armazenamento, 100 ovos foram transferidos para 25 degree C e avaliados quanto a emergencia e funcoes reprodutivas. A emergencia de T. pretiosum nao foi influenciada pelo periodo de armazenamento nas tres temperaturas (Tukey P less than or equal to 0,05) e as menores taxas de emergencia foram de 85,6%, 84,5% e 77,6%, respectivamente para os parasitoides armazenados a 5, 8 e 10 degree C. Nao houve perda da viabilidade reprodutiva dos parasitoides provenientes da estocagem nas temperaturas avaliadas, pois todas as femeas acasaladas produziram individuos de ambos os sexos. Estes resultados auxi-liarao no planejamento da criacao massal, embalagem e