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.

O objetivo deste trabalho foi estudar a capacidade de parasitismo de Trichogramma pretiosum Riley e de Trichogramma acacioi Brun, Moraes and Soares (Hymenoptera: Trichogrammatidae) em ovos do hospedeiro alternativo Sitotroga cerealella (Olivier) (Lepidoptera: Gelechiidae), visando o uso desses inimigos naturais em programas de controle biológico da praga do abacateiro Nipteria panacea Tierry-Mieg (Lepidoptera: Geometridae). O ritmo de parasitismo de T. acacioi e T. pretiosum variou com a temperatura, sendo maior nas primeiras 24 horas de vida desses parasitóides. Além disso, o período de parasitismo foi maior para essas duas espécies de parasitóides na menor temperatura, enquanto o parasitismo total por fêmea variou com a temperatura.

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 exigências térmicas de Trichogramma pretiosum e T. acacioi (Hymenoptera: Trichogrammatidae), parasitóides 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 biológico desta praga em pomares de abacate. T. pretiosum apresentou temperaturas base (Tb) de 10.70 e 10.75°C e constantes térmicas (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.

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.