Thermal requirements of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) lines in Neoleucinodes elegantalis (Lepidoptera: Crambidae) eggs.

This study aimed to evaluate the impact of temperature on the development of two lines of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae), to determine the thermal requirements of this parasitoid wasp on Neoleucinodes elegantalis (Lepidoptera: Crambidae) eggs. The experiment was carried out with two lines (“Ubajara” and “Guaraciaba”, Ceará State) of T. pretiosum collected naturally parasitizing eggs of N. elegantalis in tomato (Solanum lycopersicum) fruits. In this experiment, 40 eggs of the host N. elegantalis and 4 females of the parasitoids were used, with exposure to parasitism for 24 hours at 25 ± 1 °C, relative humidity of 70 ± 10 %, and 12-h photophase. At the end of this period, females were removed and the tubes were transferred to incubators (RH = 70 ± 10 %; 12-h photophase), exposed to 15, 20, 25, 30, or 35 °C, until emergence of the following generation of the parasitoids. The percentage of emergence, sex ratio, the number of parasitoids that emerged per egg, and cycle duration were assessed. The experiments were set up in a completely randomized experimental design with 5 treatments (temperatures) and 12 replicates. ANOVA was conducted and the means were compared by Tukey test (P < 0.05). The base temperatures were 10.77 °C and 10.86 °C and the number of generations per year were 33.29 and 35.63 for “Ubajara” and “Guaraciaba”, respectively. The study showed that temperature changed the biological parameters, and cycle duration of the “Ubajara” and “Guaraciaba” lines decreased as temperature increased

Requerimientos térmicos de las líneas de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae) en huevos de Neoleucinodes elegantalis (Lepidoptera: Crambidae)

This study aimed to evaluate the impact of temperature on the development of two lines of Trichogramma pretiosum (Hymenoptera: Trichogrammatidae), to determine the thermal requirements of this parasitoid wasp on Neoleucinodes elegantalis (Lepidoptera: Crambidae) eggs. The experiment was carried out with two lines (“Ubajara” and “Guaraciaba”, Ceará State) of T. pretiosum collected naturally parasitizing eggs of N. elegantalis in tomato (Solanum lycopersicum) fruits. In this experiment, 40 eggs of the host N. elegantalis and 4 females of the parasitoids were used, with exposure to parasitism for 24 hours at 25 ± 1 °C, relative humidity of 70 ± 10 %, and 12-h photophase. At the end of this period, females were removed and the tubes were transferred to incubators (RH = 70 ± 10 %; 12-h photophase), exposed to 15, 20, 25, 30, or 35 °C, until emergence of the following generation of the parasitoids. The percentage of emergence, sex ratio, the number of parasitoids that emerged per egg, and cycle duration were assessed. The experiments were set up in a completely randomized experimental design with 5 treatments (temperatures) and 12 replicates. ANOVA was conducted and the means were compared by Tukey test (P &lt; 0.05). The base temperatures were 10.77 °C and 10.86 °C and the number of generations per year were 33.29 and 35.63 for “Ubajara” and “Guaraciaba”, respectively. The study showed that temperature changed the biological parameters, and cycle duration of the “Ubajara” and “Guaraciaba” lines decreased as temperature increased.El objetivo de este estudio fue evaluar el impacto de la temperatura en el desarrollo de dos líneas de Trichogramma pretiosum (Hymenoptera: Trichogrammatidae), para determinar los requisitos térmicos de este parasitoide en huevos de Neoleucinodes elegantalis (Lepidoptera: Crambidae). El experimento se llevó a cabo con dos líneas (“Ubajara” y “Guaraciaba”, Ceará) de T. pretiosum a partir de huevos parasitarios de N. elegantalis en frutos de tomate (Solanum lycopersicum). En este experimento, se usaron 40 huevos del huésped N. elegantalis y 4 hembras de los parasitoides, con exposición al parasitismo durante 24 horas (a 25 ± 1 °C, 70 ± 10 % de HR y fotofase de 12 h). Al final de este período, se retiraron las hembras y los tubos se transfirieron a incubadoras (HR = 70 ± 10 % y fotofase de 12 h, a 15, 20, 25, 30 o 35 °C, hasta la aparición de la generación siguiente de parasitoides. Los parámetros evaluados fueron el porcentaje de emergencia, la proporción de sexos, el número de parasitoides que surgieron por huevo y la duración del ciclo. Los experimentos se establecieron en un diseño experimental completamente al azar con cinco tratamientos (temperaturas) y 12 repeticiones. Se realizó ANOVA y se compararon las medias mediante la prueba de Tukey. La temperatura base fue de 10,77 y 10,86 °C y el número de generaciones por año fue de 33,29 y 35,63 para “Ubajara” y “Guaraciaba”, respectivamente. La temperatura cambió los parámetros biológicos, y la duración del ciclo de las líneas “Ubajara” y “Guaraciaba” disminuyó a medida que aumentaba la temperatura