Parasitism capacity of Telenomus remus Nixon (Hymenoptera: Scelionidae) on Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) eggs

Abstract

This work studied the parasitism capacity of Telenomus remus Nixon (Hymenoptera: Scelionidae) on Spodoptera frugiperda (Smith) (Hymenoptera: Scelionidae) eggs at 15, 20, 25, 28, 31, and 35°C, aiming to use this natural enemy in biological control programs in crops where S. frugiperda was considered pest. The parasitism during the first 24 h was 60.90, 81.65, 121.05, 117.55 and 108.55 parasited eggs per female from egg masses of approximately 150 eggs, at 15, 20, 25, 28 and 31°C, respectively. Females of T. remus reached parasitism higher than 80% at 15, 20, 25, 28 and 31ºC at 5, 27, 8, 2, and 2 days, respectively. At 35ºC, there was no parasitism. The highest parasitism rates occurred at 20, 25, 28 and 31°C. T. remus female longevity varied from 15.7 to 7.7 days from 15 to 31°C. The highest tested temperature (35°C) was inappropriate for T. remus development. At that temperature, female longevity was greatly reduced (1.7±0.02) and egg viability was null. All T. remus survival curves were of type I, which showed an increase in mortality rate with time.Este trabalho estudou a capacidade de parasitismo de Telenomus remus Nixon (Hymenoptera: Scelionidae) em ovos de Spodoptera frugiperda (Smith) (Hymenoptera: Scelionidae) nas temperaturas de 15, 20, 25, 28, 31 e 35ºC objetivando usar esse inimigo natural em programas de controle biológico em culturas onde S. frugiperda é considerada praga. O parasitismo ocorrido nas primeiras 24 h foi de 60,90; 81,65; 121,05; 117,55 e 108,55 ovos parasitados por fêmea em massas ovos com aproximadamente 150 ovos, nas temperaturas de 15, 20, 25, 28 e 31ºC. Fêmeas de T. remus causaram mais de 80% do parasitismo dos ovos nas temperaturas de 15, 20, 25, 28 e 31ºC aos 5, 27, 8, 2 e 2 dias, respectivamente. Na temperatura de 35ºC não houve parasitismo. As maiores taxas de parasitismo ocorreram nas temperaturas de 20, 25, 28 e 31ºC. A longevidade média de fêmeas de T. remus nas temperaturas compreendidas entre 15 e 31ºC variou de 15,5 a 7,7 dias. A temperatura máxima testada (35ºC) foi inadequada ao desenvolvimento de T. remus, sendo que nessa temperatura as fêmeas apresentaram longevidade bastante reduzida (1,7±0,02 dia) e não houve emergência de adultos. Todas as curvas de sobrevivência para T. remus foram do tipo I o que mostram que para todas as temperaturas há um aumento da taxa de mortalidade com o tempo.

Keywords

• Eggs parasitoid
• fall armyworm
• biological control
• Integrated Pest Management