Reproduction of Trichospilus diatraeae (Hymenoptera: Eulophidae) in the pupae of Diaphania hyalinata (Lepidoptera: Crambidae) of various ages

Isabel Moreira Silva, Teresinha Vinha Zanuncio, Fabricio Fagundes Pereira, Carlos Frederico Wilcken, José Eduardo Serrão, Jose Cola Zanuncio

Abstract


Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) is a gregarious parasitoid of a wide variety of lepidopterans including melonworm, Diaphania hyalinata L. (Lepidoptera: Crambidae), pupae in the field. The latter is a key pest of Cucurbitaceae; it primarily damages their leaves and secondarily their fruit, and it reduces the productivity of the plants. The aim of this study was to determine the effect of the age of D. hyalinata pupae on the development of T. diatraeae. Diaphania hyalinata pupae aged 24, 48, 72, 96, 120, and 144 h were individualized and exposed to eight 48-h-old T. diatraeae females for 24 h. The emergence and parasitism rates, sex ratios, and longevities of T. diatraeae males and females were found to be similar with D. hyalinata pupae of different ages. The number of progeny, width of the head capsule, and duration of the life cycle (egg to adult) of T. diatraeae decreased with the increasing age of D. hyalinata pupae. Importantly, the number of parasitoid progeny per host pupa and size of the parasitoid adults were larger when 24-h-old host pupae were parasitized than when 48- to 144-h-old pupae were parasitized. Trichospilus diatraeae was very effective in parasitizing D. hyalinata pupae of ages ranging from 24 to 144 h.

 

Resumo

Trichospilus diatraeae Cherian e Margabandhu (Hymenoptera: Eulophidae) é um parasitoide gregário de uma ampla variedade de Lepidoptera e parasitou pupas de Diaphania hyalinata L. (Lepidoptera: Crambidae) em campo. Este inseto é praga chave e causa desfolha e redução da produtividade de Cucurbitaceae. O objetivo deste estudo foi avaliar o efeito da idade de pupas de D. hyalinata no desenvolvimento de T. diatraeae. Pupas de D. hyalinata com idades de 24, 48, 72, 96, 120 e 144 h foram individualmente expostas a oito fêmeas de T. diatraeae com 48 h de idade, por 24 h. A taxa de emergência e parasitismo, razão sexual e longevidade de machos e fêmeas de T. diatraeae foram semelhante para pupas de diferentes idades de D. hyalinata. A progênie, largura da cápsula cefálica e duração do ciclo de vida (ovo a adulto) de T. diatraeae diminuiu com o aumento da idade de pupas de D. hyalinata. Trichospilus diatraeae foi eficaz no parasitismo de pupas de D. hyalinata com diferentes idades.

 

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Keywords


host pupa age; oviposition; host quality

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