Neotropical Entomology (2002) 31, 109-113

Maria C. Nunes and Beatriz S. Corrêa-Ferreira (2002)
Danos Causados à Soja por Adultos de Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), Sadios e Parasitados por Hexacladia smithii Ashmead (Hymenoptera: Encyrtidae)
[Soybean damage by Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) non-parasitized and parasitized by Hexacladia smithii Ashmead (Hymenoptera: Encyrtidae)]
Neotropical Entomology 31 (1), 109-113
Abstract: Damage on soybean [Glycine max (L.) Merrill] caused by Euschistus heros (Fabricius) parasitized by Hexacladia smithii Ashmead was studied in greenhouse. Soybean plants, cultivar BR-37, were covered with nylon screen net and artificially infested with two bugs/plant, for a 15-day period, from the stage corresponding to the end of pod development (R4) up to filled seeds (R5-R6). Plants infested by non-parasitized bugs were compared with plants infested by bugs parasitized by H. smithii and with non-infested plants (control), with 20 replicates per treatment. The yield (g/plant), total number of pods and number of failed pods per plant did not differ between plants attacked by non-parasitized as well as by parasitized bugs, but they both differed from the control. Similarly, the qualitative analysis of seeds (good, medium and bad) and the tetrazolium test (punctured seeds, damaged seeds and vigor) demonstrated the same effect. However, the germination potentiality of the seeds attacked by parasitized bugs was higher than those seeds attacked by non-parasitized ones, indicating that less damage was caused by parasitized bugs.

O dano causado à soja [Glycine max (L.) Merrill] por Euschistus heros (Fabricius) parasitado por Hexacladia smithii Ashmead, foi estudado em casa-de-vegetação. Utilizaram-se plantas de soja da cultivar BR-37, cobertas com tela de filó, infestadas com dois percevejos/planta por um período de 15 dias, do final do desenvolvimento de vagens (R4) até o estádio de enchimento de grãos (R5-R6). Plantas infestadas com percevejos parasitados por H. smithii foram comparadas a plantas infestadas com percevejos sadios e a plantas livres do ataque de insetos (testemunha), com 20 repetições por tratamento. Pelos resultados obtidos, o rendimento (g/planta), o número total de vagens e o número de vagens chochas por planta foram semelhantes entre as plantas atacadas por percevejos sadios e parasitados por H. smithii, diferindo ambas da testemunha. Da mesma forma, a análise qualitativa dos grãos, através do teste visual (sementes boas, médias e ruins) e do tetrazólio (sementes picadas, sementes inviabilizadas e vigor), demonstrou que percevejos sadios e parasitados causaram danos estatisticamente iguais entre si e diferentes da testemunha. Entretanto, o potencial germinativo das sementes atacadas por percevejos parasitados foi maior do que o das sementes sugadas por percevejos sadios, demonstrando que ocorre menor dano quando os percevejos estão parasitados.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Portuguese)
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Database assignments for author(s): Beatriz S. Correa-Ferreira

Research topic(s) for pests/diseases/weeds:
damage/losses/economics
biocontrol - natural enemies
Research topic(s) for beneficials or antagonists:
general biology - morphology - evolution

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Euschistus heros	Soybean (Glycine max)
Hexacladia smithii (parasitoid)	Euschistus heros	Soybean (Glycine max)