Arthropods associated with young orchard of pecan in southern Brazil / Artrópodes associados a um plantio jovem de nogueira-pecã no sul do Brasil

A produção mundial de noz-pecã Carya illinoinensis (Juglandaceae) é liderada pelos Estados Unidos. No Brasil, em especial no Rio Grande do Sul, houve uma expansão da área plantada com a cultura nos últimos anos. No entanto, faltam pesquisas relacionadas à entomofauna associada à noz-pecã, bem como práticas culturais que auxiliem no Manejo Integrado de Pragas, mesmo havendo uma expansão da cultura. Assim, o presente estudo objetivou avaliar a fauna de artrópodes na copa de plantas de C. illinoinensis, submetido a diferentes manejos de solo, em Santa Maria, Rio Grande do Sul, Brasil. Para tanto, utilizou-se delineamento experimental de blocos ao acaso, com cinco blocos e quatro tratamentos: plantio em cova pequena, com 20 × 60 cm (Sp); utilização de subsolador mais grade niveladora e cova pequena (Ssp); utilização de enxada rotativa e cova pequena (Tsp); e plantio em cova grande, com 40 × 60 cm (Lp). De novembro de 2014 a maio de 2015, foram coletadas 7.617 espécimes nas copas de árvores jovens de nogueira-pecã. Foram identificados 150 grupos taxonômicos, sendo Coleoptera a ordem com maior riqueza de espécies. Monellia caryella (Hemiptera: Aphididae) apresentou elevada densidade. Foram registrados os inimigos naturais himenópteros parasitoides e Coccinellidae. Conclui-se que a artropodofauna em copas de plantas jovens de nogueira-pecã apresenta diversidade similar entre os tratamentos e predomínio de M. caryella nas áreas avaliadas.(AU)

World production of pecan Carya illinoinensis (Juglandaceae) is led by the United States. In Brazil, especially in the Rio Grande do Sul State, there has been an expansion of the planted area in recent years. Despite this expansion of pecan culture, there is a lack of research on entomofauna associated with pecan and on cultural practices which aids in Integrated Pest Management. This study aimed to evaluate the arthropod fauna in the canopies of C. illinoinensis trees grown under different soil management practices in Santa Maria, Rio Grande do Sul, Brazil. A randomized design was used with five blocks and four treatments: planting in small pits of 20 × 60 cm (Sp) using a subsoiler with a leveling grader/shank, planting in small pits (Ssp) using a rotary tiller (Tsp), and planting in large pits of 40 × 60 cm (Lp). A total of 7,617 specimens were collected from November 2014 to May 2015 from the young pecan canopies. Among the 150 taxonomic groups identified, Coleoptera was the most taxonomically rich order. The blackmargined aphid Monellia caryella (Hemiptera: Aphididae) had the greatest abundance. Hymenopteran parasitoids and Coccinellidae spp. were among the natural pest enemies detected. We conclude that the arthropod fauna found in the young pecan canopies is similarly diverse among the different soil managements, with a predominance of pest species M. caryella in all the evaluated areas.(AU)

Occurrence of Amblycerus species in Cordia trichotoma seeds and their influence on germination

ABSTRACT Forest species can have their seeds damaged by granivorous insects, especially by those in their larval stage. In this context, this study aims to report the occurrence of Amblycerus species in Cordia trichotoma seeds, to describe their main damage to seeds and effects on germination, as well as their associated hymenopteran parasitoids. Therefore, seven trees were selected in the municipality of Taquaruçu do Sul, RS, Brazil. Fruits were collected weekly from the medium third of the tree crown, from the beginning of their formation until total dehiscence. To examine the damage caused by granivorous insects within the fruits, 15 fruits from each tree were sectioned with a scalpel. Furthermore, 10 fruits from each tree were stored individually in clear plates to verify the occurrence and identification of granivorous insect species. Evidence of the damage caused to seeds was verified through the germination test by comparing preserved and damaged seeds, with four repetitions of 25 seeds each. The species Amblycerus longesuturalis and Amblycerus profaupar (Chrysomelidae: Bruchinae) were found associated with fruits of C. trichotoma. Female insects predominantly laid eggs on the superior part between the marcescent calyx and the fruit, and larvae perforated the fruit tegument to start consuming seed embryos and reserves. Bruquine larvae are parasitized by Hymenoptera of Bracon, Mirax, Omeganastatus and Triapsis genera. In conclusion, the germination of C. trichotoma seeds is significantly affected by emergence orifices caused by granivorous species.