Mites associated with açaí palm trees (Euterpe oleracea: Arecaceae) in native and cultivated areas of the state of Pará (Eastern Amazon, Brazil)

Abstract

The objective was to quantify and analyse the diversity of mites associated with native and cultivated açaí palms crops, as well as their distribution in the dry and rainy seasons in the municipalities of Bragança and Augusto Corrêa, state of Pará. Rarefaction curves were generated for diversity values using the statistical programming language R, rarefaction curves for estimates of richness and equitability and analysis of variance with permutations. A total of 2,069 mites from 28 families were sampled, being most representative Phytoseiidae (32.4%), Phytoptidae (13%), Cunaxidae (7.7%), Tetranychidae (5.6%) and Tydeidae (4.9%). Among predators, the most abundant species were Amblyseius sp. 1, Armascirus amazoniensis Wurlitzer & Silva, Iphiseiodes zuluagai Denmark & Muma, Scutopalus tomentosus Rocha, Skvarla & Ferla, and the phytophagous mites Acaphyllisa sp., Davisella sp., Oligonychus sp. and Retracus johnstoni Keifer. In the rainy season, more mites were sampled (n = 1,176) than in the dry season (n = 893). The greatest richness was observed in the dry period (73 species) and diversity was also greater in this period. In the municipality of Bragança there was greater richness (78 species) and the cultivated açaí trees had greater acarine abundance (74.7%) than the native ones. However, natives had slightly higher wealth (6%) than those cultivated. The diversity and richness of predatory mites show the potential of the Amazon biome to be used in applied biological control. (Santos et al. 2015). The occurrence of mite species in high populations can compromise the productivity of açaí groves, and it is important to identify arthropods that cause damage and injuries. In view of this, the need to know and identify the associated acarofauna, highlighting the phytophagous and predatory mites, is justi ed, aiming to create possibilities for alternative control of pest mites in that crop. This work aimed to understand the acarofauna associated with native açaí crops and cultivated in the dry and rainy seasons, as well as their distribution on the plant, in the municipalities of Bragança and Augusto Corrêa, state of Pará. Materials and methods Study location and sampling procedureThe study was carried Northeast of the state of Pará. The collections were carried out in commercial areas at Fazenda Alto Arajivu (coordinates 1º10'18.6''S, 46º43'49.3"W), at 41 m altitude and Sítio Jiquiri (1°03'59.8"S 46°44'40.0"W) 16 m above sea level, in areas of natural and commercial açaí cultivation in the Bragança (Bragantina microregion) and Augusto Corrêa, in the Sítio Coisas da Roça (1º03'58.91"S 46º66'23.30"W) and Fazenda Bacuri (1º04'11.10"S 46º66'33.82"W) (Fig. 1).