Effect of pollen of different plant species on the oviposition of two phytoseiid mites (Acari: Phytoseiidae) commonly found in citrus orchards in the Brazilian Amazonia

Abstract

The suitability of the use of pollen to foster the control of citrus pests by facilitating the maintenance of predatory mites in the area has been extensively studied. The aim of this study was to evaluate the effect of pollen of 13 plant species commonly found in Manaus region (Brazilian Amazonia) on the oviposition of Amblyseius aerialis and Iphiseiodes zuluagai, phytoseiid species abundant in citrus orchards in that region. The study was conducted under laboratory conditions, using mostly pollen grains recently collected in the field. For comparison, a commercially available pollen (ECOPolen) and pollen obtained from two bee species were also included in the study. For about 65% of the evaluated pollen types, the average oviposition was low (less than 0.4 egg/female/day). These differed from other pollen types by the speculate wall (sunflower) or high hygroscopic property (Agave sp., Amaryllis sp., Citrus sinensis, Helianthus annuus and Turnera ulmifolia), or were collected by Apis mellifera. Highest oviposition levels of A. aerialis were obtained on pollen of Typha dominguensis, Elaeis guineensis, Cocos nucifera and the commercial pollen (1.9, 1.5, 0.9 and 0.9 eggs/female/day, respectively). For I. zuluagai, highest levels of oviposition were obtained on E. guineensis, C. nucifera, T. dominguensis, and Elaeis oleifera (1.6, 1.5, 1.2 and 0.9 egg/female/day, respectively). These results suggest that C. nucifera, E. guineensis and E. oleifera, found in the vicinity of citrus orchards in Manaus region, may play a role in maintaining predatory mite populations in such orchards. Complementary studies are needed to investigate the feasibility of maintaining those plants near orchards to increase the abundance of the predators.