Preference of Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) for weed and cultivated species

Abstract

Being capable of infesting a wide variety of plant species, the whitefly Bemisia tabaci MEAM1 (Hemiptera: Aleyrodidae) is responsible for severe losses in numerous agricultural crops. In order to increase knowledge regarding interactions involving B. tabaci MEAM1 and plants associated with agricultural landscapes, the present study sought to identify preferential hosts by comparing 15 different common weed species and five cultivated plants (tomato, bell pepper, soybean, maize and cotton) through free and no-choice tests. Additionally, a possible correlation between physical-morphological plant aspects and insect’s colonization behavior was assessed. Positive correlations were verified between the oviposition index and trichome density, and between the number of adults and b* (yellow intensity) index. Negative correlations were observed between the number of adults and L* and a* (luminosity and green intensity, respectively) indexes. In the free choice test, the species Solanum lycopersicum, Senna obtusifolia, Glycine max, Emilia sonchifolia and Euphorbia heterophylla were the most infested during the mean of the evaluation periods, differing from Spermacoce latifolia, Amaranthus viridis and Richardia brasiliensis, which presented the lowest means of insect infestation. In this same test, S. lycopersicum and E. sonchifolia had the greatest oviposition, differing from most of the species. In the no-choice test, E. heterophylla, Galinsoga parviflora and S. latifolia had the highest means of eggs and nymphs per cm². Our results show evidence of the expressive potential of weed species frequently found in Brazilian agricultural fields, such as E. sonchifolia, S. obtusifolia, and E. heterophylla, as alternative hosts of B. tabaci MEAM1.