Seasonal Occurrence and Reproductive Suitability of Weed Hosts for Sweetpotato Whitefly, Bemisia tabaci (Hemiptera: Aleyrodidae), in South Georgia

Abstract

Abstract South Georgia represents an area of intensive agricultural production where cultivated crops serve as hosts of the sweetpotato whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), throughout the year. In addition to cultivated hosts, there are numerous weed species present in the agricultural landscape that are undoubtedly responsible for supporting B. tabaci population development. This study provided information on the most abundant weed hosts of B. tabaci from this region. We evaluated 31 different weed species, of which 16 weed species are reproductive hosts with varying degrees of preference. Suitable weed hosts included cypressvine morningglory (Ipomoea quamoclit L.), nodding spurge (Euphorbia nutans Lag.), prickly sida (Sida spinosa L.), sharppod morningglory (Ipomoea cordatotriloba Dennst.), smallflower morningglory (Jacquemontia tamnifolia L.), tall vervain (Verbena bonariensis L.), and wild poinsettia (Euphorbia heterophylla L.). These species are highly abundant and therefore likely influence B. tabaci populations in the landscape. Other species including bristly starbur (Acanthospermum hispidum DC) and redweed (Melochia corchorifolia L.) were highly preferred by B. tabaci but not nearly as abundant in the landscape. Furthermore, we identified 10 very common weed species that were poor reproductive hosts including wild radish (Raphanus raphanistrum L.), Palmer amaranth (Amaranthus palmeri S. Watson), common ragweed (Ambrosia artemisiifolia L.), Florida pusley (Richardia scabra L.), and henbit (Lamium amplexicaule L.).