Host selection and establishment of striped mealybug, Ferrisia virgata, on cotton cultivars

The striped mealybug, Ferrisia virgata (Hemiptera: Pseudococcidae), is a polyphagous and cosmopolitan species, which attacks a wide variety of crops, including cotton. Lately, it has been found infesting colored fiber cotton and emerging as an important pest in the Northeast of Brazil. Therefore, this study investigated the effects of colonization, establishment, plant distribution and dispersal of F. virgata on cotton cultivars. Preference experiments were set up in the laboratory and in the greenhouse, in which cultivars were offered simultaneously to nymphs or females and the number of insects on each cultivar was counted after 24 h, 48 h, 22 days and 60 days, respectively. Meanwhile, attack of different plant structures and dispersal were investigated under field conditions. Results showed that F. virgata is able to become established on colored cotton fiber cultivars (BRS Verde, BRS Rubi, and BRS Safira) as well as on white cotton cultivars (BRS 201 and CNPA 7H) without showing any preference among these cultivars. Females produce a large number of offspring to enhance nymph survival and host plant colonization, since the number of first instars successfully established after migration is low (<10%). In addition, its short range dispersal can easily occur from plant to plant. Therefore, strategies to manage F. virgata will be needed to facilitate colored cotton production, especially in organic farms infested by this mealybug species.