Increasing distribution, biology and population dynamics of invasive woolly whitefly, Aleurothrixus floccosus on guava

Abstract

Distribution, population dynamics, natural enemies and biology of recently introduced woolly whitefly Aleurothrixus floccosus (Maskell) (Hemiptera: Aleyrodidae) was studied on guava (Psidium guajava L.). The study revealed the further spread of this pest to Karnataka, Tamilnadu and Lakshadweep within span of one year and well established on guava. Severity of infestation was varied from 10.16 to 100% across the different study locations, thus indicating the potential of the pest to spread to all guava growing areas in India. So far, no parasitism has been found on the pest in India except few predators viz., Pseudomallada astur Banks (Neuroptera: Chrysopidae), Acletoxenus indicus Malloch (Diptera: Drosophilidae), Cryptolaemus montrouzieri (Mulsant) and Scymnus nr. utilis Hoang (Coleoptera: Coccinellidae). The population of eggs, nymphs and adults of A. floccosus were relative high during dry season months (November-January) and generally very low during rainy season (June-September) in Karnataka. The mean developmental time of egg (incubation), first instar, second instar, third instar and fourth instar was 9.8 ± 0.75, 3.4 ± 0.49, 2.8 ± 0.40 and 5.8 ± 0.75 days, respectively. A. floccosus took 20.4 ± 1.74 days to complete development (egg-adult) and total life span was 51.6 ± 2.80 days including adult longevity on guava. Average fecundity was found as 81.76 ± 3.58 eggs/ female and laid eggs within a day after emergence. This information would help in formulating management strategies of this invasive pest in guava.