Description of adult and immature female instars of Pseudococcus viburni (Hemiptera: Pseudococcidae) found on apple in South Africa
Pseudococcus viburni (Signoret), commonly known as the obscure mealybug, was responsible for the rejection of large consignments of South African apple fruits destined for the U.S.A. market during 2002 because the immature stages could not be identified. Thus an identification guide is required as an aid to the correct identification of all developmental stages of this species before or during foreign quarantine inspections on export fruits. The first-instar, second-instar female, third-instar female and adult female were described from mealybug populations on field-collected apples (Malus domestica Korkh.). Illustrations and a diagnostic key to the different stages are provided. Morphometeric characteristics useful for separating the stages are discussed.