Gullan, P.J. 2000 Identification of the immature instars of mealybugs (Hemiptera: Pseudococcidae) found on citrus in Australia.. Australian Journal of Entomology 39: 160-166.
Notes: An identification guide is provided to most of the immature stages of six mealybug species (Hemiptera: Coccoidea: Pseudococcidae) that might be collected from citrus (Rutaceae) in Australia. This information is important for foreign quarantine inspections because mealybugs intercepted on Australian citrus exports are often nymphs. A key and a table, based on microscopic features, allow separation of the first-, second- and third-instar nymphs and identification to species for second- and third-instar females. Selected diagnostic features of second-instar females are illustrated. Second-instar male nymphs also can be identified as they resemble the second-instar females of their species except for the possession of dorsal ducts that secrete the wax of the male cocoon. Immatures stages are diagnosed for the pink hibiscus mealybug Maconellicoccus hirsutus (Green), the spherical mealybug Nipaecoccus viridis (Newstead), the citrus mealybug Planococcus citri (Risso), the citrophilous mealybug Pseudococcus calceolariae (Maskell), the longtailed mealybug Pseudococcus longispinus (Targioni Tozzetti), and the tuber mealybug Pseudococcus viburni (Signoret) [formerly Pseudococcus affinis (Maskell)].