Life-History of the White Mealy - Bug Ferrisia virgata (CKLL.) (Homoptera, Pseudococcidae)

Abstract

Five generations of Ferrisia virgata (CKLL.) have been reared per year; singly on sprouting potato tubers, although the fifth generation was not completed because of cold weather. This method produces only parthenogenic females, while males and females may be produced by dense rearing. Copulation was never observed, while oviposition behaviour and hatching process were described. Eggs are deposited singly and the incubation period averages 2.11–2.62 hr. with no significant difference under various thermal conditions. Hatchability ranges from 96.2–99.1%. Total nymphal duration in females averages 43.2 and 92.6 days at 28.9 and 16.6°C., respectively, while that in males elapses 25.4 days at 25.1–26.5°CC. Duration of the three nymphal instars of females and the four ones in males are estimated in various generations. The differences in duration between generations and those between instars within each generation were highly significant. Rate of mortality during nymphal stadia in the autumn/winter generations is higher than that in the spring/summer ones; being 14.3–100 and 0–23%, respectively. Longevity of parthenogenic ovipositing and non‐ovipositing females as well as that of males is estimated. The total life period (from egg to adult death) averages 76.2–154.6 days in females opposite to 19–47 in males. Eggs laid by a female averages 64.1–78 eggs; producing 61.6–67.6 nymphs/female/life. Average number of eggs/female/day averages 3.4–4.5 eggs. Three hymenopterous parasites and five predators are found associated with F. virgata. However, numbers of these bioagents are considerably low compared to the relatively high population of the pest.

Population growth and within-plant distribution of the striped mealybug Ferrisia virgata (Cockerell) (Hemiptera, Pseudococcidae) on cotton

“…Females were monitored daily to record the beginning of reproduction, which was characterized by the presence of ovisacs and first-instar nymphs around the female body. Moreover, the eggs were not observed because nymphs hatch within 4 h (Rawat & Modi 1969;Awadallah et al 1979). Thus, the presence of first-instar nymphs defines the end of the pre-oviposition period of F. virgata.…”

A taxonomic revision of the mealybug genus Ferrisia Fullaway (Hemiptera: Pseudococcidae), with descriptions of eight new species and a new genus

“…Ferrisia virgata is clearly ovoviparous because eggs hatch usually within 30 minutes of being laid (Ghose & Paul 1972). Fecundity per adult female has been reported as 64-78 eggs (Awadallah et al 1979b) to 222-737 eggs (Ghose & Paul 1972) under similar rearing conditions in the laboratory. In nature, the lower surface of leaves and the junction of the petiole with the stem were preferred oviposition sites on its main host plant in Egypt, A. macrophylla [this may refer to the cultivar A. wilkesiana "macrophylla'] (Awadallah et al 1979b).…”

“…With the exception of records of F. malvastra, all other reports of Ferrisia from outside of the Nearctic and Neotropical regions are of F. virgata. Thus descriptions of immature stages (Awadallah et al 1979a;Paul & Ghose 1989) and studies of the biology (e.g., Ghose & Paul 1972;Awadallah et al 1979b) of F. virgata in Egypt and India probably do refer to this species. Ferrisia virgata has been reported widely as a destructive pest on ornamental plants in India (reviewed by Ghose & Paul 1972).…”

“…Ferrisia virgata has been reported widely as a destructive pest on ornamental plants in India (reviewed by Ghose & Paul 1972). Awadallah et al (1979b) found that F. virgata produced five generations per year if maintained on sprouting potato tubers at temperatures ranging from 16-29°C and 54-71% RH. These authors reported production of males if the mealybugs were maintained at high density on either potato sprouts or on Acalypha foliage, and claimed the occurrence of parthenogenetic reproduction for females maintained singly (but not isolated).…”

“…(Encrytidae) and two Tetrastichus spp. (Eulophidae), three species of Coccinellidae and two species of Neuroptera were reported as natural enemies in Egypt (Awadallah et al 1979b), although numbers were low relative to the high numbers of mealybugs. In India, Ghose & Paul (1972) recorded only a coccinellid predator (Scymnus sp.…”