Planococcus vovae (Nasonov)
Taxonomic placing: Insecta, Hemimetabola, Hemiptera, Sternorrhyncha, Coccomorpha, Coccoidea, Pseudococcidae.
Common name: Cypress mealybug.
Geographical distribution: A Trans-Palaearctic species that occurs from Central Europe to sea level in most Mediterranean countries.
Host plants: Only members of the family Cupressaceae.
Morphology: The adult female is about 3.0 mm long, its size dependending on the host plant, specific feeding site and the infestation density. The oval body is reddish under the white-grey mealy wax and the abdomen segmentation is clear. Antennae are 8-segmented, covered with thin white wax flecks. It lacks ventral multilocular disc pores on the lateral abdominal margins. Male pupae develop in a cottony-white cocoon. The emerging male is about 1.0 mm long, with red eyes and two caudal filaments that are slightly longer than the body. The female nymphs and two early male instars are similar to the female, but smaller.
Life cycle: Oviposition starts 2-3 days after mating, lasting for 2 weeks, the female producing a waxy ovisac, that contains 50-450 eggs. Fecundity is highest in the spring, lower during late summer and autumn. After hatching the crawlers settle on small twigs and on male flowers, initially occurring in small aggregates, usually under protecting shelters such as scales or brachyblasts. They undergo 3 nymphal stages; the male develops only through two stages, a prepupa and a pupa. Feeding ceases at the prepupal stage, when the insect seeks a pupation site, frequently on leaves at the growth edges. Young females disperse by walking along branches, chosing trees with dense crowns, preferring to feed on twig stems and small-diameter branches. Development lasts 30 days at 30°C. They usually congregate at the bases of the whorls or on side shoots. By October the females produce the hibernating neonates that are usually smaller than those that occur in early summer. As temperatures drop in autumn they hide. In the Middle East the cypress mealybug raises 3-4 annual generations, whereas in cooler climates and in central Europe only two annual generations occur.
Economic importance: This mealybug is an important pest of Juniperus spp., Cupressus spp. and Thuja spp. Damage is due to toxins injected into the plants, manifested by a yellowing of growth and eventual die-back of branches, growth stagnation, drying of needles and branches, and even death of heavily infested plants. In addition, the foliage and branches become soiled by the scale’s honeydew, which is colonized by sootymold fungi. The pest’s occurrence in natural and planted cypress forests in the Middle East is negligible, but the ornamental bluish and yellow-greenish juniper varieties are susceptible. High scale populations frequently occur on windbreak cypress belts around citrus orchards; economic injury to such trees has rarely been seen. These mealybugs probably serve as hosts and prey for the natural enemies that occur in the citrus orchards and attack their mealybug pests.
Management
Monitoring: The pest’s populations are monitored by sex pheromone traps
Chemical control: There is no current need for chemical control measures against the pest in cypress plantations or on windbreaks. If necessary, the pest could effectively be controlled by the organophosphate azinphos-methyl as a foliar spray or by a soil application of the systemic neonicotinoid imidacloprid.
Biological control: Several parasitoids of the families Encyrtidae, Eulophidae and Pteromalidae attack the pest. Their effect may be reduced by encapsulation. Common non-specific predators include Scymnus pallidivestris Mulsant (Coccinellidae), Dicrodiplosis sp. (Cecidomyiidae), and Chrysoperla carnea (Stephens) (Chrysopidae).
References
Blumberg, D., Klein, M. and Mendel, Z. 1995. Response by encapsulation of four mealybug species (Homoptera: Pseudococcidae) to parasitization by Anagyrus pseudococci. Phytoparasitica 23: 157-163.
Francardi, V. and Covassi, M. 1992. Biological and ecological notes on Planococcus vovae (Nasonov) (Homoptera Pseudococcidae) living on Juniperus spp. in Tuscany. Redia 75: 1-20.
Graora, D., Spasić, R. and Ilić, S. 2014. Biology and harmfulness of Planococcus vovae (Nassonov) (Hemiptera: Pseudococcidae) in Belgrade area. Pesticides and Phytomedicine (Belgrade) 29: 67–74.
Samani, T. 2007. Aspects of the reproductive biology of the cypress mealybug Planococcus vovae (Hemiptera: Pseudococcidae). M. Ag.Sc. Thesis, 56 pp. (in Hebrew, with an English Abstract).
Talebi, A.A., Ameri, A., Fathipour, Y., and Rakhshani, E. 2008. Natural enemies of cypress tree mealybug, Planococcus vovae (Nasonov) (Hem. Pseudococcidae), and their parasitoids in Tehran, Iran. Journal Agricultural Science and Technology 10: 123-133.
Williams, D.J. and Moghaddam, M. 1999. Mealybug species of the genus Planococcus Ferris in Iran (Homoptera: Coccoidea: Pseudococcidae) with a discussion of Planococcus vovae (Nasonov). Journal of Entomological Society of Iran 18: 32-43.
Authors:
Zvi Mendel and Alex Protasov. E-mail: zmendel@volcani.agri.gov.il. Agricultural Research Organization; The Volcani Center Department of Entomology; P.O. Box 6, Bet-Dagan, 50250, Israel. Tel.: 972-3-9683636; Fax: 972-3-9683849
Daniel Blumberg. Email: dblum@volcani.agri.gov.il Agricultural Research Organization; The Volcani Center Department of Entomology; P. O. Box 6, Bet Dagan 50250, Israel. Tel.: 972-3-9683518; Fax: 972-3-9604180