Pseudococcus viburni
Pseudococcus viburni | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Insecta |
Order: | Hemiptera |
Suborder: | Sternorrhyncha |
Family: | Pseudococcidae |
Genus: | Pseudococcus |
Species: | P. viburni
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Binomial name | |
Pseudococcus viburni Signoret, 1875
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Pseudococcus viburni (formerly Pseudococcus affinis (
around the world.Distribution
P. viburni is a pest of vineyards in
Taxonomy
The obscure mealybug is thought to have evolved in Australia or South America. Its history in North America is not clear; from 1900 (when P. maritimus, the grape mealybug, was first described) to 1960, the obscure mealybug was variably misidentified as or synonymized with P. maritimus, P. longispinus, P. obscurus Essig, P. capensis Brian, P. malacearum Ferris, and P. affinis (Maskell).[6] This taxonomic confusion has hampered attempts to trace the exact origin of the species, but its presence in both Australia and South America strongly suggests that it is of Gondwanan origin.
Morphology
Obscure mealybugs exhibit a high degree of sexual dimorphism; females are flightless, larger, and longer-lived than the winged males, who cannot feed and die immediately after mating.[citation needed]
Females
The bodies of
Males
Male obscure mealybugs are tiny, fragile insects with long
Identification
It is important for vintners to distinguish between the obscure mealybug and its close relatives, the grape and
The obscure mealybug more closely resembles the grape mealybug than it does the vine mealybug, but the two can be distinguished by the color of the defensive fluid they secrete when disturbed; grape mealybugs secrete reddish-orange fluid, while obscure mealybugs secrete clear fluid.
Life cycle
Females
Being in the order
Obscure mealybugs lay eggs all year long, and during winter, under the bark of trees and vines (though there is no true
Males and mating
Male obscure mealybugs do not feed, and have very short lifespans (2–3 days); males will spin cocoons shortly after hatching, where they develop wings. Upon emerging from their cocoons, male obscure mealybugs will fly toward the scent of the female's sex pheromone, mate as many times as possible, then die.[7] Given the male's short lifespan, the timing of the female's emission of sex pheromone is crucial; females will emit the pheromone day and night around the time of male emergence (especially in the spring), then cease immediately after fertilization. Obscure mealybugs generally mate at dusk and at dawn.[12]
The female obscure mealybug sex pheromone has the unfortunate property of sometimes attracting parasitic wasps (such as Tetracnemoidea peregrina), and is therefore a kairomone.[13]
Ecology
Diet
Obscure mealybugs feed on the phloem of vines and woody-stemmed plants, especially pear and apple trees and grape vines.[4] Some individuals are vectors for infectious pathogens and can transmit them from plant to plant while feeding; mealybug-spread grapevine leafroll associated virus type III (GRLaV-3), in particular, has wreaked havoc among the grapes of New Zealand, reducing the crop yield of infected vineyards by up to 60%.[1]
Symbiosis
Female mealybugs excrete honeydew, a thick, sugary fluid created as a byproduct of digestion (large colonies of mealybugs can produce enough honeydew to seep through bark and leaves, leaving shiny, sticky patches on the exterior of the plant). Some ants have developed a mutualistic symbiotic relationship with obscure mealybugs, tending and protecting the insects from natural enemies to increase the production of honeydew, on which the ants feed.[4] This relationship is similar to the one that some ants have with aphids.
Pestilence
This species is a
Control
Many attempts have been made to control obscure mealybug populations in commercial greenhouses and vineyards, using both synthetic pesticides and introduced mealybug parasites. Since the obscure mealybug's waxy coating and habit of seeking sheltered feeding sites protect it from water-based pesticides, oil-based organophosphate pesticides (among the more toxic of pesticides) are most effective in reducing population density, though such pesticides can harm plants if applied after the first budding. Even so, some New Zealand obscure mealybug populations have developed a resistance to organophosphate pesticides.[3][15]
Because of the high toxicity and strict regulation of organophosphate pesticides, some Californian vintners have imported natural parasites of the obscure mealybug from
Late-season
References
- ^ a b Hamlet (2005), p. 1.
- ^ Varela et al. (2006), p. 1.
- ^ a b Abbasipour et al. (2007), p. A120.
- ^ a b c d e Varela et al. (2006), p. 2.
- ^ a b Mathulwe, Malan & Stokwe 2021, p. 7.
- ^ Daane et al. (2008), pp. 44–45.
- ^ a b c d New England Greenhouse Floriculture Guide (2003–2004), p. B-14. [dead link]
- ^ a b Hamlet (2005), p. 5.
- ^ Varela et al. (2006), pp. 2–3.
- ^ Varela et al. (2006), p. 3.
- ^ Hamlet (2005), pp. 5–8.
- ^ a b Hamlet (2005), pp. 5–6.
- ^ Hamlet (2005), p. 6.
- ^ Daane et al. (2008), p. 44.
- ^ Hamlet (2005), pp. 6–7.
- ^ Daane et al. (2008), p. 45.
- ^ New England Greenhouse Floriculture Guide (2003–2004), p. B-15.
- ^ Daane et al. (2008), pp. 45–46.
Bibliography
- Abbasipour, H.; A. Taghavi; A. Askarianzadeh (2007). "Biological Studies of obscure mealybug, Pseudococcus viburni (Signoret) (Homoptera: Psaeduococcidae) in the tea gardens of Iran". Entomological Research. 37 (1): A119–A125. S2CID 221736062.
- Daane, Kent M.; Monica L. Cooper; Serguei V. Triapitsyn; John W. Andrews Jr; Renato Ripa (2008). "Parasitoids of obscure mealybug, Pseudococcus viburni (Hem: Pseudococcidae) in California: establishment of Pseudaphycus flavidulus (Hym.: Encyrtidae) and discussion of related parasitoid species". Biocontrol Science and Technology. 18 (1): 43–57. S2CID 85182457.
- Hamlet, Jonathan (2005). "Mealybug: Why we should sit up and take notice" (PDF). Hawke's Bay Focus Vineyard Project.
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: Cite journal requires|journal=
(help) - "Insect and mite descriptions" (PDF). New England Greenhouse Floriculture Guide 2003–2004. University of Connecticut. 2004. Archived from the original (PDF) on 2004-02-06. Retrieved 2008-05-03.
- Varela, Lucia G.; Rhonda J. Smith; Mark Battany; Walt Bentley (January–February 2006). "Which mealybug is it, why should you care?" (PDF). Practical Winery & Vineyard. Archived from the original (PDF) on 2007-02-07. Retrieved 2008-05-03.
- Mathulwe, L.L.; Malan, A.P.; Stokwe, N.F. (2021-03-23). "A Review of the Biology and Control of the Obscure Mealybug, Pseudococcus viburni (Hemiptera: Pseudococcidae), with Special Reference to Biological Control Using Entomopathogenic Fungi and Nematodes". S2CID 232357751.