Planococcus
Lab sample of planococcus citri
Lab sample of planococcus citri
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Sternorrhyncha
Family: Pseudococcidae
Genus: Planococcus
Ferris, 1950

Planococcus is a genus of true bugs belonging to the family Pseudococcidae.[1] The genus has a cosmopolitan distribution.[1][2] A number of species are invasive agricultural pests.[3]

Species

Species identification

Identification of mealybug species in the Planococcus genus has been difficult due to an unusually high amount of intraspecies morphological variation. In the 1980s, entomologist Jennifer Cox at the British Museum discovered that the offspring of a single female raised on the same host will develop differently based on environmental conditions. She showed that higher temperatures induced smaller specimens overall with fewer pores, shorter appendages, and shorter setae.[4] From Cox's experiments, the greatest number of tubular ducts in adult females was present at intermediate temperatures, whereas the smallest number were present when temperatures were higher or lower. Cox's work showed that the proposed species Planococcus citricus was in fact a warm temperature variant of Planococcus citri.[5] This created issues in the discrimination of species as these characteristics were among those used by Ezzat & McConnell in their treatment of Planococcus species in 1956.[6] In 1989 Cox revised the genus and listed 35 species.[7] She also created a point-based system to distinguish between Planococcus minor and Planococcus citri based on a matrix of six characters, known as the 'Cox score'. However other morphologically similar species, such as Planococcus ficus and Planococcus halli, a single diagnostic characteristic was not identified. With the improvements in genotyping, efforts to develop different systems to distinguish between cryptic species of Planococcus are ongoing.[6]

References

  1. ^ a b "Planococcus Ferris, 1950". www.gbif.org. Retrieved 3 March 2021.
  2. ^ Daane, Kent M.; Cooper, Monica L.; Triapitsyn, Serguei V.; Walton, Vaughn M.; Yokota, Glenn Y.; Haviland, David R.; Bentley, Walt J.; Godfrey, Kris E.; Wunderlich, Lynn R. (2008). "Vineyard managers and researchers seek sustainable solutions for mealybugs, a changing pest complex". California Agriculture. 62 (4). UC Agriculture and Natural Resources (UC ANR): 167–176. doi:10.3733/ca.v062n04p167. ISSN 0008-0845. S2CID 54928048.
  3. ^ "Vine Mealybug". Center for Invasive Species Research. Retrieved 2022-04-27.
  4. ^ COX, JENNIFER M. (October 1983). "An experimental study of morphological variation in mealybugs (Homoptera: Coccoidea: Pseudococcidae)". Systematic Entomology. 8 (4): 361–382. doi:10.1111/j.1365-3113.1983.tb00489.x. ISSN 0307-6970. S2CID 85137903.
  5. ^ COX, JENNIFER M. (January 1981). "Identification of Planococcus citri (Homoptera: Pseudococcidae) and the description of a new species". Systematic Entomology. 6 (1): 47–53. doi:10.1111/j.1365-3113.1981.tb00012.x. ISSN 0307-6970. S2CID 84105579.
  6. ^ a b Rung, A.; Scheffer, S. J.; Evans, G.; Miller, D. (2008-05-01). "Molecular Identification of Two Closely Related Species of Mealybugs of the Genus <I>Planococcus</I> (Homoptera: Pseudococcidae)". Annals of the Entomological Society of America. 101 (3): 525–532. doi:10.1603/0013-8746(2008)101[525:miotcr]2.0.co;2. ISSN 0013-8746. S2CID 86189276.
  7. ^ Cox, Jennifer M. (1989). "The mealybug genus Planococcus (Homoptera: Pseudococcidae)". Bulletin of the British Museum. 58: 1–78.
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