Bulletin of Entomological Research (1988) 78, 561-571

Jennifer M. Cox and Mark N. Wetton (1988)
Identification of the mealybug Planococcus halli Ezzat and McConnell (Hemiptera: Pseudococcidae) commonly occurring on yams (Dioscorea spp.) in Africa and the West Indies
Bulletin of Entomological Research 78 (4), 561-571
Abstract: Multivariate analysis was used to demonstrate that specimens of Planococcus collected from yams (Dioscorea spp.) in both the West Indies and Africa can be differentiated from the similar P. ficus (Signoret) which occurs on figs, grapevines and pomegranates in the Mediterranean Basin, Pakistan, South Africa and Argentina. The specimens from yams are considered here to be a distinct species, to which the name P. halli Ezzat and McConnell is applied. Examination of material of both species reared on potato tubers at various temperatures showed that the differentiation is not a host-induced effect. Independent canonical variates analysis of the field-collected and reared material each showed clear differentiation of the two groups. However, the coefficients obtained for each character differed markedly between the analysis of the field-collected material and that of the reared material, and thus could not be used to assign individuals to groups. This difference in the values of the coefficients is considered to have been due to the peculiarities of individual populations, as the field-collected material included many genotypes while only three genotypes were represented by the reared material. A key and illustrations are provided for the separation of the two species.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
identification/taxonomy
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Planococcus ficus		Pakistan
	Planococcus ficus		South Africa
	Planococcus ficus		Argentina
	Planococcus ficus	Grapevine (Vitis)
	Planococcus ficus	Ficus (crop)
	Planococcus ficus	Pomegranate (Punica granatum)
	Planococcus halli	Yam (Dioscorea)