Callococcus Leptospermi

''Callococcus'' is a genus of Australian scale insect that feeds on species of ''Leptospermum'', '' Hypocalymma'', '' Kunzea'' and some other members of the tribes Chamelaucieae and LeptospermeaeGullan P.J., Miller D.R. & Cook L.G. (2005). Gall-inducing scale insects (Hemiptera: Sternorrhyncha: Coccoidea). In: Biology, Ecology, and Evolution of Gall-Inducing Arthropods (eds. Raman A, Schaefer CW & Withers TM). Science Publishers New Hampshire, pp. 159-229. in the myrtle family Myrtaceae. ''Callococcus leptospermi'' induces stem-swelling galls on some species of ''Leptospermum'', and it is considered to be a potential biological control agent of '' Leptospermum laevigatum'' in South Africa. The other described species of ''Callococcus'' do not induce galls.

Morphology

As for most scale insects, the taxonomy of ''Callococcus'' is based on the morphology of the adult female. Like adult females of other scale insects, those of ''Callococcus'' have no wings. They also have no legs and their antennae are reduced to tiny stubs. Adult females are sack-like and range in colour from burgundy to yellowish or brown.

Adult females of ''Callococcus acaciae'' are globular and a red-burgundy colour. They feed on species of '' Kunzea'' and are covered in a curly, stretchy wax that is exuded from glands on their dorsum.

Adult females of ''Callococcus newmanni'' and ''C. pulchellus'' are similar to each other, and females of both species produce a waxy covering that looks like a small clam or shell-fish.

Adult females of ''C. leptospermi'' are sausage-shaped and brownish in colour.Coles R.B., Verberne F. & Brookes H.M. (1988). The immature and adult stages of ''Callococcus leptospermi'' (Maskell) (Homoptera: Coccoidea: Asterolecaniidae), with observations on life history. ''J. Aust. Entomol. Soc.'', 27, 15-25. Once a female initiates a gall as a nymph she never leaves, and she mates, reproduces and dies inside the gall. ''C. leptospermi'' is ovoviviparous, meaning that the embryos develop inside the female, nourished by special cells (not a placenta), and are born fully developed. First-instar nymphs (crawlers) of ''C. leptospermi'' are generally a pinkish colour and have well developed legs and antennae. They have numerous 8-shaped pores on their dorsum (back). Unusually among scale insects, male and female crawlers of ''C. leptospermi'' exhibit sexual dimorphism. Adult males of ''C. leptospermi'' are winged (single pair, as in other winged male scale insects), pinkish in colour, and have a long slender abdomen.

Systematics

The type species, ''C. pulchellus'', was described by Maskell in 1897 (as ''Sphaerococcus pulchellus'') and the genus ''Callococcus'' was erected in 1918 by Ferris because it was recognised that the species did not belong in the mealybug genus ''Sphaerococcus''.

''Callococcus'' had been placed in the family Asterolecaniidae (the pit scales) based on the presence of 8-shaped pores on the dorsum of nymphs, because this character was interpreted as being diagnostic for this family. Recent DNA-based phylogenies indicate that the genus is closely related to some Australian gall-inducing eriococcid scale insects.Cook L.G. & Gullan P.J. (2004). The gall-inducing habit has evolved multiple times among the eriococcid scale insects (Sternorrhyncha: Coccoidea: Eriococcidae). ''Biol. J. Linn. Soc. Lond.'', 83, 441-452
DOI: 10.1111/j 1095-8312.2004.00396.x
/ref> Subsequently, ''Callococcus'' was transferred to the family Eriococcidae (the felt scales).

References

External links

ScaleNet: a database of the scale insects

{{Taxonbar, from=Q16975374

Hemiptera of Australia
Eriococcidae