Asterolecaniidae
Taxonomic placing: Insecta, Hemimetabola, Hemiptera: Sternorrhyncha, Coccomorpha, Coccoidea.
Common name: Pit scales.
Geographical distribution: World-wide. The family Asterolecaniidae consists of about 20 genera and 220 described species.
Morphology: The body of the female is fused, the head, thorax and abdomen not being clearly separated. The antennae are small, unsegmented, and the legs (except in the crawlers) are usually absent. They have two pairs of spiracles, the anterior pair near the unsegmented labium, the other pair behind that structure, and with bands of pores leading from both pairs towards the margin of the body. The anal ring is usually present and the margin of body often bears large 8-shaped pores. The body is covered by an almost transparent yellow-green adhering shield.
Life cycle: Members of this family occur mainly in temperate regions. Most species have only a single annual generation. Reproduction may be parthenogenic or bisexual. The female lays eggs or (seldom) larviposits the crawlers beneath its body. The crawlers, which bear three pairs of legs and antennae, are the only agents of dispersal. They move for 1-2 days, settle and secrete a (usually transparent) waxy shield. Females lose their legs after the 1st instar and remain where they had settled. When feeding they probably secrete toxins into the host plant, which cause the pits or (in rare cases) yellowing.
Economic importance: This family contains only a few pests. These include Palmaspis phoenicis, which attacks date palms, Pollinia pollini, which infests olives and Russellaspis pustulans, which damages apples.
References
Ben-Dov, Y. 2006. A Systematic Catalogue of Eight Scale Insect Families (Hemiptera: Coccoidea) of the World Aclerdidae, Asterolecaniidae, Beesoniidae, Carayonemidae, Conchaspididae, Dactylopiidae, Kerriidae and Lecanodiaspididae. Elsevier, Amsterdam.
Ferris, G.F. 1937-1950. Atlas of the Scale Insects of North America, Parts I-VII. Stanford University Press, Stanford, California.
Stumpf, C. and Lambdin, P. 2002. Distribution and phylogenetic relationships of the pit scales (Hemiptera: Coccoidea: Asterolecaniidae) in North and South America. Journal Bollettino di Zoologia agraria e Bachicolture 33:139-150.