Scale insect

Template:Taxobox begin Template:Taxobox image Template:Taxobox begin placement Template:Taxobox regnum entry Template:Taxobox phylum entry Template:Taxobox subphylum entry Template:Taxobox classis entry Template:Taxobox subclassis entry Template:Taxobox infraclassis entry Template:Taxobox superordo entry Template:Taxobox ordo entry Template:Taxobox subordo entry Template:Taxobox superfamilia entry Template:Taxobox end placement Template:Taxobox section subdivision Aclerdidae
Asterolecaniidae
Beesoniidae
Carayonemidae
Cerococcidae
Coccidae
Conchaspididae
Dactylopiidae
Diaspididae
Electrococcidae
Eriococcidae
Grimaldiellidae
Halimococcidae
Inkaidae
Jersicoccidae
Kermesidae
Kerriidae
Kukaspididae
Labiococcidae
Lecanodiaspididae
Margarodidae
Micrococcidae
Ortheziidae
Phenacoleachiidae
Phoenicococcidae
Pseudococcidae
Putoidae
Stictococcidae
Template:Taxobox end

The scale insects are small insects of the order Hemiptera, generally classified as the superfamily Coccoidea. There are over 7,000 species of scale insect.

Scale insects are all parasites of plants, feeding on sap drawn directly from the plant's vascular system. Adult scales are immobile and permanently attached to the plant they have parasitized. They secrete a waxy coating for defense; this coating causes them to resemble reptilian scales, hence the name.

Scale insects feed on a wide variety of plants, and the majority of scale species are considered pests. Some types are economically valuable, such as the cochineal and lac scales. Scale insects' waxy covering makes them quite resistant to pesticides, which are only effective against the juvenile crawler stage. However, scale can be controlled with horticultural oil, which suffocates them, or through biological controls. Soapy water is also reported to be effective against infestations of houseplants.

Female scale insects, unusually for hemiptera, retain their larval form at sexual maturity. Adult males have wings but never feed and die within a day or two. The specifics of their reproductive systems vary considerably within the group, including hermaphroditism and seven forms of parthenogenesis.

External links

• ScaleNet homepage
• Cottony Cushion Scale: the pest that launched a pest control revolution with photos