Azalea bark scale and cryptomeria scale can be seen in our area. Apply insecticidal soap or horticultural oil to treat crawlers in late June through late July. Giordano’s has these organic treatments by Bonide in stock.
Do you have scale in your landscape?
Learn how this harmful insect can be recognized & treated using organics. Scale can be treated using insecticidal soaps or horticultural oils that we sell here at Giordano’s in Sea Cliff.
The scale insects are small insects of the order Hemiptera, suborder Sternorrhyncha. They comprise the superfamily Coccoidea, previously placed in the now obsolete group called “Homoptera”. There are about 8,000 described species of scale insects.
Armored scale insects:(A) Lepidosaphes gloverii, adult females. (B) Parlatoria oleae, adult females (circular, with dark spot) and immatures (oblong). (C) Diaspidiotus juglansregiae, adult female walnut scale with waxy scale cover removed.
Oystershell scale (Ceroplastes sp.), a waxy scale on young blueberry
Contents
1 Description
2 Ecology
3 Economic significance
4 Systematics
5 See also
6 References
7 Further references
8 External links
Description
Scale insects vary dramatically in appearance; some are very small organisms (1–2 mm) that grow beneath wax covers (some shaped like oyster shells, others like mussel shells), to shiny pearl-like objects (about 5 mm), to creatures covered with mealy wax. Adult female scales are almost always immobile (aside from mealybugs) and permanently attached to the plant they have parasitized. They secrete a waxy coating for defense; this coating causes them to resemble reptilian scales or fish scales, hence their common name.
The group shows high degrees of sexual dimorphism; female scale insects, unusually for Hemiptera, retain the immature external morphology even when sexually mature, a condition known as neoteny. Adult males usually have wings (depending on their species) but never feed, and die within a day or two.
Species in which males do have wings generally possess only one pair of fully functional wings, and in particular, the fore-wings. This is unusual among insects; it most closely resembles the situation in the true flies, the Diptera. However, the Diptera and Hemiptera are not at all closely related and do not closely resemble each other in morphology; for example, the tail filaments of the Coccoidea do not resemble anything in the morphology of flies. The hind (metathoracic) wings of scale insects are reduced, commonly to the point that they generally are overlooked. In some species the hind wings have hamuli, hooklets, that couple the hind wings to the main wings, a condition usually associated with the Hymenoptera. The vestigial wings often are reduced to the point where they are referred to as halteres or pseudohalteres, but again, their resemblance to the halteres of flies is analogous, not homologous.[3] It is not at present clear to what extent the pseudohalteres have any substantial control function to match the true halteres of the flies.
The first instars of most species of scale insects emerge from the egg with functional legs and are informally called “crawlers”. They immediately crawl around in search of a favourable spot to settle down and feed. In some species they delay settling down either until they are starving, or until they have been blown away by wind onto what presumably is another plant, where they may establish a colony separate from the parent. There are many variations on such themes, such as scale insects that are associated with species of ants that act as herders and carry the young ones to favourable protected sites to feed. In either case, many such species of crawlers, when they change their skins, lose the use of their legs if they are female, and stay put for life. Only the males retain their legs and use them in seeking females for mating.[4]
The specifics of their reproductive systems vary considerably within the group, including three forms hermaphroditism[5] and at least seven forms of parthenogenesis.