Common name

Cochineal scales or dactylopiids

Field characters

Body of adult female grayish when undisturbed but bright red when crushed; covered by sticky, weblike strands of filamentous wax; occurring on the pads of cacti of the genera Nopalea and Opuntia usually in clumps in protected areas. Dactylopius coccus Costa does not produce filamentous wax.

Validation characters

Enlarged setae truncate apically; anal ring without pores and setae; translucent pores on hind legs; invaginated tubular ducts; clusters of quinquelocular pores surrounding orifice of some tubular ducts.

Notes

Molecular data suggest that cochineal scales are really just specialized eriococcids (Gullan and Cook 2001). Dactylopiids have been transported to all parts of the world as a potential source of red dyes, but are apparently endemic to the New World. Most occur in desert areas of the southwestern United States, Mexico, and central and South America. The true conchineal, D. coccus has been used as a source of red dyes for the past several centuries. Even today cochineal industries persist in southern Mexico, Peru, and the Canary Islands. Cochineal scales have been used successfully in the control of opuntia cacti where they have become serious weeds. Dactylopiidae Signoret was first used as a family by Enderlein (1914).

Distribution

Cochineal scales occur in all zoogeographical regions of the world but are introduced into all but the Nearctic and Neotropical regions. Click here for a list of species from the Australasian region, Afrotropical region, Nearctic region, Neotropical region, Oriental region, and Palaearctic region. They are most speciose in the Neotropical region, and least numerous in the Oriental area.

Hosts

Dactylopiids occur primarily on the pads of Opuntia and Nopalea cacti.

Life history

Cochineal scales have 3 instars in the female and 5 in the male. There are 3 to 6 generations each year, and development is continuous. Eggs hatch from a few minutes to several hours after being laid; it is likely that in some instances first instars hatch inside the body of the female before being laid. First instars produce long filaments from truncate setae located on the head; they are longest on females and shorter on males. The filaments are apparently important in increasing buoyancy to aid wind dispersal. The first instar produces small amounts of weblike secretions. Second and third-instar females produce large amounts of weblike secretions that enclose the body. Males are common in most species. Cochineal scales usually occur in protected, often shaded areas of the nonsubterranean protions of the plant and usually are in large aggregations.

Important references

DeLotto 1974a; Ferris 1955a; Gullan and Cook 2001; Gunn 1978; Karny 1972; Mann 1969; Perez and Kosztarab 1992.

Diversity

Click here for a check list of all dactylopiid species.