Common name

False pit scales or lecanodiaspidids

Field characters

Adult females produce a waxy test that encloses the body. The test usually is papery in texture, giving a corrugated appearance. The dorsal surface of the test often has 7 to 9 transverse ridges that roughly correspond to body segmentation and a dorsomedial ridge along the middle of the test. An anal opening occurs at the posterior end of the test that usually has an elevated rim surrounding it. Color varies from yellow to reddish brown. Tests are produced by adult females and second-instar males. A few false pit scales are known to induce some form of host deformation, usually a pit under the body of the insect.

Validation characters

Cribriform plates and 8-shaped pores present; spiracular furrows usually present, posterior furrow usually divided; either with 2 lateral anal plates or plates fused into 1; antennae normally with multiple segments; legs absent or represented by unsegmented sclerotized area; without protruding anal lobes; small anal cleft; labium normally 1- or 2-segmented.

Notes

This is a relatively homogeneous group of scales without a large range of morphological diversity. Lecanodiaspididae Targioni Tozzetti was first used as a family by Borchsenius (1965).

Distribution

False pit scales occur in all zoogeographical regions of the world. Click here for a list of genera and species from the Australasian region, Afrotropical region, Nearctic region, Neotropical region, Oriental region, and Palaearctic region. They are most speciose in the Oriental area with significantly fewer species in the Palaearctic region.

Hosts

Lecanodiaspidids are normally collected on the stems or branches of woody shrubs or trees and are not recorded from grasses and most herbaceous plants. The family occurs on a diverse array of host plants encompassing about 67 different plant families. The most common hosts are in the family Fabaceae, Fagaceae, Myrtaceae, Moraceae, and Rutaceae. Nearly twice as many species occur on fabaceous hosts as on any other host family.

Life history

False pit scales apparently have 3 instars in the female and 5 in the male. Lecanodiaspis prosopidis (Maskell) has 1 generation each year and overwinters in the egg stage inside the adult female test. Eggs hatch in early spring, and first instars leave the test through a small hole at the posterior end. Second instars appear in early to mid summer. Adults are present in mid to late summer, and eggs are laid in the fall. Males probably occur in most species. Species in other genera are frequently tended by ants and are found in carton tents or hollow stems.

Important references

Borchsenius 1960d; Howell and Kosztarab 1972; Lambdin and Kosztarab 1973; Wang 2001; Williams and Kosztarab 1970.

Diversity

Click here for a check list of all lecanodiaspidid genera and species.