Common name

Steingeliids

Field characters

Body elongate, yellow, antennae projecting forward in "V". Stomacoccus platani Ferris causes brown necrotic spots on sycamore leaves and occurs in clusters of wax on sycamore trunks.

Validation characters

Claw with 6 or more digitules; 5 or 6 pairs of abdominal spiracles; first antennal segment with conspicuous bar; first antennal segment noticeably longer than other antennal segments; quinquelocular or multilocular pores scattered over body; 1 pair of unusually long setae on venter of each body segment.

Notes

This group has been fairly consistently placed in a steingeliine family group taxon. There is considerable variation in characters such as the number of setae on the legs, but the 2 included genera seem to form a distinct group. Steingeliidae Morrison was first treated as a family by Koteja (1989b).

Distribution

Steingelia is recorded from the Palaearctic and northern Nearctic and Stomacoccus is known from the Nearctic only.

Hosts

Steingelia is probably restricted to Betula and Stomacoccus feeds on Platanus.

Life history

Stomacoccus platani Ferris has at least 3 instars in the female and there are 5 in the male. Adults overwinter on the bark and migrate to the leaves in the spring. There are as many as 9 generations a year. Steingelia gorodetskia Nassonov has 4 instars in the female and 5 in the male. Most feeding occurs in the second and third instar cysts which are located on main roots underground or deep in bark cracks. Adult females emerge from the third-instar female and move onto the trunks of trees. After mating, adult females produce an ovisac and lay eggs. Crawlers move back to the main roots. There is 1 generation per year.

Important references

Boratynski 1951a; Brown and Eads 1965; Gill 1993; Hodgson and Foldi 2006; Koteja 2000; Koteja and Zak-Ogaza 1981a.

Diversity

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