Indiana University Studies 
19A. Head mostly bright or dark rufous, pronotum bright or dark 
rufous on edge; bisexual forms unknown; southern Ga.-so. 
Ind. and Kans. 19C 
Head mostly black; bisexual form known (for variety gem- 
mula) in seed-like gall in bud or on young stems or flowers; 
Mass.-Mo. 19B 
19B. Head with some rufous about eyes, mesonotum hairy, insects 
2.3-3. 5 mm.; Mass.-Mo., south in mts. to Tenn. 
var. gemmula 
Head entirely black, mesonotum nearly smooth and naked, 
insects 1. 5-2.7 mm.; so. Mich.(?)-so. Ind. var. suspecta 
19C. Head, thorax, and base of abdomen bright rufous, antennae 
brown, rufous basally; abdomen somewhat compressed; Ga.- 
so. Ind. and so. 111. var. cruenta 
Head and thorax dark rufous to rufo-piceous, antennae black, 
blackish basally, abdomen swollen cylindric; Ozark area, Ind.- 
Kans. var. fuscata 
Abdomen of agamic form compressed; bisexual form with mesono- 
tum smooth and naked but not shining, with parapsidal grooves 
distinctly discontinuous; agamic galls spheroidal to ellipsoid, with 
1 to 8 larval cells, the surfaces faceted, naked to spiny; bisexual 
galls elongate-cylindric or more compressed; on true white oaks. 
C. pezomachoides, 19a 
19a. Head of agamic form rufous without any black; bisexual form 
not known. 19b 
Head of agamic form with at least some distinct black mark- 
ing; bisexual form known for erinacei only. 19d 
19b. Abdomen of agamic form in part piceous or black; Q. alba. 
19c 
Abdomen of agamic form largely rufous; Q. bicolor; Fla. 
var. echinoides 
19c. Agamic insects small (2.5 to 3.2 mm.), mesonotum largely 
naked, coriaceous or smoother, abdomen yellow rufous basally; 
gall small to medium, naked; Coastal Plain. 
var. pezomachoides 
Agamic insects large (2.5 to 4.0 mm.), mesonotum quite hairy 
and roughly punctate, abdomen red rufous basally; gall naked, 
spheroidal, distinctly large; west of Appalachians. 
var. derivatus 
19d. Face of agamic insects laterally and abdomen basally more or 
less bright rufous; bisexual form known for erinacei. 19e 
