This uncommonly encountered milkweed beetle is found in western Oklahoma and the panhandle region of Texas.
Forty-nine individuals were found in association with
T. femoratus LeConte on
Asclepias latifolia in
Texas: Dickens Co., Double Rafter Ranch, 30-VII/29-VIII-79, 2/8-VII-80, [Marlin E. Rice]. Chemsak (1963) indicated that when a single host is utilized among two sympatric milkweed beetle species, one species is usually much less numerous than the other, and during a two year period, ca. 200
A. latifolia growing in a fallow field, yielded fewer
T. mandibularis than
T. femoratus, with the ratio being 1:3.2.
(2)