Neocoelidia tumidifrons Gillette & Baker, 1895 (Fig. 1A, B)

Material. USA, 2 ♀, Illinois, Mason Co., Matanzas Prairie, 31 VII 1997 (Dietrich).

Description. Coloration yellowish white. Inner margins of fore and hind wing pads with black spot at base. Body length 4.6–4.9 mm, head width 1.1 mm.

Notes. N. tumidifrons Gillette & Baker, was previously illustrated by Osborn (1928), DeLong (1948), and Oman (1949). Nymphs of Retrolidia sp. and several unidentified Neotropical species of Neocoelidiinae were also studied; their characters are incorporated in the tribal description.

Subfamily Deltocephalinae Dallas, 1870

Tribe Acinopterini Oman, 1949