Hodges (1999) assigned Blastobasidae as a subfamily (Blastobasinae) of Coleophoridae. Six of the seven North American genera occur in Illinois. This group is well represented in North America, with more than 100 described species, but life histories are known for only a very few. Larvae of some species are known or suspected to be "scavengers" or to feed on roots of composites (Asteraceae); others are known to feed internally on seeds of pines, Pinus spp. (Pinaceae) or on acorns of oaks, Quercus spp. (Fagaceae). A substantial contribution to our knowledge of Nearctic microlepidoptera could be made by working out life histories of a good representation of Blastobasidae species. Specimens of adult Blastobasidae are recognized most easily by their having a transverse row of small spines at the posterior margin of each segment on the dorsum of the abdomen (Fig. 1).
Figure 1. Abdomen of Blastobasidae, dorsal aspect, showing the characteristic transverse rows of small spinelike structures at the posterior margin of each segment, a distinctive character of the group.
Blastobasid forewing coloration most commonly involves shades of gray and/or brown, overlaid with paler scaling, and frequently showing either a contrastingly pale band at about one third of the wing length from the base, or an abrupt color change from paler to darker in the same position, depending upon species (this particular combination of coloration and pattern is reminiscent, analogously, of that of many species of phycitine Pyralidae). Color pattern in Blastobasidae is not diagnostic; as can be observed in the illustrations below, a similar pattern can be seen in more than one genus. Adamski and Brown (1989) gave characters for determining adults of North American Blastobasidae to genus. Among genera occurring in Illinois, Pigritia can be recognized by its markedly reduced labial palpi (Fig. 2).
Figure 2. Heads of Pigritia spp., ventral aspect, showing reduction of the labial palpi, from vestigial (left panel) to indiscernible (right panel).
Males of Blastobasis, Asaphocrita, and Holcocera have a distinctive "notch" on the first antennal flagellomere (Fig. 3).
Figure 3. Antennae of Blastobasidae belonging to genera in which the basal flagellomere of the male moth forms a characteristic "notch"; Blastobasis sp. (left panel), Holcocera sp. (right panel).
Beyond the characters of labial palpi and antennal morphology given above, there are reliable characters of wing venation and genital morphology that can be used to determine blastobasid adults to genus (Adamski and Brown 1989).
Figure 4. Asaphocrita spp. Adults, collected at light.
Figure 5. Holcocera spp. Adults, collected at light.
Figure 7. Blastobasis spp. Adults, collected at light.
Figure 8. Hypatopa spp. Adults, collected at light.
Figure 9. Pigritia spp. Adults, collected at light.