Adult Recognition
FWL: 7.5-9.0 mm
Forewings are yellowish white with a well-defined brown to dark-brown basal patch and a black spot in the median fascia. Males lack a forewing costal fold.
In California, adult H. umbrabasana are commonly found in Epiphyas postvittana pheromone traps. Distinguishing between individuals of these two species by wing pattern may be difficult if the forewings are heavily stained from sticky traps. The two species can be separated by the male forewing costal fold: present in E. postvittana, absent in H. umbrabasana.
Larval Morphology
Mature larvae are dark maroon with a brown or black head and black prothoracic shield.
Biology
Henricus umbrabasana completes a single generation per year. Adults are present from May through September.
Eggs are laid during the summer or fall and overwinter until the next spring. Larvae emerge in March and feed on young leaves and shoots inside a shelter covered in frass and debris. Pupation occurs within a cocoon covered in frass and debris.
Host plants
Larvae feed on oak (live oak or valley oak).
| Family | Genus/species | Common name |
| Fagaceae | Quercus agrifolia Nee | California live oak |
| Fagaceae | Quercus chrysolepis Liebm. | canyon live oak |
| Fagaceae | Quercus lobata Nee | valley oak |
Distribution
Henricus umbrabasana is recorded from California and southwestern Washington. It likely also occurs in Oregon.
References
Opler, P. A. 1974. Biology, ecology, and host specificity of microlepidoptera associated with Quercus agrifolia (Fagaceae). University of California Press. vol. 75. 83 pp.
