Faculta

Busck, 1939

Palo Verde Webworm (F. inaequalis)

Faculta is a of small in the , established by Busck in 1939. The genus contains three described : F. inaequalis, F. synthetica, and F. triangulella. F. inaequalis, commonly known as the Palo Verde , is the best-known species due to its conspicuous larval of spinning silken tubes on trees. The genus is restricted to arid regions of the southwestern United States and adjacent Mexico.

Faculta triangulella by the Smithsonian. Used under a CC0 license.Faculta triangulella by the Smithsonian. Used under a CC0 license.Faculta triangulella by the Smithsonian. Used under a CC0 license.

Pronunciation

How to pronounce Faculta: //fəˈkʊltə//

These audio files are automatically generated. While they are not always 100% accurate, they are a good starting point.

Identification

are small, nondescript best identified by association with plants and larval signs. F. inaequalis is distinguished by the presence of silken tubes on Palo Verde trees. The can be separated from similar Gelechiidae by genitalic characters and association with specific host plants in the Sonoran Desert region.

Images

Habitat

Arid and semi-arid regions of the southwestern United States and northwestern Mexico. F. inaequalis is associated with upland areas of the Sonoran Desert in coarse soils where trees occur.

Distribution

Southern California, Arizona, southern New Mexico, and Baja California Sur. Records are concentrated in the Sonoran Desert and adjacent regions.

Seasonality

of F. inaequalis have been collected from January to April and in August, suggesting multiple per year.

Diet

of F. inaequalis feed on Foothills Palo Verde (Parkinsonia microphylla) and occasionally on Whitethorn Acacia (Acacia constricta). Larvae nibble leaves and bark during cooler hours.

Host Associations

  • Parkinsonia microphylla - primary Foothills Palo Verde, preferred of F. inaequalis
  • Acacia constricta - occasional Whitethorn Acacia, for F. inaequalis

Life Cycle

Multiple per year inferred from collection records spanning January–April and August. construct silken tubes on twigs for shelter. occurs within or near these tubes.

Behavior

of F. inaequalis are feeders, emerging from silken tubes during cooler hours to feed. The silken tubes are connected by a network of threads forming visible webbing. are nocturnal and attracted to artificial lights.

Ecological Role

function as primary consumers on their trees. Damage to host plants is generally negligible; the is not considered a significant pest despite occasional localized abundance.

Human Relevance

F. inaequalis is occasionally a nuisance in urban areas where Palo Verde trees are planted as ornamentals. may drop from trees and cause minor skin irritation. The is not an agricultural pest.

Similar Taxa

  • Gelechiidae (other genera)Many small resemble Faculta ; identification requires examination of or association with specific plants and larval signs.
  • BryotrophaF. inaequalis was previously placed in Bryotropha; these are distinguished by morphological and molecular characters.

More Details

Taxonomic history

F. inaequalis has been known under multiple names including Gelechia inaequalis, G. clistrodoma, and Bryotropha inaequalis, contributing to confusion in the literature.

Tags

Sources and further reading