Subject: New Mexico Bagworms
Location: Albuquerque, NM
January 14, 2017 5:19 pm
These bagworm “cocoons” are now very common in the bosque (forest) along the Rio Grande in the area of Tingley Beach in Albuquerque, NM.
They are almost exclusively hanging from the salt cedar AKA Tamarisk on the flood plains adjacent to the river.
Can anyone identify a genus/species for these?
Signature: James Hunter
Our inability to provide you with a conclusive identification is no reflection on the excellent quality (and aesthetic merits) of your high resolution image. In the pupal state, many Bagworms look very similar. We thought that providing a food plant might help with identification, but in attempting to provide you with an identification, the most valuable information we learned on Texas Invasives is that Salt Cedar is an invasive exotic plant, which leads us to believe the Bagworm might not be a native species.
Thanks for your reply.
My very limited research has led me the genus Thyridopteryx; possibly a variation of the species ephemeraeformis.
A quick reference (http://entnemdept.ufl.edu/creatures/MISC/MOTHS/bagworm.htm) notes that for host plants:
“Thyridopteryx ephemeraeformis can feed on over 50 families of deciduous and evergreen trees and shrubs. Common hosts include juniper (Juniperus spp.), arborvitae (Thuja spp.), live oak (Quercus virginiana), Southern red cedar (Juniperus silicicola), and willow (Salix spp.) (FDACS 1983). Other hosts include maple (Acer spp.), elm (Ulmus spp.), pine (Pinus spp.), Indian hawthorn (Raphiolepis indica), ligustrum (Ligustrum japonica), and viburnum (Viburnum spp.). One of the authors has received unconfirmed reports of common bagworm as an economic pest of Adonidia palms (Veitchia merrillii) in south Florida (S.P. Arthurs 2016).”
Willows are very common in the Rio Grande bosque, and/or these little guys may have adapted to feeding on Tamarisk.
The map on this page (http://www.butterfliesandmoths.org/species/Thyridopteryx-ephemeraeformis) and the detail (http://www.butterfliesandmoths.org/sighting_details/917285) reports ephemeraeformis feeding on a willow in Albuquerque. The closest other records are in eastern TX, OK and KS. Perhaps an “invasion” is in progress.
James C. Hunter, RG
Hi again James,
Thanks for providing all your research for our readership. We just do not have the staffing to research every posting as thoroughly as you have done. That is quite a diverse group of food plants for a single species.