Species Pyrrharctia isabella - Isabella Tiger Moth - Hodges#8129

8129

Woolly Bear (caterpillar) (1)

Black-ended Bear (caterpillar) (2)

Banded Woolly Bear (caterpillar) (3)

Isia Isabelle - En français - … Ilze V-G.,

Pyrrharctia isabella (J.E. Smith)

Orig. Comb: Phalaena isabella J.E. Smith 1797

* phylogenetic sequence # 930335

The only species north of Mexico.(4)

Wingspan 45-65mm (2)

Larvae to 57mm (5)

Adult: Sexually dimorphic, male HW is pale orange and female HW is rosy

Larva: Caterpillars are fuzzy and variably banded with black ends, rusty red in the center.

Common throughout North America - Map (5)(MPG data)

mostly Mar-Nov (MPG)

Larvae eats many plants and trees including grasses, asters, birches, clover, corn, elms, maples, milkweed and sunflowers (2)(3)(6)

The first of two broods pupates in Summer. The second brood overwinters as a caterpillar and pupates in Spring. (2)

Life cycle images:

eggs; first instar larvae; larvae; larvae; larvae; larvae; older larva; cocoon with newly emerged adult; adult

The only species of Pyrrharctia. (3)

Folk wisdom holds that the relative lengths of the bands of the caterpillar foretell the severity of the coming winter (5). Actually, the variability of the bands depends on many factors. As larvae mature, the reddish bands lengthen (2). Wetter weather lengthens the black bands (3). So while not a reliable measure, it makes some sense that onset of an early and thus longer winter will force younger and less red caterpillars into hibernation.

Caterpillars may resort to cannibalism.

Lafontaine J. D., and B. C. Schmidt 2010. Annotated check list of the Noctuoidea (Insecta, Lepidoptera) of North America North of Mexico. p. 19.(4)

Powell, J. A., and P. A. Opler 2009. Moths of Western North America. pl. 47.18f; p. 269.(7)

Arnett provides a black and white adult photo, figure 27.291 (3).

Peterson's First Guide illustrates all life stages, page 99 (5).

Covell provides color illustrations of caterpillar and adult, plates 1 and 14 (2).

Moth Photographers Group - range map, photos of living and pinned adults.

BOLD - Barcode of Life Data Systems - species account with collection map and photos of pinned adults.

Natural history and tidbits from Iowa State University.