Heterocampa guttivitta

The saddled prominent is a native insect that is occasionally a severe defoliator of its host plants in parts of New England and eastern Canada. A single generation is noted to occur per year (Johnson and Lyon, 1991), however other sources indicate that two generations per year are possible over much of the east with mature caterpillars present from late May to November in some locations (Wagner, 2005). The overwintering life stage of this moth species are the pupae, which can be found in the leaf litter near host trees. Most of the adult moths will emerge from these locations by the last week in May over a two week period. During this time, they fly frequently in the twilight, normally resting on the trunks of trees (well camouflaged) during the day time. Egg laying by the adult female moths occurs over a 4-5 week period, starting by approximately the second week in June. Eggs are 1 mm in diameter, round, and pale green when first deposited and laid on the undersides of host plant leaves. Each female moth can lay up to 500 eggs, but on average 200-250 are laid. Fecundity may depend upon the host plant the female caterpillar had fed upon. Eggs turn a reddish color as they develop, unless they have been parasitized. Parasitized eggs turn gray with black spots. When first hatched from the egg, the caterpillars are dark red in color with a pair of black horn-like projections directly behind the head, and eight pairs of black abdominal spikes. After the first molt of the caterpillar, the horns and abdominal spikes are lost. The first three instar caterpillars feed as skeletonizers on leaf undersides. Skeletonized patches of the leaves will allow more light to pass through, and if seen this can be an early indication of saddled prominent activity. The fourth and fifth instar larvae begin to feed from the leaf margin of the foliage. This species is a late-season defoliator, typically stripping host plants of their leaves in late July and August. This feeding activity typically is more noticeable in forested locations. Fully grown caterpillars are approximately 1.5 inches long, smooth, variable in color (pale to lime green or reddish brown) with a creamy colored subdorsal stripe. A red/brown/purple-ish pattern often forms a V-shaped saddle over abdominal segments A3 and A4 which are counted beginning with the first segment after the third pair of hardened thoracic legs. This is a common species of caterpillar that is often easily sampled on its hosts during any given growing season. Pupae are stout, shiny, dark brown, and 0.75 inches long and enclosed in a thin, loose, cocoon made of leaf fragments and silk. Adults are inconspicuous moths, varying in color from greenish gray to brownish gray to olive with white and black markings. This coloration helps them to blend in with their surroundings. Moths are also approximately 0.75 inches long.