Walking through South Platte Park the other day, I looked ahead and saw bright red masses on the side of the trail. Initially thought to be some type of fungus or slime mold, I found that they were large clusters of small bugs.....milkweed bug nymphs to be exact.
Found throughout North America, from southern Canada to Mexico, these true bugs feed exclusively on milkweed plants. Eggs are repeatedly laid on the plants by the adult female; during her month of adulthood, she will lay thousands of eggs. Upon hatching, the nymphs molt five times before reaching the adult stage; each nymph phase is about 6 days in length. While the elongated adults have a striking black and orange pattern on their dorsal surface, the younger nymphs are bright orange-red. Both adults and nymphs may cluster where milkweed seed pods are abundant and their bright coloration warns potential predators that they are toxic (due to compounds ingested from milkweed sap).
Unlike most insects, milkweed bugs overwinter as adults; those that mature in northern latitudes must migrate to southern climes or find a protected site in which to wait our the season. Considering the date, most of the nymphs that I encountered will likely not reach the adult stage before cold autumn weather envelops the Front Range.
Found throughout North America, from southern Canada to Mexico, these true bugs feed exclusively on milkweed plants. Eggs are repeatedly laid on the plants by the adult female; during her month of adulthood, she will lay thousands of eggs. Upon hatching, the nymphs molt five times before reaching the adult stage; each nymph phase is about 6 days in length. While the elongated adults have a striking black and orange pattern on their dorsal surface, the younger nymphs are bright orange-red. Both adults and nymphs may cluster where milkweed seed pods are abundant and their bright coloration warns potential predators that they are toxic (due to compounds ingested from milkweed sap).
Unlike most insects, milkweed bugs overwinter as adults; those that mature in northern latitudes must migrate to southern climes or find a protected site in which to wait our the season. Considering the date, most of the nymphs that I encountered will likely not reach the adult stage before cold autumn weather envelops the Front Range.
