Anatomy of an Infestation

Oncopeltus Fasciatus, known as the Large Milkweed Bug is a medium-sized hemipteran (true bug) of the family Lygaeidae. It is distributed throughout North America. It ranges from Central America through Mexico and the Caribbean to southern areas in Canada. Costa Rica represents this insects southern limit.

It inhabits disturbed areas, roadsides and open pastures. Due to this widespread geographic distribution this insect exhibits varying life history trade-offs depending on the population location. Also, this species is known to be beneficial for home gardens by acting as a parasite to milkweed plants.

This large milkweed bug is a hemimetabolous insect, meaning it grows in stages called instars and goes through incomplete metamorphosis exhibiting small changes throughout development such as coloration changes, development of wings and genitalia. O. fasciatus begins as an egg and experiences 4 nymphal stages over 28–30 days before molting to adulthood. Females become sexually receptive within a few days of adulthood. Geographic location has a large effect on egg production rate and clutch size.

Nursery on Milkweed Pods - Nature preserve, September, 2016

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