Monarch Butterfly Chrysalis
Just before they pupate, monarch caterpillars spin a silk mat from which they hang upside down by their prolegs (the silk comes from a spinneret on their head). The caterpillar then stabs a stem into the silk pad to hang from. This stem extends from its rear, and is called a cremaster. Once they are in the pupal stage, they will begin their final transformation to become an adult butterfly. Just before the monarch butterfly emerges, their wing pattern becomes visible through the pupal covering. This is not because the pupa is transparent; rather, it is because the pigmentation on the wing scales only develops at the very end of the pupal stage. This stage of development lasts 8-15 days under normal conditions. Monarch metamorphosis from egg to adult takes as little as 25 days, However, it is estimated that fewer than 10% of monarch eggs and caterpillars survive because they are so vulnerable to weather, parasites, and disease. Monarchs are harbingers of environmental change, and it seems that their numbers may be continuing to decline.
The monarch butterfly or simply monarch is a milkweed butterfly in the family Nymphalidae. Other common names depending on region include milkweed, common tiger, wanderer, and black veined brown. It may be the most familiar North American butterfly, and is considered an iconic pollinator species. Its wings feature an easily recognizable black, orange, and white pattern, with a wingspan of 8.9–10.2 cm The viceroy butterfly is similar in color and pattern, but is markedly smaller and has an extra.. more