The Life Span of Mealworms

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The mealworm is familiar to many caged pet owners and fishermen, and in many countries around the world it’s even on the human dinner menu. This small brownish creature is actually the larval stage of the darkling beetle. The life span of these insects is variable, but with more than 1,400 types of darkling beetles in North America it’s not surprising to find some differences.

Early Life Cycle

Mealworms start out as eggs laid in the soil by adult darkling beetles. The beetles don’t provide any care for their young; they will eat the eggs if they get a chance. They can take three days to hatch or more than a month. A warm, humid environment will usually speed up the process. Tiny mealworms emerge from the eggs -- darkling beetles in the larval stage. The larvae spend all of their time eating and growing. The mealworm stage usually lasts about 10 weeks.

Secondary Development

Once they’re big enough, mealworms spend one to two weeks as pupae. After that, they emerge as darkling beetles and can live for just a few months or up to 15 years, depending on the species and environmental factors such as climate and food availability. The beetles begin laying eggs as soon as two weeks after they emerge from their pupal form and will continue to lay throughout their lives.

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