Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Upcoming Events

Interested in a 2022 BugGuide gathering in New Mexico?

Photos of insects and people from the Spring 2021 gathering in Louisiana, April 28-May 2

National Moth Week 2020 photos of insects and people.

Photos of insects and people from the 2019 gathering in Louisiana, July 25-27

Discussion, insects and people from the 2018 gathering in Virginia, July 27-29

Photos of insects and people from the 2015 gathering in Wisconsin, July 10-12

Photos of insects and people from the 2014 gathering in Virginia, June 4-7.

Previous events

Micromalthus debilis  - Micromalthus debilis

Micromalthus debilis - Micromalthus debilis
Wisconsin, USA
Micromalthus has perhaps the most convoluted life cycle of any animal, involving adults that sometimes look like larvae, female forms that either give live birth or lay a single egg, larvae that start life as highly motile speedsters and grow into legless sluggish grubs (shown here), and males that must cannibalize their own mothers in order to mature.

Paedogenesis - not adults that look like larvae.
This is what we learned in advanced taxonomy of coleoptera here at the University of Wisconsin:

The adults are actually no longer able to reproduce, and the species has evolved to utilize paedogenesis, which is reproduction in the larval stage. They have all the characteristics of larvae other than that one tiny detail, and it occurs before a pupal stage, the adults are still typical beetles occuring after a pupal stage with truncate elytra and dead-end genitalia.

Adults are rare, only emerging after a spike in temperature (Prairie fires perhaps?) and the females actually have a grasping mechanism that will destroy the male adeagus in their efforts to mate despite the fact that it'll be fruitless because they are sterile in the adult stage.

They really do have the most convoluted life cycle of any animal in my opinion. Amazing research being done right now to figure them out. Including the male larvae that cannibalize their own mothers.

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.