MicromalthidaeDavid R. Maddison
Micromalthus debilis is one of the more amazing beetles, with a very complex life cycle. It lives in rotting wood, and most specimens one finds in the wood are all females, and are larviform, either larvae or are developed enough that they can reproduce but look like larvae. Mature female "larvae" generally give birth to living larvae (without laying eggs); these young larvae are active, and with legs, and are called a "triungulin". A triungulin moults into legless female larva, which can then develop either into (1) a pupa that then emerges as awinged adult, (2) a larviform female that will itself will give birth to triungulins, (3) a larviform female that lays a single male egg that hatched into a larva that eats its mother, (4) a larviform female that can reproduce in both of the latter ways.
Females are diploid, and males are haploid.
Micromalthus debilis, active first instar larva. © 2007 Alex Wild. Dan Young (University of Wisconsin) provided the specimens
Micromalthus debilis, female larvae. © Alex Wild. Specimens provided by Dan Young (University of Wisconsin)
MoviesView Micromalthus adult
Beutel, R. G. and T. Hoernschemeyer. 2002. Larval morphology and phylogenetic position of Micromalthus debilis LeConte (Coleoptera: Micromalthidae). Systematic Entomology 27(2):169-190.
Philips, T. K. 2001. A record of Micromalthus debilis (Coleoptera: Micromalthidae) from Central America and a discussion of its distribution. Florida Entomologist 84(1):159-160.
Pollock, D. A. and B. B. Normark. 2002. The life cycle of Micromalthus debilis LeConte (1878) (Coleoptera: Archostemata: Micromalthidae): Historical review and evolutionary perspective. Journal of Zoological Systematics and Evolutionary Research 40(2):105-112.
About This Page
David R. Maddison
Oregon State University
Correspondence regarding this page should be directed to David R. Maddison at
Page copyright © 2011 David R. Maddison
Page: Tree of Life Micromalthus debilis. Micromalthidae. Authored by David R. Maddison. The TEXT of this page is licensed under the Creative Commons Attribution License - Version 3.0. Note that images and other media featured on this page are each governed by their own license, and they may or may not be available for reuse. Click on an image or a media link to access the media data window, which provides the relevant licensing information. For the general terms and conditions of ToL material reuse and redistribution, please see the Tree of Life Copyright Policies.
- Content changed 27 June 2007
Citing this page:
Maddison, David R. 2007. Micromalthus debilis. Micromalthidae. Version 27 June 2007 (temporary). http://tolweb.org/Micromalthus_debilis/9000/2007.06.27 in The Tree of Life Web Project, http://tolweb.org/