Temporal range: 228–0 Ma Late Triassic - Recent
Blattodea is an order of insects that currently combines the Cockroaches and the Termites. Formerly, the Termites were considered a separate order, Isoptera, but genetic and molecular evidence suggests an intimate relationship with the Cockroaches, both cockroaches and termites having evolved from a common ancestor. The Blattodea and the Mantises (order Mantodea) are now all considered part of the superorder Dictyoptera. There are approximately 4,400 species of cockroach in almost 500 genera, and about 3,000 species of termite in around 300 genera.
A research study sought to find the phylogenetic relationships between cockroaches and termites. 107 species were sampled including examples of all the termite families and subfamilies, all 6 cockroach families, including 22 of the 29 subfamilies, and 5 of the 15 mantis families (to act as out-groups). Five gene loci were selected for comparison which provided around 4900 aligned base pairs. A maximum parsimony analysis was also undertaken. A Bayesian consensus tree was drawn upand the results show that the termites nest within the cockroaches and that Cryptocercus, the only genus in the family Cryptocercidae, is a sister group to the termites. The maximum parsimony analysis provided identical results. The mantids were shown to be the sister group to Blattodea.
Cryptocercus has a number of characteristics in common with termites, such as identical species of gut bacteria, and phylogenetic studies have shown that these cockroaches are more closely related to termites than than they are to other cockroaches.
- Integrated Taxonomic Information System entry
- "Order Blattodea: Cockroaches and Termites". BugGuide. Retrieved 2015-08-27.
- Inward, Daegan; Beccaloni, George; Eggleton, Paul (2007). "Death of an order: a comprehensive molecular phylogenetic study confirms that termites are eusocial cockroaches". Biology Letters 3 (3). doi:10.1098/rsbl.2007.0102.
- Djernæs, M. (2012). "Phylogeny of cockroaches (Insecta, Dictyoptera, Blattodea), with placement of aberrant taxa and exploration of out-group sampling". Systematic Entomology 37 (1): 65–83. doi:10.1111/j.1365-3113.2011.00598.x.
- Eggleton, P., Beccaloni, G. & Inward, D. 2007. Invited reply: Response to Lo et al. Biology Letters, 3(5): 564-565 [Published online 14 August 2007. doi: 10.1098/rsbl.2007.0367]
- Beccaloni, G. W. & Eggleton, P. 2011. Order Blattodea Brunner von Wattenwyl, 1882. In: Zhang, Z.-Q. (Ed.). Animal biodiversity: An outline of higher-level classification and survey of taxonomic richness. Zootaxa, 3148: 199-200.