Measurements of soldier head capsules of cuticular hydrocarbon phenotypes of Reticulitermes (Blattodea: Heterotermitidae) from Northern California identify morphologically cryptic and sibling species
| Authors: | Michael Haverty, Lori J. Nelson, Jim Baldwin |
| Year: | 2025 |
| Type: | Scientific Journal |
| Station: | Pacific Southwest Research Station |
| DOI: | https://doi.org/10.1093/jee/toaf154 |
| Source: | Journal of Economic Entomology |
Abstract
Four undescribed species or subspecies of Reticulitermes Holmgren 1913 in northern California have been identified by chemotaxonomic and phylogenetic analyses of voucher specimens used for chemotaxonomy. To date, useful morphological keys do not exist. We present eight direct and 22 derived measures and indices of soldier head capsules of multiple colonies of each of five cuticular hydrocarbon (CHC) phenotypes. Our objective was to identify one or more morphological measurements of soldier head capsules that would unequivocally separate taxa previously identified by CHCs and phylogenetic analyses. Phenotypes CA-A, CA-A', and CA-D are found in the coastal areas, whereas phenotypes CA-A, CA-B, and CA-C are found in the foothills of the Sierra Nevada. For all direct measurements, as well as the derived measurements and indices, we discovered extensive variation within all five phenotypes and overlap in values for nearly all variables. The discriminant analysis did not provide unequivocal separation of phenotypes CA-A and CA-D. The discriminant analysis provided unequivocal separation of phenotypes CA-A from both phenotypes CA-B and CA-C. From these results, we consider phenotypes CA-A and CA-D to be cryptic, but not sibling, species because they are very difficult to separate on the basis of soldier head capsule measurements and they are not closely related by phylogenetic analyses. Phenotypes CA-B and CA-C should be considered both cryptic and sibling species because they are impossible to separate on the basis of soldier head capsule measurements and they are separate, but closely related, species on the basis of phylogenetic analyses.