SYSTEMATICS OF BEETLES IMPORTANT TO AGRICULTURE, ARBORICULTURE, AND BIOLOGICAL CONTROL
Title: The evolution of food preferences in Coccinellidae
| Giorgi, Jose - ENT. UNIV. OF GA, ATHENS |
| Mchugh, Joseph - ENT. UNIV. OF GA, ATHENS |
| Forrester, Juanita - ENT. UNIV. OF GA, ATHENS |
| Slipinski, S. Adam - CSIRO ENT. AUSTRALIA |
| Miller, Kelly - BIOLOGY UNIV. OF NM |
| Shapiro, Lori - PA STATE UNIV. UNIV. |
| Whiting, Michael - BIOLOGY & M.L. BLSM, BYU |
Submitted to: Biological Control
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: May 26, 2009
Publication Date: August 1, 2009
Citation: Giorgi, J.A., Vandenberg, N.J., McHugh, J.V., Forrester, J.A., Slipinski, S., Miller, K.B., Shapiro, L.R., Whiting, M.F. 2009. The evolution of food preferences in Coccinellidae. Biological Control. ISSN 1049-9644. http://dx.doi.org/10.1016/j.biocontrol.2009.05.019.
Interpretive Summary: Most lady beetles are predatory and feed on a variety of crop and garden pests such as aphids, scale insects, psyllids, whiteflies, and thrips. In contrast, some lady beetles feed primarily on powdery mildews or pollen, and one group contains a number of agricultural plant pests that feed on leaves and stems. The evolutionary relationships among lady beetles are poorly known and studies based on external structures have not been very informative. The present study uses modern molecular techniques to investigate the relationships among the different kinds of lady beetles as a tool for understanding the evolution of their feeding preferences. This research will lead to changes in their classification, and it will allow us to better predict biological characters of poorly known taxa, such as the role they may play as beneficial or pest species. This research will be of interest to scientists, insect pest managers, and quarantine officials.
Despite the familiarity and economic significance of Coccinellidae, the family has thus far escaped analysis by rigorous phylogenetic methods. As a result, the internal classification remains unstable and there is no framework with which to interpret evolutionary events within the family. Coccinellids exhibit a wide range of preferred food types, spanning kingdoms and trophic levels. To provide an evolutionary perspective on coccinellid feeding preferences, we performed a phylogenetic analysis of 62 taxa based on the ribosomal nuclear genes 18S and 28S. The entire dataset consists of 3,957 aligned nucleotide sites, 787 of which are parsimony informative. Bayesian and parsimony analyses were performed. Host preferences were mapped onto the Bayesian tree to infer food preference transitions. Our results indicate that the ancestral feeding condition for Coccinellidae is coccidophagy. From the ancestral condition, there have been at least three transitions to aphidophagy; two transitions to herbivory and one transition to mycophagy. The analyses recovered a clade comprising Serangiini plus Microweiseini as the sister group to the rest of Coccinellidae. The subfamily Coccinellinae is monophyletic; however, Sticholotidinae, Chilocorinae, Scymininae and Coccidulinae are paraphyletic. Our results do not support the traditional view of phylogenetic relationships among the coccinellid subfamilies. These results indicate that the current classification system poorly reflects the evolution of Coccinellidae and therefore needs revision.