Marta Martínez Wells, Ph.D. Lecturer Ecology and Evolutionary Biology Yale University 168b Gibbs Lab New Haven, CT 06520-8106 USA phone: 203-432-6294 email: marta.wells@yale.edu

UConn Web-site

Research areas: Evolutionary biology, molecular evolution, speciation on green lacewings (Neuroptera), courtship song behavior.

For the past 10 years I have been working with Charles Henry on green lacewings (Neuroptera, Chrysopidae). We are interested in understanding the role of mating signals in reproductive isolation among cryptic species of insects. Even though, it is not clear whether the changes in courtship song features precede, induce, or develop after speciation, courtship songs become a very important factor in the process of speciation, because they result in the formation of swarms of sibling species distinguished only by differences in their songs.

Green lacewings of the order Neuroptera, are a good case study to look at the role of courtship songs in reproductive isolation and at evolutionary changes in song features among closely related species.

Male and female green lacewings establish duetting behavior through a low frequency tremulation courtship song, that always precedes copulation. A combination of playback experiments, laboratory hybridization, electrophoretic and mitochondrial DNA studies has shown that many species of green lacewings are really groups of cryptic sibling biological species previously unknown.

In organisms that use acoustic signals, there are some features that are used in species recognition. In many insects, it has been shown that the temporal features of songs such as pulse rate or inter-chirp interval play a key role on species recognition. In Chrysoperla plorabunda, the temporal features of the courtship song (volley duration and interval) seem to be very important features to elicit duetting responses in females.

The process of speciation must frequently involve the evolution of novel signals and preferences and the problem is to understand how this occurs. Data on behavioral responses of hybrid green lacewings to both hybrid and parental songs, suggest that the mechanisms of production and reception of songs may be coupled. Then, changes on song features during speciation could be accompanied by changes in the receiver's signal, allowing for populations to diverge through assortative mating.

Currently, I am doing a study using mitochondrial and nuclear DNA sequence data, in Chris Simon's Laboratory, to reconstruct the phylogenetic relationships among several closely related species within the genus Chrysoperla. The objective is to enhance the understanding of the evolution of courtship songs, and try to clarify the relationship between song divergence and rapid speciation within certain of its species lineages, such as the C. plorabunda complex, C. downesi complex and C. carnea complex. Some of the preliminary results show the song species within each complex as being more close related to each other than to any other species in the other complexes. This results agree with the prediction that if speciation trough song divergence is the evolutionary process occurring in these insects, the song species should be sister taxa within each complex.

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