Application of the electroantennography (EAG) of olfactory stimuli in the cork oak (Quercus Suber L.) woodborer Prinobius Germari Dejean (Coleoptera, Cerambycidae)

Resumen

This work shows the first results about the application of the electroantennography (EAG) of olfactory stimuli in the cork oak (Quercus suber L.) woodborer Prinobius germari Dejean (Coleoptera, Cerambycidae). This insect is one of the worse one known between the species that affect Q. suber; nevertheless, the presence and relevance of its damages recommend considering these species as one of main woodborers in the cork oaks in Western Andalusia (Spain). The most recent proposals on the possibility of population management of this type of insects, in a context of integrated pest management, they point out the knowledge of cues that condition the host selection, particularly the influence of semiochemical compounds, as an important aspect of such strategy. The electroantennography constitutes a valuable tool to approach this type of studies. EAG recordings in P. germari using the green leaves volatile (E)-2-hexenal, acetic acid and turpentine indicate that the latter can be used like standard stimulus to improve the characterization of olfactory behavior of this cerambycid. The EAG response using turpentine (0,39 mV ± 0,46; mean ± SD) are in the range of results founded in other species using different volatile compounds, and shows a great variability between individuals. These results suggest, in addition, that mean EAG response of the Females could be superior to those of the males. Some parameters implied in EAG experimentations have been studied. The results show that stimulation frequency of 15 seconds with amounts solution of 20 microliters is suitable; moreover, EAG preparations remain quite stable throughout the time (loss of average response around 10% after five hours). These results allow to raise studies about the role of the olfactory mechanisms in the behaviour of this species.