02167nas a2200217 4500008004100000245010800041210006900149260001600218490000600234520146800240653001301708653001501721653001601736653001401752100002201766700001901788700002201807700001701829700002101846856008201867 2016 eng d00aSubstrate vibrations mediate behavioral responses via femoral chordotonal organs in a cerambycid beetle0 aSubstrate vibrations mediate behavioral responses via femoral ch cJan-12-20160 v23 a

Background
Vibrational senses are vital for plant-dwelling animals because vibrations transmitted through plants allow them to detect approaching predators or conspecifics. Little is known, however, about how coleopteran insects detect vibrations.

Results
We investigated vibrational responses of the Japanese pine sawyer beetle, Monochamus alternatus, and its putative sense organs. This beetle showed startle responses, stridulation, freezing, and walking in response to vibrations below 1 kHz, indicating that they are able to detect low-frequency vibrations. For the first time in a coleopteran species, we have identified the sense organ involved in the freezing behavior. The femoral chordotonal organ (FCO), located in the mid-femur, contained 60–70 sensory neurons and was distally attached to the proximal tibia via a cuticular apodeme. Beetles with operated FCOs did not freeze in response to low-frequency vibrations during walking, whereas intact beetles did. These results indicate that the FCO is responsible for detecting low-frequency vibrations and mediating the behavioral responses. We discuss the behavioral significance of vibrational responses and physiological functions of FCOs in M. alternatus.

Conclusions
Our findings revealed that substrate vibrations mediate behavioral responses via femoral chordotonal organs in M. alternatus.

10aBehavior10aColeoptera10aSense organ10avibration1 aTakanashi, Takuma1 aFukaya, Midori1 aNakamuta, Kiyoshi1 aSkals, Niels1 aNishino, Hiroshi uhttp://zoologicalletters.biomedcentral.com/articles/10.1186/s40851-016-0053-4