TY - JOUR
T1 - Penetration mechanics of elongated female and male genitalia of earwigs
AU - Matsumura, Yoko
AU - Kamimura, Yoshitaka
AU - Lee, Chow Yang
AU - Gorb, Stanislav N.
AU - Rajabi, Hamed
N1 - Funding Information:
We are grateful to Shahab Eshghi and Mohsen Jafarpour (Kiel University, Germany) for their assistance to estimate Young’s moduli and to calculate the second moment of area. We are grateful also to Jan Michels, Alexander Kovalev and Esther Appel (Kiel University, Germany) for their technical support for drying samples at the critical point and for sputter coating of the samples. This study was supported through funding from the German Research Foundation (DFG grant no. MA 7400/1-1) to YM and Grants‐in‐Aid for Scientific Research (KAKENHI #19K06746) from the Japan Society for the Promotion of Science to YK.
Publisher Copyright:
© 2021, The Author(s).
PY - 2021/12
Y1 - 2021/12
N2 - We unveiled the penile penetration mechanics of two earwig species, Echinosoma horridum, whose intromittent organ, termed virga, is extraordinarily long, and E. denticulatum, whose virga is conversely short. We characterised configuration, geometry, material and bending stiffness for both virga and spermatheca. The short virga of E. denticulatum has a material gradient with the stiffer base, whereas the long virga of E. horridum and the spermathecae of both species are homogeneously sclerotised. The long virga of E. horridum has a lower bending stiffness than the spermatheca. The virga of E. denticulatum is overall less flexible than the spermatheca. We compared our results to a previous study on the penetration mechanics of elongated beetle genitalia. Based on the comparison, we hypothesised that the lower stiffness of the male intromittent organ comparing to the corresponding female structure is a universal prerequisite for the penetration mechanics of the elongated intromittent organ in insects.
AB - We unveiled the penile penetration mechanics of two earwig species, Echinosoma horridum, whose intromittent organ, termed virga, is extraordinarily long, and E. denticulatum, whose virga is conversely short. We characterised configuration, geometry, material and bending stiffness for both virga and spermatheca. The short virga of E. denticulatum has a material gradient with the stiffer base, whereas the long virga of E. horridum and the spermathecae of both species are homogeneously sclerotised. The long virga of E. horridum has a lower bending stiffness than the spermatheca. The virga of E. denticulatum is overall less flexible than the spermatheca. We compared our results to a previous study on the penetration mechanics of elongated beetle genitalia. Based on the comparison, we hypothesised that the lower stiffness of the male intromittent organ comparing to the corresponding female structure is a universal prerequisite for the penetration mechanics of the elongated intromittent organ in insects.
UR - http://www.scopus.com/inward/record.url?scp=85104258554&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85104258554&partnerID=8YFLogxK
U2 - 10.1038/s41598-021-86864-1
DO - 10.1038/s41598-021-86864-1
M3 - Article
C2 - 33846369
AN - SCOPUS:85104258554
VL - 11
JO - Scientific Reports
JF - Scientific Reports
SN - 2045-2322
IS - 1
M1 - 7920
ER -