http://www.collembola.org/publicat/stenacid.htm - Last updated on 2022.03.14 by Frans Janssens
Checklist of the Collembola: Stenacidia violacea courtship (Collembola: Sminthurididae)

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Mirella Zeeders, Cala Serena, 07669, Mallorca, Spain

Abstract.
The courtship ritual of Stenacidia violacea is documented.

Introduction

Bretfeld (1999:61) states "The mating behavior is unknown". In this short paper we describe the courtship ritual.
Note : the text is still in draft state...
To be completed.

Material and methods

Observations and video recordings of the courtship ritual have been performed by the second author.
Specimens were observed and have been recorded in situ, behind the house of the second author, on an old pavement in the shade covered with some moss.
Location = Mallorca, Spain.
Date = 2022.02.03

The MP4 video recordings were made hand held using a Nikon Coolpix P950 camera equiped with a Raynox DCR-250 macro lens. Neither flash nor tripod were used. In total, 32 minutes of video recording were made, between 15h45 and 16h19. The recordings were cut into short video clips using the free video cutting tool Free Cut Video. The video clips were resized to 240x180 pixels, and converted to animated gif format using the free online Video to GIF converter.

Results

Summary of courtship ritual :

Stenacidia violacea ♂ & ♀ from Spain
Courtship begin
2022.02.03 © Zeeders, M.

Time 00m. Begin of courtship ritual. The male grabs both the basal antennal segments of the antennae of the female using the clasping mechanism of its highly modified antennae. This is typical courtship behaviour for all members of the family Sminthurididae.
The female lifts up the male and walks around with him being clasped to her antennae. The male as well as the female occasionally clean their flanks with striking movements of the backlegs. While turning around head against head, the male seems to have difficulties with walking using its legs. In addition its legs seem to tremble occasionally.

Stenacidia violacea ♀ & ♂ from Spain
Courtship continuation part 1
♂ trembles with front & middle legs
2022.02.03 © Zeeders, M.

Time 28m. The male waves/trembles its front and middle legs at high frequency. The legs are held horizontally and orthogonally to its body. The legs are moved up and down at high speed. The legs are moved alternativelly : front legs up - middle legs down, then front legs down - middle legs up. This is repeated continuously.

Stenacidia violacea ♀ & ♂ from Spain
Courtship continuation part 2
♂ trembles ant.4 while depositing spermatophore
2022.02.03 © Zeeders, M.
Stenacidia violacea ♀ & ♂ from Spain
Deposition of spermatophore
2020.12.23 © Zeeders, M.

Time 30m. The male folds its 4th antennal segments together and trembles them at high frequency. At the same time he deposits a spermatophore. Notice, the illustration of the spermatophore depostion is from another observation. We assume that the trembling antennae signals to the female that the spermatophore has been deposited.

Stenacidia violacea ♀ & ♂ from Spain
Courtship continuation part 3
♀ climbs over ♂ to take-up spermatophore
2022.02.03 © Zeeders, M.

Time 31m. The male releases the female. The female climbs over the male. The male supports the female by lifting its head while she climbs over him. At the other side the female takes up the spermatophore.
Both partners clean them selves and go their own way. It was noticed that the male ate the residu of the spermatophore. End of courtship around 32m.

Conclusion

The courtship ritual of Stenacidia violacea is quite remarkable. Especially the male communication/signalisation using legs and antennae is quite peculiar. The male waving with front and middle legs then trembling its folded together 4th antennal segments while depositing a spermatophore, after which the female climbs over the male to uptake the spermatophore.

References