http://www.collembola.org/publicat/tripod.htm - Last updated on 2022.06.19 by Frans Janssens

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Marie Louise Huskens, Opitterkiezel 223 bus 0.1, B-3960, Opitter, Belgium

Abstract

Introduction

Material and methods

Results

Neelidae

Fig.Mm. Megalothorax minimus grooming on 3 right legs.
Huskens, M.L. © 2021.12.09

Megalothorax minimus grooming on 3 right legs (fig.Mm).

Fig.Nsp. Neelides sp. grooming on 3 left legs.
Cheng, H.-J. © 2022.01.04

Neelides sp. from Taiwan, kept in culture, suddenly grooming on 3 left legs (fig.Nsp).

Isotomidae

Fig.Is. Vertagopus arboreus grooming on 3 right legs.
Huskens, M.L. © 2021.03.23

Vertagopus arboreus grooming on 3 right legs (fig.Is).

Entomobryidae

Fig.Em. Entomobrya multifasciata grooming on 3 right legs.
Huskens, M.L. © 2016.12.23

Entomobrya multifasciata grooming on 3 right legs (fig.Em).

Sminthurididae

Fig.Sa1. Sminthurides aquaticus ♀ standing on 6 legs.
Huskens, M.L. © 2016.10.27

Fig.Sa2. Sminthurides aquaticus ♀ standing on 4 legs.
Huskens, M.L. © 2016.10.27

Fig.Sa3. Sminthurides aquaticus ♀ standing on 3 legs.
Huskens, M.L. © 2016.10.27

Sminthurides aquaticus female on 6 to 3 right legs. (fig.Sa1, Sa2, Sa3). In the start position, the specimen is standing still on 6 legs (fig.Sa1). The right proleg and metaleg are placed under the body while the left proleg and mesoleg are lifted from the substrate to clean the left antenna. The left metaleg is still used to stand on (fig.Sa2). Eventually, also the left metaleg is lifted from the substrate (fig.Sa3). All left legs are now involved in cleaning the furca.

Fig.Ss. Sminthurides schoetti juv. ♂ standing on 3 legs.
Huskens, M.L. © 2021.02.03

Sminthurides schoetti juvenile male on 3 right legs (fig.Ss).

Katiannidae

Fig.Sao. Sminthurinus aureus forma ochropus grooming on 3 legs.
Huskens, M.L. © 2016.12.18

Sminthurinus aureus forma ochropus on 3 right legs, handling a drop of saliva using its 3 left legs (fig.Sao).

Fig.St. Sminthurinus trinotatus passing drop of saliva to the metaleg.
Huskens, M.L. © 2016.11.22

Sminthurinus trinotatus on 3 right legs. The body is cleaned using a drop of saliva, that is held at the tip of a leg by the hydrophil outer claw and tenent setae of the footcomplex. The drop of saliva originally is collected by the footcomplex of the left proleg. It is then passed from one leg to the other (fig.St).

Fig.Sr. Sminthurinus reticulatus cleaning the lateral bothriotricha.
Huskens, M.L. © 2016.12.02

Sminthurinus retculatus on 3 right legs. The drop of saliva has been passed to the metaleg, with which the lateral bothriotricha A, B and C are cleaned (fig.Sr).

Fig.K. Gen.1 nov. sp. nov. 0.4mm juvenile, grooming.
David W. © 2017.02.02

Fig.KK. Gen.1 nov. sp. nov. 0.4mm juvenile, grooming.
Fred's Uncle. © 2021.02.06

Gen.1 nov. sp. nov. from the UK, juvenile instar of 0.4mm on 3 legs (figs K, KK).

Sminthuridae

Fig.T. Temeritas sp. cleaning the dorsum.
Cheng, H.-J. © 2022.06.12

Temeritas sp. on 3 right legs, cleaning at high speed flank of body, legs and antennal basis using collophore vesicle (fig.T).

Dicyrtomidae

Fig.Dfr. Dicyrtoma fusca var. rufescens cleaning the mucro of the furca.
Huskens, M.L. © 2016.12.14

Dicyrtoma fusca var. rufescens on 3 right legs. The mucro of the furca is cleaned while passing a drop of saliva from the left proleg to the left mesoleg (fig.Dfr). The right proleg, and metaleg, are placed underneath the body, while the body itself is tilted to the right to stay in balance on the 3 right legs.

Fig.Dffs. Dicyrtoma fusca f. signata grooming.
Huskens, M.L. © 2017.01.10

Dicyrtoma fusca f. signata on 3 right legs. The 3 left legs are engaged in a grooming activity (fig.Dffs). The right proleg and metaleg, are placed underneath the body, while the right mesoleg is placed outside the body. The right legs form as such a stable tripod while the body itself is tilted to the right to stay in balance on the 3 right legs.

Fig.Do. Dicyrtomina ornata juvenile cleaning the furca.
Huskens, M.L. © 2016.11.20

Fig.Do2. Dicyrtomina ornata cleaning the furca.
Huskens, M.L. © 2016.12.20

Dicyrtomina ornata on 3 right legs. The juvenile specimen cleans the furca using the 3 left legs (fig.Do). The right proleg is placed underneath the body, and the body itself is tilted to the right (fig.Do2). The unguis of the right proleg is held in 'knuckle-walking' position. The left proleg and mesoleg interact with a drop of saliva, while the left metaleg is used to keep the body in balance (fig.Do2).

Fig.Jns. Jordanathrix nr superba ♂ cleaning the furca.
Huskens, M.L. © 2016.12.16

Jordanathrix sp. nov. nr superba male on 3 right legs. The relatively large drop of saliva is handled by all left legs together to clean the furca (fig.Jns).

Discussion

Given 6500 ° K corresponds to the colour temperature of daylight, overcast condition (clouds obscuring the sky at least 95%), apparantly the tripod grooming is typically triggered by an increase in light intensity due to changed wheather conditions : such as a change from a cloudy overcast day to a sunny clear sky day.

The tripod grooming was observed only in surface active species such as species of Neelidae, Isotomidae, Entomobryidae, Sminthurididae, Katiannidae and Dicyrtomidae.

To be continued.

Conclusion

Acknowledgements

Bibliography

• ...