- Last updated on 2017.02.08 by Frans Janssens
Checklist of the Collembola: Note on the seasonal occurence of Sminthurus hispanicus Nayrolles 1995 (Sminthuridae) from Ibiza, Spain

Frans Janssens, Department of Biology, University of Antwerp, Antwerp, B-2020, Belgium
Ronald Beer, ... Ibiza, Spain


Based on observations ranging from 2009 to 2016, it is conclusive that Sminthurus hispanicus Nayrolles 1995 in Sant Jordi de Ses Salines, Balearic Islands, Spain is active mainly in the wet season from October to February.


In Sminthurus viridis from Australia, the time of appearance and disappearance of the active stages is closely related to the ratio of rainfall to evaporation at the beginning and end of the season respectively (Davidson 1933 cited from Walters 1964:67). Four generations occur during the active season (Davidson 1934 cited from Walters 1964:67).

Surface active specimens of Sminthurus hispanicus were photographed on daily basis. The data collected from 2009-2012 is incomplete. Since 2013 to 2016, data was collected in a more systematic matter.


Material and methods

Fig.1. Sminthurus hispanicus juvenile and adult (note spermatophore).
Beer, R. © 2013.09.18
Specimens of Sminthurus hispanicus Nayrolles 1995 were observed in their natural habitat, Sant Jordi de Ses Salines, Balearic Islands, Spain, since 2009 up to end of 2016. Specimens were recorded photographically in situ (Fig.1). The photographs were made using a digital reflex camera Canon EOS 40D. A Canon Macro MP-E65 mm f/2.8 lens was mounted on the camera. Extension tubes were not used.
Fig.Fl. Flash extender. Minimum extension.
Beer, R. © 2015.01.03
Fig.Ext. Flash extender. Maximum extension.
Beer, R. © 2015.01.03
Illumination was provided by the on camera flash using a white plastic extendable tube that runs from the camera flash and directs the light over the end of the lens (Fig.Fl.,Ext).


Table 1. Seasonal surface activity
Number of days active specimens were recorded

Seasonal occurence.


Fig.Ib. Ibiza climate graph. © 2016.12.23

Effect of temperature on seasonal occurence.


Effect of moisture conditions on seasonal occurence.
There is a distinct correlation between the presence of active stages and the precipitation, the relative humidity and the number of wet days (Fig.Ib). Active specimens are absent from May to July (Table.1). This period coincides with a period with a precipitation of less than 24mm (=24 ltr/m2), a relative humidity of less than 61%, and a number of wet days/month of less than 4.
Active specimens are always present from October to February (Table.1), in which the precipitation is at least 27mm, the relative humidity is more than 63%, and the number of wet days is at least 6.
From september to december 2016 almost only juveniles were observed.
In december 2016 a lot of rain, the white flowers have been smothered and it is hard to find Collembola.


Effect of various other environmental factors on seasonal occurence. Availibility of food, the soil texture (its water-holding capacity), the soil reaction.
Correlation with presence of ???little white flowers??? as pollen food source.


The occurence of different generations.



In Sminthurus hispanicus from Ibiza, Spain, the time of appearance and disappearance of the active stages is closely related to the ratio of precipitation. Specimens are surface active as long as the precipitation level is more then 27mm.