frans_janssens

Note the two dark pigment dots on the 5th and 6th abdominal segment (forming the posterior 'small abdomen').

Hi Krister, this is one of the Collembola that can become a pest in agriculture.

There is a close relative Sminthurus nigromaculatus that has a black spot on both abdomen 5 and 6. This cannot be checked in this picture.

An adult specimen.

Forms with a black head, such as this adult specimen, were called 'var. melanocephala'. These variants are now considered being infraspecific variants without separate taxonomic status.

A juvenile specimen.

Note the 'knuckle-walking' position of the meta- and meso-foot!

Dear Krister, after comparing many Dicyrtomina in frontal aspect I have come to the conclusion that it is possible to distinguish D.ornata and D.saundersi even in frontal aspect (thus without seeing the Maltheser cross patch at its butt). Currently I use the colour of the 2nd antennal segment as a key character to distinguish the two species in frontal aspect. If the colour of the 2nd antennal segment is the same as that of the 3rd and 4th, or gradually changes in colour from basis to apex (ending up with the same colour as the 3rd), it is D. ornata. If the colour of the 2nd antennal segment is distinctly lighter (especially at the basis and apex of the segment) then that of the 3rd and 4th, it is D. saundersi. Based on this character, I consider your specimen now as D. saundersi. Sorry for the confusion caused. Kind regards, Frans PS: this is just a hypothesis for now. You might want to keep an eye on this if you meet any more species of D.ornata or saundersi. To see whether or not the character is stable.

Dear Krister, after comparing many Dicyrtomina in frontal aspect I have come to the conclusion that it is possible to distinguish D.ornata and D.saundersi even in frontal aspect (thus without seeing the Maltheser cross patch at its butt). Currently I use the colour of the 2nd antennal segment as a key character to distinguish the two species in frontal aspect. If the colour of the 2nd antennal segment is the same as that of the 3rd and 4th, or gradually changes in colour from basis to apex (ending up with the same colour as the 3rd), it is D. ornata. If the colour of the 2nd antennal segment is distinctly lighter (especially at the basis and apex of the segment) then that of the 3rd and 4th, it is D. saundersi. Based on this character, I consider your specimen now as D. saundersi. Sorry for the confusion caused. Kind regards, Frans PS: this is just a hypothesis for now. You might want to keep an eye on this if you meet any more species of D.ornata or saundersi. To see whether or not the character is stable.

Dear Krister, after comparing many Dicyrtomina in frontal aspect I have come to the conclusion that it is possible to distinguish D.ornata and D.saundersi even in frontal aspect (thus without seeing the Maltheser cross patch at its butt). Currently I use the colour of the 2nd antennal segment as a key character to distinguish the two species in frontal aspect. If the colour of the 2nd antennal segment is the same as that of the 3rd and 4th, or gradually changes in colour from basis to apex (ending up with the same colour as the 3rd), it is D. ornata. If the colour of the 2nd antennal segment is distinctly lighter (especially at the basis and apex of the segment) then that of the 3rd and 4th, it is D. saundersi. Based on this character, I consider your specimen now as D. saundersi. Sorry for the confusion caused. Kind regards, Frans PS: this is just a hypothesis for now. You might want to keep an eye on this if you meet any more species of D.ornata or saundersi. To see whether or not the character is stable.

Dear Krister,

after comparing many Dicyrtomina in frontal aspect I have come to the conclusion that it is possible to distinguish D.ornata and D.saundersi even in frontal aspect (thus without seeing the Maltheser cross patch at its butt). Currently I use the colour of the 2nd antennal segment as a key character to distinguish the two species in frontal aspect. If the colour of the 2nd antennal segment is the same as that of the 3rd and 4th, or gradually changes in colour from basis to apex (ending up with the same colour as the 3rd), it is D. ornata. If the colour of the 2nd antennal segment is distinctly lighter (especially at the basis and apex of the segment) then that of the 3rd and 4th, it is D. saundersi.

Based on this character, I consider your specimen now as D. saundersi.

Sorry for the confusion caused.

Kind regards,

Frans

PS: this is just a hypothesis for now. You might want to keep an eye on this if you meet any more species of D.ornata or saundersi. To see whether or not the character is stable.

In L. cyaneus, the antennae and legs are not scaled, as in this specimen. In its look-alike relative L. violaceus, they are scaled.

Merry Christmas, Krister.

Female.

Ceratophysella? Does this specimen has distinct anal spines?

Megalothorax is one of the smallest Collembola, about 1/4 mm.

The checkboard pattern on this specimen is not that common. I have not seen it before. Recently, it has also been reported from the UK.

Good catch!

A juvenile?

A juvenile?

Perhaps. There are no anal spines visible.

according to Fauna Europaea.

Compares well with the picture of Steve Hopkin at his website.

Hi Matty. I agree with your tentative ID. Originally I assumed it was a kind of melanocephala variant or triangulimaculata form of flavescens. O. flavescens has so many different described forms...

Thanks for pointing this out.

My first attempt to idy this specimen is definitely wrong. Sminthurinus does not have subsegmented fourth antennal segment.