grant burleigh's picture

Blaniulids (cont.)

Observed: 16th March 2013 By: grant burleighgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebratesgrant burleigh’s reputation in Invertebrates
005 (2)
016
015
003
Description:

see Comment.
Image 3: 25/01/2012; Image 4: 17/02/2011
In Images 1 and 2, Blaniulids appear to be attacking a slug and in Image 3 they are aggregated around some decaying material which could be the remains of a slug. These images continue previous posts of mine which include examples of Blaniulids attacking a worm and, less certainly, woodlice*. Image 4 is a more convincing supplement to the last observation.
*see iSpot (“Blaniulid “, 01/02/2011 and “Two millipedes” 09/11/2012).

Identifications
Species interactions

No interactions present.

Comments

grant burleigh's picture

Blaniulid/collembola

As in previous images, small white collembolan–like creatures are present. Accepting now that they are not immature Blaniulids (re Andyk’s comment in “Blaniulid”), some questions arise: (i) why is one seeing only these creatures? ..and (ii) is there something about their metabolism that attracts them to products of biological decay that result from Blaniulid predation? (iii) Could a degree of Blaniulid/ Collambolan mutualism even be involved?
These preliminary questions appear to invite further observations - including a more systematic look at numbers of the collembola at locations in which Blaniulids are either concentrated or lacking.

stevegregory's picture

Blaniulus is a scavenger!

Blaniulus is a vegetatian species, a notorious pest of potatoes, sugar-beet and can eat seedlings in greenhouses. It is very opportunistic in its diet and will readily consume rotting plant and dead animal material. However, it DOES NOT attack live healthy animals! The collembola are probably also opportunistic scavengers (as would be the slugs and woodice - which are Oniscus asellus - if they were still alive!)

notpop's picture

moles ?

Regularly see thin pale worm like creatures around the anus of dead moles I trap.
Could it be these ?
My intention is to photograph them for iSpot next time I see them,as I always wondered if they were emerging from the moles e.g. roundworm ,or attacking from the soil.

grant burleigh's picture

Blaniulids as aggressors?

This problem goes back to Natural History Museum posts of mine (2010-11)* in which I did raise the question of whether B. guttulatus is purely a scavenger or has an offensive capability. It was thought doubtful that the latter was the case in the particular case of woodlice. The underlying question is whether the “repellent” glands of several B. guttulatus individuals operating in concert might be enough to overwhelm another invertebrate and perhaps even dissolve it. Are there actually any published studies on this? In Images 1 and 2 here the slug is mainly intact and the only overt damage is where the millipedes are, suggesting that we need more evidence on these lines

http://www.nhm.ac.uk/natureplus/message/2299; http://www.nhm.ac.uk/natureplus/message/8572#8572

stevegregory's picture

Very interesting.....

This is a very interesting topic. I am not aware of any reference in literature to ‘predatory’ millipedes (but my knowledge is not exhaustive). Certainly Julidans and Polydesmidans are able, at will, to secrete from their ozadenes very noxious chemicals (hydrocyanides, etc), but this is always claimed to be for defensive purposes. It they were able to discharge their ozadenes in an aggressive manner the chemicals are more than capable of subduing other invertebrates. Species such as Tachypodoiulus niger can be used in a 'killing jar' (give them a good shake!) as ‘poor man’s’ ethyl acetate to kill insect specimens (as can chopped Laurel leaves; both produce hydrogen cyanide). I suggest you put this out to a wider audience, such as BMIG Google Group (email: bmigroup@googlegroups.com), which includes many people more learned than I.