Cricket nymph ? - Myrmecophilus pergandei

Based on the dark color

this should be M. pergandei, but it's near the western limit for that species. M. nebrascensis should be much paler in color. The only way to be absolutely certain is to count the spines on the inner side of the hind tibiae, and I can't quite do that in these images. There are 4 on M. pergandei and three on M. nebrascensis. I am putting it under M. pergandei for now.

Moved from Myrmecophilus.

… David J. Ferguson, 12 December, 2010 - 3:17pm

Wow!

That is very cool. It looks like it has frog legs!

… Vespula Vulgaris, 16 February, 2009 - 11:02am

Very interesting - Myrmecophilus sp.

These small "Ant loving Crickets" are difficult to spot, let along to photograph properly. Adults are wingless and difficult to tell apart from similar nymphs. From its size, this one individual is at least a late instar nymph.
As the genus - and family - name indicate, there is a relationship, mandatory for the Crickets who can't survive for long outside an ants' nest.

… Richard Vernier, 16 February, 2009 - 10:08am

Very cool!

But why can't they survive away from the ants?
And what exactly is the relationship?

… Sam Houston, 16 February, 2009 - 10:10am

Perhaps this is an example of

Perhaps this is an example of Gryllidae Myrmecophila who according to Holldobler and Wilson in The Ants, lick host secretions, prey on ant host eggs, solicit regurgitated food, follow ant trails and feed on prey brought in by the ants.

… Gary M. Drake, 16 February, 2009 - 11:13am

Ok, so

what do they do for the ants?
Why do they put up with that?

… Sam Houston, 16 February, 2009 - 11:28am

They engage in a strategy kno

They engage in a strategy known as tactile mimicry. Apparently they mimic the rate of movement of the host ants and are able to blend in. Introducing a new batch of crickets to a disturbed nest the crickets will be treated as hostile. But if introduced to an undisturbed nest the crickets just blend in over a period of a few days. They are of no direct benefit to their hosts as far as I've read. The degree of motion typical of the species is adopted by the invading cricket as witness by the respective movements of crickets introduced to a rather phlegmatic colony of Myrmica rubra versus a more bustling colony of Formica fusca. There is also the taking on of the colony odor as a component of the masquerade and finally apparently there are parts of the crickets body that mimic portions of the ants body that are key for tactile recognition. In short these crickets are after a period of adjustment able to line up at cafeteria and eat eggs in the nursery without being recognized as aliens by their hosts.

… Gary M. Drake, 16 February, 2009 - 11:55am

Wow!

That's just weird that they can get away with it.

… Sam Houston, 16 February, 2009 - 11:59am

Ya!

Ya! The chapter in The Ants on Symbioses with Other Arthropods is very weird and amazing.

… Gary M. Drake, 16 February, 2009 - 12:05pm

From what Gary described...

they seem more like nest parasites..perhaps the crickets "smell" like the ants- they may emit pheromones that mimic those that ants give off or scents that the ants are attracted to, which may explain why the ants don't seem to mind (and even welcome). A similar mechanism may occur with other arthropod species that spend part of to all of their lives in nests of ants and other social insects.

… Tim Loh, 16 February, 2009 - 11:50am