The Dead Crematogaster

Pella planifer

Please enjoy this awesome satanic instrumental by The Dead Weather whilst you awe at this amazing action shot of Pella planifer ravaging a Crematogaster sp.

I ♡ Scydmaeninae

I want to introduce a new paper by Paweł Jałoszyński. This March in Systematic Entomology, Paweł described a new extinct genus and species of clidicine Ant-like stone beetle, ✝Euroleptochromus sabathi together with a phylogenetic analysis of the supertribe Mastigitae. This species is interesting because unlike the previously described fossil clidicine ✝Palaeoleptochromus, ✝Euroleptochromus has an elongate maxillary palpus with a setose process and a genal setose process similar to the extant sister genus Leptochromus.

Leptochromus agilis

Hopefully you can see the genal and palpal setoses processes in the photo above of Leptochromus agilis.

Paweł, in his phylogenetic analysis also sheds light on the enigmatic position of Papusus, a highly unusually staphylinid that has apparently adapted to living in the deserts of Western North America.

Near Owens Lake in California, habitat of Papusus macer

Papusus has been thought to be a member of the tribe Clidicini, but according this new study, Papusus is either the earliest diverging Clidicini or sister to Leptomastacini + remaining Clidicini. Once staphylinids abbreviated their elytra, biologically, it appears that ability to adapt to arid environments were lost. Presumably the rate of water loss increased with the exposure of the abdominal dorsal surface. Given this, the arid environmental preference of Papusus is intriguing and divergent adaptive regimes may be responsible for poor resolution in phylogenetic placement of the genus – based on morphology.

I think that this is an impressive beginning to elucidating the evolutionary history of the Masitigiate – so so exciting, I love scydmaenines, and their congruent morphology with pselaphines is spectacular. But, I do believe that several pertinent questions persist:

• What, if any, are the adaptive adaptive advantages of the setose maxillary and genal processes? Prey capture?
• Is the  phylogenetic placement of Papusus based on morphological evidence accurate? Could the adaptive evolutionary changes, induced by the unique environmental pressures on Papusus, have complicated the inference into the proper phylogenetic placement of the genus within the Mastigitae?
• Are the branch length estimates based on morphological data precise? If we were to include molecular data for the extant taxa, would we get a different view on evolutionary history of the Mastigitae?
• Finally, would divergence time estimates of the Mastigitae represent a congruent portrayal of biogeographical history?

Oh, and here’s the reference to the paper:

Jałoszyński, P. 2012. Description of Euroleptochromus gen.n. (Coleoptera, Staphylinidae, Scydmaeninae) from Baltic amber, with discussion of biogeography and mouthpart evolution within Clidicini. Systematic entomology, 37(2): 346-359.

Spiders that live with ants?

As a ridiculously early spring was establishing itself here in Lawrence, Kansas, I noticed a Formica colony reopening its nest in front of my door. I searched around the house for stones and the sort, and came up with a couple bricks and a large rock which I then used to cover up the newly opened nest entrance. Soon the ants reopened the nest underneath the bricks and rock. Now lifting these nest entrance covers reveals a large area of nest – this is a commonly employed technique when collecting for myrmecophiles.

A myrmecophilous linyphiid spider sucking a collembolan dry.

To my surprise, for several weeks now, I have been consistantly picking up this species of what I think is a spider in the family Linyphiidae. My series consists mostly of females, but also includes males and juveniles. When threatened, some of them have been observed to run into the nest, and as you can see from this picture, they appear to at least partially feed on the ant-symbiotic collembolan Cyphodeirus albinus. The collecting has slowed down a little as of late, but I hope to get a nice series that lends weight towards a myrmecophilous life style and aids in identification down the road.

Anyone know of people that might have the expertise toidentify this spider?

Cremastocheilus

Cremastocheilus are a myrmecophilous genus of cetoniine scarabs, endemic to the New World. Larvae develop in soil adjacent to host nests, and the adults feed on larvae and pupae of host ants. Adults often congregate on open sandy ground to mate. They also have trichomes, most commonly at the posterior corners of the pronotum, and ants are attracted to these and will guide the scarabs to their nests, tugging at the trichome tufts.

Cremastocheilus sp., found flying low to the ground in a riparian forest in California. Notice the sand is dry and has a sandy feel to it.

Cremastocheilus sp., excavated with a Formica sp. nest in a decaying log in California.

Possibly due to their intimate life with ants, I often find Cremastocheilus missing distal portions of their tarsi.

New Publication

I have a new pub out in the Coleopterists Bulletin – please access the paper here.

Bothronotoxenus tishechkini

You can also reference my website here.

Thanks for your support.