3 replies to this topic

[johnsankey]

A curious interaction, new to me: a winged male Formica fusca was walking sideways towards a Lasius americanus worker as if to crowd it away from an area of the stone patio. However the Lasius was acting as though it wanted to stay about half its body length away from the Formica; when it zipped around to the other side of the Formica, it kept facing its thorax while the Formica 'pushed' it around in a half circle so both were moving the original direction again. This behaviour continued even across a crack large enough for the Lasius to fall into.

I raced to get my macro camera, but by the time I returned, a small spider had intervened, attacking the Formica and presumably biting it, for the Formica stayed mostly still after that, while the Lasius went back to its normal scurrying around, ignoring the Formica.

Any suggestions as to what was happening?

 

[Kaelwizard]

If you are in the US it is not Formica fusca, but a species in the fusca group most likely. To answer your question, I'm not sure. Is it possible that the male was Lasius and you just misidentified it? Otherwise I have no clue why the Lasius worker wouldn't have been hostile.

[johnsankey]

I'm old-fashioned and follow Chapman. Given that Formica are 10x the weight of a Lasius americanus worker, and a different colour, I think I'm capable of telling the difference. If anything, the Lasius seemed in awe of the Formica...

[Kaelwizard]

I meant no offense, it’s just that I couldn’t think of any other reason as to why it wouldn’t be hostile or try to get away. It is definitely not “in awe.” Also Lasius and Formica are not always different colors, and you didn’t provide any info on what they looked like besides one being a winged male.