Archive for July, 2005

In an elegant study on the renowned Cataglyphis ant, the secret behind their remarkable ability of estimating distances has been found not to be involved with any visual cues at all. Their related hymenopterans, the honey bees and bumble bees use optic flow on their retina to calculate distances to reach both the food source and their hive. The absence of visual cues in ants, thus strengthens the possibility of distance estimation (odometry) to be driven by the pro-prio-receptors on the legs of these tiny fellows.

from: Thiellin-Bescond and Beugnon 2005. Naturwissenschaften 92: 193-197

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Ants of the species Pheidole magacephala recruit more nestmates, especially large numbers of soldiers, when they find hostile chemical cues around a food resource. A first for Myrmicines, soldiers castes of these ants carry liquid droplets under their head and thorax owing to surface tension, very similar to certain Ponerines.

from: Dejean et al,
Naturwissenschaften, 2005. 92: 324-327.

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One amongst the top 100 invasive species, a fire ant Wasmannia auropunctata, has males and females each reproducing clonally. Male ants develop parthenogenetically, thus having one copy of each gene, while females develop from fertilized egg, thus having two copies of each gene. Some females develop into a sterile worker class, while some others into reproductive class, called “gyne”. The gynes in this bizarre little ant, have similar genetic makeup as of the reproducing queen. Males for the first time have retaliated by banishing maternal genes from the diploid egg. A stunning similarity in the genotype of the sperm in the speramatheca of the queen and in the newly produced males, revealing this. Would this male dominance or selfishness, result in the need to rewrite colony organisation and kin-selection theories?

from Fourneir et al, 2005. Nature: 1230-1234

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