CORIXA, front legs

Corixa (-punctata?), female
(Click to enlarge) seen it √

Like a mesh basket the front legs of this Lesser Water boatman, possibly Corixa punctata, are hanging below the snout. It reminds a bit of an empty rack in front of a horse. The front legs of most Lesser Water boatmen are flattened to form a little shovel(pala), for the male this broadening is more obvious than for the pictured female. They shovel up lose material from the bottom and the long sieve hairs help in raking a little heap of this detritus to the snout, with which they than browse for eatable paricles they can suck in. The waste of the material is thrown backwards in small clouds. Note the position of the front legs, starting deep behind the large head and ending embracing the snout.



ENLARGEMENT √
The snout is equipped with long hairs too, maybe be these clean the front legs, when these brush the head... On the four pictures on the right you see the front legs of Sigara falleni, on the two on top those of the male, on the lowest two those of the female. The first picture is a view from below: the front legs are neatly curved in the contoour of the head, so they can do a tight brushing. (Click on any one of the four pictures for a page with enlarged pictures). Please notice on the top pictures the wide pala and the line of little spines it wears: only the males have these. With that and the fact that only the males of certain species can chirp, it was assumed that they rubbed these spines over the ribbed snout in order to create the chirping sound. For this reason they are called stridulatory pegs in older literature. Later it appeared that not these pegs, but little grooves in the thigh are used for chirping.
Some species of the Lesser Water boatman have more cylindrical front legs without the sieving hairs, for example Cymatia. These species are predators and use their front legs to hold the prey.