The Nesting Habits of the Little Carpenterbee, Ceratina Calcarata

Abstract

The large carpenter-bee, Xylocopa virginica, is rightfully entitled to this name; the small carpenter-bee, Ceratina calcarata Robt., (Fig. 1), can furnish only part of the qualifications necessary to entitle her to the name. The former actually carves out with her powerful jaws new tunnels in the solid wood, grinding out sawdust as yellow and as real as any that comes from a steel blade. She seeks no soft or decayed portions, but cuts on into the sound wood with joyous vigor. The small carpenter-bee, so-called, burrows only into the soft pith of elder or sumac, and even then is able to use only the stems which have been cut or broken off, so as to afford her direct access to the soft pith within. If the soft portion is unexposed, Ceratina is unable to break through the ligneous wall and is obliged to seek another stem. Thus it is in only a very limited sense that this species may be called a carpenterbee. The similarity of common name of the two insects might lead one to expect similarity in looks, but in their physical appearance there is all the difference of David and Goliath, the one large and powerful in build, the other small and delicate. That they find the stems which have been cut was proven by a little experiment. In the middle of June, 1918, a large clump of sumac at Meramec Highlands gave no evidence of harboring any of these bees within their stems. I cut off the tops of about one-fourth of them (sixty-five in number) to make a place which would be attractive to home-seekers. When I returned a month later, seventy-five per cent, of the cut twigs were occupied by Ceratina calcarata, and not one of those uncut contained an occupant.