Conoaxima, A New Genus of the Hymenopterous Family Eurytomidæ, With a Description of its Larva and Pupa

During the course of his investigations on myrmecophilous plants in British Guiana, Professor I. W. Bailey obtained specimens of a remarkable Hymenopterous insect parasitic on antqueens. The following notes on its habits have been furnished by Professor Bailey. "The colonies of Azteca constructor Emery and of A. alfaroi Emery which inhabit the fistulose stems of Cecropia angulata I. W. Bailey, the common myrmecophytic Cecropia of the Kartabo Region of British Guiana, are initiated by young fecundated queens in juvenile plants. The queens enter the internodal chambers through circular perforations cut in groovelike depressions (Prostomata) in the sides of the stem. These entrance apert.ures are covered with triturated pith on their central sides and ultimately become occluded by callus, which seals the queens within the ’primordial chambers.’ "Although many of the successive internodal cavities of each young plant become inhabited, few of the queens succeed in raising a brood. When the stems are cut open, most of the chambers are found to contain dead queens. I was unable to account tor this high mortality until I discovered the presence of a small scar in the callus which fills the entrance aperture. This scar within a scar indicated, of course, that some insect had emerged since the queen became sealed within her domatium. Following up this clue, I soon found chambers--with modified callus in the apertures--which contained, in addition to the dead and frequently dismembered queen, the larva, pupa or imago of a Hvmenopterous parasite. The evidence at hand seems to indicate that the queens are parasitized before they enter their dwellings."