1922] Conoaxima 153 



CONOAXIMA, A NEW GENUS OF THE HYMENOPTE- 

 ROUS FAMILY EURYTOMID^, WITH A DESCRIP- 

 TION OF ITS LARVA AND PUPA. 



By Charles T. Brues^ 



During the course of his investigations on niyrniceophilous 

 plants in British Guiana, Professor I. W. Bailey obtained speci- 

 mens of a remarkable Hymenopterous insect parasitic on ant- 

 queens. 



The following notes on its haliits have been furnished by 

 Professor Baile3\ 



"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 fe- 

 cundated queens in juvenile plants. The queens enter the 

 internodal chambers through circular perforations cut in groove- 

 like depressions (Prostomata) in the sides of the stem. These 

 entrance apertures are covered with triturated pith on their 

 central sides and ultimately become occluded by callus, which 

 seals the queens within the 'primordial chambers.' 



"Although man}' 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 for 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 scaled within her domatium. 

 Following up this cine, 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 Hymenopterous parasite. The evidence at hand seems to 

 indicate that the queens are parasitized i^efore the}' enter their 

 dwellings." 



^Contribution from the Entomological Laboratory of the Bussey Institution, Harvard 

 University, No. 209. 



