129 



eggs, averaging over twentj-eight to a batch, the minimum 

 being fifteen and the maximum fifty-two in the eight batches 

 referred to. Mj earlier observations disclosed the fact that 

 the females in captivity in large glass breeding jars oviposited 

 to a much greater extent than when placed under a net on 

 branches of the tree in the open, and these later investigations 

 further show that in the smaller enclosure (a jam jar) the 

 oviposition was still more rapid and that the batches contained 

 a much larger percentage of eggs than in the previous experi- 

 ments. 



The sexes of the beetles comprising the whole colony under 

 observation (including those bred in jars) has been determined 

 as thirteen males and eight females. 



At the beginning of the outdoor experiments referred to, 

 koa trees were searched for egg batches and after much labor 

 one leaf was found apparently similar in appearance to those 

 produced by the colony. This leaf was taken home and placed 

 in a glass test tube and ten days later instead of the larvae I 

 found that Chalcid parasites were emerging, eleven of which 

 were saved and three or four others accidentally lost. At this 

 early period of my observations it was not certain, however, 

 that this Chalcid was a true parasite of the egg of Rhyncogo- 

 nus, but that it really was such was afterwards proven. One 

 of the egg batches which had been left exposed on the tree, at 

 a subsequent visitation, was placed in a glass tube and some 

 of the eggs began hatching on the sixth day after their removal 

 from the tree. !N'oticing but few larvae emerging from this 

 particular batch, it was left in the tube for a longer period than 

 usual and nineteen days later two Chalcid parasites emerged 

 through the protecting leaf cover of the egg mass. This fact 

 and later investigations of the remaining eggs proved conclu- 

 sively that these Chalcids were similar to the previous species 

 above referred to, and that they were true egg parasites. Both 

 these Chalcids, as well as the previous, lot, were identified by 

 Dr. Perkins as an Eupelmid (Text Fig. on p. 133). I understand 

 Dr. Perkins intends to supplement my observations on the 

 breeding of this parasite by a few notes of his own, which may 

 further elucidate its habits. 



EXPLANATION OF PL. 3. 



Fig. 1. Rhyncogonus blackburni $ ; fig. 2. $ of the same; fig. 3. Koa 

 leaves enclosing egg batch; fig. 4. Egg batch exposed. 



