78 



formed. After blooming was well advanced fertilization was effected 

 by the introduction of various insects, no attempt being made to 

 determine which particular species accomplished the desired work. 

 Adults of the chalcis-fly (JBruchophagus funebris), were later intro- 

 duced, after the corollas of the flowers were well formed. These 

 insects had been selected from lots reared from clover seed taken in 

 Washington, D. G. Damage by rain ruined many heads and others 

 failed to mature, but in the end several heads became sufficiently 

 matured to be picked, and from these there were secured late in the 

 fall a few adult individuals of the chalcis-fly. Very few of the seeds 

 in the heads developed. 



The egg was usually laid in the young forming clover seed. It is 

 apparently inserted into the seed beneath the cuticle. The egg is pale 

 white, polished, slightly elongate, and rather slender in form, no trace 

 of sculpturing being seen. 



The larva seems to feed on the softer semiliquid portions of the 

 seed and does not attack the essential organs until nearly mature. As 

 it grows it fills about two-thirds of the interior of the seed, curving 

 itself into the wider portion. When nearly mature the larva finishes 

 the seed contents, practically filling the cavity and then pupates. The 

 full-grown larva is pale white from 1.5 to 2 mm long. When mature, 

 rather stout, the ridges on the segments quite prominent. 



The pupa, at first pale white, changes in color to a deep brown as it 

 matures, and the adult insect, when it emerges from the seed, is 

 shining jet-black with white markings, which latter soon change to 

 deep } T ellow. 



The adult emerges from an irregular hole cut in the seed, usually in 

 what is the upper portion as it stands in the head. I have, however, 

 found the hole cut in various other places. Further rearings will be 

 necessary before any statement regarding length of life in various 

 stages can be made. 



Several instances were noticed when for some reason the seed failed 

 to develop (perhaps because utterly destro} r ed by the young larva), 

 and the larva had made its way through the soft tissues and entered 

 another seed, there finishing its growth. In one instance three seeds 

 were found partly devoured, apparently by the same larva. 



A number of parasites were reared from the clover heads received 

 from the various localities, but at present I am unable to definitely 

 state which enemy of the clover head was parasitized by them. One 

 specimen of Bracon mettitor Say was reared from a head taken at 

 Washington, D. C. This parasitic insect has hitherto been recorded 

 only from Coleoptera. It could not be determined from what it 

 bred in this instance, but a single coleopterous larva might easily 

 have been present. 



The chalcis-fly conducts its ravages in such an insidious manner that 



