1924 ] Note on the Habits of Sphenophorus pondeterice Chttn. 311 
NOTE ON THE HABITS OF SPHENOPHORUS 
PONTEDERI^ CHTTN. 
By D. H. Blake. 
Bureau of Entomology, Washington, D. C. 
In late August of 1924 the ponds of eastern Massachusetts 
were very low and in some instances dry because of a long 
drought. In two ponds in Stoughton and Easton beds of pickerel 
weed {Pontederia cordata L.) outside water level were brown and 
dying, while other plants nearby, although not any more supplied 
with pond water than the dying ones, were apparently healthy. 
Investigation showed that the dead patches of plants were 
heavily infested with larvae, pupae, and newly emerged adults of 
Sphenophorus pontederice Chttn. The thick rootstocks were 
completely hollowed out and rotten, and each plant contained 
several larvae or pupae. So disintegrated were these plants that 
when one took hold of the leaves and stalks they separated at 
once from the rootstock. The larvae were most frequently found 
tunneling the rootstocks, but when they became mature they 
generally bored up into the flowering stem an inch or two above 
the earth to pupate. 
In several stalks a dipterous puparium was found beside the 
remains of the larva, plainly a parasite of Sphenophorus. The 
adultfly that emerged has been identified by Dr. J. M. Aldrich as 
Lixophaga variabilis Coq. This parasite, closely allied to the 
parasite {Lixophaga diatrcece Tns.) of the sugar-cane borer 
{Diatrcea saccharalis Fab.) has been reared in one instance, ac- 
cording to Dr. Aldrich, from Lixus scrobicollis Lee. at Dallas, 
Tex. In another case a carabid larva was found feeding on a 
pupa. Several carabid and staphylinid beetles also occurred 
suspiciously near the infested plants. 
