1918] Glaser and Wileox—A Mermis Epidemic amongst Grasshoppers 13 
he says was common in Locusta carolina near Philadelphia; but 
there can be no certainty about the matter until males of the pres- 
ent species are obtained and a comparison made with Leidy’s 
material, which may or may not be in existence.” Dr. Cobb 
further stated that after the nematodes leave the grasshoppers, 
they make their way into the soil and that their further history is 
obscure. 
In Vermont the nematodes parasitized both M. atlanis and M. 
bivittatus. 'The worms seem to leave the bodies of the grasshoppers 
when these insects are maturing. We had not the opportunity 
to observe grasshoppers in the early stages of parasitism, but in 
August and September dissection of a large number of the insects 
showed that the worms were located within the body cavity. 
Later in the season, when the worms are about to emerge, the 
grasshoppers fall over on one side, kick for a time and then die. 
In the meantime, the worms gradually bore their way through 
the body wall and reach the exterior after which they make their 
way slowly into the earth. Usually only one worm parasitizes a 
grasshopper, but by dissection we have often found two or three 
and in one case we found forty. Needless to say, that when an 
Insect contains so many worms the abdomen is considerably 
swollen. 
The length of these female worms varied from two to eight 
inches. It is extraordinary that with hundreds of hoppers dying 
everywhere, we were unable to find any males. 
A great many nematodes, at one stage of their life cycle, seek 
water on leaving their hosts and there mature, or wait until another 
host presents himself. We placed about two dozen of our worms 
in a bowl of water in which they seemed to flourish for about two 
weeks. However, the localities where the hoppers, and conse- 
quently the worms abounded were free from streams, ponds or 
marshes of any kind. The Connecticut River flows through a val- 
ley at a distance of about one-half mile so it seemed unlikely that 
the worms would travel sofar. In all probability, we thought, the 
worms make their way into the soil on leaving the insects and this 
we found true. We placed recently dead parasitized hoppers in 
boxes containing earth. In about three days the boxes were ex- 
amined and the worms were found coiled up at a depth of about 
one foot. Often a number would be coiled up together in one 
