1931 ] 
The Biology of the Mecoptera 
55 
abdominal prolegs during the first instar (according to 
Brauer), but lose them later. There are at least four in- 
stars, during which time the larvse feed on moss roots and 
liverworts. The full grown larva, usually about 6 or 7 
millimeters long, is shorter and stouter than that of Bitta- 
cus. The larval stage is the longest, lasting from Decem- 
ber to August, when the larva prepares for pupation by 
forming a vertical tube in the soil, nearly extending to the 
surface. The pupa is more active than the larva, rapidly 
wriggling up and down the tube when it is disturbed. 
After from 4 to 8 weeks the imagines appear. The adults 
may be found in the spring and early summer among moss 
roots and under stones, but they are only active in the 
winter, when on sunny days they can be seen hopping 
about on the surface of the snow, covering as much as 
6 inches in a single leap. 
From this survey of the biology of the Mecoptera I hope 
it is clear that our knowledge of the life-history of the 
American species of scorpion-flies is very meagre and that 
we have great want of further observations on their habits. 
This is particularly true of the remarkable Merope tuber , 
which inhabits only our Atlantic states. Perhaps one of 
you, while searching in the soil for a beetle or a member 
of some other large order, will be fortunate enough to 
stumble upon the larva or pupa of Merope, and thus fill 
in one of the most disconcerting gaps in our knowledge 
of complete metamorphosis. 
