IIEMIPTERA. 189 



superfluous moisture of the body evaporates, and the insect 

 becomes strong enough to fly. 



During several successive nights the pupa? continue to issue 

 from tlie earth; above fifteen hundred have been found to 

 arise beneath a single apple tree, and in some places the whole 

 surface of the soil, by their successive operations, has appeared 

 as full of holes as a honeycomb. In Alabama the species 

 under consideration leaves the ground in February and March, 

 in Maryland and Pennsylvania in May, but in Massachusetts 

 it does not come forth till near the middle of June. Within 

 about a fortnight after their final transformation they begin to 

 lay their eggs, and in the space of six weeks the whole gener- 

 ation becomes extinct. 



Fortunately these insects are appointed to return only at 

 periods so distant that vegetation often has time to recover 

 from the injury inflicted by them; but were they to appear at 

 shorter intervals, our forest and fruit trees would soon be 

 entirely destroyed by them. They are moreover subject to 

 many accidents, and have many enemies, which contribute to 

 diminish their numbers. Their eggs are eaten by birds; the 

 young, when they first issue from the shell, are preyed upon 

 by ants, which mount the trees to feed upon them, or destroy 

 them when they are about to enter the ground. Blackbirds 

 eat them when turned up by the plough in fields, and hogs 

 are excessively fond of them, and, when suffered to go at large 

 in the woods, root them up, and devour immense numbers 

 just before the arrival of the period of their final transforma- 

 tion, when they are lodged immediately under the surface of 

 the soil. It is stated that many perish in the egg state, by the 

 rapid growth of the bark and wood, which closes the perfora- 

 tions and buries the eggs before they have hatched ; and many, 

 without doubt, are killed by their perilous descent from the 

 trees. 



There are several other harvest-flies in the United States, 

 the males of which are musical ; but their drums are concealed 

 within little cavities in the sides of the first abdominal ring. 

 One of these is found in Massachusetts, and, though it never 

 appears in such great numbers as the preceding species, it is 



