THE LOCUSTS PROPER. 
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are transparent, with a very pale greenish-yellow tint next 
to the body, and are netted with brown lines. The hind- 
most thighs have two large spots, on the upper side, and the 
extremity, black ; hut are red below, and yellow on the in- 
side. The appendages at the tip of the body in the male 
are of a long triangular form. Length from J inch to 1 
inch; exp. 1J to If inch. 
The red-legged locust was first described by De Geer from 
specimens sent to him from Pennsylvania, and I have re- 
tained the scientific name which he gave to it. It is the 
Gryllus ( Locusta ) erythropus of Gmelin, and the Acrydium 
femorale of Olivier. It appears to he very generally diffused 
throughout the United States, and sometimes so greatly 
abounds in certain places as to be productive of great injury 
to vegetation. I have already described its prevalence on 
our salt-marshes ; and it seems to constitute those large mi- 
o-ratino- swarms whose flight has been observed and recorded 
in various parts of this country. It comes to maturity with 
us by the latter part of July ; some broods, however, a little 
earlier, and others later. It is most plentiful and destructive 
during the months of August and September, and does not 
disappear till some time in October. 
II. Locusta. Locusts Proper. 
With the English entomologists, I apply the name Locusta 
to that genus which includes the celebrated migrating locust, 
or Gryllus Locusta miyratoria of Linnaeus. By the older 
French entomologists the insects contained in it were united 
to the genus Acrydium; but Latreille afterwards separated 
them from Acrydium under the generical name of (Edipoda 
(which means swelled leg), and he is followed in this by 
Serville, the latest writer on the Orthoptera. In the in- 
sects of this genus the breast is not armed with a blunt 
spine or tubercle, a character which distinguishes the genus 
Acrydium from it. In other respects these two genera are 
much alike. 
