16 
it is here compared. The accompanying figure (Fig. 5), that of a female 
specimen, is not quite typical of the species, but will greatly aid in its 
recognition. The following description of this locust is that given by 
Prof. Cyrus Thomas, who named it: 
Large size, robust ; tegmiua passing the abdomen, unspotted ; olive brown above, 
yellow beneath. 
Vertex elongate, depressed, broadly sulcate, closed in front; frontal costa broad, 
flat, or slightly sulcate; sides parallel; lateral carina? distinct, slightly divergent. 
Antenme of males half as long as the body. Pronotum quadrate ; sides perpendicular, 
parallel; lateral carina? or humeral angles obtusely rounded; median carina distinct, 
except on post-median lobe of the female ; third transverse incision very distinct and 
deeply indented, others distinct. Posterior femora much enlarged near the base, the 
disk convex, about as long as the abdomen; posterior tibia? enlarged toward the 
apex, hairy. Prosternal spine cylindrical, bent slightly backward. Subanal plate 
of the male triangular; apex blunt, entire; cerci with basal half broad, an obtuse 
tooth about the middle of the posterior margin, above this bent and tapering. 
Color (male). — Head and anterior lobes of the pronotum reddish or olive brown; 
sides paler, with from one to three oblique, black lines; transverse incisions dark on 
the sides. Tegmina unspot- 
ted, olive brown; reddish at 
the base, semi-transparent. 
Wings pellucid ; nerves of the 
apical and front portions dark, 
rest yellowish. Posterior fem- 
ora yellow ; three black spots 
Fig. 5,-Mekmoplus diferentialis-nztwal size (after Ruey). < m the upper edge ; interspaces 
of the disk black, ribs pale yel- 
low; tibiae yellow, spines black. Abdomen yellow, with small, black spots and 
stripes. Venter and pectus yellow. The female differs from the male in having 
the head and thorax olive; the legs and venter a brighter yellow than her mate. 
Length of body — male, 1.2 inches; female, 1.5 to 1.7 inches; of tegmina— male, 1 
inch; female, 1.25 inches. 
This insect has very frequently multiplied in such numbers in limited 
areas over its range as to do considerable injury to cultivated crops 
growing upon low, moist ground; and has even been known very fre- 
quently to spread over higher and dryer lands adjoining these, its cus- 
tomary haunts. It is one of the few species of locusts that has thus 
far shown a tendency toward civilization. This it has done readily, 
since its habits are in unison with the cultivation of the soil. It is 
only since the settlement of the country where it originally occurred 
that it has multiplied so as to become sufficiently numerous to become 
a serious pest. Blfferentialis frequents plowed fields, and is a lover of 
rank growing, juicy food, just such as is offered in Corn, Clover, Alfalfa, 
etc., as well as various garden products. 
The eggs of differentials are laid in cultivated grounds that are more 
or less compact, preferably old roads, deserted fields, the edges of weed 
patches, and well-grazed pastures adjoining weedy ravines. Egg-lay- 
ing begins about the middle of August and continues into October, 
varying, of course, according to latitude and climatic conditions. Usu- 
ally, but not always, only a single cluster of eggs is deposited by each 
