290 FAMILY VI. ACRIDID.E. THE LOCUSTS. 



has taken it only along the Mississippi in the southeastern part. 

 He adds: "The flight of fenestralis differs from that of Trimero- 

 tropis in being low and direct, but is not as swift as in Mestobreg- 

 ma. The male has a faint aerial stridulation. The coloration of 

 this insect is such that when on its normal habitat of almost clear 

 sand with scattered vegetation and a background of broken lights 

 and shadows, its detection is almost impossible. We have often 

 been unable to see them, even when within a few inches, except by 

 the movements or by the shadows they cast." 

 II. MESTOBREGMA Scudder, 1876a, 264. (Gr., "full" + "front") 



Species in general fades resembling Psinidia, but having the 

 occiput less elevated, more or less tuberculate, disk of vertex 

 much as in Psinidia, but more shallow, broader in female, its sides 

 more sinuous and strongly declivent to unite with those of fron- 

 tal costa; foveolaB in our eastern species, large, prominent, trian- 

 gular ; frontal costa narrow, deeply sulcate throughout, slightly 

 constricted above the ocellus; autenme about as long as hind fe- 

 mora, the basal joints so depressed as to form one sharp edge; 

 pronotum strongly constricted at middle, hind margin acute-an- 

 gled, male, right-angled, female; median carina sharp, slightly 

 higher on prozona, notched twice in front of middle, the interval 

 between the notches scutellate, its carina arched ; lateral carinse 

 rounded, visible only on metazona, represented on prozona by nu- 

 merous tubercles ; lateral lobes much as in Psinidia ; tegmina nar- 

 row, the apical third membranous and semi-transparent; hind fe- 

 mora slender, reaching tip of abdomen, female, much surpassing 

 it, male; valves of ovipositor as in Psinidia. 



Kirby (1910, 247) accredits to Mestobregma (Tracltyrachys**) 

 17 species, two from Mexico, the others from the western United 

 States. Some of these are doubtless synonyms, and but one 

 crosses the Mississippi into the western portion of our territory. 

 125. MESTOBREGMA THOMASI Caudell, 1904f, 125. Ash-brown Locust. 



Small, slender, compressed, the male moderately the smaller. General 

 color ash-gray or yellowish-brown, spotted with fuscous. Face ash-gray, 

 with minute dark spots; occiput and disk of pronotum darker, often with 

 a yellowish x-shaped mark extending back from eye along the sides of 

 disk; lateral lobes of pronotum with traces of alternate lengthwise bars of 

 pale and fuscous, the former the narrower. Tegmina yellowish-brown or 

 grayish, often darker in male, the costal area with two squarish dark spots 

 separated by an oblong whitish one, apical third transparent, often with 

 a few small dark spots along the costal margin. Wings with basal third 

 greenish- or lemon-yellow, a narrow curved faint fuscous band on middle 



"Bruner (1905) wrongfully replaced Mestobregma by Trachyrachys Scudd. In 

 this he was followed by Kirby, although R. & H. (1906, 380) had shown that Bruner's 

 replacement was incorrect. 



