﻿OF THE STATE ENTOMOLOGIST. 175 



reported as feeding on the eggs and on the weak, sickly and disabled 

 hoppers — it will be well to treat more fully of those parasitic species 

 which render effective service to man in destroying this locust. These 

 consist principally of two mites (class AracJinida^) which are exter- 

 nal feeders, and two Dipterous flies belonging to the family Muscidce, 

 which are internal feeders."^' 



The Silky Mite {Tromhidium sericeum Say, Fig. 35). — Last May, 

 Prof. C. E. Bessey sent me a pale red mite with an account of its attack- 

 ing the eggs of the Rocky Mountain Locust in northwestern Iowa, and 

 numerous accounts were published of the efficient work of this little 

 animal in destroying said eggs, wherever these had been deposited in 

 Iowa and Minnesota. The following may be quoted as a sample : 



A discovery has been made of g:reat interest. A small red hxxg^ or spider, about 

 the size of a small kernel of wheat, is lound in great numbers, creepinj? into the holes 

 to the grasshopper eg^gs and eating the contents of the eggs voraciously. Great num- 

 bers were found in the act of eating the e<?gs, with empty egg-shells in the same nest. 

 The extent of the little friends is not limited, but they have been seen in many localities 

 in different directions in this place. Mr. J. D. Johnston, Antrim, proved conclusively 

 that these red bugs are making sure work among the eggs. — [jfiladelia (Minn.) Times. 



This mite belongs to the genus Tromhidium.^ only two N. A. spe- 

 cies of which have been described, viz., the scabrwn Say, and the 

 sericeum Say. The descriptions in both instances are very brief, and it 

 is difficult to say whether the species in question, and which is here- 

 with figured (Fig. 35) belongs to either. It answers to sericeum how- 

 [Fig. :i5.] ever, so far as the description goes, and I prefer to so 

 r^> l/X refer it rather than describe it as new. The specimens 

 ss*'>v i^M ^ which I have examined have not been full grown, and 

 W7'('7'\t \^1 0; the pale red color which they possessed would doubt- 

 if/teM! !^jtv less have intensified with age. Every European is 

 familiar with the Scarlet Mite ( T, liolo sericeum., Z), 

 which is common in the soil of gardens in Spring and 

 thtj Silky mitk P^^ys upon young larVcB of various descriptions. In 

 natural si^e shown at ^^j^^.^ silkiness and habit it greatly resembles our spe- 

 cies and may indeed be identical. All the species of this genus are 

 highly colored and the Tromlidium tinctorium found in Guinea and 

 Surinam is employed as a dye. 



* The only other internal parasite affecting locusts in this countrj- is a small, undescribed Chalcid- 

 fly which Mr. Scudder refers to as having bred from the eggs of (Edipoda Carolina (Proc. Bost. Soc. 

 Xat. Hist. , Xir, p. 99) . He has kindly furnished me with female specimens. They are about 0.20 Inch 

 long, pitchy black, the head and thorax very deeply pitted and roughened, and the abdomen which is 

 llattened and quite tapering also deeply marked with irregular, longitudinal depressions. The antennae 

 have the scape as long as tlie flagellum, which is curved and enlarges to tip, which is suddenly docked. 

 The scape, basal joint of Hagellum and legs are honey-yellow ; the wings hyaline. 



