122 SEVENTEENTH Report STATE ENTOMOLOGIST OF MINNESoTA—1918 
doubtedly great. The larvae, even if present in large numbers, prob- 
ably do little more than weaken the grasshoppers to which they at- 
tach, but the adults and nymphs render a considerable service by 
destroying large numbers of grasshopper eggs. While they may not 
destroy all the eggs in any egg pod the fact that both nymphs in late 
summer and the adults in spring and to some extent in autumn feed on 
them, must make the aggregate destroyed quite large and we must con- 
sider them as one of the important natural checks on grasshopper in- 
crease. 
The larvae of this species seem to have no connection with 
“Chiggers.” They have twice been placed in large numbers inside 
the clothing of the writer but no unpleasant results followed. The 
fact that they inhabit open ground would clear them of any connection 
with the “Chiggers.” 
Microtrombidium magnitarse Ewing. 
Micro. magnitarse Ewing. Ill. Univ. Studies Vol 3, p 92; 1909. 
Adult female. Color, dull scarlet, size 1.50 mm long by 1 mm 
wide. Body oval, only very slightly constricted at the middle, wide- 
iy rounded behind, wider in front, anterior edge concave, clothed thick- 
ly with short slender plumose hairs, the dorsal surface with a trans- 
verse groove just posterior to the forward margin, a second groove 
near the middle may be present or absent. Ventral surface with 
grooves corresponding to those on dorsum. Genital opening opposite 
coxae IV. Anus half way between genital opening and posterior 
margin. 
Cephalothorax rather elongate, base concealed only in part by the 
abdomen. Dorsal groove expanded at the posterior end. Eyes sessile. 
Mandibles long and slender. Palpi stout but not much swollen, seg- 
ment II nearly twice as long as wide, segment III as wide as long, 
segment IV twice as long as III, two long heavy claws at the tip, the 
inner one smaller. On the inner side, a crest of three or four heavy 
curved spines on the dorsal margin and three irregularly placed spines 
at the base of the thumb; thumb short and tapering, about three times 
as long as wide. 
Legs slender, legs I not as long as the body; legs II and III 
three-quarters as long as I : legs IV reach beyond the end of the body. 
Tarsi I very much swollen, more than half as wide as long, usually 
held so that they are turned backward toward the.body. 
Male, smaller than female, 1 mm long by 0.50 mm wide, grooves 
more marked. 
Adults of this species were collected in decaying leaves and wood 
