BIOLOGY AND CONTROL OF CHIGGERS. ve 
This examination of the small mammals of the infested area, it 
should be noted, was made late in the season. It is possible that if 
the trapping had been done earlier, different results would have been 
obtained. During the summer of 1921 such trappings are planned 
for the months of June and July. It will be interesting to observe 
the results. ; 
Among other hosts held under suspicion were reptiles. Tortoises 
were found in the vicinity of the infested area. These were caught 
and examined, but no chigger larvee were found. Early in July, 
1920, Mr. William Palmer, of the National Museum, captured a large 
king snake, Lampropeltis getulus getulus, at Chesapeake Beach, Md., 
that had hundreds of mite larve attached to its skin, between the 
scales. He brought the snake to the Museum, and when it was 
shown to the writer a few days later it had molted. In the cast 
skin were found hundreds of trombidiid larvee in various stages of 
engorgement. An examination of these showed them to be no other 
than the chigger that attacks 
man along the Atlantic slope. 
Parts of the cast skin with 
chiggers attached were placed 
in breeding cells, and chig- 
gers that appeared fully en- . 7 
gorged were likewise placed in 2,2 ;Rlght seters of & hlernite tare 
breeding cells, but in neither specimen taken at Lake Minnetonka, Minn., 
case did any of the larvie pees pega to the University of Minne- 
transform into nymphs. 
Those attached to the skin of the snake remained attached and 
soon died unless forcibly removed. ‘The actions of the chiggers 
in remaining attached to the skin after the latter was cast and their 
dying in this attached position would seem to show that the king 
snake is not a natural host. Further, it is known that chiggers exist 
in enormous numbers where very few snakes of any kind are found. 
The determination of the natural hosts of our American chiggers 
has not been made. Further investigation along this line is needed. 
INJURY. 
CHIGGER INJURY CONFUSED WITH MANY OTHER KINDS OF INJURY. 
Of the many complaints about chiggers that have come to the 
writer, a very large number, fully one-half in certain sections, were 
found upon investigation to be due to hives, caused by the disagree- 
ment of some food eaten and probably accentuated by hot weather. 
A very large number of complaints supposed to be concerning 
chigger attacks were found to be due to nettling from some thorned 
plant. Serious attacks in a front lawn in Virginia, reported to be 
