BIOLOGY AND CONTROL OF CHIGGERS. ll 
Attachment of chiggers followed irregularly within a few hours 
after exposure. The itching which appeared during the latter part 
of the first 24 hours following attachment grew in intensity. At 24 
hours after attachment not a single papule had appeared at any one 
of the 10 points of attachment. During the second day swelling 
subsided, and the pinkish coloration around the puncture points was 
followed, first by a light blood-red and later by a deep blood-red 
color. The immediate area around each larva changed to a whitish 
color, and the discolored area as a whole was large and in some cases 
mottled with light and dark red. The itching sensation reached its 
maximum the second day. 3 
During the third day after infestation most of the spots changed 
from the pinkish or light blood red of the second day to a dark 
blood-red or purplish red. At the end of the third day one-half of 
the larve had become detached. 
During the fourth day few changes were noticed. One more larva 
had dropped off, and a few of the spots were observed to be lighter 
in color than the day before. 
During the fifth day all the remaining larve dropped off. Spats 
retained most of their color and in four instances small water blisters 
developed near the center of discolored spots. 
On the sixth day the color of the spots continued to fade and in 
one instance was practically lost. . 
During the seventh day several of the spots regained almost their 
normal flesh color. Five water blisters were observed, but only one 
was conspicuous. 
On the eighth day the discoloration had entirely disappeared in 
one instance and almost so in two others. Two water blisters were 
left.* 
GENERAL DISTURBANCES. 
As has been known for many years, general disturbances fre- 
quently follow serious attacks from chiggers. Among the most 
serious of these is the development of a fever and a temporary up- 
setting of certain nervous responses. Oudemans has recently called 
attention (//, p. 70) to the narrative of Alfred Russel Wallace rela- 
tive to the latter’s experience with chiggers in the Malay Archipelago. 
This eminent naturalist wrote: 
All the time I had been in Ceram I had suffered much from the irritating 
bites of an invisible acarus, which is worse than mosquitoes, ants, and every 
other pest, because it is impossible to guard against them. This last journey 
in the forest left me covered from head to foot with inflamed lumps, which 
after my return to Amboyna, produced a serious disease, confining me to the 
house for nearly two-months * * *, 
3The appearance of these water blisters is well illustrated by Riley and Johannsen 
(11, fig. 43). 
