HARVEST MITES, OR ‘‘CHIGGERS.’’ 5 
Several reports have been received of a plague of these mites in 
the vicinity of Chicago, Ill., showing similar distribution in that 
State. Chiggers are well distributed in Kansas, and reports would 
indicate similar conditions in Indiana and portions of Iowa. 
Harvest mites are well known in England and Scotland under this 
name and as ‘‘gooseberry bugs.” On the Continent of Europe, also, 
they are abundant, especially in Belgium and the Netherlands, in 
parts of Germany, and in France. Indeed, in some of these countries 
they have at times caused considerable annoyance to the peasantry, 
whom they have hindered or prevented in the harvesting of certain 
crops. The mites are troublesome, too, in tropical America, in the 
West Indies, and in Japan. 
LIFE HISTORY. 
The life history of a harvest mite, as related by Mr. Nathan Banks, 
is substantially as follows: The female lays her eggs in or upon the 
ground, sometimes to the number of 400 in one place. The eggs are 
usually brown and spherical and have been considered by some early 
writers as fungi. The chorion or outer skin splits soon after the eggs 
are deposited, dividing the eggs into halves and exposing the pale 
vitellne membrane. The larva when hatched is circular or ovoid in 
outline, and each of its three pairs of legs is tipped with two or three 
prominent claws. After the larva has become attached to its insect 
host it elongates and becomes swollen with food. When full fed it 
drops off, seeks a convenient shelter, and gradually changes in shape 
without molting. The new parts are formed under the larval skin, 
which after a few weeks cracks and discloses the adult Trombidium. 
The mature harvest mite is predaceous, wandering about and feeding 
on aphides, small caterpillars, and, in the case of one species, on the 
eges of grasshoppers or locusts. It hibernates in the soil or in other 
sheltered locations and in the spring deposits its eggs. There appears 
to be asingle generation produced each year. Only a few forms have 
been reared. The larva of one occurs commonly on the house fly in 
autumn. 
REMEDIES. 
As harvest-mite infestation is usually contracted by walking or 
working among blackberry and other shrubbery which harbors them, 
or by walking, sitting, or lying among grasses or similar herbage 
along streams or pools, on the edges of marshes, or under trees 
near such places, it is obvious that the best means of prevention is 
the avoidance of exposure by susceptible persons. If, however, a 
bath is taken in hot water, or water containing salt or strong soap, 
within a few hours after exposure, no ill effects will be experienced. 
After a longer exposure a bath has practically no effect, and direct 
remedies are necessary. 
