TROMBIDIIDAE OF MINNESOTA 129 
This species has been collected in Hennepin, Ramsey, Otter Tail, 
Roseau and Nicollet counties, and is probably distributed over the en- 
tire state. This is undoubtedly the species which Banks calls Trom- 
bidium seucium. It is the commonest and most evenly distributed 
trombidium found in Minnesota, altho not so abundant in any given 
locality. The minute, short, chunky, bright scarlet adult can be found 
almost any day from early spring to midsummer, running about the 
soil of cultivated fields. They move with a nervous energy looking into 
every crack and crevice in search of food. Not only are they com- 
mon in cultivated land, but also in woodland, among the fallen leaves, 
on dry hillsides and in wet bottom lands. Sometimes one can collect 
this species, Allothrombium pulvinus, Eu. locustarum and Micro. magni- 
tarse in the same place. Occasionally one may be found climbing the 
bark of a tree. 
We have never yet seen one feeding in the open. On one occasion 
they refused grasshopper eggs. 
Oviposition has occurred in breeding jars on several occasions. 
One lot of eggs was ‘aid on July 1. These hatched about July 15, 
a nymph was found in the soil on August 13 but died before the 
adult emerged. A second lot of eggs was laid on June 13, these 
hatched on July 22. A third lot of eggs laid on May 22, hatched 
about July 1. The rupturing of the egg shell occurred seven to ten 
days after the eggs were laid. Ina fourth attempt to rear this species, 
adults were fed on small insects collected by sweeping grass and 
shrubbery. Engorgement was secured easily, but it was not possible 
to find what insects were chosen for food. When fully engorged they 
become very rotund and the stretched skin shiny. Egg masses were 
placed on June 20 to 22 under leaves at the surface of the soil or 
in the soil even to the depth of an inch. Each mass contained about 
200 eggs of a lemon yellow color, becoming more orange colored with 
the development of the embryo. After about seven to ten days the 
shells began to rupture. About twenty-two days were required before 
hatching took place. 
It was found that these larvae would readily attack a white rat, 
but not a young pigeon or a thirteen-lined gopher. On the rat they 
burrowed into the skin and caused lesions similar to those caused by 
chiggers on man. 
The eggs are easily distinguished from those of the other common 
species by their larger size and lemon yellow color. 
Trombidium maculatum. n.sp. 
Adult female. Color dark scarlet, an irregular transverse white 
