fed larva drops off the host, burrows into soil, and molts to an eight-legged nymph. The
nymph and later the adult feed on immature stages of other arthropods, frequently the
eggs of grasshoppers. Chigger larvae, the only medically important stage, do not
disperse far from the point they hatched in their search for a host. Thus, they tend to be
much clumped in distribution, forming what are referred to as "chigger islands," in areas
of tall grass, weeds, and brushy vegetation.
1-11. SCORPIONS
Scorpions are most commonly found in warm climates. They prefer damp
locations and are particularly active at night. Although all the scorpions found in the
United States are capable of inflicting painful stings, the stings are seldom fatal.
However, in the Middle East, South America, Mexico and some parts of North Africa,
the stings of certain species can be fatal. Scorpions are recognizable by their crablike
foreparts and their long, fleshy, six-segmented taiI that ends in a sharp spine or stinger
(see figure 1-26). Their diet consists of insects, spiders, miIIipedes, and other small
animals. They seize their prey with their pincers and mouthparts and strike with the
stinger, which is thrust forward, in a characteristic fashion, over the scorpion's head.
Scorpions have four pairs of legs and one pair of large claws or pedipalps. The body
has two divisions: the anterior, unsegmented cephalothorax; and the posterior,
segmented abdomen. The last six abdominal segments form the "taiI." The last
segment is modified to form a hooked stinger. Adult scorpions vary in length from less
than an inch to almost 8 inches. Colors vary from nearly black to straw-color and some
are striped. Most scorpions have smooth bodies, though some are hairy. Scorpions
bear their young alive. When the young are born, they attach themselves to their
mother's body, and they are carried around for some time.
Figure 1-26. Scorpion.'
MD0170
1-21