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Assassin Bugs

(Family Reduviidae.)

This is a large and important family of bugs comprising more than two thousand species of which more than one hundred and fifty inhabit the United States. Its forms vary much in structure and have been divided among thirteen subfamilies and three hundred and thirty-six genera. All are predatory in their habits and feed on other insects which they pierce and whose blood they suck by means of their strong, sharp beaks. From this food some of the subfamilies are known as "cannibal bugs" or "pirate bugs." Comstock calls them the "assassin bugs." With many species the beak is so strong as to readily pierce the skins of human beings, and one species, known as the "bloodsucking cone-nose" (Conorhinus sanguisuga) so often frequents houses, especially in the southwest, and is so fierce a biter that it is often referred to as "the gigantic bed-bug." It seems, according to Schwarz, to normally inhabit the nests of field mice. Other species, especially Melanolestes picipes and Reduvius personatus, were especially abundant in the eastern states in the summer of 1898, and their bites were responsible for the extraordinary so-called "kissing bug" scare which was greatly advertised by the newspapers. A western species, Rasahus binotatus is also a severe biter. Of these "kissing bugs," Reduvius personatus, is a cosmopolitan form which, in the northern states, is found in basements and cellars of dirty houses and preys upon bed-bugs and cockroaches. When immature it covers itself with dust and presents a very odd appearance.

Some very odd species are found in the subfamily Emesidae, which have been called "thread-legged bugs." Their legs are excessively long and they have a peculiar habit of swinging the body up and down. One of them frequents spiders' webs and robs the spiders of their prey.

The eggs of nearly all Reduviids are of very strange appearance and are frequently distinguished by some form of protective resemblance. None of these predatory bugs seem to possess the strong and frequently disagreeable odor so characteristic of many of the plant bugs.

Life History of the Wheel Bug

(Arilus cristatus L.)

This is a large predatory bug common all through our southern states and Mexico and which extends up into sourthern Illinois and New Jersey and even to Long Island and Rhode Island. It is popularly known as the "wheel bug" and sometimes by the negroes as the "devil's riding horse" and is referred to in the older books as Reduvius novenarius and Prionotus or Prionidus cristatus.

The eggs of the wheel bug look like miniature leather bottles standing on end and in hexagonal clusters, seventy or more in a group, and attached to the bark of trees, on fence rails, or whereever the female chances to be. In this stage the insect passes the winter. In the late spring the cap of the bottle is pushed off and the young bug emerges. The young insect has a blood-red abdomen and its thorax is marked with black. In walking it frequently elevates the abdomen, curving it over forwards. It feeds upon soft-bodied insects, its attacks, while young, being confined mainly to such weak, delicate species as plant-lice. As they grow larger they attack larger insects and when full-grown destroy large caterpillars. They seem to inject a poison into the wound made by the beak and Glover tells of a bite on his thumb which was severely poisoned and gave him great trouble. After four molts the peculiar crest on the thorax appears which has given this insect its specific scientific name cristatus (crested) and its popular name "wheel bug." This is a semicircular longitudinal crest bearing nine teeth, prongs or cogs like a cog-wheel.

The full grown bug is sordid black in color. It captures its prey not by agility but by stealth. Its coloration is protective and it slowly crawls up to some caterpillar or other insect, advancing one leg after another with a movement so slow as almost to be imperceptible. When once within striking distance, however, the beak is thrust into the victim which is at the same time grasped with the front legs with a movement which is quite the reverse of slow.

The wheel bug is a very beneficial insect. It is a common inhabitant of southern cities and in such places as Baltimore and Washington is an important factor in the destruction of the numerous caterpillars which defoliate shade trees.