Fig. 77.—Chilopoda. A common type of woodland centipede found in leaf mold and rotten logs. Actual length 1.0 inch. (Drawing from R. E. Snodgrass.)
Elongate animals each having a distinct head and a long, many-segmented body with two pairs of legs on every segment. The commonest Illinois representative is the large Parajulus impressus (Say), [fig. 75], a robust, cylindrical, reddish species commonly found in rotten logs or moist leaf mold. Most species feed on decaying vegetable matter. A few occasionally do considerable damage in greenhouses.
Chilopoda
Centipedes
Elongate animals, similar in general appearance to the millipedes but with only one pair of legs on each body segment. Many species are predacious, feeding on insects and other small animals in rotten logs and humus. Most familiar to the city dweller is the house centipede, Scutigera forceps Rafinesque, [fig. 76]; this is a common inhabitant of dark places in houses, where it runs about with incredible speed in search of the small insects upon which it feeds. Other species may be encountered under boards and stones in gardens, [fig. 77]. Some Illinois centipedes found in woody or rocky situations are 2 inches or more long. No chilopod group in this state is dangerous to human beings, but to the south occur centipedes nearly a foot long that may inflict serious bites.
THE STATE INSECT COLLECTION
Fig. 78.—The Natural Resources Building. This building, on the campus of the University of Illinois, is the home of the Illinois Natural History Survey and houses the state insect collection on the second floor of the west wing. (Photograph from Illinois Geological Survey.)
Illinois is one of the very few states that maintain a large research insect collection. This collection is under the care and guidance of the Section of Faunistic Surveys and Insect Identification of the Illinois Natural History Survey. It is housed in the west part of the fireproof Natural Resources Building on the University of Illinois campus at Urbana, [fig. 78]. Begun about 1880, the collection has grown steadily until now it is the most extensive representative collection of the insect fauna of any state in the nation. The collection consists of over 5,500,000 specimens of insects housed in steel cabinets, [fig. 79]. The pinned collection includes about 750,000 specimens in trays. The collection preserved in alcohol contains over 3,500,000 insects including not only a great number of valuable adult insects but also a very useful collection of immature insects. The slide collection contains nearly 250,000 specimens mounted as permanent microscopic preparations. The papered and boxed material comprises more than 1,000,000 specimens of dried insects.
