DIRECTIONS FOR 



COLLECTING AND 



INSECTS. 



PRESERVING 



By Nathan Banks, 



■ Custodian of Arachnida, U. S. National Museum. 



CHARACTERISTICS OF INSECTS. 



Insects are readily distinguished from similar animals by a number 

 of structures or characters. The body is segmented — that is, com- 

 posed of a series of rings or segments. They have jointed or articu- 

 lated appendages, such as legs and feelers, or antennae. Worms do 

 not have these jointed appendages. Insects possess six of these true 

 legs and one pair of antennae. Spiders do not have antennae, but 

 have eight legs. Millipedes and centipedes have more than six legs; 

 and crustacea or crabs also have more than six legs and often two 

 pairs of antennae. Nearly 

 all insects are winged in 

 the adult form. The 

 other groups are not 

 winged . The insects are 

 known scientifically as 

 Insecta, and, together 

 with the crustacea, spi- 

 ders, centipedes, and mil- 

 lipedes, they form a group 

 known as Arthropoda. 

 Sometimes the insects are ^ 1G - i— habrocytus thyridopterigis, showing principal 



.. . TT -. . PARTS OF AN INSECT. 



called Hexapoda, or hex- 

 apod insects, to distinguish them from centipedes and the spiders. 

 Most insects have the body more or less distinctly divided into three 

 or four parts. The head is always distinct (fig. 1), bearing below 

 the mouth-parts and above the antennae or feelers and a pair of com- 

 pound eyes. In many cases there are between the compound eyes 

 two or three simple eyes or ocelli. Behind the head is the thorax, but 

 in the case of beetles and some other insects the prothorax is a distinct 

 main division of the body. The thorax is of three parts — prothorax. 

 mesothorax, and metathorax — each part bearing a pair of jointed 



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