TRUE ORTHOPTERA 3153 



corresponding to the mandibles and maxillae of other insects, but here transformed 

 into piercing organs. All these parts are covered at the base in front by the 

 narrow and slightly elongated upper lip (labrum). From the structure of their 

 mouth, which is fitted only for the reception of liquid nutriment, it is easy to infer 

 that these insects live by piercing tissues of plants and animals, and extracting the 

 juices. The larvae differ little from the adults except in size, the absence of 

 wings, and their usually shorter and more slender antennae. In many, however, 

 the females are without wings at all stages; and in some cases both sexes are thus 

 unprovided. When wings are present, they may be all of similar texture, or the 

 front pair may be somewhat stiffer and less membranous than the hinder. Wings 

 of both these kinds are found in the section Homoptera. In other cases, 

 while the hind-wings are entirely membranous, the front pair are stiff and horny 

 for some distance from their base, and thin and membranous toward their extremi- 

 ties. Such wings, which characterize the section Heteroptera, are known as 

 hemi-elytra. Over eighteen thousand species are already known. Fossil remains 

 of the order are found in strata of the Jurassic epoch, and are tolerably abundant in 

 amber and other beds of Tertiary age. 



All the Heteroptera, no matter how different the} 7 may be in external form or 

 mode of life, are termed bugs, although this name was originally applied only to 

 the bedbug and a few closely-allied species. Most are winged insects, in which the 

 fore-wings known as hemi-elytra, or simply as elytra, always have the form 

 described. Their antennae are either short and inconspicuous, as in the water 

 bugs, or distinctly visible as in the land bugs, and are generally composed of a 

 small number of joints. As a rule, they have two compound eyes, and often two 

 or three ocelli. The first segment of the thorax is usually large, with the head 

 sunk deeply into it. The abdomen generally has an oval flattened form, and the 

 legs are mostly slender. With few exceptions bugs are characterized by a peculiar 

 and somewhat unpleasant odor, which arises from a liquid secreted by special 

 glands placed in the front part of the abdomen, and opening to the exterior by 

 means of two small ostioles on the ventral surface of the metathorax. 



Bugs are divided into two tribes, based upon their mode of exist- 

 ence, and the fact that in one tribe the land bugs, or Geocorisa 

 the antennae project, and are distinctly visible, while in the other the water bugs, 

 or Hydrocorisa they are very short, and hidden below the eyes. The shield bugs 

 (Pentatomatidas), which constitute one of the largest families of the Geocorisa, 

 are so called on account of their large scutellum, which reaches at least to the 

 middle of the abdomen, and sometimes quite to its extremity, covering it over 

 completely. The fore-wings are sometimes chitinized only near the basal margin, 

 especially in those species with a very large scutellum. The body has in general 

 an elliptical outline, or is shaped like a scutcheon, owing to the projecting lateral 

 angles of the somewhat hexagonal pronotum. These bugs are mostly found on low 

 plants, some in concealment, many showing themselves openly, and often attracting 

 observation by their striking colors. The adults pass the winter sheltered under 

 bark or dried leaves. In early spring the females lay their eggs on the foliage of 

 low plants, shrubs, and pine trees. The oval or spherical eggs are provided with an 

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