Chapter 22 



IDENTIFICATION AND CLASSIFICATION 

 (TAXONOMY) OF INSECTS 



Since insects are of such great economic importance, so numerous and 

 ubiquitous in their distribution, it seems desirable that one should know 

 something about them. Even from such a limited study as suggested 

 here, many benefits from esthetic and practical standpoints may be 

 derived. Possibly, a maximum of benefits, with a minimum of time 

 expended, may be secured by a study of the various representative orders. 

 The information is given in table form in order to expedite the work and 

 to make pertirient contrasts and comparisons more easily. The more 

 important features used in the differentiation of the orders include wings, 

 mouth parts, and type of metamorphosis. 



Depending on the species, the sex, or even the particular stage of the 

 life cycle, insects may have two pairs of wings or one pair of wings or 

 may be wingless. Typically, most insects have two pairs of membranous 

 wings which vary as to shape, construction, venation, foldings, etc. 

 When at rest each species has a particular method of holding the wings 

 which is taken into consideration in classification. Typically, only one 

 order [Diptera) has one pair of wings, the second pair being repre- 

 sented by a pair of threadlike knobbed halters (hal-te' rez) (Gr. halter, 

 weight or balancer). The forewings of such forms as the Orthoptera, 

 Coleoptera, and Dermaptera are thickened for protection. The fore- 

 wings of the Hemiptera are thickened only at the base. The particular 

 type of wing venation is also taken into consideration in classification. In 

 some species, one sex has wings, while the opposite sex is wingless. For 

 example, the male canker worm moth has two pairs of wings, while the 

 female is wingless. 



Insect mouth parts may be for (1) chewing (mandibulate) (Fig. 192) 

 or (2) sucking. Mouth parts consists typically of a flaplike upper lip 

 {labrum) , a pair of upper jaws (mandibles) , a pair of lower jaws (maxil- 

 lae), and a lower lip (labium). In addition, there may be, in certain 



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