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TERZI

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Originally appearing in Volume V13, Page 262 of the 1911 Encyclopedia Britannica.
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TERZI . -_. After See also:

Howard, See also:Year See also:Book U.S. Dept. Agr., 1894. into a See also:process or See also:hood-like structure which may extend far behind the tail-end of the See also:abdomen. Two other allied families, the Cercopidae and Jassidae, are more numerously represented in our islands. The See also:young of many of these See also:insects are See also:green and soft-skinned, protecting themselves by the well-known frothy secretion that is called " See also:cuckoo-See also:spit." In all the above-mentioned families of Homoptera there are three segments in each See also:foot. The remaining four families have feet with only two seg- Pmm See also:Osborn (after See also:Deane), meets. hey are of B:dl. 5 (N.S.), Div. Ent. very See also:great zoological G.S. Dept.

Agr. See also:

interest on See also:account of ( Pediculus vestimenti). their See also:life-See also:history—See also:par- Magnified. thenogenesis being of normal occurrence among most of them. The families Psyllidae or " jumpers ") with eight or ten segments in the feeler and the Aleyrodidae (or " snowy flies ") distinguished by their See also:white mealy wings, are of comparatively slight importance. The two families to which See also:special See also:attention has been paid are the Aphidae or plant-lice (" green See also:fly ") and the Coccidae or See also:scale-insects. The aphids (fig. II) have feelers with seven or fewer distinct segments, and the fifth abdominal From Osborn (after segment usually carries a pair of tubular See also:pro- Schiodte), See also:Ball., (IV .S.), cesses through which a waxy secretion is dis- Div. Ent. U.S. Dept. charged. Tha sweet " See also:honey-See also:dew," often Agr. . sought as a See also:food by ants, is secreted from the FIG. 15. — Pro-intestines of aphids.

The See also:

peculiar life-See also:cycle in boscis of Pediculus. which successive generations are produced Highly magnified. through the summer months by virgin See also:females —the See also:egg developing within the See also:body of the See also:mother—is de-scribed at length in the articles See also:APHIDES and See also:PHYLLOXERA. The Coccidae have only a single claw to the foot; the See also:males (fig. 12 a) have the fore-wings See also:developed and the See also:hind-wings greatly reduced, while in the See also:female wings are totally absent and the body undergoes marked degradation (See also:figs. 12, e, 13, a, b). In the Coccids the forma- tion of a protective waxy secretion—See also:present in many genera of Homoptera—reaches its most extreme development. in some coccids —the " mealy-bugs " (Dactylopius, &c.) for example—the secretion forms a white See also:thread-like or See also:plate-like covering which the See also:insect carries about. But in most members of the See also:family, the secretion, See also:united with See also:cast cuticles and excrement, forms a See also:firm " scale," closely attached by its edges to the See also:surface of the plant on which the insect lives, and serving as a See also:shield beneath which the female coccid, with her eggs (fig. 13 a' and brood, finds shelter. The male coccid passes through a passive See also:stage (fig. 4) before attaining the perfect See also:condition. Many scale-insects are among the most serious of pests, but various See also:species have been utilized by See also:man for the See also:production of See also:wax (See also:lac) and red dye (See also:cochineal). See ECONOMIC See also:ENTOMOLOGY, SCALE-INSECT. ANOPLURA The Anoplura or lice (see See also:LOUSE) are wingless parasitic insects (fig.

14) forming an See also:

order distinct from the See also:Hemiptera, their sucking and piercing mouth-See also:organs being apparently formed on quite a different See also:plan from those of the Heteroptera and Homoptera. In front of the See also:head is a See also:short See also:tube armed with strong recurved hooks which can be fixed into the skin of the See also:host, and from the tube an elongate more slender tucking-See also:trunk can be protruded (fig. 15). Each foot is provided with a single strong claw which, opposed to a process on the shin, serves to grasp a See also:hair of the host, all the lice being parasites on different mammals. Although G. Enderlein has recently shown that the jaws of the Hemiptera can be recognized in a reduced condition in connexion with the louse's See also:proboscis, the modification is so excessive that the See also:group certainly deserves ordinal separation.

End of Article: TERZI

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