Page:The New International Encyclopædia 1st ed. v. 17.djvu/681

SCALA SANTA. 613 SCALE INSECT. SCALA SANTA, sUn'td. See Laterax, Cm Kill OK Sai.m John. SCALCHI, skiil'k^, Sofia (1850-). An Itiilian n|ifi;tip sin^or, horn in Tuiin. Slip inailc luT cli'liut in Mantua, in IStili, and san;; in opera tlirougliout Europe. In 18S3 she nuiilc her tirst appearance in the I'nited States, where she became a <,'reat favorite. Her voice, a rich contralto of extensive compass, enabled her also to sing mezzo-soprano. Her most successfnl roles include Siebel in Gounod's Faust; Fides in Meyerbeer's I'rojjhrlc; ^Vnnu'ris in 'e,rdi's A'ida : Arsaee in Rossini's Soniramidc : and Pierotto in Donizetti's Linda di Vhamoumx. SCALD HEAD. See Favus. SCALDS. See BuR.xs and Scalds. SCALE (Lat. scala, staircase, ladder, from sc(i>i(!t IT, to climb. Ski. shaitd. to sjiring, ascend). In nui-ie, a succession of notes arranged in the order of pitch, and comprising those sounds which nuiy occur in a piece of nuisic written in a given ke,v. The scale consists of a series of seven steps leading from a given note ( fl.ed on as the tonic or key-note) to its octave, which may be extended indefinitely up or down, so long as the sounds continue to be musical. For an explanation of the principles on which these scales are founded, and of their derivation from the harmonic triad, see Major; Minor. See also Greek Mrsic; Modes. SCALE INSECT (AS. scealn, sceale, OHG. scfild. (iiT, Schiilc, shell, husk, scale, Goth, skaija, tile; connected with OChurcli Slav, sicolikd. mus- sel, Russ. skala, bark, shell, Lith. skelti, to split; probably connected ultimately with Eng. shell). Anv insect of the famil.v Coccid* (q.v. ), some- times also called 'scale-bug.' or 'bark-louse.' The scale insects are distinguished from their nearest allies by the absence of wings in the females, by the possession of only two wings in the males, by the absence of any mouth or feeding apparatus in the adult males, which, instead, are usually sup])Iied with large supplementary eyes. Further, in both sexes the legs (when present) terminate in a single claw at the tip of a single-jointed tarsus. The group is now diviiled into twelve subfamilies, which are distinguished as follows: The true scale-bearers belong to the subfamilies Conchaspinip and Diaspinte, the scale in the former group being composed of secreted matter, in the latter cast skins and secreted matter to- gether. ■ The so-called 'naked' scales compose the ten other subfamilies, nearlj- all the species of which secrete some substance which more or less disguises tliem. The subfamilies are more or less characterized as follows: Dactylopiinis (mealy bugs, q.v.). covered with a white, waxy, pow- derv secretion which sometimes forms long, ap- piirently fibrous bundles; Lecaniiniv projier, a cleft posterior extremit.v in the female ; Hcmi- coccina', larvae with abdominal lobes; Tachar- diin.Tp. hic insects (see Lac), inclosed in a resinous cell with three orifices; Coccinae, no anal tiiliercles in the female ; Idiococcina>.' short an- tenna'; Brachyscelinfe, gall-making coccids. In each of these subfamilies the males have simple e.yes; in the Ortheziina> and Monophlebina; the.v have compound e.ves. The last-named group, mainly Australian, contains the largest species, some of which are more than an inch long. The scale insects live upon the sap of plants, and with few exceptions are considered pests. (See San Josfi Scale; Oyster-Shell Kark- LorsE; Orange Insects.) Since they are in- significant in appearance and are attached to all parts of the plant, some of theni have spread upon nursery stock and fruit and have become cosmopolitan in their di>tril)Ution. With many (he original home is a matter of doubt. Among the most notable .meriian scale insects are the following: Cottony cushion scale [Iccrya I'lirrliiisi) , once troublesome in California, but subdued by a ladyliird {S'orius ciirdinalis) im- Iiorted from .Australia (see I.auyhird) ; species of the genus Kernies, remarkable for the gall-like form of the adult females, which clo.scly re- SAN JOs£ 8CAI r. A young Inrva; a pear covered with 8i'al<^ InsectR; and the scales^ eiiUii-Ked. semble small oak galls; cotton.v maple scale {Pul- viiiuria iiiiiuiiirnibilis) , a brown naked scale which secretes a large, white, waxy, unribbed egg-mass; black scale of the orange and olive (Lccanium olc(v), a cosmopolitan species, trouble- some in California; hemispherical scale (Lcca- nium hcmisi)licnicum) , a common greenhouse pest throughout the world, living out of doors upon citrus trees in the Gulf States. Of the true armored scales, aside from those mentionecl, there arc the scurfy bark-louse of the apple (I'liiatuispis furfurufy) ;pine-lcaf scale (Chionds/iis pinifoliir) ; and the common rose scale (Diaspis ro.sfr), all of which are often troublesonie upon their host plants. Jlost scale insects arc oviparous. Certain species, however, are viviparous, and some must be parthenogenetic. With one species, the common 'flat' scale { Lccniiiiim hespcridum) , which is cos- mopolitan and a frequent denizen of hothouses, the male has never been found, although the fe- males occur in incalculable numbers. Remedies fok Scale Insects. In temperate regions, with those s])ecies which hibernate in the egg stage, scale' insects can usually Iw con- trolled by spra.ving the plants with kerosene emulsion in the early spring as soon as the young have hatched, the young insects being un- protected by a scaly covering. With species which hibernate in the adult or half-grown condition protected by the scale, and which give birth to young at irregular and prolonged periods, pure kerosene and crude petroleum may be lightly