4 
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378 
THE DICTIONARY OF GARDENING, 
Scevola—continued. 
as long as, or longer than, the tube ; corolla jin. long, pubescent 
outside. August. l. obovate-oblong, 3in. to 5in. long, rounded 
and obtuse at bat entire or rarely broadly crenate, on short 
petioles. h. 2ft. 1820. An erect shrub. (B. M. 2732.) . 
S. microcarpa (small-fruited). fl. violet, in a usually long and 
_ interrupted apike : ely lobes an ; corolla hairy outside, seven 
to nine lines long. July. jr. small. l. petiolate, obovate, ovate, 
or cuneate, coarsely toothed, the lower ones often lin. to lin. 
— the upper ones — into sessile floral leaves or bracts. 
1790. An erect or diffuse perennial. (L. B. C. 1327; B. M. 287, 
under name of Goodenia levigata.) 
S. pilosa (pilose). jl. blue ; calyx tube pubescent ; corolla Zin. to 
lin. long ; peduncles axillary, longer than the leaves, one-flowered. 
May. Ll., lower ones petiolate, obovate or oblong, coarsely toothed, 
2in. to 3in. long; upper ones much smaller, sessile and rigs 
ing, varying from oblong-cuneate to lanceolate. h. lft. to 3ft. 
1841. A hispid perennial or sub-shrub, 
S. platyphylla (broad-leaved). fl. white, sessile or shortly pedi- 
. eellate, in a terminal, leafy spike ; calyx lobes very small ; corolla 
above lin. long, silky-hairy, the lobes winged. May. l. sessile 
and stem-clasping, ovate, obovate, or oblong, entire or few- 
toothed, lin. to 14in., or ae aah long ; upper floral ones gradu- 
ally becoming smaller. A. 2ft. 1841. 
woody at base, with rigid, herbaceous branches. 
S. Plumieri (Plumier’s). M. white, usually in axillary, peduncled 
cymes; calyx limb truncate-repand or obsoletely denticulate ; 
corolla eight to ten lines long, villous within. August. J. fleshy, 
obovate, quite entire. h. 2ft. West Indies, 1724. Stove shrub. 
S. suaveolens (sweet-smelling). M. blue, sessile, in interrupted, 
terminal, hirsute spikes ; calyx equally five-lobed ; corolla seven 
to eight lines long, villous or glabrous outside, toothed or softly 
bristly in the throat. August. l. petiolate, from obovate to 
oblong-spathulate, quite entire, thick, the larger ones 2in. to šin. 
long ; upper ones smaller, or linear when on elongated branches. 
1793. A prostrate or decumbent, hardy perennial or sub-shrub, 
(A. B. R. 22, under name of Goodenia calendulacea.) 
SCALARIFORM. Ladder-shaped. 
SCALE INSECTS (Coccide). These form one of 
the most destructive families among Insects. They belong 
to the class Homoptera, in which are also included the 
Frog-hoppers and the very numerous Aphides or Green- 
flies, both very hurtful to many plants. The Scale In- 
sects have been studied by several entomologists, and, 
of late years very important advances have been made 
in working out the life-histories of many species; but 
there are very wide gaps still to be filled before satis- 
factory results can be arrived at with regard to the 
transformations and life-histories of most of the species. 
Among those who have done most in this field for some 
time past are M. Signoret, in France, and Professor 
Comstock, in the United States of America. Our British 
species have been worked out, and the results have 
been published in the March and April numbers of the 
“ Entomologists’ Monthly Magazine” for 1886, by Mr. 
J. W. Douglas. He has succeeded in identifying a large 
number of species of these insects in our islands. Most of 
them are found on wild plants; but in greenhouses some 
Fic. 441. LECANIUM HESPERIDUM (FEMALE)—a, Twig and Leaf- 
stalk of Orange, bearing Female Scale Insects, natural size ; 
b, Female magnified. 
species (see Fig. 441) infest many of the shrubs and other 
plants to such a degree that, by the continued suction of 
the sap, and the consequent tax on their strength, the 
An erect; hispid plant, 
Scale Insects—continued. 
plants are much weakened, and ultimately die. The 
females and larve are the hurtful members of the family ; 
while the males, when fully developed, do no harm to 
plants. The females are by far the more numerous, and 
the more conspicuous; in fact, the males of even the com- 
monest species are seldom seen, and those of a good 
many are still unknown. They are most successfully 
procured by collecting the larve and pupæ, which some- 
what resemble scales, very early in spring, upon branches, 
which, with these scales on them, should be put into 
some secure vessel, e.g., a glass jar. 
The males are very unlike the females. They usually 
emerge early in the year, in the form of minute flies, 
with the head, thorax, and abdomen distinct and well 
formed—two delicate wings, six legs, and usually two 
si 
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Fig. 442. LECANIUM PERSIC&, showing (a) Leaf with Male on it, 
slightly enlarged ; (6) Male Flying, much enlarged. 
slender filaments at the hinder end of the body (see 
Fig. 442). They have no mouth, and therefore cannot 
take food in this state. They seldom live more than a 
few days, their sole function, as perfect.insects, being to 
fertilise the females. In certain species, both wingless 
and winged males have been found. 
Female Scale Insects are much larger than the males, 
and they alone fully deserve the name of Scale Insects. 
They are developed from larve of an oval form, which 
have three pairs of small legs (by the aid of which they 
can crawl about), small antennz, and a beak with which 
to bore into leaves and young stems of plants, in order to 
suck up the sap. The larve are protected by a scale-like 
covering on the back. This scale is formed either by an 
excretion from the body (in Coccine and Lecanine), which 
increases in size as the larva grows, or also by the cast 
skins (in Diaspine). After the larve have fixed them- 
selves in a suitable location on a plant, by pushing in 
the beak, they never leave the spot. As they increase 
in size, they undergo great alterations in structure, 
whereby the body becomes more rounded, and the beak 
becomes situated in the middle of the lower surface of 
the body. The legs and antennæ, and the rings of the 
body, almost or altogether disappear. The females thus 
at last lose all power of movement. After being fer- 
tilised by the winged males, or, in some species, without 
the action of the male being necessary, the females pro- 
duce eggs, which are packed away below the scale-like 
bodies, and are thus protected by them, even after the 
death of the mothers. The females of some Scale Insects 
cover the eggs also with a white coat of felted threads. 
In certain species, the females are: viviparous. 
The number of species of Scale Insects already named 
is very large; but of many the males, as before observed, 
are still unknown. A large proportion live on the woody 
kinds of wild plants, fixed to the bark or to evergreen 
leaves, but many others select hardy cultivated plants ; 
while others are confined, in this country, to greenhouse 
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