Scutellum

“ The feelers are elongate and conspicuous. The Pentatomidae (shield-bugs) , some of which are metallic or otherwise brightly coloured, are easily recognized by the great development of the scutellum, which reaches at least half-way back towards the tip of the abdomen, and in some genera covers the whole of the hind body, and also the wings when these are closed. The Coreidae have a smaller scutellum, and the feelers are inserted high on the head, while in the Lygaeidae they are inserted lower down. These three families have the foot with three segments. ”

“ The Scutellerides also have the body covered by the scutellum, but their organs of flight are less peculiar than they are in the Plataspides; the Insects of this sub-family are highly remarkable on account of their varied and frequently vivid coloration; some of them are metallic, and the colour of their integuments differs greatly in some cases, according to whether the specimen is wet or dry; hence the appearance after death is often very different from that of the living specimen. These Insects are extremely numerous in species. ”

“ Scutellum testaceous. Abdomen elongate-oval, longer than the thorax. Wings greyish, rather short, limpid towards the base; veins black, testaceous towards the base; præbrachial vein forming a very slightly acute angle at its flexure, near which it is very deeply curved inward, and is thence straight to its tip which joins the tip of the costal; discal transverse vein straight, parted by much less than its length from the border, and by little more than half its length from the flexure of the præbrachial. ”

“ Scutellum small, and semi-oval. Elytra pale clay-coloured, having on each two spines at the tip of each, the inner one being the smaller; and having also four oblong yellow spots, two placed at the middle and two at the base. Each of these spots appears to be composed of a large and a small one joined close together; the largest (in the upper spots) being the inner one, and in the lower spots being the outer one. Abdomen and legs of the same colour as the head, &c.; the four posterior femora with two small spines at the tips. ”

“ Habitat: New York, Virginia, Maryland, Antigua.
Head brown orange; but round the eyes (which are black) and next the thorax of a shining brassy green. Thorax and elytra brown orange, and faintly margined; the former with two small black spots, and the latter with three on each side, one close to the thorax, another near the corner of the wing-cases, and the third in the middle. Scutellum shining bright green. Abdomen and legs greenish black. Tibiæ spinose and denticulated, especially at the tips; the three middle articulations of the tarsi are also furnished with spines. ”

“ Head conically produced. Front in the female noticeably wider than the eye, in the male about half as wide as in the female. Antennae three-jointed, first and second joints about equal in length, third much longer than the other two together and composed of six rings. Posterior orbits wide in both sexes, but widest in the female, scutellum without spines, four posterior veins arising from the discal cell, abdomen short and broad, nearly circular in outline.
Named for Akron, Ohio, in which vicinity I have procured many rare species. ”

“ Both sexes with abdomen ferruginous, apically more or less dusky, but the whole effect lighter and redder than typical; scutellum green with the hind margin red. Tuft on female scutellum light fulvous. The female, from Kalacoon, (Hym. 212) is the type of the variety.
Euglossa ignita Smith, var. chlorosoma, new variety
Green, without coppery tints, but variably suffused with purple. It is smaller than E. piliventris, with shorter mouth-parts, and the labrum pallid with a pair of dusky spots. A male in the U. S. Nat. ”

“ The species normally have narrow curved median head-scales, and similar ones on the scutellum; the female palpi are shorter than in the former genus and the male palpi are pointed; the lateral vein-scales are narrow and linear.
The type is Culex pipiens, Linn., the common gnat of Europe. The thorax is covered with narrow curved golden-brown scales, the abdomen has basal pale bands to the segments and the legs and proboscis are unbanded. The stem of the first submarginal cell is always less than one-fifth the length of the cell. ”

“ Head only moderately broad, usually covered with upstanding forked scales, though scales of other kinds are also present in a few species. Maxillary palps long and spathulate in the male; as long as, or not much shorter than, the proboscis in the female. Free edge of scutellum simply convex, not trilobate; metanotum bare. Abdomen either sparsely hairy or with localized patches of scales; sometimes with a considerable expanse of scales which, however, never form a uniform, complete, and compact investment. Wings commonly dappled or profusely speckled, but occasionally quite spotless. ”

“ General colour brownish yellow. Head smooth. Eyes rather prominent and dark brown, with a whitish streak between them. Antennæ the length of the insect. Mouth furnished with four palpi, knobbed at the extremities. Thorax margined, and a little indented. Scutellum, which is not seen when the wings are closed, whiteish and triangular. Tegmina thin, and full of tendons. Wings nearly diaphanous, and prettily speckled with cross marks in a zigzag manner. Legs strong; the hinder ones formed for leaping. Tibiæ armed with spines, pointing downwards; those on the hinder ones being shortest. ”

“ Antennæ slender, and almost as long as the insect. Thorax dark muddy green, almost black, which is the general colour of the insect. Next the head there is a white mark, somewhat resembling a crown, the sides terminating in two angles. Scutellum triangular. Hemelytra and wings of the same dark colour with the other parts. Rostrum slender, extending to the middle legs. Fore and middle legs slender, the thighs being dentated. Hinder legs very long, the thighs very thick and strong, and much dentated; the tibiæ being very broad and thin, and the inner edges serrated. Tarsi dark orange. ”

“ The scutellum meanwhile feeds the developing embryo from the endosperm. The growth of the primary root is limited; sooner or later adventitious roots develop from the axis above the radicle which they ultimately exceed in growth.
Means of Distribution.—Various methods of scattering the grain have been adopted, in which parts of the spikelet or inflorescence are concerned. Short spikes may fall from the culm as a whole; or the axis of a spike or raceme is jointed so that one spikelet falls with each joint as in many Andropogoneae and Hordeae. ”

“ In many insects it is almost invariably concealed, but in others it is exposed and conspicuous; in such cases its form is usually square, and there is a superficial indication of its consisting of two parts; the one of these, the true back, exactly corresponds to the dorsolum of Kirby, the other is the scutellum, which appears as a triangular piece interposed between the wings at their base; it is very conspicuous in most beetles, and, in the heteropterous section of the hemiptera, it is sometimes so large (as in Tetyra, Fab.) ”

“ The præscutum and postscutellum are usually minute and crowded down out of sight between the opposing segments. As seen in Fig. 90, the præscutum of most moths (Telea) is a small rounded piece, bent vertically down so as not to be seen from above. In Polystœchotes and also in Hepialus the præscutum is large, well-developed, triangular, and wedged in between the two halves of the scutum. The postscutellum is still smaller, usually forming a transverse ridge, and is rarely used in taxonomy. ”

“ It is bent upon itself with an angle open forwards, and is divided into two halves (each of which contains seven scutes) by the union of the middle scutes of the fifteenth subcervical with those of the first row of what may be termed the subdorsal scutes, or those which lie under the thorax and abdomen. Of subdorsal and subcaudal scutes there are, up to the broken-off end of the tail, thirty-seven rows, with the following numbers of scutes:—
It will be noticed that there are three more rows of ventral than of dorsal scutes. ”

“ Neck rather short. Body rather slender. Wings very long. Feet of moderate length, rather strong; tibia bare below for a short space, covered behind with narrow scutella; tarsus compressed, anteriorly covered with numerous scutella and three inferior 215 series of transverse scales, laterally with oblong scales, posteriorly with oblique scutella. Toes slender, with numerous scutella; first extremely small, second considerably shorter than fourth, third longest; anterior toes connected by reticulated webs, of which the anterior margins are deeply concave, the outer and inner slightly marginate. ”

“ In S. vulgare the males are attached, often several together, to the extreme edges of the two scuta, and therefore immediately over the orifice leading into the sack; in S. rutilum and ornatum, they are attached in concavities on the under side of both scuta, just above the depression for the adductor scutorum muscle. In the former of these species, the pit for the reception of the male is formed by shelly matter not having been deposited over a certain space on the under side of the valve; and the pit is converted by a covering of membrane into a pouch. ”

“ The scuta are ornamented, rarely with a white blotch on each side of the mesial line, but generally with two lateral black dots. The first scutum in the female has the anterior margin oblique as to the main axis of the body, and is prolonged laterally so as to form processes, mostly canaliculate, with a rounded border. In the male the anterior margin is at right angles to the axis of the body, and the lateral parallel to it, so that there are no processes. ”

“ When surface markings exist on the scuta, they are very useful in defining species. The color is also a good character in some groups. Where one of these fails us the other very generally assists. The form of the last scutum is sometimes distinctive. The best characters, however, are those derived from the genital organs. The form, &c., of the antennæ and head often afford some clue.
Genus POLYDESMUS, Latreille. [24]
Meatus laterales in scutis 5—7—9—10—12—13—15—16—17—18—19—positus. ”

“ The outer edges of each scutum are prolonged into curved hooked spines. The first scutum is the shortest and broadest, and has the heavier spine or hook, while the last two segments often lack the hook. The abdomen is finely granulate and at the lower edge of each scutum there are eight heavy, short, simple hairs.
Pedipalps: Longer than body, coxa smooth, trochanter with large protuberance ending in a strong spine on outer side; femur longer than cephalothorax, slightly concave on inner edge, convex on outer edge. Tibia pedicellate, shorter than femur. ”

“ The basal portion of the mandibles on each side project, so that if a vertical section of the head through the middle were taken it would be an oval with its greater diameter transverse. The eyes are in strictly triangular patches, with remarkably straight sides. The scuta are so deeply canaliculate along their dorsal centre as to be almost divided into two parts. The dorsum is not perfectly rounded, but there is somewhat of a ridge or angle in the centre. Each scutum is furnished with a regular series of distant large puncta, or perhaps more properly, pores. ”

“ They are connected by a black band, which is much broader in the middle than at the ends. The first scutum is large, with very small lateral processes even in the female. There is on its anterior edge a very obscure light border, and a little posterior to this a black, more or less obsolete, band. The scuta are regularly, although rather lightly and distantly canaliculate over their whole surface. The last scutum is distinctly but minutely punctate, has its edge whitish, and is not at all mucronate. The anal scales are not at all pilose. ”

“ Scuta.—These valves are important, inasmuch as the animal’s body is attached to them; in Pl. 25, fig. 1, the broken line, surrounding a, b, shows where the body has been cut, in removing the scutum on the near side, the other scutum, S, being left articulated to the tergum, T. In shape the scuta are generally sub-triangular; but in some species of Pyrgoma and in Chelonobia, &c. they are much elongated. ”

“ The two commonest species of scutellaria in England are the Scutellaria galericulata and Scutellaria minor. They do not inhabit the same localities. The former, which is at the same time the commonest, grows on the river-banks, and especially delights in the mould accumulated in the hollow trunks of old willows. It is easily known by its tender blue corolla, but especially by its calyx, which, after the fall of the corolla, develops itself in a singular manner. ”

“ I may, however, remark that in Scalpellum, the scuta first grow downwards, and afterwards in most of the species upwards, whereas here from the beginning, the growth is both upwards and downwards. In the mouth and cirri, there is rather more resemblance to Scalpellum than to Pæcilasma and Lepas: in habits, also, this genus agrees with Scalpellum, and if it had possessed a lower whorl of valves, it would have quite naturally entered that genus. It is unfortunate, that so insignificant and poorly characterised a form should require a generic appellation. ”