Page:Encyclopædia Britannica, Ninth Edition, v. 13.djvu/161

INSECTS group of often minute insects, of winch the larva- n re predaeeous, ami ditier but little in form from the imago ; with these the curious and aberrant Pselaphidaa are usually united. Clawcornia have clavate aiitenme, and are sometimes termed Nccrophaga, from the habit many of the species have of feeding upon dead and decaying animal matter; the forms are very numerous, and include the well-known Burying Beetles (Necrophorus) and the destructive Dcrmcstidae (in which is the Bacon-Beetle) ; Parnidss are aquatic ; Paussidse. are wonderfully curious creatures with singularly formed antenna , living in ants nests : in this division are now placed the almost microscopic Triclwptcrygidse, most of which are not larger than small grains of sand, and remarkable for their narrow ciliated hind wings, and also other groups sometimes placed in the Trimcra. Lamellicornia have the apex of the antenna; pectinate or provided with lamelliform plates: they include the Stag-Beetles and the very numerous Dung-Beetles, amongst which is the Scaral&us of the Egyptians, together with the numerous Chafers. Stcrnoxi have the prosterimm produced and pointed, and mostly filiform antenna , with ordinarily an elongate oval form : in this division are the, beautiful Buprestiihr and the familiar Elateridse, the latter known as Click-Beetles, and able to spring by means of the process of the prosternum acting on a peculiar structure of the mesosternum: the larva? are all vegetable feeders, and have the legs only slightly de veloped; those of Elateridse are known as Wire-Worms, and are often very destructive ; some of the exotic Elateridse, are brilliantly luminous. Malacodermi are a group of mostly soft-bodied insects very variable in form and habits ; the prosternum is not produced, and the antennae are usually pectinate or serrate : included in it, are the Telephoridss (Soldier- Beetles), JjampyridsB (Glow-Worms), Clcridis (often parasitic in the nests of bees), the wood-eating Ptinidsc (in which is Anobium, or the Death- Watch), and BostrychidsR. The Heteromera are a large group of forms connected together by the tarsal structure, but otherwise o.f the most diversified nature ; in fact it may be said that, so far as outward appearance is concerned, there are forms in it that might be readily mistaken as belonging to almost all the other principal groups, so protean are they both in structure and in habits. Two principal points of structure have been used for separating them into two great divisions. In one of these they have been divided into Globicoxse, and Conicoxie, accord ing to the form of the anterior coxae; in the other the two divisions are termed Atrachelia, in which the head does not form a neck, and Trachelida, in which tho head is narrowed into a neck. To some extent both these points of structure are correlated ; we adopt the latter ; but it must be remarked that the protean nature of the group as a whole is equally exemplified in its primary subdivisions. They appear to be invariably terrestrial, and for the most part phytophagous. The Atracliclia are mainly composed of a large number of genera of which Tcnebrio (the Meal- Worm) maybe taken as a type, and Blaps (the Churchyard Beetle) is also amongst its members. In the Trachr.lida the forms are more varied, and include some of the most remarkable instances of anomalies of form and struc ture, and even of metamorphosis, that exist amongst Coleoptera. Here are placed the CantJiaridse ( Blister-Beetles, &c. ), so remarkable for the hypermetamorphosis that exists in the larvae, and parasitic in tho nests of bees and locusts ; the extraordinary genus Sitaris (equally hypermetamorphotic), a parasite in bees nests ; Mcloe (the Oil- Beetles, the history of which reads almost like a romance, the very young larvae being active little creatures living on the bodies of bees, but afterwards becoming obese and almost footless, and feed ing on the bee larva; in the nests) ; and Rhipidius, parasitic on cockroaches. As a crowning point of eccentricity the extraordinary Strepsiptera (or Stylopidse) seem likely to find their resting place here, after having been considered a distinct order, as Diptera, as Hymenoptcra, and as Neuroptera ; but even yet it is probable their position may be warmly disputed. These anomalous creatures are parasitic in the bodies of bees, and the female, which is vermiform, and without antenna;, legs, or wings, never leaves its host, and is viviparous. The male has very large eyes, and extraordinary short antenna; ; the anterior wings (or elytra) are represented by small narrow processes, not unlike the halteres of Diptera ; the posterior wings are folded in repose, but when expanded are extraordinarily broad, whitish in colour, and almost without nervures. The meta- thorax occupies the greater part of the body; the abdomen is termi nated by a short stout process. The very young larva; are minute, active, and not unlike the young larva; of Cantliaris and Mcloc in form, and escape from the body of the mother by a slit in the neck; they are conveyed into the nests of their hosts, and penetrate the larvae of the latter, where they undergo hypermetamorphosis. Although originally supposed to be exclusively parasites on Hymenpptera, one species has recently been detected in the body of an homopterous insect. Tetramera. Although the beetles of this great division have apparently only four-jointed tarsi, it was long ago demonstrated by Westwood that there is actually a very minute joint between the lobes of the third joint, so that they are actually pentamerous, but the concealed joint is probably functionless; thus the terms Pseudo- Tetramera and Orypto- Tetramera have been proposed in lien of Tetramera. The chief groups are the Rhyncojihorct, Xi/ld/tinga, Lonijicornia, Phytqphaga, and Olavipalpi. All are vegetable feeders! The Bhyncophora (or Weevils) have the head produced into a ros trum, varying enormously in length, and in its lowest condition scarcely appreciable. The larvae are footless grubs, feeding almostuni- versallyin the interior of the stems or seeds of plants, and occasionally causing galls. Some exotic members of this group are amongst the most beautiful of insects. A peculiarity exists in the antenna;, which are attached to the rostrum, and usually elbowed, the basal joint being ordinarily very long (and termed the "scape") and the rest shorter, the terminal joints usually forming a club (the portion between the scape and the club is termed the "funiculus"). Bhyn cophora have been very variously subdivided. Schonherr separated them into Orthoccri and Gonatoccri, according to the absence or pre sence of an elbow to the antenna; ; Westwood has three families, Bruchidse, Attclalidai,aud. Curculionidas,f<mndcd on the antennae and palpi ; Lacordaire a groups are Adclognathcs and Phancrognathes, founded 011 the covered or uncovered mentum. Adopting Westwood s system, we have three families. Bruchidse, have only a short flattened snout, unelbowed antennae, and filiform palpi ; they are probably universally seed or nut feeders in the larval stage. " Bruchits gra- narius causes great destruction to grain; species of the genus Caryo- borus affect palm-nuts, some even living in the so-called vegetable- ivory nuts; Anthribidee, which form a subfamily of Bruchidse accord ing to Westwood, live in dead wood. Attelabidas have the antenna; unelbowed, the palpi conical, and the rostrum long and curved; the genera Brcnthus and Attdalus form the types of two subfamilies differing chiefly in the form of the club of the antenna; ; the first of these is almost entirely extra-European, and its members ap pear to feed on dead wood ; the second includes the brilliant species of Bhynchitcs (the larva; of which roll up leaves and feed on them, or live upon fruits) and the minute species of Apion, of which the larva; variously attack seeds, the interior of the stems of plants, &c. CurculionidK have elbowed antenna; and conical palpi, and are further subdivided into two main groups according to the length of the rostrum, each again forming numerous smaller groups ; the family contains many of the most familiar weevils, and some of the most destructive; the habits are extremely diversified : Sitophilus feeds on grain, Calandra in the stems of palms, sugar-cane, &c., Balaninus on nuts, Hylobius on the wood of pine trees, and a mul titude of other instances of peculiar habits might be cited. It must be remarked that other main groupings of Bhyncophora consider ably modify both the sequence and family position of many genera to an extent that cannot even be glanced at here. Xylophaga form a small group sometimes united with the Bhyncophora, consisting of small wood-boring beetles, in which the rostrum may be termed obsolete, and the insertion of the antenna; is close to the eyes. Some of the members of this group (of which Tomicus and Scolytus are familiar examples) are supposed to cause great damage through their larva; feeding beneath the bark of trees; but it is possible they only appear when an unhealthy condition has been set up from other causes. The Longicornia may be mainly distinguished by their elongate elegant form, long antenna;, which are generally fili form, but often pectinate, serrate, or ornamented with tufts of hair, the head not rostrate and armed with powerful jaws, the femora often clavate, and the tarsi having the basal three joints cushioned beneath. The larvae mostly feed on dead or dying timber, boring into its interior, and but seldom on living healthy wood, the females being provided with an ovipositor ; these larvae are fat, with very strong mandibles, and extremely short legs ; in some species several years elapse before they attain their full growth. The most modern classification recognizes three families, Prionidse, Cerambycidee, and Lamiidfe. The Prionidae have the sides of the prothorax margined, and usually toothed, and comprise the largest known beetles in length, even if not in bulk. (JerambyddsB have the head porrect, and the prothorax not margined ; some authors separate from these a family Lcpturidee as of equal value. Lamiidse have the head vertical. The Phytophaya form a large group of beetles feeding essentially, in all their stages, on the leaves of plants (hence the name). They are usually of short and thick form, with filiform, moniliform, or serrate (never clavate) antenna;, the head ordinarily immersed in the prothorax and without rostrum, and the elytra covering the sides of the abdomen ; the mandibles comparatively weak ; the femora often enlarged. The larvae are usually external feeders, with well-developed legs, and often very curious in form. Much diversity in the classification of Phytophaga exists, and as to the number of families and the value of their characters. By Latreille they were divided intoJSupoda (Paramcca, Westwood) and C yclicn, of which the most prominent character is in the external form, the Eupoda having the head and thorax narrower than the abdomen, whereas in the C yclica the base of the elytra is not broader than the hinder part of the thorax, hence the form is more rounded. Another grouping is according to the insertion of the antennae at the sides, or on the middle, of the front. The number of families varies from four to nine according to different authors. A glance at the prominent forms, according to later ideas, is here given. Crioccridse (by some divided into Orioceridte, Dona-