The footless larvae are elongate, worm-like and very active; they feed upon almost any kind of waste animal matter, and when full-grown form a silken cocoon.
The oak in Europe is liable to injury from a great variety of insect enemies: the young wood is attacked by the larvae of the small stag-beetle and several other Coleoptera, and those of the wood-leopard moth, goat moth and other Lepidoptera feed upon it occasionally; the foliage is devoured by innumerable larvae; indeed, it has been stated that half the plant-eating insects of England prey more or less upon the oak, and in some seasons it is difficult to find a leaf perfectly free from their depredations.
The ground and the young larvae make their way into grasshoppers, in whose bodies they pass most of their larval life.
Manson showed in 1881 that the larvae (Microfilariae) were not at all times present in the blood, but that their appearance had a certain periodicity, and the larvae of F.
Ten years later Manson discovered a second species, Filaria perstans, whose larvae live in the blood.
Next the larvae make their way into the connective tissue in the pro-thorax, and ultimately bore a channel into the base of the piercing apparatus and come to rest between the hypopharynx and the labium.
From their position in the proboscis the larvae can easily enter the blood of man the next time the mosquito bites (Low, Brit.
Shortly after Low had published his results, Grassi and Noe issued a paper dealing with the larvae of F.
A paper by Noe (Atti Acc. Lincei, ix., 1900) seems to prove beyond doubt that the larvae of F.
The females produce thousands of larvae, which circulate in the blood, and show a certain periodicity in their appearance, being much more numerous in the blood at night than during the day.
The young larvae, nourished by the yolk xIx.
It is of nocturnal and burrowing habits, and feeds on decomposed animal substances, larvae and termites.
P. alba suffers much from the ravages of wood-eating larvae, and also from fungoid growths, especially where the branches have been removed by pruning or accident.
In the Aglossal Xenopus, the tadpoles are likewise devoid of circular lip, horny teeth, and beak, and they are further remarkable in the following respects: There is a long tentacle or barbel on each side of the mouth, which appears to represent the "balancer" of Urodele larvae; the spiraculum is paired, one on each side; the fore limbs develop externally, like the hind limbs.
Many larvae of beetles, moths, &c., bore into bark, and injure the cambium, or even the wood and pith; in addition to direct injury, the interference with the transpiration current and the access of other parasites through the wounds are also to be feared in proportion to the numbers of insects at work.
Various local hypertrophies, including galls, result from the increased growth of young tissues irritated by the punctures of insects, or by the presence of eggs or larvae left behind.
The dace feeds on worms, insects, insect-larvae, and also on vegetable matter.
In the case of certain beetles whose larvae do not find themselves amid appropriate food from the moment of hatching, but have to migrate in search of it, an early larval stage, with legs, is followed by later sluggish stages in which legs have disappeared, furnishing examples of what is called hypermetamorphosis.
The distribution of many groups of beetles is restricted in correspondence with their habits; the Cerambycidae (longhorns), whose larvae are wood-borers, are absent from timberless regions, and most abundant in the great tropical forests.
Some of the scavengers, like the burying beetles, inter the bodies of small vertebrates to supply food for themselves and their larvae, or, like the "sacred" beetle of Egypt, collect for the same purpose stores of dung.
Stridulating organs among beetle-larvae have been noted, especially in the wood-feeding grub of the stag-beetles (Lucanidae) and their allies the Passalidae, and in the dung-eating grubs of the dor-beetles (Geotrupes), which belong to the chafer family (Scarabaeidae).
The root-feeding larvae of the cockchafer and allied members of the Scarabaeidae have a ridged area on the mandible, which is scraped by teeth on the maxillae, apparently forming a stridulating organ.
The eggs and larvae of the fire-flies are luminous as well as the perfect beetles.
Macleay's classification (1825), which rested principally on the characters of the larvae, is almost forgotten nowadays, but it is certain that in any systematic arrangement which claims to be natural the early stages in the life-history must receive due attention.
Ganglbauer (1892) divides the whole order into two sub-orders only, the Caraboidea (the Adephaga of Sharp and the older writers) and the Cantharidoidea (including all other beetles), since the larvae of Caraboidea have five-segmented, two-clawed legs, while those of all other beetles have legs with four segments and a single claw.
Kolbe, on the other hand, insists that the weevils are the most modified of all beetles, being highly specialized as regards their adult structure, and developing from legless maggots exceedingly different from the adult; he regards the Adephaga, with their active armoured larvae with two foot-claws, as the most primitive group of beetles, and there can be little doubt that the likeness between larvae and adult may safely be accepted as a primitive character among insects.
The larvae (fig.
Two very small families of aquatic beetles seem to stand at the base of the series, the Amphizoidae, whose larvae are broad and well armoured with FIG.
Short cerci, and the Pelobiidae, which have elongate larvae, tapering to the tail end, where are long paired cerci and a median process, recalling the grub of a Mayfly.
2 b) possess slender, curved, hollow mandibles, which are perforated at the tip and at the base, being thus adapted for sucking the juices of victims. Large dyticid larvae often attack small fishes and tadpoles.
Mandibles being well adapted for the capture of small insect-victims. The larvae are more specialized than those of other Adephaga, the head and prothorax being very large and broad, the succeeding segments slender and incompletely chitinized.
The larvae that live underground have spiny dorsal plates, while those of the Silpha (fig.
The Staph y linid larvae are typically campodeiform.
Beetles and larvae are frequently carnivorous in habit, hunting for small insects under stones, or pursuing the soft-skinned grubs of beetles and flies that bore in woody stems or succulent roots.
The beetles are hairy and their larvae well-armoured and often predaceous.
According to Sharp, all Dermestid larvae probably feed on dried animal matters; he mentions one species that can find sufficient food in the horsehair of furniture, and another that eats the dried insect-skins hanging in old cobwebs.
The larvae are elongate and worm-like, with short legs but often with hard strong cuticle.
The larvae of Elateridae are elongate, worm-like grubs, with narrow bodies, very firm cuticle, short legs, and a distinct anal proleg.
Several of the elaterid larvae, however, gnaw roots and are highly destructive to farm crops.
The larvae are remarkable for their small head, very broad thorax, with reduced legs, and narrow elongate abdomen.
The larvae are stout and soft-skinned, with short legs in correlation with their burrowing habit.
The larvae in this family are well-armoured, active and predaceous.
In the European species of Sitaris and Meloe these little larvae have the instinct of clinging to any hairy object.
The larvae are furnished with large heads, powerful mandibles and well-developed legs, but the body-segments are feebly chitinized, and the tail-end is swollen.
The larvae of Lucanidae live within the wood of trees, and may take three or four years to attain their full growth.
The larvae have the three pairs of legs well developed, and the hinder abdominal segments swollen.
Such larvae, and also many with soft cuticle and swollen abdomen - those of the notorious "Colorado beetle," for example - feed openly FIG.
The larvae of the beautiful, elongate, metallic Donaciae live in the roots and stems of aquatic plants, obtaining thence both food and air.
The larvae have soft, white bodies and, with very few exceptions, no legs.
Metamorphosis in Diptera is complete; the larvae are utterly different from the perfect insects in appearance, and, although varying greatly in outward form, are usually footless grubs; those of the Muscidae are generally known as maggots.