adjective
definition
Of or relating to a larva or larvae.
definition
Being a larva.
definition
Characteristic of larvae.
definition
Having the form or shape of a larva.
definition
(disease) Undeveloped, latent.
Examples of larval in a Sentence
A third form, Microfilaria diurna, is found in the larval stage in blood, but only in the daytime.
Some members of this order spend the winter in the adult state, others in the " larval " or " pupal " condition.
The parasitic and free-living Nematodes are connected by transitional forms which are free at one stage of their existence and parasitic at another; they may be divided into two classes those that are parasitic in the larval state but free when adult, and those that are free in the larval state but parasitic when adult.
Mermis (in the larval state) is confined to the Invertebrata and Sphaerularia to bees.
Although several species belonging to the second class occasionally enter the bodies of water snails and other animals before reaching their definitive host, they undergo no alteration of form in this intermediate host; the case is different, however, in Filaria medinensis and other forms, in which a free larval is followed by a parasitic existence in two distinct hosts, all the changes being accompanied by a metamorphosis.
They, however, show no periodicity, and are found continuously both by day and by night; and their larval forms are termed Microfilaria perstans.
After the second larval moult, he passes through a passive stage comparable to the pupa-stadium of an b insect, and during this stage, which occurs inside the root, the reproductive organs are perfected.
The sensory cells are slender epithelial cells, often with a cilium or stiff protoplasmic process, and should perhaps be regarded as the only ectoderm-cells which retain the primitive ciliation of the larval ectoderm, otherwise lost in all Hydrozoa.
In Cunina parasitica, however, the ovum develops into an actinula, which buds actinulae as before, but only the daughter-actinulae develop into medusae, while the original, parent-actinula dies off; here, therefore, larval budding has led to a true alternation of generations.
This must not be taken to mean, however, that the medusa is derived from a sessile polyp; it must be regarded as a direct modification of the more ancient free actinula form, without primitively any intervening polyp-stage, such as has been introduced secondarily into the development of the Leptolinae and represents 'a revival, so to speak, of an ancestral form or larval stage, which has taken on a special role in the economy of the species.
The development of the Trachomedusae, so far as it is known, shows an actinula-stage which is either free (larval) or passed over in the egg (foetal) as in Geryonia; in no case does there appear to be a free planula-stage.
The actinula, when free, may multiply by larval budding, but in all cases both the original actinula and all its descendants become converted into medusae, so that there is no alter nation of generations.
Strictly speaking, however, the term ant-lion applies to the larval form, which has been known scientifically for over two hundred years, on account of its peculiar and forbidding appearance and its skilful and unique manner of entrapping prey by means of a pitfall.
As regards growth after hatching, all beetles undergo a "complete" metamorphosis, the wing-rudiments developing beneath the cuticle throughout the larval stages, and a resting pupal stage intervening between the last larval instal1 and the imago.
Such a typically "campodeiform" grub, moving actively about in pursuit of prey, is the one extreme of larval structure to be noticed among the Coleoptera.
Whatever may be the true explanation of stridulating organs in adult beetles, sexual selection can have had nothing to do with the presence of these highly-developed larval structures.
The most interesting of the Heteromera, and perhaps of all the Coleoptera, are some beetles which pass through two or more larval forms in the course of the life-history (hypermetamorphosis).
The first larval stage is the "triungulin," a tiny, active, armoured larva with long legs (each foot with three claws) and cercopods.
After a resting (pseudo-pupal) stage and another larval stage, the pupa is developed.
This is followed by a resting (pseudo-pupal) stage, and thisby two successive larval stages like the grub of a chafer.
The wasps are said to leave the larval or pupal Metoecus unmolested, but they are hostile to the developed beetles, which hasten to leave the nest as soon as possible.
They are vegetable feeders, both in the perfect and larval stages, and are often highly injurious.
Any organism may pass through a series of free-living larval stages.
In the Cyclorrhapha on the other hand, in which the actual pupa is concealed within the hardened larval skin, the imago escapes through a circular orifice formed by pushing off or through the head end of the puparium.
To a geographical distribution of the widest extent, Diptera add a range of habits of the most diversified nature; they are both animal and vegetable feeders, an enormous number of species acting, especially in the larval state, as scavengers in consuming putrescent or decomposing matter of both kinds.
No specialized system of spermathecae, sperm reservoirs, and copulatory apparatus, as in Oligochaeta; development generally through a larval form; reproduction by budding also occurs.
It has been ascertained that the nephridia of Oligochaeta are preceded in the embryo by a pair of delicate and sinuous tubes, also found in the Hirudinea and Polychaeta, which are larval excretory organs.
The insects in the larval or wireworm stage attack the roots of plants, eating them away below the ground.
Larval " weevils " mostly feed on the roots of plants, but some, such as the nut weevil (Balaninus nucum), live as larvae inside fruit.
These two-winged insects attack all kinds of plants, and also animals in their larval stage.
Many of the adults are bloodsuckers (Tabanidae, Culicidae, &c.); others are parasitic in their larval stage (Oestridae, &c.).
Large pits are dug across the line of advance of these great insect armies to stop them when in the larval or wingless stage, and even huge bonfires are lighted to check their flight when adult.
This acts as a larval heart, but ceases to pulsate after a time.
Similar larval nephridia occur in other Gastropoda.
Enderlein and C. Bdrner (1904), and they are very evident in larval may-flies.
Sharp (1898), the marked divergence among the Hexapoda, as regards life-history, is between insects whose wings develop outside the cuticle (Exopterygota) and those whose wings develop inside the cuticle (Endopterygota), becoming visible only when the casting of the last larval cuticle reveals the pupa.
In other insects the imaginal disks are less completely disconnected from the superficies of the larval hypodermis, and may indeed be merely patches thereof.
The process of destruction of the larval tissues was first studied in the forms where metamorphosis is greatest and most abrupt, viz.
Many larval Hexapods might be defined in similar general terms, unlike as they are to their parents in most points of detail.
These differences in larval form depend in part on the surroundings among which the larva finds itself after hatching; the active, armoured grub has to seek food for itself and to fight its own battles, while the soft, defenceless maggot is provided with abundant nourishment.
Among a few of the beetles or Coleoptera, and also in the neuropterous genus Mantispa, are found life-histories in which the earliest instar is campodeiform and the succeeding larval stages eruciform.
These later stages, comprising the greater part of the larval history, are adapted for an inquiline or a parasitic life, where shelter is assured and food abundant, while the short-lived, active condition enables the newly-hatched insect to make its way to the spot favourable for its future development, clinging, for example, in the case of an oil-beetle's larva, to the hairs of a bee as she flies towards her nest.
The presence of the two successive larval forms in the life-history constitutes what is called hypermetamorphosis.
In conjunction with the association mentioned above of the most highly developed imaginal with the most degraded larval structure, it indicates clearly that the active, armoured grub preceded the sluggish soft-skinned caterpillar or maggot in the evolution of the Hexapoda.
After a prolonged aquatic larval and nymphal life-history, the winged insect appears as a sub-imago, whence, after the casting of a delicate cuticle, the true imago emerges.
In the metabolic Hexapoda the resting pupal instar shows externally the wings and other characteristic imaginal organs which have been gradually elaborated beneath the larval cuticle.
Generally the larval is the feeding, the imaginal the breeding, stage of the life-cycle.
Thus a mass or chain of embryos is produced, lying in a common cyst, and developing as their larval host develops.
Young animals always unlike parents, the wing-rudiments developing beneath the larval cuticle and only appearing in a penultimate pupal instar, which takes no food and is usually passive.
Pupa incompletely obtect or free, and enclosed in the hardened cuticle of the last larval instar (puparium).