(n.) Any young insect from the time that it hatches from the egg until it becomes a pupa, or chrysalis. During this time it usually molts several times, and may change its form or color each time. The larvae of many insects are much like the adults in form and habits, but have no trace of wings, the rudimentary wings appearing only in the pupa stage. In other groups of insects the larvae are totally unlike the parents in structure and habits, and are called caterpillars, grubs, maggots, etc.
(n.) The early, immature form of any animal when more or less of a metamorphosis takes place, before the assumption of the mature shape.
Example Sentences:
(1) Larvae from fresh water eggs, cultured in fresh water and 'normal' laboratory cultures reached 50% infectivity in 3-5 days, losing potential infectivity in 11-15 days post-hatching.
(2) After treatment of larvae of instar 1 at preimago stages about 77% of the insects died.
(3) A total of 3,532 females of various engorged weights was collected from all calves, resulting in a mean female tick yield of 1.78% based on the number of larvae used for all infestations.
(4) Similar concentrations of free ecdysteroids were recorded in adults and larvae, although the two life cycle stages differed in their ratio of ecdysone: 20-hydroxyecdysone.
(5) Larvae of both mutants also excrete 3H-3-hydroxykynurenine and 3H-kynurenine rapidly, which probably accounts for the normal levels of kynurenine during larval life.
(6) Guinea pigs exposed to 200 and 400 H. truncatum larvae elicited the greatest change in feeding efficiency during the fourth infestation.
(7) In cultures of medium ML-15 containing a feeder layer of Dog Sarcoma (DS) cells larvae successfully moulted and showed a small but significant increase in length.
(8) The test is based on the ability of larvae to freely migrate through selected mesh sizes of nylon sieves and the reduced ability of larvae to migrate after preincubation with, and in the presence of, substances that inhibit or reduce larval motility.
(9) This study provides evidence for a maternal yolk factor associated with increased tolerance and resistance of larvae to copper.
(10) Human activity not only increases risk, but influences control by killing mosquito larvae, killing adult mosquitos or preventing mosquitos from feeding.
(11) Infected ticks were reared from larvae feeding on each of 11 rabbits taken from the same site.
(12) Histopathology examination from the margin of the ulcerative area confirmed the diagnosis of basal cell carcinoma, which was infested secondarily with larvae of flies.
(13) Tolypocladium tundrense and T. terricola UV-irradiated conidia exhibited acute toxicity to Aedes aegypti larvae in concentrations of 5 x 10(5) and 5 x 10(6) ml-1, respectively.
(14) These products, as well as several synthetic intermediates, were evaluated for antifilarial activity against Molinema dessetae either in vivo in its natural host, the rodent Proechimys oris, or in vitro by a new test using cultures of the infective larvae.
(15) However, mosquitoes infected with more than 4 larvae became more active than uninfected mosquitoes 8 days after infection.
(16) Metabolism of carbaryl by the fat body is affected by the age of the larva, the pH of the incubation medium, and the concentration of magnesium chloride in the incubation medium.
(17) The mutant larvae are apparently normal, but they harbor serious defects in the organs containing proliferating cells of both somatic and germ line origins.
(18) Changes in haemolymph juvenile hormone (JH) concentrations of larvae of the southwestern corn borer, Diatraea grandiosella, were used to estimate the activity of the corpora allata.
(19) Statistical analysis has shown the following: a) the growth inhibition, which is especially distinct in autumn-spring generation, takes place in the Ist instar larvae 1.76-2.20 mm long inhabiting the walls of the nasal cavity and concha (their average body length at hatching is 1.08 plus or minus 0.004 mm); the inhibition is associated with interpopulation relations and apparently does not depend on the date of its beginning and can last from 6 to 7 months; c) after the growth resumption the development continues uninterruptedly up to the moulting; the inhibition is also possible at the beginning of the 2nd instar and then the development proceeds without any intervals up to the complete maturation of larvae.
(20) It is present throughout development and is as abundant in embryos as in larvae and adult flies.
Planula
Definition:
(n.) In embryonic development, a vesicle filled with fluid, formed from the morula by the divergence of its cells in such a manner as to give rise to a central space, around which the cells arrange themselves as an envelope; an embryonic form intermediate between the morula and gastrula. Sometimes used as synonymous with gastrula.
(n.) The very young, free-swimming larva of the coelenterates. It usually has a flattened oval or oblong form, and is entirely covered with cilia.
Example Sentences:
(1) Adult specimens of Astrangia danae (Agassiz) and settled planulae of Porites porites (Pallas) contain crystals averaging 0.7 mu by 0.1 mu by 0.3 mu within Golgi-derived vesicles.
(2) Planulae processed with the SPG histofluorescence technique, specific only for catecholamines, exhibited blue-green fluorophores which were most prominent in the anterior ectoderm.
(3) Exposure of planulae to exogenous norepinephrine caused premature, rapid metamorphosis and produced polyps with slightly stunted tentacles and pitted, irregular hypostomes.
(4) Exposure of planulae to nicotine caused similar effects.
(5) RFamide antiserum bound a subset of ganglionic cells in the anterior and upper middle regions of the planula and a few ganglionic cells in the upper tail region.
(6) During gastrulation, the cnidocytes are Incorporated intO the ectoderm and become an integral part of the planula.
(7) Pretreatment of planulae with neuropharmacological agents which prevent reuptake (reserpine) or cause release (nicotine, ephedrine) of catecholamines caused a diminution of the fluorophores.
(8) The early embryonic development of Hydractinia lasts about 2.5 days until the developing planula larva acquires competence for metamorphosis.
(9) Using the same technique the reappearance of RFamide-positive ganglionic cells in epithelial tissue of chimeric grafts of planulae was observed.
(10) However, planulae raised in sea water containing propranolol, a beta blocker, ceased all movement, became tack-shaped and died within 72 h. These results meet multiple criteria for the identification of catecholamines in hydrozoan planulae and suggest that such catecholamines may function as neurotransmitters, neurohormones or neuromodulators during larval development.
(11) Ultrastructural examination of reserpine-treated planulae revealed a dramatic reduction in the populations of dense-cored vesicles and electron-dense droplets.
(12) Rearing planulae in sea water containing alpha blockers, phentolamine and tolazoline, had no discernible effect on behaviour (motility, phototactic response) or gross morphology.
(13) Planula larvae of Halocordyle disticha were examined for the presence of catecholamines using a multipronged approach.
(14) In non-metamorphosing planula larvae, PAF triggered the differentiation of nerve cells that normally develop only upon initiation of metamorphosis and that occur in the polyp stage.
(15) Stained repopulated ganglionic cells always formed in the same position in the epithelial tissue as was observed in control planulae suggesting that the expression of RFamide-like substances may be position dependent in the planula.
(16) A suggestion is put forward that at the final phase of larval development a special RNA is synthesized which participates in the genetically determined control of the complicated morphogenetic phenomenon of attachment and transformation of the planula in polyp.