Larva

In cases where zooplankton are reared as a food for predatory larvae or fry, it may be necessary to maintain three cultures. Though wild zooplankton have been used successfully in some instances (eg, in Norway wild zooplankton have been collected and fed to larval Pacific haUbut), the normal process involves culturing algae to feed to zooplankton that are fed to a young shrimp or fish. 

Fibers (see Fibers, survey) used in textile production can have a wide variety of origins plants, ie, ceUulosic fibers (see Fibers, cellulose esters) animals, ie, protein fibers (see Wool) and, in the twentieth century, synthetic polymers. Depending on the part of the plant, the ceUulosic fibers can be classified as seed fibers, eg, cotton (qv), kapok bast fibers, eg, linen from flax, hemp, jute and leaf fibers, eg, agave. Protein fibers include wool and hair fibers from a large variety of mammals, eg, sheep, goats, camels, rabbits, etc, and the cocoon material of insect larvae (sUk). Real sUk is derived from the cocoon of the silkworm, Bombjx mori and for a long time was only produced in China, from which it was traded widely as a highly valuable material. 

Other substituted phenyl A/-methylcarbamates that have been used for insect control include metalkamate [8065-36-9] a 1 4 mixture of y -(l-ethylpropyl)-phenyl A[-methylcarbamate [672-04-8] and y -(l-methylbutyl)-phenyl A/-methylcarbamate [2282-34-0], rat oral LD qS 87, 170 mg/kg, used as a soil insecticide MTMC [1129-41 -5], 3-methylphenyl N-methylcarbamate (mp 76°C), rat oral LD q 268 mg/kg, used for rice pests MPMC [2425-10-7], 3,5-dimethylphenyl A/-methylcarbamate (mp 79°C), rat oral LD q 380 mg/kg, used for rice pests TBPMC [780-11-0], 3-/ l -butylphenyl A/-methylcarbamate (mp 140°C), mouse oral LD q 470 mg/kg, for rice pests and butacarb [2655-19-8], 3,5-di-/ l -butylphenyl A/-methylcarbamate (mp 98°C), rat oral LD q >4000 mg/kg, for sheep blowfly larvae control. 

Bacillus popilliae Bacteria Japanese beetle larvae in soil... 

Bacillus thuringiensis ai wa diamond back larvae, wax moth... 

Bacillus thuringiensis israelensis mosquito and black fly larvae... 

Sediment Toxicity. Because of their low solubiUty ia water and lipophilic nature, phthalates tend to be found ia sediments. Unfortunately httle work has previously been carried out on the toxicity of phthalates to sediment dwelling organisms. Eor this reason ECPI has commissioned some sediment toxicity studies designed to measure the effect of DEHP and DIDP ia a natural river sediment on the emergence of the larvae of the midge, Chironomus riparius. 

Insect Cells. In this system the cDNA is inserted into the genome of an insect vims, baculovims. Insect cells, or Hve insect larvae, are then infected with the vims. In this way advantage is taken of the vims s natural machinery for repHcation utilizing the insect cell. This is one of the best systems available for high level production of native protein having post-translational modifications similar to those seen in mammalian cells. Disadvantages of this system include lytic—batch variations, comparatively slow growth, and cosdy scale-up. 

Carbon disulfide (qv) is used, in combination with other orally administered anthelmintics, by stomach tube for hots Gastrophilus sp. larvae) and ascarids (roundworms) of horses. 

Wool, as a keratin, is a highly cross-linked, insoluble proteinaceous fiber, and few animals have developed the specialized digestive systems that aUow them to derive nutrition from the potential protein resource. In nature, these few keratin-digesting animals, principally the larvae of clothes moths and carpet beetles, perform a useful function in scavenging the keratinous parts of dead animals and animal debris (fur, skin, beak, claw, feathers) that ate inaccessible to other animals. It is only when these keratin-digesting animals attack processed wool goods that they are classified as pests. Very often they enter domestic or industrial huildings from natural habitats such as birds nests. 

Minte2ol, soluble in ethanol cutaneous larva migrans. ... 

Both the adult and the larval cysticerci (bladderworm) of Taenia solium (pork tapeworm) are able to Hve in humans the parasite is found sporadically in uncooked pork. In the stomach, the larva is digested out of the pork flesh it then grows and attaches to the wall of the small intestine. Maturity is reached in 5—12 weeks. The adult is 5 m long, and untreated adult worms may survive for 25 years. 

The filariform larva found in moist soils may be either ingested or penetrate the skin of its host. It is then carried through the circulatory system to the lungs and migrates up the respiratory tree into the digestive tract. The worms feed on intestinal tissue and blood. Some worms may persist in humans as long as nine years. Infestations cause cutaneous reactions, pulmonary lesions, intestinal ulcerations, and anemia. 

Trichinosis is the condition caused by the adult worm of T. spiralis which is between 1 and 2 mm long. The cysts are found in contaminated meat, primarily pork. When ingested, cysts release immature larvae, which invade the intestinal lining and develop into adult worms. Mature worms mate in the... 

Malaria affects an estimated 270 million people and causes 2—3 million deaths annually, approximately one million of which occur in children under the age of five. While primarily an affliction of the tropics and subtropics, it has occurred as far north as the Arctic Circle. The disease essentially has been eradicated in most temperate-zone countries, but some 1100 cases of malaria in U.S. citizens returning from abroad were reported to the Centers for Disease Control during 1990. Malaria is seen today in Southeast Asia, Africa, and Central and South America. It is on the increase in Afghanistan, Brazil, China, India, Mexico, the Philippines, Sri Lanka, Thailand, and Vietnam. Escalation of the disease is because of the discontinued use of the insecticide DDT which effectively kills mosquito larvae, but has been found to be toxic to Hvestock and wildlife. Also, chloroquine (6), a reUable dmg for the prophylaxis and treatment of falcipamm malaria, is ineffective in many parts of the world because of the spread of dmg-resistant strains. 

---