Animals wood-boring

Lindane is used predominately as a seed dressing and soil insecticide, for the control of ectoparasites of humans and domestic animals, for the control of locusts and grasshoppers, and as a residual spray to control the Anopheles vectors of malaria. Because of its relatively high volatility it is useful to control wood-boring insects of timber, fmit trees, and ornamental plants. The mode of action is not well understood but is thought to be competitive blocking of the y-aminobutyric acid (GABA) transmitter of synaptic nerve transmission. 

The first commercially available HCH insecticide sometimes misleadingly called benzene hexachloride (BHC) was a mixture of isomers, principally alpha HCH (65-70%), beta HCH (7-10%), and gamma HCH (14-15%). Most of the insecticidal activity was due to the gamma isomer (Figure 5.1), a purified preparation of which (>99% pure) was marketed as lindane. In Western countries, technical HCH was quickly replaced by lindane, but in some other countries (e.g., China) the technical product, which is cheaper and easier to produce, has continued to be used. HCH has been used as a seed dressing, a crop spray, and a dip to control ectoparasites of farm animals. It has also been used to treat timber against wood-boring insects. 

WOOD PRESERVATIVE. A material applied to wood to prevent its destruction by fungi, wood-boring insects, marine borers and fire. A common characteristic of these materials is toxicity to those organisms that attack wood, or in the case of fire retardants the ability to control combustion in terms defined by the Underwriters Laboratory. In addition, a satisfactory wood preservative must aiso (a) be capable of penetrating wood, (bi remain in the wood for extended periods withonl losing its effectiveness due to chemical breakdown, (c) be harmless to humans and animals, (d) be noncorrosive and. (e) be available in quantity at a reasonable cost, Foi certain uses, the preservative may be required to be colorless, odorless, nonswellmg and paintable. 

The marine environment presents a hostile and seemingly unlikely situation for the survival of archaeological wood, yet it does survive. Normally, wood does not survive long enough in marine environments to enter the archaeological record because of the activities of wood-boring animals and aerobic microbes. However, studies have shown that rapid burial in the anoxic sediments of the seabed will protect ships timbers and wooden artefacts from the physical, chemical and biological processes that influence the deterioration of exposed wood. 

The natural degradation of wooden shipwrecks in-situ can be slowed down, or even eliminated, by covering the site with a physical barrier such as polyethylene or polypropylene textile (Figure 15). This method is very effective because it uses the wrecked environment to create an overlying mound of sediment, which becomes part of the site. It also physically prevents colonisation of any subsequently exposed wreck timbers by wood-boring animals, like shipworm. 

In circumstances in which wood is exposed in a marine environment, attack by marine organisms, such as fungi, bacteria and marine boring animals, can occur. Of these, the marine boring organisms (molluscs and crustaceans) are responsible for most of the damage. There is relatively little literature on this subject in connection with modified wood. 

Nitrogen fixation has also been reported from marine shipworms. Shipworms are bivalves, which live attached to wooden ships, in which they bore holes, and thus have a diet of wood alone. Cellulose is the principal component of wood, and is indigestible to animals. Certain bacterial species, however, contain the necessary enzymes to break down cellulose, and shipworms are often reported with gut associated bacterial symbionts. 

In addition to the cactophilic habitat, there are at least three other yeast habitats where dispersal is primarily by animal vector wood, flowers and sap (slime) fluxes. The potential diversity of yeast associated with beetles that bore in wood is high (Suh et al., 2005) and there is evidence that the beetles are the means of dispersal (Ganter, 2006). However, neither the biogeography of yeast from this habitat nor genetic... 

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