Pest (organism)
Some animals are disliked because they bite or sting; wolves, snakes, wasps, ants, bed bugs, fleas and ticks belong in this category.
Others enter the home; these include houseflies, which land on and contaminate food; beetles, which tunnel into the woodwork; and other animals that scuttle about on the floor at night, like rats and cockroaches, which are often associated with unsanitary conditions.
Agricultural and horticultural crops are attacked by a wide variety of pests, the most important being rodents, insects, mites, nematodes and gastropod molluscs.
The damage they do results both from the direct injury they cause to the plants and from the indirect consequences of the fungal, bacterial or viral infections they transmit.
The pests affecting trees are predominantly insects, and many of these have also been introduced inadvertently and lack natural enemies, and some have transmitted novel fungal diseases with devastating results.
Grasshoppers are usually solitary herbivores of little economic importance until the conditions are met for them to enter a swarming phase, become locusts and cause enormous damage.
[7] Jellyfish can form vast swarms which may be responsible for damage to fishing gear, and sometimes clog the cooling systems of power and desalination plants which draw their water from the sea.
"[12] An example of such a plant prescribed under this regulation is caltrop, Tribulus terrestris, which can cause poisoning in sheep and goats, but is mainly a nuisance around buildings, roadsides and recreation areas because of its uncomfortably sharp spiny burrs.
Macaranga triloba for example has adapted its thin-walled stems to create ideal housing for an ant Crematogaster spp., which, in turn, protects the plant from herbivores.
[18] Similarly, several Acacia tree species have developed stout spines that are swollen at the base, forming a hollow structure that provides housing for ants which protect the plant.
Vast numbers of nematodes are found in soil and attack roots, but others affect stems, buds, leaves, flowers and fruits.
[35] The nematode eggs survive in the soil for many years, being stimulated to hatch by chemical cues produced by roots of susceptible plants.
[36] Slugs and snails are terrestrial gastropod molluscs which typically chew leaves, stems, flowers, fruit and vegetable debris.
[37] Terrestrial molluscs need moist environments; snails may be more noticeable because their shells provide protection from desiccation, while most slugs live in soil and only come out to feed at night.
They devour seedlings, damage developing shoots and feed on salad crops and cabbages, and some species tunnel into potatoes and other tubers.
The larch sawfly and spruce budworm are two insect pests prevalent in Alaska and aerial surveys can show which sections of forest are being defoliated in any given year so that appropriate remedial action can be taken.
The larvae of wood-boring beetles, for example, are notorious for spending years excavating tunnels under the bark of trees, leading to significant structural damage.
An insect may be of little importance in its native range, being kept under control by parasitoid wasps, predators, and the natural resistance of the host trees, but be a serious pest in a region into which it has been introduced.
[46] Another example of a beetle species that exhibits pest behavior are Melolontha Hippocastrani, that cause severe, long-term damage on young trees by feeding on roots.
[47] Animals able to live in the dry conditions found in buildings include many arthropods such as beetles, cockroaches, moths, mites, and silverfish.
They may be introduced to the home in any product containing animal fibres including upholstered furniture; the moths are feeble fliers but the carpet beetles may also enter houses through open windows.
Constant vigilance is required to prevent an attack, and newly acquired items, and those that have been out on loan, may need quarantining before being added to the general collection.
The insects may be present in the warehouse or maybe introduced during shipping, in retail outlets, or in the home; they may enter packets through tiny cracks or may chew holes in the packaging.
The phylloxera (a powdery mildew) damage to the wine industry in the 19th century resulted in the development of resistant varieties and grafting, and the accidental discovery of effective chemical pesticides, Bordeaux mixture (lime and copper sulphate) and Paris Green (an arsenic compound), both very widely used.
Biological control also became established as an effective measure in the second half of the 19th century, starting with the vedalia beetle against cottony cushion scale.
Cultural measures include choosing appropriate species, keeping competing vegetation under control, ensuring a suitable stocking density, and minimizing injury and stress to trees.
Methods include improving sanitation and garbage control, modifying the habitat, and using repellents, growth regulators, traps, baits and pesticides.
[62] Clothes moths can be controlled with airtight containers for storage, periodic laundering of garments, trapping, freezing, heating and the use of chemicals.
For example, the 10th century Greek monk Tryphon of Constantinople is said to have prayed "Snails, earwigs and all other creatures, hurt not the vines, nor the land nor the fruit of the trees, nor the vegetables ... but depart into the wild mountains.
[68] The 20th century "prayer against pests" including the words "By Your power may these injurious animals be driven off so that they will do no harm to any one and will leave our fields and meadows unharmed" was printed in the 1956 Rural Life Prayerbook.
