Pesticide - Research Paper Example

The term pest includes insects, weeds, mammals, and microbes, among others” (Tadeo 2). They are categorized based on the pest that they destroy. For example, herbicides kill eradicate weeds and other plants growing in places where they are unwanted, insecticides destroy insects and other anthropods and fungicides are used to kill fungi (Atterholt). Other types of pesticides are acaricides, molluscicides, nematicides, pheromones, plant growth regulators, repellants, and rodenticides (Tadeo 2).

Pesticides are usually chemical substances, although they can be sometimes biological agents such as virus or bacteria. “They may be derived from natural sources such as pyrethrin insecticide extracted from certain chrysanthemum plants. Another example is azadirachtin, an extract from the neem tree” (“ natural and synthetic”). Pesticides are also made from artificial (synthetic) sources such as pyrethriods, which is an insecticide. Herbicides can be further classified as soil- or foliage-applied compounds which are normally absorbed by roots or leaf tissues, respectively.

These compounds can be total or selective herbicides. Total herbicides can kill all vegetation, whereas selective herbicides can control weeds without affecting the crop (Tadeo 4). Insecticide Pyrethrum, the dried flower of Chrysanthemum cinerariaefolium, or its solvent extract, has been used for centuries in order to kill insects. The plant, is originally native to the Near East (Adriska 24). The active substances of pyrethrum are pyrethrin I , pyrethrin II, Cinerin I, cinerin II, the 3-but-2-enyl analogues, as well as jasmolin I and jasmolin II, the 3-pentyl-2-enyl analogues of the pyrethrins.

When an insect is intoxicated with pyrethroids, it quickly develops hyperexcitation and tremors, which are followed by paralysis. These symptoms of poisoning imply that pyrethriods act primarily on the neuromuscular system (Narahashi 337). The highly lipophilic nature of the synthetic pyrethoids