Pesticide Resistance Essay

sucking lo drill advance is a serious agricultural problem leading to yield losses and reduced product quality. Insects can cause damage both in the field and during storage in silos. Each year, insects destroy about 25 percent of food crops worldwide. The larvae of Ostrinia nubilalis, the European corn stone drill, can destroy up to 20 percent of a maize crop.European corn borerA major gadfly in southern and central Europe. Insect resistant Bt maize is already being grown in Spain, France, Germany, Portugal and the Czechoslovakian Republic. Western corn rootworm beetles feeding on a maize cob. veritable cultivars of Bt maize atomic number 18 resistant to this serious pest. GM rootworm resistant crops are not approved for cultivation in the European Union and are promptly being grown in the US.The Bt concept pest resistant transgenic plantsBacillus thuringiensis, or Bt, is a bacterium that has attracted much attention for its use in pest adjudge. The defect bacterium pr oduces a protein that is deadly to assorted herbivorous insects. The protein, known asBt toxin, is produced in an inactive, crystalline form.When consumed by insects, the protein is converted to its active, toxic form (delta endotoxin), which in turn destroys the gut of the insect. Bt preparations are commonly utilise in organic agriculture to control insects, as Bt toxin occurs naturally and is totally safe for humans.More than 100 different variations of Bt toxin have been identified in diverse strains ofBacillus thuringiensis. The different variations have different target insect particularity.For example, the toxins classified infra Cry1a group target Lepidoptera (butterflies), while toxins in the Cry3 group are potent against beetles.Researchers have used genetic engineering to take the bacterial genes require to produce Bt toxins and introduce them into plants. If plants produce Bt toxin on their own, they can defend themselves against specific types of insects. This means farmers no longer have to use chemical insecticides to control certain insect problems. Critics claim that in some cases the use of insect resistant crops can harm beneficial insects and other non-target organisms. Extensive ecologic impact assessments have been addressing these issues. In the field, no significant adverse effect on non-target wildlife nor long term effects of higher Bt concentrations in soil have yet been observed.New concepts on the wayBt crops have been deep-rooted commercially for more than eight years. Other naturally occuring insecticidal compounds are now becoming available as alternatives to the Bt approach. Among these are chitinase, lectins, alpha-amylase inhibitors, proteinase inhibitors, and cystatin. Plants genetically limited to express these defense proteins are still in early stages of development.