Some species of which of the above kinds of organisms are employed as bio-pesticides?
Correct Answer:
(D)
1, 2 and 3
Biopesticides fall into three major classes: Microbial pesticides consist of a microorganism (e.g., a bacterium, fungus, virus or protozoan) as the active ingredient. Microbial pesticides can control many different kinds of pests, although each separate active ingredient is relatively specific for its target pests. For example, there are fungi that control certain weeds and other fungi that kill specific insects. Neem is the best example as biopesticide among flowering plants.
Ques:
17
Which one of the following is a microbial insecticide?
Correct Answer:
(A)
Bacillus thuringiensis
Bacillus thuringiensis (Bt) is a Gram-positive, soil-dwelling bacterium which naturally produces a toxin that is fatal to certain herbivorous insects. The toxin produced by B. thuringiensis has been used as an insecticide spray since 1920 and is commonly used in organic farming. Bt is also the source of the genes used to genetically modify a number of food crops so that they produce toxin on their own to deter various insects or pests. The toxin is lethal to several orders of insects, including Lepidoptera (butterflies, moths and skippers); Diptera (flies) and Coleoptera (beetles).