Agricultural Entomology - Study Mode

[#171] Jowar stem borer causes dead heart in early stage of crop, redning of sorghum midribs and holes on the whorl of newly opened leaves belongs to family
Correct Answer

(D) Crambidae

Explanation

Solution: Jowar stem borer causes dead heart in the early stage of crop, redning of sorghum midribs and holes on the whorl of newly opened leaves belonging to family Crambidae. Jowar stem borer is one of the major pests of Jowar and has a wide distribution. The infestation is noticed till harvest and the grown-up plants when damaged lose their vigour and put forth week ears. The Crambidae is the grass moth family of lepidopterans. They are variable in appearance, the nominal subfamily Crambinae taking up closely folded postures on grass stems where they are inconspicuous, while other subfamilies include brightly coloured and patterned insects which rest in wing-spread attitudes.

[#172] Red cotton bug lay its egg on/in
Correct Answer

(C) Soil

Explanation

Solution: Red cotton bug lay its egg in Soil. Eggs are laid in the soil near the plants. Lays round eggs on the apical portion of the undersurface of leaves in clusters of 13 - 42 eggs. Larvae emerge from eggs after 3 - 6 days. Feed on leaves for 16 - 20 days. Adults emerge within 15 - 20 days. The incubation period is 7 days and nymphs become adults in 49 - 90 days. Nymphs and adults suck the sap from tender parts of plants like leaves, petioles and shoots in early stages.

[#173] Grubs which feed on the inner content of seed in pulses belongs to
Correct Answer

(B) Callosobruchus chinesis

Explanation

Solution: Grubs which feed on the inner content of seed in pulses belong to Callosobruchus chinesis. Callosobruchus chinensis is a common species of beetle found in the bean weevil subfamily and is known to be a pest to many stored legumes. Other common names include the pulse beetle, Chinese bruchid and cowpea bruchid. Grubs are the larval or immature form of certain beetle species. These C-shaped critters are white and wrinkly.

[#174] The insecticide which is used in mosquito mats is
Correct Answer

(D) Allethrin

Explanation

Solution: The insecticide which is used in mosquito mats is Allethrin. Allethrin is pyrethroids used almost exclusively to control flying and crawling insects in homes and industrial locations. Used extensively in pet animal shampoos, to treat lice in humans and home and industrial sprays for flying insects, mosquitos, etc. These insecticides have been shown to pose very low health risks to humans and other mammals, but are toxic to insects and kill them.

[#175] Which of the following chemical is used for differentiating between live and dead nematodes?
Correct Answer

(D) New Blue R

Explanation

Solution: New Blue R chemical is used for differentiating between live and dead nematodes. New Blue R and, in some respects better than Chrysoidin as stains for distinguishing dead from living nematodes regardless of whether the dead nematodes had been killed by lethal amounts of heat, cold, dryness or by certain nematicides. For nematode ecological work, and in control programmes involving the use of nematicides or hot-water treatment of plant materials, it is often important to know when a nematode is dead.