Agricultural Entomology - Study Mode
[#306] The pest management should be done at
Correct Answer
(B) Economic threshold level
Explanation
Solution: Pest management should be done at the Economic threshold level. An economic threshold is the insect's population level or extent of crop damage at which the value of the crop destroyed exceeds the cost of controlling the pest. The pest density at which management action should be taken to prevent an increasing pest population from reaching the economic injury level. EILs are usually expressed as a pest density and are developed from yield-loss relationships.
[#307] Which of the following pair is not correct
Correct Answer
(D) Italian bee - Melipona irridipennis
Explanation
Solution: A. Little bee - Apis florea Apis florea is unique for its morphology, foraging behavior and defensive mechanisms like making a piping noise. Apis florea has open nests and small colonies, which makes them more susceptible to predation than cavity nesters with large numbers of defensive workers. B. Indian bee - Apis cerana indica Apis cerana indica, the Indian honey bee, is a subspecies of Asiatic honey bee. They usually build multiple combed nests in tree hollows and man-made structures. These bees can adapt to living in purpose-made hives and cavities. C. Giant or rock bee - Apis dorsata Giant honey bees are the largest of the honey bee species. The Giant honey bee (Apis dorsata) is very large (17 - 20 mm long) however its colour is quite similar to the European honey bee, with golden, black and pale bands on the abdomen and a hairy thorax. D. Italian bee - Melipona irridipennis is not correctly matched. Apis mellifera ligustica is the Italian bee. The Italian honey bee is endemic to the continental part of Italy, south of the Alps, and north of Sicily.
[#308] Total numbers of cephalic neuromeres are
Correct Answer
(D) 6
Explanation
Solution: Total numbers of cephalic neuromeres are 6. Neuromeres can be defined as morphologically identifiable transverse subdivisions perpendicular to the longitudinal axis of the embryonic brain and extending onto both sides of the body. The rostral end of the neural tube forms amesencephalic neuromere and probably six forebrain neuromeres.
[#309] Which is known as water moth?
Correct Answer
(D) Trichoptera
Explanation
Solution: Trichoptera is known as water moth. The caddisflies, or order Trichoptera, are a group of insects with aquatic larvae and terrestrial adults. There are approximately 14,500 described species, most of which can be divided into the suborders Integripalpia and Annulipalpia based on the adult mouthparts. Trichoptera, or caddisflies, are an order of aquatic insects occurring around the world in rivers, streams, and lakes. About 15,000 species are known.
[#310] Sexual trimorphism is seen in
Correct Answer
(C) Stag beetle
Explanation
Solution: Sexual trimorphism is seen in the Stag beetle. Trimorphism is the property exhibited by certain species of having or occurring in three different forms. Adult male stag beetles have characteristic antler-like mandibles and can grow up to a whopping 75 mm in length. Females have much smaller mandibles and grow between 30 - 50 mm. Both males and females have shiny black heads and thoraxes and brown chestnut-coloured wing cases.