🔥 Important Points of Entomology 🔥
✅ Allelochemicals
Allelochemicals are intraspecific semiochemicals. They mediate the communication between two different species of organisms or insects. Allelochemicals may be classified into:
- Allomones
- Kairomones
- Synamones
✅ Allomones
Allomone is a chemical or mixture of chemicals released by one organism that induces a response in another organism which is advantageous to the releaser. For example, the defensive secretions of insects and plants that are poisonous or repugnant to attacking predators.
♦️ Ants release a defensive allomone called citral from its mandibular glands.
✅ Kairomones
Kairomone is a chemical or mixture of chemicals released by one organism that induces a response in another organism which is advantageous to the recipient. The releaser turns out to be the loser and the recipient (parasite or predator) a gainer.
✅ Synamones
Synamone is a chemical or mixture of chemicals released by one organism that induces a response in another organism which is advantageous to both the releaser and the recipient. It encourages mutualistic relationships between organisms, such as termites and protozoans.
✅ Other Important Points
- Aphids are the main transmitters of viruses to the plants.
- Apis dorsata produces about 35-70 kg honey per colony per year.
- Bacillus thuringiensis has been found most effective against lepidopterous insects of the field crops.
- Banding of mango tree trunk with alkathene sheet and applying grease on it prevents the infestation of mealy bug.
- BHC was first synthesized by Faraday.
- Bioagent Aphilinus mali has been found effective in controlling wooly aphid infesting apple.
- Carolus Linnaeus developed the binomial method of classification.
- DDT was first described by a German chemist, Othmar Zeidler in 1874, but Paul Muller (of Switzerland) in 1939 discovered its insecticidal property.
- Diapause is a specialized condition of suspended activity with body metabolism at its minimum.
- Diflubenuron inhibits chitin synthesis.
- Eggs of honey bee are fertilized to produce females.
- ETL always represents a pest density lower than that of EIL.
- In honey bee, the queen's mandibular gland produces pheromones which control the colony.
- In hypognathous type of head, the long axis of the head is vertical and mouthparts are ventral.
- Nilaparvata lugens acts as vector of tungro disease in paddy.
✅ Types of Weeds
- Parasitic weed: A weed that depends partially or fully for its growth on its host plant.
- Obligate weed: A crop-land weed incapable of surviving in a wild community.
- Objectionable weed: A problem weed, whose seed once mixed with crop seed is extremely difficult to separate.
- Noxious weed: An undesirable troublesome weed difficult to control.
- Facultative weed: Weed of wild community origin, escaping sometimes to crop-land.
- Alien weed: Weed not native of a country.
- Associated weed: Nonparasitic weed association with a specific crop.
- Satellite weed: A weed that has become an integral part of the crop ecosystem.
