Deterrents/Rejectants/Antifeedants insect control (Main functions, Chemical types, Mode of action, Advantages and Disadvantages)

Definition of Antifeedants/Deterrents/Rejectants 

Antifeedants are the chemicals which prevent feeding. Detheir et al (1960) proposed the term,  feeding deterrent which aptly fits the situation as does possibly term rejectant.

Main functions of Antifeedants Antifeedants insect control

They inhibit feeding but it not toxic to insect.

Chemical types of antifeedants Antifeedants insect control 

A. Triazenes: This group includes more than 80 antifeedants. They are tasteless, odourless,  solid, nontoxic to insect. These antifeedants are mainly used against chewing type insect but  they can also used to against bed bug, cockroach etc. e.g. 4­dimethyl triazinol acetanilide.

B. Organotins: e.g. Brestan has been found effective against the potato tuber moth larvae,  larvae of Cutworm, sweet potato weevil etc.

C. Carbamates: e.g. Thiocarbamate and phenyl Carbamates with inhibit feeding by beetles  such as potato beetle.

D. Botanical extract: Extract of fern can be used as antifeedants against army worms, extract  of neem against stored grain pest.

E.  Miscellaneous:  Several  unrelated  types  of  chemical  such  as  cupper  stearate,  copper  resinate, phosphane, carvadan etc. can be used as antifeedants.

Mode of action of antifeedants Antifeedants insect control

Apparently antifeedants inhibit the taste receptor of mouth region so that lacking of proper  gustatory stimulus, the insect fails to recognized the treated leaves as food and continuous  foraging. Unless the antifeedants comes in contact with these receptors, there is no inhibition  of feeding.

Advantages of Antifeedants insect control 

1. External feeder insect easily be controlled.

2. Antifeedants do not affect parasites, predators or pollinator like honey bee.

3. Its adverse effect is less on environment.

4. In using antifeedants, insect may turn from crops to weeds.

Disadvantages of Antifeedants insect control 

1. Only external feeding insect are prevented from feeding and internal feeders, piercing and  sucking insect proboscis burn are not affected.

2. Its action is not rapid and effective in comparison to insecticides.

3. Dosage also appears to be high, compared to insecticides.

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