Economic Threshold Levels of Insect Pests

A decision to use an insecticide should be made only when an insect population has reached or exceeded an economic threshold—that level of a pest population at which control is needed to prevent economic loss (that is, the projected cost of damage is greater than the cost of control).The utmost principles of an insect management program are scouting fields and basing control decisions on economic thresholds. Growers should incorporate scouting and the use of economic thresholds into their crop management plans. Economic thresholds of insect pests of General Crops, Vegetables & Orchards are given as under:



Brown Leaf Rust % Incidence & Low-Med-High Intensity
Smut % incidence
Armyworm On Appearance
Aphid No Spray recommended
Helicoverpa No Spray recommended


Hopper 5/ Leaf (In Summer)1/ Leaf (In Winter)10/ Inflorescence or Twig
Scales 50 Scales / Leaf
Fruit Fly 10% Damage
Mealy Bug On Appearance
Mango Midges 10 spots/ Twig or Inflorescence
Gall Farming Insect   10 Galls / Leaf
Malformation Low-Med-High
Anthracnose On Appearance


Armyworm On Appearance
Helicoverpa 3 Larvae/25 plants
Termite 10% damage
Cutworm 10% at initial stage
Blight Low-Med-High
Wilt % incidence


Citrus Psylla 6/ Leaf
Leafminer 10% affected leaves
Fruitfly 10% affected fruits
Withertip Low-Med-High
Canker Low-Med-High


Top Borer 10% Attacked Plants
Stem Borer -do-
Root Borer -do-
Gurdaspur Borer -do-
Pyrilla 3/Leaf
Black bug 10/ sheath
Whitefly 10/ Leaf
Mites 10/ Leaf
Toka 3-5/ Sweep of Net
Mealy Bug On Appearance
Termites 10% Damage
Rodents 5 Live Burrows/ Acre
Diseases Only Presence


Red Pumpkin Beetle 1/ 10 Plants (at seedling stage)
1/ Plants (at crop stage)
Fruit Borer 10%on Brinjal 5% on Tomato
Hudda Beetle 4/ Plant
Diamond Back Moth 3/ Leaf
Helicoverpa 5% Fruit Infestation
Fruit Fly 3 % Fruit Infestation
Jassid 1/Leaf on Cucurbits, 2/ Leaf on Brinjal,
3/ Leaf on Melons
Whitefly 5/Leaf on Cucurbits
2/Leaf on Chillies, Cowpeas
Aphid 5/Leaf
Powdery Mildew Low-Med-High
Downy Mildew Low-Med-High
Wilt Only Seed Treatment
Root Rot  Only Seed Treatment
Collar Rot Water must not touch the stem
Leaf Spot/ Blight Spray on appearance


Shoot fly 5%
Stem borer 5%
Helicoverpa 5 % Cobs
Armyworm On Appearance


Jassid 1 Adult or Nymph per leaf
Whitefly 5 Adult or Nymph or both per leaf
Thrips 8-10 Adult or Nymph per leaf
Cotton Mealy Bug On Appearance
Mites 10-15 per leaf
Spotted Bollworm 3 Larvae/ 25 plants
Pink Bollworm 5 Larvae/ 100 Bolls
Helicoverpa 5 Brown eggs or 3 small larvae or Both 5 / 25 plants
Armyworm On Appearance
Aphid Spray on visible damage on top terminals


Jassid 3/Leaf
Blight On Appearance


Cutworm 3% Attacked Plants

Oilseed Crops

Aphid 1/ Pod10/ Twig


Helicoverpa 1/5 Flowers


Borers No. of Moths/Trap/Night  are 8-10 at Crop
Dead Hearts 5 % at Crop
Chrotogonous (Toka) 3-5 Adults/Net


Fruit Fly 10% Attacked Fruits (4-5 pheromone traps/ acre