Type of Pests (Insects, Non-insect Pests)Introduction

A pest is an organism which is detrimental

to humans or human interest. Living

organisms are derided as pests as they

cause damage to agriculture by feeding

on crops or parasitizing livestock or

acting as carrier of diseases of man and

livestock. The term "plant pest" is any

species or strain of plant, animal, or

pathogenic agent injurious to plants or

plant products. The most important pests

in the order of importance are constituted

by insects and non-insect pests like mites,

nematodes and gastropods (snails and

slugs). Although rodents, birds and

mammals, which are inimical to welfare of

man are also called pests.

Bollworm damage in cotton

Cabbage butterfly larvae

Insects as pests

Insects are the most diverse and

dominant pests among animals. They

damage crops right from germination

to harvest in field and also in godowns

during post-harvest storage. No plant

part is virtually spared by insect pests.

Different insects can utilize different

plant parts due to specialized mouth

parts. In this way, they have reduced

competition among themselves. Pests

like termites feed on underground

plants parts as well crop residues and

also damage timber, furniture, books

and other commodities. Planthopper damage in rice

Cabbage butterfly damage

Types of insect pestsBased on feeding habits insects can be categorized as

Tissue consumers

Sap suckers

Tissue consumers include pest affecting stems, leaves, flowers, fruits and roots, and also crop residues.

Sap suckers suck sap from different plant parts affecting growth and development of crops.

Stem borer damage in rice

Planthoppers in rice

Crop lodging due to planthopper damage

Tissue consumers

A. Stem damaging insects: Stem borer: Rice stem borer, maize stem borer, sugarcane early shoot borer, top shoot borer

banana pseudo stem borer, mango stem borer

Shoot fly: Maize, sorghum and wheat shoot fly

Node borer: Sugarcane internode borer

Cutworms: Gram cutworm

Banana pseudo stem borer

Mango stem borer

Cutworm larva

C. Leaf damaging insects

Leaf folder: Rice leaf folder, cotton leaf roller, grape leaf roller

Leaf miner: Pea leaf miner, citrus leaf miner, mustard leaf miner

Defoliators: Grasshoppers, defoliating beetles

Rice leaf folder larva and adult

Grasshopper

Hadda beetle

Leaf miner damage

Flower feeding insects

Rice gundhi bug

Banded blister beetles

Thrips

Rice gundhi bug

Banded blister beetle

B. Fruit damaging insects

Fruit borer: Tomato fruit borer, lady finger fruit borer, brinjal shoot and fruit

borer

Pod borer: Gram pod borer, pigeon pea pod borer, pea pod borer

Bollworms: Cotton pink bollworm, spotted bollworm, American bollworm

Fruit fly: Mango fruit fly, cucurbit fruit fly,

guava fruit fly

Fruit sucking moth: Orange sucking moth Fruit borer damage

Pod borer damage in gram

Root damaging insects

Termites: Wheat, maize, sugarcane, gram

White grubs: Sugarcane, ground nut, maize

Root weevils: Rice root weevil

Mole cricket: Wheat, maize, gram, rice

Termite galleries

Termite workersWhite grubs

Sucking insects

Stem suckers: Rice planthoppers, sugarcane woolly aphid

Leaf suckers: Rice leafhopper, cotton leafhopper, lady finger leafhopper, cotton whitefly, cotton mealy

Flower suckers: Rose thrips, mungbean thrips, rice panicle thrips, mustard aphid

Fruit suckers: Fruit sucking moth

Root suckers: Wheat root aphid

Mustard aphid

White fly

Rice brown planthopper Rice green leafhopper

Rice white-backed planthopperThrips

Mites also known as acarina

belong to phylum Arachnida, to

which spiders also belong. These

are minute organisms that can

rarely be seen with naked eyes.

Mites cause heavy damage in

crops especially in vegetables

and ornamentals. Mites

constitute a large group with its

members inhabiting a variety of

habitats like soil, water, plants,

animals, processed food and

animal waste. Mites damage

crops by sucking sap from them.

Non-insect pestsA. Mites

Red spider mite

Damage

Phytophagous mites infest a

wide variety of plants leading

to yellowing, discolouration,

curling or other type of

deformation of leaves or

defoliation; development of

galls on leaves; deformities of

plants such as swelling of

nodes and internodes,

stunting of shoots or

malformation of fruits.

Mite damage in brinjal

Predatory mites

Predatory mites feed on

phytophagous mites thus

aiding in biological control of

harmful mites. Amblyseius

fallacis, Agistemus fleschneri

and Zetzellia mali are some of

the species of predatory mites.

Their size is more or less

similar to that of spider mitesPredatory mites

B. Snails and Slugs

Snails and slugs belong to

phylum, Mollusca and hence also

known as molluscs. Giant African

snails is most important snail

pest having spread worldwide

due to accidentally as well as

deliberately. Snails possess a

protective shell covering, formed

by their own secretion, while

slugs lack protective shell. The

snails are very active during

rainy season. Their activities are

very much correlated with the

rainfall and humidity.

Giant African snail

Damage

Garden flowers and ornamentals are

among the most susceptible plants to

attack of giant African snail. Host

range of giant African snail is very big

and includes papaya, banana, cole

crops, lobhia, beans, cucurbits,

brinjal, marigold, portulacea, violet,

money plant, arecanut, rubber buds

and coffee seedlings. Marigold and

Luffa are among the most preferred

food of this pest. It also drinks

rubber sap. Papaya is also damaged

to serious level. All parts of papaya

plant are susceptible to the attack of

the giant African snail.

Plant Parasitic NematodesNematodes are popularly called as

round worms. Nematodes belong to the

phylum Aschelminthes. Plant parasitic

nematodes constitute one of the

important groups of organisms which

live in soil around plant roots. They are

often microscopic, long and slender,

confined usually to the top soil of 20-25

cm. Plant parasitic nematodes cause

extensively damage to cultivated

plants, resulting in heavy losses.

Damage may be caused directly, or

indirectly when the phytoparasitic

nematodes transmit plant viruses or

allow pathogens to gain entry into the

plant through damaged areas created

by these nematodes.

Magnified picture of root knot nematode

Symptoms of Nematode DamageRoot knot nematodeGalls on roots, stunting and wilting as in lady’s finger.

Cyst nematodeShallow root system, chlorosis (yellowing of leaves) and wilting during hot weather even in presence of sufficient soil moisture

Ear cockle nematodeStunted growth with wrinkled and twisted leaves, reduced and irregularly developed earheads, wheat grains converting into seed galls or cocks

White tip nematodeYellowing, browning and finally whitening of 2-5 cm leaf tips which then dry up and hangs down, kernels becoming chaffy and distorted as in the case of paddy

Root knot nematode damage

Ear cockle nematode damage

Crabs Crabs are arthropods which belong to

group Crustacea and are aquatic by

nature. The rice fields crab,

Paratelphusa hydrodrumus lives in

holes in the sides of field bunds and

irrigated channels etc., where water

does not stand. Channels and holes are

protected by heaping soil around their

openings.

Nature of damage

Seedlings are cut down into bits at

ground levels and carried to the holes

for feeding. In addition to crop

damage, crab holes made into bunds

lead to beaches and water loss.

Crab

MillipedesMillipedes are also arthropods and

nocturnal, which live beneath leaves,

stones, bark and logs as well as in soil.

As the name indicates, these have a

large number of legs.

Millipedes commonly occurring in India

are Lulas sp. on Jowar and

Harpurostreptus sp. on tapioca. They are

brownish black in colour and about 8.7

cm in length.

Nature of damage

The adults and juveniles feed on tender

buds and roots of newly planted crops.

The tapioca millipedes feed on tender

buds and roots of newly planted sets

resulting in stunting and often death of

plants. Some of the millipedes consume

groundnut kernels.

Millipedes

Rats and miceRats cause severe damage to crops

and domestic commodities, thereby

requiring to be controlled effectively.

The atmosphere and surroundings of

human habitations are fouled by

them to the extent that it becomes

intolerable for man. Several types of

diseases are known to be transmitted

by rats. Besides consuming

considerable quantity of food, they

contaminate much more by urine,

faeces, and hairs and sebaceous

secretions. Religious sentiments of

some people come in the way of rat

control.

Mus booduga

Hare and rabbitHares and rabbits are one of the

best known wild mammals and of

considerable economic

importance. They are nocturnal

and graze mainly on grass,

herbs, scrubs, bulbs, roots, bark

etc. Instances of their becoming

pests on agricultural crops are

widely known throughout the

country. They do considerable

damage to crops like wheat,

barleygram, maize, jowar, bajra,

pea, mustard, bean, cabbage

and others. They are browse on

young fruit trees and forest

plants.

Hare

Rabbit

Let’s Sum Up A pest is an animal which is detrimental to humans or human interest.

Most important pests are among insects and non-insect pests like mites, nematodes, and snails and slugs.

Based on feeding habits insect pests can be categorized as tissue consumers and sap suckers.

Tissue consumers damage stems, leaves, flowers, fruits and roots, and also crop residues.

Sap suckers like aphids and whiteflies suck sap from plant parts.

Mites such as red spider mites cause heavy damage in crops especially in vegetables and ornamentals.

Giant African snails is most important snail pest having spread worldwide and causes heavy damage in ornamentals and vegetables.Crabs and millipedes also damage crops in certain localities.

Rodents and some birds and mammals are also harmful to man.