COMMON INSECTS ATTACKS ON POTATOES

BY

M.RABNAWAZ KHAN

1; Colorado Potato Beetle;

Colorado potato beetle is a very familiar insect, and the most

serious pest of potatoes.

Both the adult and the larva feed on potato leave.

Their damage can greatly reduce yield and even kill plants.

They will even enter to the soil to attack emerging foliage.

Female beetles lay eggs of about two dozen orange yellow in

colour.

Each female can lay 500 or more eggs over a four to five week

period.

LIFE CYCLE;

The life cycle of Colorado potato beetle is,

The eggs are hatched in four to five days and the larvae feed on the

leaves of the host plant.

There are four larval instars lasting 21 days.

The larvae drop the soil to pupate,

And pupation lasts 10 to 15 days.

CONTROLE;

A rotation among different classes of insecticides is

recommended to discourage resistance.

A new strain of bacillius thuringiensis that are effective

against small larvae.

An insect growth regulator, called align, has also been released

for control of this insect.

POTATO LEAF HOPPER;

Potato leaf hopper are wedge shaped , long, green, active insect.

They use their piercing-sucking mouth parts to remove sap from

the potato leaf.

Their habit of feeding on the underside of the leaf, they are easily

overlooked.

The symptom of leafhopper activity is more apparent,

A triangular brown spot at the tip of the leaf.

These symptoms are known as “Hopperburn”.

LIFE CYCLE;

Adult female lay eggs in the spring when the trees starting sprouting leaves.

She lays her eggs inside the leaves.

These eggs generally hatch within two weeks and the nymphs emerge and begin

their development.

After several weeks or months of feeding and several moltings,

They will develop into adults.

CONTROLE;

Apply diatomaceous earth to plants and spot

treat with insecticidal soap to keep pest

population under control.

If pest levels become intolerable, spot treated

with potent,

Fast acting organic insecticides as a last resort.

3; BLISTER BEETLE;

Blister beetles are narrow, elongate insects.

They may be found feeding in clusters on potato leaves.

Rarely blister beetles do enough damage to cause any

yield loss.

LIFE CYCLE;

EGG;

Eggs are yellow, cylindrical, 1.3 to 1.8mm long.

LARVA;

Each of the seven larval instars differs in size, shape, and color.

All instars have three short pairs of ventral legs and 12 body segments, excluding the head.

PUPA:

The white 10 mm long pupae darken gradually beginning with the eyes.

ADULT:

The adult blister beetles are slender insects 12 to 19 mm long.

They have prominent heads and gray with black spots.

CONTROLE;

Blister beetles can easily be controlled using any

of the insecticides containing bacillus

thurangiensis var kurstaki.

4; APHIDS;

These tiny insects can transmit virus diseases.

They suck juices from the leaves and stems of potato

plants.

Injuring them badly.

LIFE CYCLE;

In October the female lay eggs usually on the stems of

trees.

In march the eggs hatch out into wingless female nymphs,

which are similar to adults.

There is no larval or pupal stage comparable to those of

the butterfly.

After a series of ecdyses (moults) ,

They become mature and give birth to doughter

aphids without any fertilization.

CONTROLE:

The best control for aphids is insecticidal soap

sprays are an effective control.

5; WIREWORMS

Wireworms create a problem when potatoes are planted in a section

of garden that was recently sodded.

They are slender, brownish or yellowish.

They tunnel into plant roots and tubers, and spoiling them.

LIFE CYCLE;

Wireworms larvae and adults overwinter in the soil.

In early spring female beetles emerge from the soil.

They mate, and lay eggs under ground.

Pupation occurs in late summer and adult beetles emerge in the spring.

One generation per year,

The life cycle requiring 1-6 years to complete.

CONTROL;

Spray infestations of these insects with high

water pressure,

Or with slightly soapy water in a spray bottle.