Getting to know your insect pests

The type of insect pests that affect your garden will depend on where you live and the plants you grow. They are very much a seasonal problem, says Marc Tracy from Botany and Bugs. "Depending on where you live in the country, different insect pests will be a problem at different times of the year," he says.

Most insect pests do their worst damage during the peak growing times of spring and summer. People living in tropical areas have longer periods of warmth, so will be affected for longer than those down south. Here are a few common insect pests to look out for in your garden.

Aphids

These sap-sucking insect pests sit in huge numbers on ornamental plants such as roses, and sometimes fruits and vegetables. They love new growth and so, like most of these pests, are worst in spring and summer. 

Thrips

Tiny flying sap suckers, thrips will often congregate on the underside of leaves and desiccate them. Signs that your plants might be affected by these insect pests include discolouration of the leaves.

Azalea lace bug

As the name suggests, these insect pests mainly affect azaleas. Another sap sucker, they cause discolouration to the leaves, which prevents the plant from photosynthesising, causing it to wither.

Caterpillars (pictured)

The larval stage of moths and butterflies, these insect pests can chew their way through entire plants in no time.

Lawn grubs and cockchafers

These beetles do some damage on their own, but the main damage is done by their larvae. The beetles lay their eggs in the grass and the larvae eat the roots and stems, doing great harm to lawns. Infestation is indicated by large areas of your grass dying out.

Snails and slugs

These chewers are molluscs rather than insects, but they can destroy any leafy growth, especially vegetables and herbs. They can be easily controlled with pellets.

Scale insects

These insect pests are mainly a problem for domestic gardeners on citrus plants. They can be identified as little brown lumps on the leaves and stems.

Marc suggests that the best way to treat these insect pests is to correctly identify them, then seek professional advice on how to control them. "Then you'll be using the right pesticide rather than wasting time, effort and money on using the wrong one," he says.