Trap, Monitor and Kill!

Insect traps are a useful tool in the gardeners armoury for giving an early warning of pest problems ahead and for contributing toward the control of them. There are insect traps that are designed for greenhouse use only and traps that can be used outdoors.


For greenhouses the use of sticky traps is common place, but many are not used to their full potential.

Too often a dust covered yellow trap is seen forlornly hanging in a greenhouse, not achieving anything. Sticky traps can provide an early warning of insect pest attack long before the pests are noticed on plants, but if they are old and covered with dust and dirt they are of little use, with no effective catching area for insects to get caught.

New yellow sticky traps will give advance warning of whitefly, aphid and thrip. They can also be very effective at catching fungus fly/ fungus gnats, which can be an annoying pest when you are propagating plants, with clouds of flies flying up when disturbed. More importantly, their larvae will eat the roots of the young seedlings and can spread plant diseases such as pythium. Yellow traps can catch high numbers of these flies and reduce their impact in the greenhouse.

Whitefly can be difficult to control if left to develop on plants. Sticky traps are good at catching adult whitefly, especially if you hang the traps just above the growing head of the plant where whitefly congregate.

Sticky traps in the greenhouse will help control early pest infestations and warn gardeners that pests are present, so control measures can be taken to reduce the damage caused.

The Garden

Outside in the garden, there are also many types of insect traps that can be used to keep pests at bay and warn us of their presence.
The spring is a really important time of year for many of these traps to be used.

Pheromone traps are normally placed in the garden in May. This is the start of the moth flying season – the pheromone lure attracts male moths into the traps. The males are tricked into thinking some lovely female is inside the trap, only to find it is a trap and there is no escape!

Don’t feel sorry for them though. If left in nature they will mate, leading to increased egg laying by females and then the development of caterpillars and grubs.

Pests such as Codling Moth and Plum Fruit moth can devastate fruit – trapping the males will reduce this damage.

Codling Moth [Cydia pomonella] can be a destructive pest of apple and pear fruit. The caterpillars part of the Codling moth life cycle bores into the fruit making it un-edible in many cases.

The Plum Fruit Moth ; Grapholita [cydia] funebrana is a common pest of plums , damsons and greengages. The female moth lays her eggs near the plum fruit and once the eggs hatch, the larvae burrow into the fruit. The caterpillar is pinkish-white and about 10-12mm long and eat the plums from within.This sometimes is not observed until the Plum is cut into.When the caterpillar is fully fed it may exit the plum leaving a small hole.
Infected fruit often ripen first.

Plum Fruit Moth damage

Damage caused by badgers digging for Chafers.

Other garden pests can be reduced with insect trapping.

Chafer Grub damage of lawns in the summers can destroy lawns and attract birds and animals to dig up lawns, looking for the grubs. By placing Chafer Beetle traps out in the garden in May, adult Chafers can be caught. This will reduce egg laying and the development of grubs. These traps use a scented lure to attract the beetles.

Another pest that can be cuaght with this typs of trap, is the Raspberry Beetle, which causes damage to soft fruit.

Last, but not least, the British gardeners most common foe – the slug.

Slug numbers can be reduced by using pitfall traps. These traps are dug into the soil, baited with something like beer and then the slugs fall in to them and drown – not a bad way to go!

Take a bit of time to think about what insect pests cause problems in your garden and plan ahead, by placing the right traps out to monitor and reduce their effects.

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