Beneficial Nematodes- Rather than attacking the adults, beneficial nematodes go after the larvae in the soil and are a safe and natural method of control. The entomopathogenic nematodes, Steinernema and Heterorhabditis spp., have been particularly effective especially in potted plants. A few things are critical in order to get good control:
Timing & Temperature - Beneficial nematodes require a soil temperature of at least 60 F to work. Gardeners often miss the critical period in the spring since the weevil larvae pupate fairly early, before the soil warms. The late summer and early autumn is the best time to apply nematodes.
Moisture - The root zone around the plant must be moist since nematodes do not swim and require water to carry them through the soil. Water the area before and after application.
Whitefly- There are two kinds of this small triangular shaped white fly, one effecting greenhouse plants and the other affecting brassicas. Both feed on sap on the underside of leaves causing stickiness and yellow mottling.
Control- Glasshouse whiteflies can be controlled with sticky yellow traps or encarsia parasitic wasps, while cabbage whitefly can be tackled by jetting them off with jets of water from a hose.
Winter Moth Caterpillars- Mottled umber moth (Erannis defoliaria), winter moth (Operophtera brumata) and March moth (Alsophila aescularia) have wingless females which after emerging from their chrysalis stage in the soil, must climb the tree to mate and lay their eggs.
Control- Grease bands are sticky coated paper that can be cut into the required length, wrapped around the trunk of fruit trees from September - through to December and from March onwards. Alternatively apply Fruit Tree Grease, paint on lower trunk of fruit trees and any tree supports. The grease traps the wingless females before they reach the branches. Winter moth is the most common of these moths and it emerges as an adult during November to mid January.
Apply grease to fruit trees such as apple, pear, plum and cherry. On unprotected trees the eggs hatch at bud burst and the pale green or yellowish brown looper-type caterpillars feed on the leaves, blossoms and fruit-lets.
Note: Grease bands give no protection against codling moth (Cydia pomonella) and other pests that can fly onto trees.
Wireworm- (Agriotes lineatus) this creature, which grows to about 25mm long, spends four years living in the ground. During the summer they pupate, this stage lasts for three weeks, to emerge as adult Click beetles. They feed on roots particularly potatoes and other root crops, making tunnels about 3mm in diameter. They are usually widespread in grassland so will be frequently found when it is brought into cultivation. It is believed that after five years of cultivation their numbers drop considerably.
Control: - 1 Lift main-crop potatoes before September, as most of the damage is done at this time.
2 Crush any that are found when digging.
3 I have heard that a trap made of squares of potatoes attached to skewers, buried in the ground is a good way of catching them, these can be pulled up and the infested potato destroyed. I must admit that I have not used this method, but it is one I might try.
4 Keep down weeds, as this is the sort of territory that the beetle likes to lay its eggs.