Biological controlfor the larvae is available as microscopic insect pathogenic nematodes. Several species and combinations are available ( Steinernema kraussei, Heterorhabditis megidis, H. bacteriophora and S. feltiae). They are availablefrom suppliers of biological controls and as sachet formulations available from some retail outlets. They are suitable for use in containers and in the open ground.For best results apply in August or early September when the soil temperature or potting mediais warm enough for the nematodes to be effective ( Steinernema species 5-20ºC/41-68ºF Heterorhabditus species 12-20ºC/ 54-68ºF) and before the vine weevil grubs have grown large enough to cause serious damage A systemic containing the active ingredient Flupyradifurone (Provanto Smart Bug Killer)is available for use on ornamentals and selected edibles Winter wash is a plant oil application to the bark of fruit trees and shrubs targeting overwintering aphid eggs (organic e.g. Growing Success Winter Tree Wash). This may be used when the buds arefully dormant in November-early February on a dry frost-free day Be aware that products such as Neem are not registered for use in the UK and we cannot advise they are used,

BugClear Ultra 2 Insecticide, for flowers and shrubs BugClear Ultra 2 Insecticide, for flowers and shrubs

The RHS recommends that you don't use pesticides.Most pesticides (including organic types) reduce biodiversity, including natural enemies, impact soil health and have wider adverse environmental effects. Pea thrips ( Kakothrips pisivorus) Found on garden peas during June to August; causes stunted growth with a silvery brown discolouration on the foliage and pods; the latter may remain flat with just a few peas developing at the stalk end.The nematodes can give poor results in dry or heavy soils. They work best in lighter soils and open potting composts, such as peat or coir. Nematodes can be used safely on all edible and ornamental plants The life cycles of each aphid species differ in general for much of the year, aphid colonies consist of wingless females that give birth to live young. Winged forms develop when overcrowding,deterioration in the host plant or seasonal changes induce amove to another plant. Most aphid species overwinter as eggs but some can remain as active aphids, particularly in mild winters or on indoor plants. Onion thrips ( Thrips tabaci) Causes a whitish mottling on the leaves of onion and leeks. It also feeds ona wide range of other plants, including carnation, chrysanthemum, begonia, cyclamen, dahlia, tomato and cucumber. It causes silvering of the foliage and on some plants, such as dahlia, feeding at the shoot tips results in severely stunted growth and distorted leaves. Do I have to control aphids? You don’t have to kill or control them. They are part of the biodiversity of gardens and a vital food source for other wildlife in your garden. If you do decide to control aphids, these are the ways you can cause least harm to the environment and avoid pesticides.

Pesticides for Home Gardeners 2023 - RHS Gardening

The female weevils lay their eggs in the compost or soil among host plants. As a rule, this happens in August and September, though a lot depends on the weather during the previous winter and spring. In a mild year, egg-laying could start in early summer. Each female is capable of laying 1000 or more eggs. These eggs are less than 1mm across, white at first, later turning brown. They are difficult to see and much smaller than the granules of controlled-release fertiliser found in container-grown plants, which are often mistaken for insect eggs. Further information about the use of pesticides available for management of aphids is available on the pesticides for gardeners leaflet. Organic pesticides such as plant oils (e.g. Vitax Plant Guard Pest & Disease Control, Bug Clear Fruit & Veg Ultra, Vitax Rose Guard) have a lragley physical mode of action and can be effective against aphids. These pesticides have a very short persistence. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults. Plants growing in pots and containers, outdoors or under cover, are most likely to be severely damaged by vine weevil grubs. Plants growing in the open ground are less likely to be damaged, althoughheavy infestations ofgrubscanoccur on strawberries, Primula, polyanthus, Sedum ,Heuchera and young yew plants. Encourage the natural enemies of aphids in your garden, such as ladybirds, ground beetles, hoverflies, parasitoid wasps and earwigs. In spring, aphid populations increase before the natural enemies are active in sufficient numbers – so if you wait a while, they’ll often give the controlMany aphids, especially those on fruits and vegetables, go through an annual cycle that involves two or more host plants. The plant on which overwintering eggs are laid is oftena tree or shrub. In the spring, the eggs hatch and the aphids feed on the young foliage. By early summer, the foliage has grown older and tougher, this combined with increasing temperatures and day-length induces winged forms of the aphid that migrate to the summer host plant. This is usually a non-woody plant with soft, succulent foliage. Some aphids, however, spend the whole year on one type of plant, although they may be active for only part of the year.