SCALE INSECTS "My citrus plants were covered in scale - these nematodes are brilliant!" Mrs P from Ely Scale insect is difficult to spot and can increase unnoticed and will affect plants both underglass and outside. Look out for sticky "honeydew" on the lower leaves and yellowing of the top leaves. Underglass, scale is very partial to citrus. Outside, keep a close eye on camellias, rhododendrons, azaleas and box. Scale insects feed on the sap of the plant and large numbers of insects will lead to yellowing of the leaves and in extreme cases total defoliation. The main problem is caused by the fact that scale insects produce large quantities of honey dew which drips onto the lower leaves. Initially clear and sticky, it is then colonized by sooty mould which is unsightly and reduces the ability of the plant to produce food, leading to further weakness and loss of vigor. This mould and honeydew are the first signs of an attack. Left : Sooty mould on tomatoes. There are a number of species of scale insects, but they are unlike any other pest and do not look alive at all! They are motionless and are stuck firmly to the stem and the underside of leaves - often around the veins, from which they suck the sap. They are dome shaped, about 0.6cm fully grown, light brown when young but gradually darken as they mature. The female scale insect produces a mass of eggs over many days - between 500 and 2000! and then dies. The eggs are laid under the scale which protects them as they develop. The eggs hatch to produce a crawler stage which settles on a suitable part of the plant, starts to feed and becomes immobile. Large numbers of these young die but so many eggs are produced that large populations can quickly develop. The length of the life cycle depends on temperature but at 20°c it normally takes 10 weeks from egg to adult. Right : Scale on the underside of the leaf. Scale Nematodes - control scale in your greenhouse or conservatory by spraying your plants with scale nematodes. Move potted outdoor plants inside before treating. Permanent outdoors plants should be treated when the temperature is above 14°c or use the SB Invigorator spray. To control Scale in your greenhouse or conservatory : Spraying the infected plants with scale nematodes as long as the temp is 14°c. If scale is present and the temperature is below 14°c, control the scale with SB Invigorator until the temperatures are high enough. Once the nematodes have been spayed onto the plant, the nematodes will attack the scale insects. Once a nematode finds the scale insect it invades the body cavity of the scale insect and introduces a bacterium which feeds on the insides of the scale. The nematodes feed off the bacterium which in turn kill the host. The nematode numbers increase and search out new scale insects to carry on the whole process. The whole process is then repeated a total of 3 times at 21 day intervals. Right : Nematodes in close up. To be successful, the nematodes must be applied to the leaves and stems and then kept moist for at least 12 hours to allow the nematodes to "swim" to the scale insect, with a minimum temp of 14°c / 58°f. There are three steps to treating for scale :- Mix the nematodes with water and spray the infected plants, concentrating on the undersides of the leaves and stems. Keep the foliage moist for 12 hours. This can be achieved by damping down the leaves with a gentle soft water spray, being careful not to wash the nematodes off, or by covering the plant with polythene (put the plant in a bin bag if small enough) for 12 hours following treatment. The whole process is repeated 3 times at 21 day intervals. Our price includes 3 introductions sent by 1st class post at 21 day intervals. N.B. Please note that once the scale insects are killed, they will remain on the plant, which will often lead people to believe that the control is not working. The first indication that the control is working is that honeydew will stop being produced so if the mould is washed off - SB Invigorator is very good at doing this - it will not come back. The scale itself can be removed by hand. Right : Scale waiting to be removed. SB Plant Invigorator - This natural spray is going to be of great help to the green gardener as it not only controls a range of pests in a safe and effective way, but it also controls fungal diseases and contains a foliar feed. Available as a 500ml ready to use spray, as a 250ml concentrate (makes 25 litres of spray) or NEW for 2008, as a 1 litre super concentrate (makes 500 litres) for use in your own sprayer. SB Plant Invigorator should be in your store cupboard ready to :-  Control pests during the winter and spring when it is too cold to use beneficial insects (i.e. in unheated greenhouses / conservatories). There are no harmful chemical residues left behind, so beneficial insects can be introduced AS SOON as the temperatures are warm enough. Control any pest hotspots ONCE natural controls have been introduced. Use SB Plant Invigorator to target any pest hotspots. It will not harm beneficial insects once they have been introduced. Use for a pest emergency - been away or not noticed a rapid build up of pests such as red spider mite or greenfly? - use SB Plant Invigorator to get control BEFORE introducing beneficial insects. Special Offer - Emergency Scale Pest Pack - "Help every plant is covered in scale. What should I do?" Use our Emergency scale pest pack containing 250ml of SB Plant Invigorator & a full course of scale nematodes. Spray with SB Invigorator for 2 weeks. Spray with scale nematodes to establish a breeding colony for long term control. The 1st scale nematodes will be sent automatically 14 days after the invigorator. Emergency Scale Pest Pack £29.49 PRODUCTS AVAILABLE NAME DESCRIPTION PRICE Nematodes Three applications at 3 week intervals £16.99 Emergency Scale Pest Pack 250ml SB Invigorator and a full course of scale nematodes £29.49 SB Plant Invigorator 1 x 500ml ready to use spray £9.99 1 x 250ml concentrate makes 25 litres of spray £12.50 NEW - 1 x 1 litre super concentrate makes 500 litres - equivalent to 20 x 250ml bottles saving ALOT! £49.99 Release lacewing larvae and / or ladybirds into your garden to control aphids (both greenfly/ blackfly) and other soft-bodied pests. CLICK HERE to find out more.