b'BIOLOGICAL CONTROLWhitefly AphidsThe glasshouse whitefly (TrialeurodesAphids are small pear-shaped insects that vaporariorum) is a familiar pest, attacking avary in colour both within and between wide range of greenhouse crops.It feeds onspecies.With their alarming rate of the plant sap, reducing plant vigour and canreproduction and increasing resistance to multiply rapidly.It can also transmit virusespesticides, they are becoming a much more and the honeydew produced can encourageserious threat to greenhouse crops.the growth of sooty moulds, which reduceAll aphids feed by inserting their stylets the plants photosynthetic ability and mayinto the conducting vessels of the plant affect the quality of fruit and flowers. and feeding on plant sap.There are now Increasing resistance of whitefly to chemicaleffective aphid predators and parasites, and pesticides is making the use of biologicalgrowers have started to rely on these for control more important in the managementcontrol.The biological control agent used of this pest. can depend on several factors including pest levels and aphid species.Some of the biological Some of the biological agents we can supplyagents we can supply to control Whiteflyto control Aphids include: include:Encarsia formosa Aphidius colemaniEretmocerus Aphidius erviAphidoletes aphidimyzaAphelinus abdominalisChrysoperla carneaSpider MiteGlasshouse spider mite or two spotted miteSome of the biological agents we can (Tetranychus urticae) is one of the mostsupply to control Spider mite include:damaging pests which attack horticultural crops.A wide range of crops are affected, Phytoseiulus persimilisboth protected and field grown. Phytoseiulus persimilisSpider mites have a rapid reproductionFeltiella acarisugaand development which make resistanceto chemicals more likely.The mites feed by sucking sap from under the surface of the leaf.This produces groups of small white speckles which are clearly seen from the upper surface of the leaf.When mite numbers become high, these spots coalesce, giving a bleached appearance to the affected tissue.This can affect both plant appearance and reduce photosynthesis which may in turn result in plant death.Spider mite also produce webs and some strains have toxic saliva which can cause serious damage when only few mites are present (toxicity is most common on tomato plants).46E: info@agrii.co.uk | T: 0845 607 3322 | www.agrii.co.uk'