As the end of summer approaches , conditions can be ideal for nematode applications against a variety of soil borne pest grubs. Entopathogenic nematodes provide an effective natural, biological control for an increasing number of insect pests. Some of these pests have a grub stage or larval stage in the soil at the end of the summer. The soil is still relatively warm and moisture in the soil increases with cooler weather and more rainfall. These are the very conditions nematodes need to be effective when applying to lawns or soil. The ideal time for nematode applications is when it is overcast , wet and humid. Nematodes are U.V sensitive, so can be harmed if applied on bright sunny days and need lots of moisture and irrigation to help them move through grass thatch and then through the soil to find the pest grubs. Pests that should be treated with nematodes in the late summer/early autumn include;
Chafer grubs in lawns - This is the last chance to apply nematodes against Chafer grubs until next August! as spring applications are not effective. It is important to reduce and control chafer grub populations whilst they are close to the soil surface, as temperatures drop they sink deeper in the soil and become more difficult to target with nematodes.
Leatherjackets in lawns - Crane Flies, commonly known as Daddy Long legs have been busy laying eggs over the last few weeks, so fresh Leatherjacket grubs will be developing under the grass and like Chafer grubs , need to be controlled now with nematodes before they can overwinter.
Vine weevil grubs in pots or flower beds- Vine weevil larvae are active now feeding on the roots of many plant types in pots or open flower beds. They will keep feeding and damaging plant roots until temperatures drop and then will start up again next spring. Apply nematodes against them now and not only protect your plants this year but also at the start of next.
Box Tree caterpillars on box plants and hedges - A warm autumn might yet provide the conditions for another generation of Box Tree caterpillars, if you see Box tree caterpillars on Box plants, apply Box Tree Caterpillar Killer nematodes againt them a.s.a.p.