Our Pests (Late May2017)
The common gooseberry sawfly is one of several sawfly species that can attack gooseberry and red/white currant during spring and summer.
Nematus leucotrochus is a species of sawfly in the family Tenthredinidae, known as the pale-spotted gooseberry sawfly. Widespread throughout central and northern Europe, this insect is best known as a pest of gooseberries. The larvae feed on the foliage of the plant, defoliating it. Unlike Nematus ribesii, the common gooseberry sawfly, the species has a single brood. Adults appear in early May and larvae in May and June
To prevent gooseberry sawfly caterpillars, pick a bucket of foxglove leaves and pour over two pints of boiling water, leave for two days, strain and spray on gooseberry plants before any caterpillars are seen.
Foliar drenches of Nemasys Caterpillar Killer, carefully timed in early May and July, will apparently solve the problem. Supplies from, among others, Green Gardener (01603 715 096; www.greengardener.co.uk)
I used Pyrethum powder (Py?) which helped kill them off, but the caterpillars pupate in the soil over winter then crawl up the “trunk” the following year, (or something like that!) anyway I put weed membrane down which interrupts this lifecycle
I’d fork gently over the root area in the autumn to expose the over-wintering pupae to hungry birds.
If you’re picking them off the plant, spread newspaper underneath first. They respond to vibration by dropping off onto the soil, where you can’t find them…
As soon as I spot them, I spray the bush with thick soapy water and squish them all dead !
The traditional way is to turn the family chickens into the fruit garden over the winter to scratch around in the soil and get the pupating grubs. I don’t keep chickens any more, and luckily we’ve escaped the sawflies in this garden.
I’ve made up a spray of neem oil and as soon as all the leaves are out in April I drench each bush. Any spare solution goes onto the soil below the plant as the earthworms are supposed to love it. I do a second drench at the end of May (just in case) and have had great crops since.
Neem is totally organic and although it stinks a bit is easy to mix up and apply . I got mine off ebay …. wasn’t expensive for a big bottle which will last ages. At room temperature it is solid, but goes liquid again with a couple of hours in the airing cupboard.
Am using this year on the lilies as the dreaded beetle has now put an appearance in Scotland.
Just a shame it doesn’t work on slugs ….
See this link for how to make the spray.
I start when the leaves first come out which is usually April round here …. and I give them a good dousing every 4 weeks or so until end August. It’s a quick job … and also seems to stop them getting attacked by aphids.