Several insects have popped up in the fruit garden this week, so if you’re growing gooseberries, currants, apples or pears, take a look at what could be bugging them:
Currant sawflies (Nematus ribesii) have reared their heads in gooseberry shrubs. A leaf-feeding bug when young, the caterpillar-like larvae are light green with black spots, plus black head and legs – very pretty. They’re gregarious; in other words, they live and feed in a crowd when young.
As unsupervised youths, they can do a lot of damage before you notice anything’s amiss. They and a few hundred buddies will eat darned-near every leaf on the plant, defoliating it just when the plant needs that energy to ripen fruit. At this time of the season they’re more likely to be located towards the interior of the shrub, so check your plants carefully by lifting and inspecting each branch.
Look at the undersides of the leaves for the white, oval eggs and on the leaf petioles (stem attaching the leaf to the plant) for the caterpillars. Because they are nicely camouflaged by their color, the larvae can be hard to spot, so be sure to look for small holes in the leaves as a clue to their presence.
Insecticidal soaps control these critters, or you can hand pick and dispose of them. If you choose to use soap, read and follow the label, and make sure you spray it early in the morning, late in the evening, or on a cloudy day so that harsh sun doesn’t cause it to burn leaves.
Currant aphids (Cryptomyzus ribis) are also out in force, dining on currant sap and distorting leaves. You can find these small, pear-shaped, soft insects on the undersides of leaves, but the real tip-off is how they make the leaves look – parts of the leaf cup downwards, leaving a distinct puckering along the top. The bumps and lumps also take on a reddish hue, which stands out like a flag against the green foliage.
Fortunately the beneficial bugs are on patrol, and ladybugs can be seen crawling over leaves to snack on the aphids. But if you’re impatient for control, insecticidal soap or a strong jet of water will knock the aphids down.
Coddling moth (Cydia pomonella) adults are getting caught in traps, so protect your apples and pears if you don’t want to find worms in them. As these adults fly they’re looking for love, and once they’ve found it, will lay eggs on the young apples. After hatching, the caterpillars gnaw into the fruit, munching on the apple insides for three to four weeks (the first flight of adults – those we’re seeing now – will lay eggs on leaves, and larvae eat those first, then worm their way into the fruit).
When it’s time to pupate, the coddling moth caterpillars leave the fruit, crawling down the trunk to find crannies in the bark to spin a cocoon. Use this against them by wrapping the trunk with corrugated cardboard – the larvae find this a cozy place to pupate. Take the cardboard off and replace it every two weeks, and dispose of the used cardboard as desired.
Molasses traps are irresistible to the adults, and you can make your own out of molasses and water in a 1:10 ratio. Pour this into a wide-mouth container, then hang it in the tree. Check it often and replace when full of moths.