Home Page

Autumn bugs

If it's a bug-free spring you're after, it's all about controlling them in the autumn.

Aphids Autumn is a key time for sorting out the bugs in your garden. Why? Because ideally you want to have as few as possible during the winter, so that come spring your reinfestation levels are low.

Aphids can be a real problem in the garden, from early spring to autumn. They suck nutritious juices from the plants, and in large numbers they cause serious deficiency symptoms. They're also well equipped to transmit plant viruses.

At this time of the year, aphids are in overwintering mode. That means they are busily preparing for egg laying. But you can still grab them with the odd spray of Conqueror Oil — a very simple mineral oil.

Yellow sticky trap for aphidsNow, talking about oils, neem oil is another one. Beautiful organic material — three, maybe four sprays, four or five days apart. That will do them nicely. And, remember, neem oil is totally harmless to predators and parasites.

When it gets into spring, the first winged aphids will form, and they'll be flying around your garden looking for a host.

Here's a clever trick. Get some yellow sticky traps. Hang those in your roses or other plants, and aphids are attracted to the colour yellow; they will end up totally stuck on the sticky tape, stopping them from infesting your plants.  

Passion vine hopperPassion vine hoppers are sap suckers too, and cause yellowing and deficiency. At the moment they are busy laying eggs ready for next spring, just like the aphids.

There's no point in spraying them. They'll flick away as soon as the spray gets near. The trick here is to seek and destroy the eggs.

You will find the eggs on the tendrils of things like passion vines. They look like little regularly implanted fluffy things. Each fluffy thing is an egg.

Eggs of passion vine hopperOnce you've got a whole lot of them, burn them. Don't throw them through the compost because they'll survive, make no mistake.

The adults and brightly coloured immature vegetable bugs are still around. They shrivel up my beans and tomatoes.

It's easy to find lots of them, and if you squash a few the others on the plant smell the danger and drop off. They play possum — easy pickings for the organic gardener.

Green vegetable bugIt's the adults that overwinter, and if you grab them before they hide away during winter and squash them, you start off with a much smaller population for reinfestation in spring.

Scale insects are small suckers that are protected by a scaly cover. They live on the underside of the leaves and along young stems, and cause honeydew and sooty mould deposits. They're nasty suckers and they do need controlling.

Scale insectsWhat I use is mineral oil dissolved in water, because they're waterproof and the oil gets under the cover and suffocates them. So give them a good dosing.

Mealy bugs are small, white insects that love palms and citrus and a whole lot of plants. They have a waxy meal secretion, which makes them just like scales — waterproof. They often hide in nooks and crannies on the plant.

Because mealy bugs are waterproof, I would normally control them with a really good dose of mineral oil.  

Mealy bugsThe problem is, palms cannot stand mineral oil spray, so I have to do something else. In this case, I've got myself some predators — mealy bug ladybird predators.

Just let those go on the leaf. Basically, what it's going to do is find its mealy bugs, gobble it all up and keep the population down.

Remember, it won't exterminate the mealy bug, because a predator will never do that.

Two spotted spider mite infestationTwo-spotted spider mites occur on all sorts of plants, as long as they're in a nice, warm condition. There's damage here. Look at the silvering and yellow stippling on these leaves.

What can we do against two-spotted spider mite? Well, you can get some of the new Nature's Way insect spray.

Alternatively, get yourself some BioForce bean leaves with predator mites. You simply attach the bean leaves to the infested plant with paperclips. The predator mites will then go and eat your two-spotted spider mite.

ThripsThe symptoms of thrips is silvering and bronzing on the leaf surface. Adults and nymphs are easy to find, and you can control them with neem oil, three or four sprays every five days. The good news is that neem does not kill the thrips' natural predators and parasites.

It's handy to know that adult thrips overwinter on fallen leaves on the ground, so pick up all the leaves in autumn and winter and burn them. That way you can start spring with a clean bill of health.

Reproduced with permission from NZOOM Home and Garden content,
from the previous website of  TVNZ News

The views expressed here are not necessarily those of the RNZIH

More Garden Articles

Home | Journal | Newsletter | Conferences
Awards | Join RNZIH | RNZIH Directory | Links

© 2000–2022 Royal New Zealand Institute of Horticulture
Last updated: March 1, 2021