You grow what people and pests want to eat.

You get more money from people if the pests don’t eat as much ... or they spoil the look and presentation of the produce.

It’s a war!

Pests are predictable; they just want food.

They are unthinking invaders doing what they’ve always done; you are the one with the knowledge, strategies and tools to defend your business.

Here’s how you take charge:

Know your pests:

They differ in what they eat, where they eat and when they eat.

Those which live outside, on the surface are the sapsucker aphids, bugs, leafhoppers, thrips, leaf and bud-eating caterpillars, beetles and others.

Those that get inside the plant tissue includes fruit fly, leaf miners, codling moths, stem weevils, gall wasps, nut borers – and others.

And finally, those living in the soil attack the crop’s roots (although there is a variation here: some root-eating larvae will eat surrounding pasture/weed roots and emerge as adults to fly into, and onto, your crop to destroy flowers and fruit buds Monoleptas and scarab beetles are examples).

Know your options.

Any two-plus options are Integrated Pest Management (IPM):

You can use beneficial predator/parasitic insects and mites.

These can be introduced into the early stages of your crop and fingers crossed, they will keep pest levels down to what you will accept.

Some varieties of plants are more resistant to the usual suspect pests.

This is a pretty short list, and you would know more than me about this option.

Your agronomist, your neighbours, mates and yes, articles in Australian Tree Crop can introduce you to them.

Physical protection is also one of the options. In your division of tree cropping, the nearest you might get is to use nets as barriers to birds and bats.

Then there are the insecticidal options:

Systemics. These are absorbed (usually by the leaves) into the sap stream and circulate.

Any insect sucking sap or eating leaves/buds gets a toxic dose and dies.

These pests include those getting inside the plant, and using systemics may be the only way you can kill them.

All you have to do is get the timing right. By this I mean the plant gradually degrades the potency and eventually newly arrived pests do not get a lethal dose.

The label specifies the withholding period as a number of days before you can harvest your crop (the primary reason is so you don’t send fruit off to the markets with anywhere near a measurable level of insecticide which might affect a human).

Some systemics can be used a couple of times in a season – but not all of them. It’s all on the label specifying crops, pests and withholding periods.

Residuals. These may hang around on the surface of leaves, bark and developing fruit for weeks (and even longer).

If a caterpillar or beetle eats some residue on a leaf or stands/walks across residues on leaves, they are risking their lives.

Or, if say weevils, earwigs or other pests hide in bark during the day, residuals get ’em.

But, new shoots, new leaves are uncontaminated and woosie insects such as aphids are only interested in the newest, tenderest tissue and a residual insecticide, mere inches away, will not have any effect.

Residuals applied to the soil can last for months (read the label).

They can be applied beneath your trees, between the rows and surrounding pasture/weeds/whatever with sufficient volumes of water to get them well down into root zones where curl grubs/larvae (scarabs/weevils, etc) are munching fibrous roots.

Contacts. Again, read the label as some have a few days of residual life, recognised by a day or three withholding period.

The natural pyrethrum insecticidal concentrates can be applied about sundown (when all the bees have gone home) and you can pick fruit next morning, not spoiling the taste of any hungry fruit-pickers.

These can be used to clean out all the insects so there are none presented to your purchaser.

Know your equipment

When it comes to spraying, it’s all up to you (or your team).

Whether it is fungicides, foliar fertiliser or insecticide application it was your job to choose the appropriate equipment.

Almost any sprayer will hit and kill aphids; they choose to suck the sap out of growing tips where there is nowhere to hide.

Thrips are similar size but many of them are very interested in flowers and a touch harder to hit down among the profusion of petals. Olive lace bugs, whiteflies and many others are always under the leaf and, as droplets are in downward motion, almost anything but a boom sprayer is a better choice.

Application of residual insecticides to pasture/weeds to kill scarab curl grubs and others before they become beetles/monoleptas and eat your trees is definitely a boom sprayer job – unless you choose a granular residual (which needs another form of equipment).

Varying your application rate of liquid insecticides is dependent on your target.

If you have equipment which can change droplet size, you should work out the correct droplet size for which pest(s).

Your job is just to hit them with just enough.

You can’t kill them any deader-than-dead.

Smaller droplets can swirl upwards to the undersides of leaves as well as fall; too small a droplet may not settle at all and be wasted.

Fogging is seldom effective outdoors (except for mozzies, etc).

Know your application rate

Bigger droplets from a boom spray can range up around 1000-plus litres per hectare … a lot of which falls through to the ground. Traditional and modern variations of the air fan blasters can hit both under-leaf and growing tip pests but setting it to suit your crop and the current pest(s) is worth the effort:

• Find 2-3 trees at the end of a row with pests.
• Use your current setting and apply to both sides as you make your turn.
• Stop and check. Py-Bo will kill most pests in a few minutes… at least you’ll see they have been affected as they twitch or fly off erratically.
• Unaffected pests have not been hit and will continue feeding… so change something!
• Do another test (and maybe another) until it is right. If the first application was 100 per cent, reduce the application a bit … you don’t need to put unnecessary money in the Py-Bo manufacturer’s pocket. And use that setting from then on … depending on the size of your trees, of course.

Ion Staunton is the Entomologist at Pestech.com.au manufacturers of Py-Bo Natural Pyrethrum Insecticidal Concentrate. Keep some ready in your shed. 1800 12345 7