This is the time of the year some of a gardener’s bug enemies get out and cause damage. I have had my first phone call this week in regards to grass grub beetles eating the foliage of plants. The beetles are nocturnal, they will come out at dusk to mate and feed, lay eggs during their short life span. One beetle might consume a few leaves but hundreds and even thousands start to become a biblical plague.
I remember a few years ago about this time a lady phoned me with a sad story. She had purchased a horticultural block of land with hundreds of blueberry plants which she had figured out; that the income from the harvest would cover her mortgage repayments. What she had not calculated on was the block being surrounded by paddocks which were full of grass grubs. The beetles were out in their thousands feeding on the blueberry foliage and shredding the plants.
What to do?
When this happens in towns; plants get eaten at night and there is no sign of any culprits in daylight hours then it is beetles that are doing the damage. Take a torch after dusk and go check the plants that are being eaten for the beetles. When you see them then spray them directly with Wallys Super Pyrethrum at commercial strength. That is 2.5 mils per litre of water. It is a strong knock down affecting the pest’s nervous system and killing them.
You need to go out each night to check and spray till after a few nights there are no more beetles. If you are not able to go out then just before dusk, spray any target plants with Wallys Super Neem Tree Oil with the Super Pyrethrum added. When the beetles arrive later on they will get a dose of Neem when they feed and also have contact with the pyrethrum so a double whammy.
There is another way to control the beetles because they are attracted to light. This is an old method where you set up a strong light inside a window facing out to the area you want to control. Under the window you place a wall paper trough or similar against the bottom of the window pane. The trough is half filled with water and a little kerosene added to float on top of the water. The beetles fly at the light hit their heads on the window pane and they drop down into the trough below. The kerosene prevents them from climbing out and next day you can either feed the beetles to the chickens or flush them down the toilet. Have your light trap working every night until there is no more activity.
A more modern way is what butchers in days gone by used to have to zap flies; but a modern compact version of those zappers. I purchased one recently to use indoors for flies. It is a Sansai Insect Killer SK-120C. Put that into Google and you will find a number of suppliers in NZ around the $50 price. Plug into the power and the UV tubes light up which are the light that attracts flies etc and the grid is electrified static electricity. Any pest coming towards the grid gets executed.
Now this could be used outside in a weather proof situation as you do not want to mix electricity with water/rain. Also ideal to use for mosquitoes and sand flies if outside having a BBQ. It will also incinerate untold moths and any other flying night insects. Likely it will be zapping away most of the night so next day you can unplug and clean up the burnt bodies.
Another pest that will appear about now is the pear-slug or cherry slug. It is a black slimy looking slug that feeds on the foliage of cherry and pear trees and is the larva of the sawfly. The first infestation is often not noticed because the numbers are often few but the second infestation later in January/February period is large and damage to the foliage is certainly seen. Being a slug like pest they are controlled by sprays of Wallys Liquid Copper with Raingard added
So check your trees for them and if seen spray. If you can eradicate the first wave of them then there will be few to cause damage later on.
For other pest insects now is the time to get on top of them before they can breed masses of their offspring. Whitefly, leaf hoppers, scale, thrips, mites, caterpillars, etc. Fill up your sprayer with Wallys Super Neem Tree Oil combined with Wallys Super Pyrethrum to spray any and all target plants just before dusk. You can add to this spray Magic Botanic Liquid if you want to also promote healthier plants.
If you do this say every two weeks before problems start to arise or if already a problem them once a week till you have control. Settled weather means population explosions.