#11 - Nov 2017 - Garden Stuff - © Sandy Lang - slang@xtra.co.nz
ARTHROPODS November/December: Late spring/early summer. Warm, buzzing bees, and all manner of crawly things around. What to do about all these tiny animals you didn’t invite…?
In addition to plants, your garden is full of tiny animals. You can see these walking, hopping and flying all about - some only at night (nocturnal), others only in daytime (diurnal), some are vegetarians (eat plants), others are carnivores (eat each other).
These tiny animals are the arthropods – invertebrates, with an exoskeleton, a segmented body, and a number of jointed legs (6 or 8 or many), and maybe wings. Plant scientists think of these as of three general sorts: (1) pests, (2) residents and (3) beneficials.
(1) Pests: There aren’t many pests. The worst are the sap suckers - aphids, mites and scale insects. They weaken infested plants and can kill them.
(2) Residents: There are a large number of these. They don’t help your plants - but they don’t harm them either - they just live there.
(3) Beneficials: Then, there are the ones you want. There are two sorts of beneficials - a) the ‘good-doers’ and b) the ‘bad-stoppers’.
a) The ‘good-doers’ include bees that collect nectar to make honey and move pollen from flower to flower. Honey is good and pollination is essential - no pollination = no seed = no fruit.
b) The ‘bad-stoppers’ are predators - they hunt and eat the pests. Ladybirds and lacewings eat aphids, steel blue ladybirds eat scale insects, and there’s a large number of general predators - ants, spiders, earwigs, parasitic wasps and praying mantises – these eat anything that walks, hops or flies, including each other and the pests.
Sprays: If you spray with traditional insecticides they leave behind residues that kill the lot – the good, the bad and the indifferent. You will have to keep spraying, as the bad guys come back quicker than the good guys.
•For aphids and mites, spray with 2% dishwashing liquid in water (use an old household spray bottle, well washed out). •For scale, spray with a horticultural oil, e.g. Yates Conqueror.
Neither of these sprays leaves a harmful residue, so they damage only the animals you’ve sprayed.
Better: Avoidance beats fighting.•Grow a few plants here and there that encourage the beneficials (e.g. phacelia, buckwheat). •Grow modern plant varieties, bred to be less susceptible to pests and diseases. •Give your plants healthy conditions. Same as with you, stress lowers a plant’s resistance to pests and diseases. Give them the right light, the right water, and the right soil minerals.___________________________________