Observing pests

I learn from practical experience, from books, from listening to people, from reflection on past events, and from observation. Observation is a very important tool for an organic grower.

I get pleasure from observation, so I make time for it. I often combine insect watching with hand weeding, watering or other light garden tasks. I also do it at night, in the rain and in all seasons. Watching the changing seasons is one of the joys of first hand observation.

One of the best tools for night observation is to leave the veranda light on and see what comes to the light. I also dig pit traps to catch spiders and beetles. I occasionally resort to an aquarium for observation too. usually I am most interested in the range of food my captives will accept. I only need to keep them a few days, and I let them go as close as possible to where I caught them, except for large spiders, centipedes and scorpions, which I relocate away from the house.

I am fortunate to live near bush and a creek, where we still have a great diversity of insect life. I can count several hundred different insect species on my porch on a warm still spring evening.

I remember one pool in another creek nearby which I visited regularly over several years to observe the water skinks and frogs. Here I watched little brown froglets attacked by leeches. I fed every manner of food I could bring to the skinks (very tiny portions) and they excepted sweet, sour, salt and bitter with equal glee. They would take a live cockroach from our hands.

One season I observed millipedes munching on the chamomile lawn. I had to get the magnifying glass and lay down there watching their little mandibles chop away before I could believe they could destroy a lawn so fast. Later they ate the strawberries, then the strawberry plants.

I my night crawls (snail hunting mainly - also observing any other activity in the garden) I would collect snails and crush them on the path. The millipedes came streaming out of the strawberries, to feed on the high protein, mineral rich snails. I was amazed how attracted they were and soon gathered every snail within 30 metres. Running out of snails, I tried canned dog food and it worked perfectly. The strawberries started to recover and to my surprise responded to defoliation by producing a rapid crop of flowers. Rather than continue buying dog food, I scrapped up heaps of millipedes from around the baits and removed them, thereby relieving the population pressure somewhat. They really did go for snails and for the dog food, so I could get a lot of millipedes with one scrape.

Opportunities like this are invaluable for learning the power of simple methods, if they are used well.

Who remembers grandmas trick for removing blowflies from the house? Close the curtains, turn off lights and open the door to a lighter room (or the outside). The blowfly leaves.

I sometimes give my students the following homework. Select an area about one metre by one metre square, which is typical of your garden. Sit still (that gets difficult for some of my students) for ten minutes (impossible for some of them) and observe every thing which walks, crawls, slithers or flies across that area. Write down the number and a rough description (eg ‘ant’, ‘big ant’, ‘red ant’). We are mainly interested in diversity at this point but you could also record a note on how many individuals you can see.

Do the same exercise in the morning, in the afternoon and half an hour before dusk (do it at night if you can).

Do the same exercise in all four seasons, at each time of day.

You will be amazed at the diversity of life which inhabits a typical garden.

A ten x magnifying lens is an essential tool for any keen gardener. I have a larger one for observing insects in a tray or jar, and a folding one for use in the field. It is the first thing I put in my tool kit when ever I make field inspections.

If you are more timid, and unlikely to safari further than the compost heap, try your local museum. Many of them have rooms with preserved specimens of insects and other beasties which you can safely observe close up, and they may have microscopes which the public can use. They will help you to become familiar with some of the amazing diversity of the micro world. Then you might be tempted to take the time to observe behaviour - the live animal, in all its interactions with plants and animals and the soil, including shelter, mating, egg laying, feeding range and hunting habits, pupating and predation.

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