Aphids are one of the more difficult plant pests to deal with in an Aquaponics fish garden. How do they get into the garden? Usually they are brought in on plants, seedlings that you purchase from a nursery, or carried there by ants from some nearby garden.
Evidently there are around 4000 different types of aphid and at times I am sure most of them have been in my garden at some time!
Controlling them is a little difficult in Aquaponics because we do not have available to us sprayable material such as insecticides that would be commonly used on the regular farm or garden. We really don't want to use that kind of pest management for a couple of reasons.
1... We want to get away from using dangerous chemicals on our food supply.
2... If we spray that kind of poison we will most likely kill the fish.
3... Poisonous sprays kill beneficial insects as well as destructive insects.
One spray able solution is Neem Oil. This product is an oil extracted from the neem tree which is native to India. Neem oil is considered to be a non toxic solution and is used as one insect control mechanism on some organic farms. Neem oil is not very fish friendly so if it is intended to spray this material on your aphid infected plants then great care must be taken to prevent the oil spray drift getting into contact with the water. This is, in practice, very difficult to do. We spray garlic concentrate, chilli spray, molasses spray regularly in summer but find that these methods help but are not nearly as effective as the use of beneficial insects.
The best way to control aphids is by the use of “IPM” or Integrated Pest Management. IPM aims to suppress pest populations below the economic injury level (EIL)[i]
Seen here is an aphid infestation that is under attack by parasitic wasps Aphidius ervi
These wasps are multiplying rapidly to cope with the aphid infestation.
In keeping with the underlying mantra of our Aquaponics Garden being an ECO system it would be counterproductive to find some poison to kill the aphids for example, because at the same time we would very likely also despatch any beneficial insects. Particularly threatened by these "poison" approaches is the honey bee, and all would agree that would be disastrous.
The most "all purpose" beneficial insect is the Green Lacewing.
As the common name implies, adult green lacewings are green, with four clear wings. Adult female lacewings live for approximately three or four weeks and lay up to 600 eggs. The eggs hatch and the insect goes about its task of dealing with a variety of garden pests such as,
Aphids (various species)
Twospotted mite Tetranychus urticae
Greenhouse whitefly Trialeurodes vaporariorum
Scales (various species)
Mealybugs (various species)
Moth eggs and small caterpillars
So they are pretty handy to have around the greenhouse.
These can be purchased fairly inexpensively and do a great job. Visit the “Bugs for Us” website for detailed information on how to purchase these little critters and release them in your garden or farm.
Here is another insect that we have in our Indy 23 greenhouse doing its share of work on the resident aphid population.
The Striped Ladybird Beetle.
There are 27 main groups of this little beauty that are a very important part of our Integrated Pest Management approach in Aquaponics gardening either for home or in a commercial farm setting.
See more info about these wonderful little creatures at Brisbane Insects.