Aphids

Aphids, greenfly, black fly, call then what you will, they are all pests and not really something you want near your vegetables as they will cause damage. They are also pink, some reddish and other colors but are all doing one thing. They are feeding on your plants and in doing so are causing damage to them.

What they do is pierce your plant and suck the sap from it. In doing do they are causing puncture wounds which can allow disease to enter the plants. Indeed the aphids may themselves be carrying plant diseases which they pass on. They are not doing anything wrong in aphid terms but are simply existing, feeding and breeding. However, when I pick my lettuce, I want healthy plants not ones infected and damaged by aphids.

So what can you do about them. I have used three treatments all with good effect but some better than others. My neighbor, many years ago, told me of his preferred method when he got aphids or white fly in his greenhouse. He used to hose them off his tomato plants with a fairly strong jet of water. It worked up to a limit but within a few days they were back but not as many so he would do it again and so on. Every time he did it he killed more. This may work well on tomato plants but not on plants like lettuce where a strong jet of water will damage them.

The other option which I used last year with great effect was to buy a chemical aphid spray and treat them with this. I do not have it to check but I am sure it was organic and so safe to use. The problem with many of these sprays is that they can be used on some vegetables but not all, of used you may have to wait several days before eating and so on. It is vital to read the label when buying chemicals. You can also use a soft soap solution which is organic and will kill the aphids, again follow the instructions. You can also spray with a garlic wash - which deters them, a nicotine spray made from unused cigars steeped in water for 24 hours or just plain old washing up liquid, a few drops in a pint of water and sprayed on.

Last year my runner beans were affected and I was surprised at how quickly they spread from plant to plant. However, on closer examination they were being moved by ants who were effectively setting up an aphid farm. They milk the aphids for the sugary juice they obtain from them. I did not want to spray the plants as at 6ft tall the spray would drift onto other crops so I poured some out and applied it using a small artists paint brush directly on to the aphids. It took 2 or 3 applications but was devastating to the aphids and highly targeted onto the areas that needed it without a lot of over spray.

This year, again I have tried something different. I have gone for a biological control. Ladybirds or Ladybugs love to eat aphids and I decided to buy some of those to combat the spread of aphids. I also though that they can fly away so I decided to buy some ladybug larvae and release these onto the affected plants. As these are chill plants and in my greenhouse I thought this was the best method of control It also has the added effect of adding to the ladybird population in my neighborhood as they will eventually turn into ladybugs and fly away to find somewhere to lay their eggs. Problem solved, well not necessarily.

Within four days of release, I am struggling to find an aphid. They have all disappeared, I assume they have been eaten by the ladybug larvae. The trouble is what will they eat now, each other? Well it is a possibility or they may migrate to find more food. They seem to be able to travel very easily. Whatever happens, I hope I have helped to increase the local ladybug population. I also have a ladybug house I bought 2 years ago to help them have somewhere to overwinter. I have never seen it used but then again I do not have any proof it hasn't been used so maybe that will help as well.

Thanks to Jens Buurgaard Nielsen for use of the photo of aphids