A Battle with Bugs

Since writing the original notes about bugs (back from here) I had a long running saga with greenfly. I assume one or two came in through an open window (summer 2001). It took me a long time to get rid of them at all. At first I tried to pick them off, or blow them away outside. Then I tried some ‘natural’ insecticide. But one or two always seemed to survive, and a couple of weeks later they would be back to their original numbers. Very difficult with me having so many plants to get them all, it's easier if you have only got a few to look after.  Anyway, after struggling with them for ages I had (eventually) to use ‘proper’ chemicals (Bug Gun - containing bifenthrin) - though I made sure it was ‘safe to eat’ e.g. it said you could treat lettuce, cabbage and fruit. Although I wouldn’t quite use the leaf same day, I did harvest it some weeks after spraying, making sure to give the leaf an extra thorough wash just to err on the side of caution.

I thought the bugs were all gone after the first ‘proper’ spraying. Plants were clear for about six weeks. Then after that I found a few more. I took the most affected plant outside, with the others I picked the bugs off and re-sprayed. This was on my plants in utility room, artificially lit, nowhere near an open window. I don’t think that they could have hidden in the leaf for six weeks, so maybe they can have a larval stage and hide in the soil. I kind of suspected this, if not greenfly then there are at least some bugs that ‘hide’ in the soil in this way. I now only use soil that I’ve first ‘cooked’ in the microwave to kill anything of that sort.

Assuming that other bugs are similar to greenfly, you’ll just need to be vigilant for a few weeks if your plants do get attacked. One good spraying will get rid of the majority of them, but unless you’re lucky, you’ll need to keep your eye on the plants in case they return. Possibly I’d recommend a ‘safe’ chemical spray in preference to an organic spray.

Incidentally, I’m not really familiar with the distinct damage that different bugs can do, but greenfly can cause later growth of the leaf to become curly and distorted. Other than that the plant is still usually quite viable. Aphids, I have heard, can carry a virus, which would be more of a threat to the plant (I suppose). Anyway, I got the Horticultural Department at the Scottish Executive to have a look at one of my damaged plants and they confirmed that it was at least clear of any ‘infection’. So bear in mind that even a badly attacked plant will usually make a full recovery once clear of bugs.