July 28, 2011 § 10 Comments
This blog post, planned for weeks, was supposed to be a warm and cosy one, coming to you from my kitchen. It was going to be about growing and pickling my own chillies, something I’ve been doing for years.
However, this comfortable, domestic idea was swept aside when, after noticing that the chilli leaves were a little mottled, I started looking at them with a loupe. I suspected an infestation of red spider mite (which loves the hot dry conditions in our conservatory). This tiny pest is usually deterred by frequent misting with water — but not in this case, it seemed. A closer look was required.
When magnified eight times, the surfaces of the leaves showed themselves to be thronged with livestock. I knew that there would be plenty of aphids (those are easily seen with the naked eye), but I could not see a single red spider mite — minute eight-legged characters that look like the tiniest ticks imaginable. However, rambling between the aphids were small green sausages on legs. Thrips! I had thrips! A new pest! It was exciting and disgusting in equal measure.
I can’t show you a thrip, as they are too small for my camera lens to capture, but I can show you the damage that their larval sausages do, when they rasp away at the leaves with their mouthparts.
I’ve nearly defeated them by spraying the afflicted plants regularly with insecticidal soap, an organic pesticide suitable for soft-bodied pests. I don’t use any sprays in the garden, as matters there are generally kept under control by the higher-ups on the food ladder eating the lower-downs. And I don’t want to harm any beneficial insects. But, indoors is a different environment. Pests increase rapidly in the heat, and I don’t have birds, hoverflies, ladybirds or other predators to keep order.
Or do I? Recent leaf inspections have shown an increasing number of mummified aphids. A few weeks ago, I had noticed one of these characteristic items, which look like bronze aphid statues, on a chilli plant that was a gift from organic grower Madeline McKeever at Brown Envelope Seeds.
Aphids such as this have been parasitised by a tiny wasp. The female injects an egg into an aphid, and when the larva hatches, it consumes the insect from the inside out. Next, it pupates inside the empty body, and finally, hatches out, leaving a neat round porthole where it exits. Females lay 100 to 300 eggs during their two-week adult phase.
The wasp is so small that it could be mistaken for a fungus fly, but it flits around the leaves of a plant, rather than above the compost or soil.
At present, on the chillies that I treated only once or twice with the insecticidal soap, there are aphid mummies all over the undersides of the leaves, like precious bronze decorations.
This is far more exciting than thrips, which fortunately haven’t reached this side of the conservatory yet. While taking the above photos, I came across a fly on one of the chilli plants. It has nothing to do with this story, but here are two portraits anyway, as I think it is a fine-looking creature. In the first one, it is eating something on the faded flower (aphid honeydew, perhaps), and in the second, it is rubbing its “hands” together in that annoying way that flies have.