Thursday, July 18, 2013

Aphids living on borrowed time...........




































The tops of the broad beans in our garden are infested with aphids that are breeding at a phenomenal rate in this hot weather.


The wingless forms stay more or less where they were born, sucking sap from the plant, while the winged forms disperse from plant to plant. There's a simple way to control infestations like this now that the beans have finished flowering - just break off the aphid-infested tops - but natural predators are also doing their bit.


If you take a close look at the top aphid in this group you'll see a white cylindrical object next to it: that's a hoverfly egg, one of many that have been laid amongst the aphid colonies. As soon as they hatch the hoverfly larvae have almost unlimited food within easy crawling distance. It only those aphids knew the horror that is about to be unleashed .....

You can see what happens next by clicking here.



2 comments:

  1. What about the aphids' other predator, the Ladybird? Have you had a dearth of these, too, I wonder? Last year I was sending records off to the two UK Ladybird Surveys at very frequent intervals ...

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  2. Now you come to mention it Caroline, I have seen very few ladybirds since early spring. I wonder if it's due to the late spring, with late egg laying and late appearance of the first generation, or whether something else is amiss. There was one year, about a decade ago, when a parasite drastically reduced ladybird numbers. Whatever the cause, there are far fewer ladybirds in our garden than there were twenty years ago.....

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