 Wild About Britain
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Ian Gray
Officer of the Wild Empire
Registered: December 2006
Location: coventry
Posts: 794
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Thu February 28, 2008 2:17pm
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interesting sequence of photos hedgerow. does this wasp rely solely on acorns to reproduce.
Ian
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"A smile increases face value"
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hedgerow
Wild Member
Registered: January 2008
Posts: 116
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Fri February 29, 2008 12:42am
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not neccesarily on the acorn itself in a way but always in the acorn bud for the agamic generation only. The eggs are layed in the bud of the acorn and can be seen in place of the acorn or on the end or side of it. The agamic generation is the second generation of the year which consists of entirely female wasps that form the knopper gall. They overwinter in the gall and emerge in spring to lay their eggs in the catkins of Quercus cerris. These then form small rugby shaped galls with male and female wasps inside. When these wasps hatch they mate and repeat the cycle by laying in acorn buds. It is more a case of relying on Quercus cerris for the life cycle, as does Andricus kollari, and without the turkey oak cannot colonise new areas.
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For everything I learn, 100 new questions need answers.
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Ian Gray
Officer of the Wild Empire
Registered: December 2006
Location: coventry
Posts: 794
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Fri February 29, 2008 1:41pm
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thanks for the extra info hedgerow. It's a fascinating subject, but similar to your signature- for everything I learn, I forget A 100 answers.
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"A smile increases face value"
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Ian Gray
Officer of the Wild Empire
Registered: December 2006
Location: coventry
Posts: 794
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Fri February 29, 2008 2:50pm
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one further question hedgerow I assume the gall will fall to the ground with the acorn. If it over winters here doesn't the gall suffer from decay and damp lying on the woodland floor.
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"A smile increases face value"
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hedgerow
Wild Member
Registered: January 2008
Posts: 116
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Fri February 29, 2008 4:27pm
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they tend to fall just before the acorn crop falls, whether this is a way of avoiding jays and squirrels is pure conjecture, and are then covered by the leaves which protect them from frost. the damp does not seem too bad other than promoting a good environment for fungal growth. fungus is lethal to something like these that can not run away yet enough of them survive the winter to breed the following year. There are some cynapid gall wasps that have sterile conditions in the gall, preventing bacterial infections, maybe there is an antifungal capability as well. I have no proof of this last point and is just a suggestion, but maybe a nice one.
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For everything I learn, 100 new questions need answers.
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