Wednesday, 24 August 2016

Grasshopper hunting wasps.

 In late summer when one opens a window, it is not unusual to find the groove at the bottom packed with pieces of cut hay packaging a number of small 'grasshoppers'.  The green insects are in fact 'sauterelles' as the French call them. To create confusion in English they are called crickets, whilst to make that yet more confusing what the French call criquets, the English call 'grasshoppers'.
Wasp hoard of hay and oak-bush crickets
This mass of sauterelles and hay is placed there by a large black and red wasp named Sphex rufocinctus.  The sauterelles are Meconema meridionalis - In English called the southern oak-bush cricket.  This species is quite tiny rarely reaching 15 mms.  Indeed they are small enough to be confused as larval forms. They tend to hide away during the day underneath the leaves of oak, high up in the trees.  
The crickets are paralysed by the wasp. And into this heap of Hay and crickets, the wasp lays about one egg to every four crickets.  After  some short period the eggs hatch and the larvae commence to eat the food stored for them. That you can see in the photo on the right.
These larvae will then pupate first enveloping themselves in silk rather as caterpillars will do.  The firm dark brown pupae will await there till the next spring.

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