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F U R T H E R OBSERVATIONS ON T H E L I F E A N D H A B I T S O F T H E F I E L D D I G G E R WASP. (.Mellinus arvensis, Linn.). C A T C H I N G ITS P R E Y . — I have watched t h e m catching flies u p o n the over-ripe fruits of the dewberry {Rubus caesius) in the m o n t h s of August and September on West Stow H e a t h . T h e wasp does not stalk its prey, there being no need for this as flies and wasps both infest the fruits, sippmg the juices. Atter the wasp has been refreshed in this way, it then has a casual walk or fly round amongst the flies, w h e n suddenly it s p n n g s u p o n the back of the species of fly which it has selected, holding the fly's wings down with its feet and grasping its proboscis with its mandible. T h e fly thus secured, the wasp then curves the tail e n d of its a b d o m e n u n d e r the fly's thorax and inserts the sting, paralysing the fly. It t h e n t u r n s it over on its back and gathers it together, carrying it over the foliage until it has f o u n d a clear take-off. T h i s accomplished, away it flies, carrying its b ü r d e n to the nest. M A T I N G AND P A I R I N G . - M a l e pupae are the first to complete the metamorphosis and appear seven or more days earher than the females. I n this time they loiter and fight each other around the nest holes. By means of a glass jar I captured male and female in the act of pairing and was thus able to observe the proceedmgs as related below. After being joined and moving about in this position for some few minutes, the female rested for a second or t w o and hen proceeded to curve her body inwards to f o r m a complete circle, the male lying upon his back with head and thorax nused clear of the bottom, thus its body formed a half circle. T h e female then proceeded to release the male, using its mandibles to clasp its own abdomen, biting and stroking it simultaneous y bearing downward to the tip, where b o t h were j o m e d This action with Short rests was repeated three times before the male was released and, w h e n he at last gained his freedom, appeared none the worse for this natural oraeal. I t will be seen f r o m the observations that the male is helpless and unable to free himself and remains f r o m the m o m e n t ol pairing at the mercy of the female. C O C O O N S AND P U P A . — F r o m the observations I have made it appears that unless the sand contains a certain a m o u n t of moisture, the p u p a dries and perishes in the cocoon. HENRY J.


Further observations on the Field Digger Wasp  
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