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Iprc&acioue & Iparaeitic lEneiniea of apbibee 



(tncluMno a Stub^ of IT^i^pet^parasttes), 



By H. C. a. Vine. 

 Part III. Plates XVIII. and XIX. 



'^T^HE Hymenoptera as originally arranged by Linnaeus included 

 X those four-winged flies whose wing venation, differing 

 wholly from the Hymenopterous type, consists of longitu- 

 dinal nervures, more or less connected by transverse branches. 

 The value of this character has been strongly disputed by later 

 naturalists, but it seems probable that in this, as in so many other 

 instances, the generalising insight of Linnaeus led him to a con- 

 clusion which the labours of entomologists will ultimately confirm. 

 I may be able in the succeeding section to adduce some facts 

 which bear upon this question of the relationship of the Odonata 

 to the Flanipetinia, which has a certain interest in connection 

 with the aphidivorous genera, as establishing their relationship to 

 a very destructive carnivorous group, which dates back in geolo- 

 gical times to the Palaeozoic formations, and which may be contin- 

 uously traced through the Triassic and Oolitic strata. Indications 

 of the aphis-eating genera are not found until a late date, the 

 remains being found chiefly, I believe, in the Tertiary deposits. 

 This may be accounted for partly by the more delicate and fleshy 

 nature of the HemerobiincB^ and if we accept their relationship with 

 the Odonata as established, we may consider the probabilities of 

 their later appearance as arising from their being the product of 

 selection acting upon the more plastic species of the earlier 

 Neuroptera. 



The beauty and elegance which characterise so many of the 

 Neuroptera are not wanting in those genera which, being aphidi- 

 vorous in their larval stage, come within the scope of the present 

 memoir. It is true that in Hemerobius one sees little save a dull 

 and often somewhat clumsy brown insect sometimes resembling a 

 small moth. But a slight examination of the wings reveals an intri- 

 cate venation and often a beautiful mottling which this genus 

 shares with many of the larger dragon flies ; while the delicate 



