256 PREDACIOUS AND PARASITIC 



But among the Neuroptera, in many species, the larvoe of which 

 live an aquatic life, the pupal form is characterised by an equal 

 amount of activity, and the imago emerges from the pupa still 

 enveloped in a delicate casing, which is thrown off after a short 

 interval. Other deviations from the normal metamorphosis also 

 occur, and will be of interest when, later on, we examine the 

 classification and internal anatomy, though, at present, we are only 

 concerned with the habits and characters of those species which 

 are Aphis-eaters, and among these the transformations are fairly 

 normal. 



The elegance and brilliancy, the ferocity and strength of wing 

 which distinguish some members of this order have always ren- 

 dered them attractive objects to those who take an interest, even 

 in a casual way, in the observation of nature. 



Mr. R. Maclachlan, writing in the pages of the Ento. Transac- 

 iiojis^ in 1868, in those valuable monographs which are the 

 standard authority on the Ahuroptera, says of them : — "The larvae 

 of these delicate insects play a great part in the economy of 

 nature, and must be considered as benefactors of the human race 

 in no'small degree. With those of Cocciiiella and Syrphus they 

 help to counteract the extraordinary fecundity of the Aphides, and 

 although their numbers are seldom so great as those of the Cocci- 

 iiella^ yet, from their activity and from the short time they take to 

 extract the juices of their prey, they must destroy innumerable 

 multitudes of these pests of the horticulturist." In another place 

 he refers to the well-established habit of some of these insects to 

 feign death when in peril. " Most of these insects fall down on 

 one side and feign death when disturbed, the legs being then 

 doubled up, the head drawn under the thorax, and the antennae 

 concealed." 



In the early mornings of hot summer days and late in the 

 afternoons, and even sometimes in the heat of the day, the great 

 Dragon Fly {Libellula) or the elegant and slender Demoiselle 

 {Calypteryx or Agrion) may often be found in the neighbourhood 

 of sheltered streams, and occasionally in open pastures or about 

 roadside hedges, in rapid flight after some insect, by the capture 

 of which they will satisfy their carnivorous instincts. Among the 

 weeds of the neighbouring streams, the larvae follow an aquatic 



