32 



Convergent Ladybiru {Hip[i<iihniii(i ronverr/ens). 



(Fig. r,. I 

 This beetle works destruction to aphis and scale insects, and is quite 



llUOU. 



Lace-Wi>'ged Fly (Chnjxopu ociilata). 



Larva. Adult. 



(Fig- 7. 1 

 When the Ladybirds are great destroyers of scale and aphis, the larvre of 



the Lace-winged flies rid trees and plants of million of Apliida: The fly has 



a slender body, with delicate, gauze-like wings, and its colour is generally 



green with gi>lden eyes. The eggs are dejiosited on pedicles and laid in the 



midst of a group of aphides. The larva is supplied with sharp mandibles, with 



which it attacks the aphis. 



Syrphus Fly'. Hovering Fly'. 



Fig. 



Natural size 



Fig. 2. 

 (Fig. .S.I 

 In tho above outs Fig. 1 rpprpsents the fly ; Fi 

 which lit transtorm.s into a fly : and Fig. 



Natural size 



2. magnified, the case in 

 magTiified. the larva. 



The Syrijhus flies are also great destroyers of aphides. The larvse feed 



entirely upon aphides, and appear and disappear as the aphides appear and 



disappear. The larva is a footless, eyeless, flattened, transversely wrinkled. 



gaily coloured, green and purple maggot, having a very extensile body, which 



enables it to reach up and grasji the aphis with its jiecuiiar looking mouth. 



The sin.gle egg. deposited in a .group of aphides, hatches fort.v-eight hours after 



it is laiil. and the larva becomes full-grown and transformed into a luijia in five 



or six da.YS. The reason of this extremel.v rapid development in the first two 



stages, the egg and the larva, is exi>lained when we consider how brief is tlie 



existence of the aphis, and how suddenly its colonies appear and disajjpear. 



When the larva is actively feeding, it destroys dozens of aphides, one after the 



other, and its body changes colour. When filled to repletion the larva falls into 



