BENEFICIAL INSECTS, PREDACEOUS AND PARASITIC 11 



FIG. 5. The twice-stabbed lady- 

 bird (Chilocorus bivulnerus] . 

 o, adult; 6, larva; enlarged. 

 (After Riley.) 



little fellows have frequently been found huddled together under 

 the rubbish at the base of some tree in a last year's cornfield 

 that they might be taken up by the handful without difficulty. 

 Many other species feed upon plant-lice, but the above are the 

 most common, and all bear a resemblance to one another, being 

 generally orange or red with black spots, and of a characteristic 



round or oval form, flattened below, 

 so that the legs may be drawn in 

 under the wing-covers. 



Those ladybirds which feed upon 

 scales are much smaller and are 

 black, though sometimes spotted 

 with red or orange. 



As far as known, there is no 

 way in which these useful allies 



may be encouraged or increased in numbers, but it is trusted 

 that the above may 'give such a brief view of their habits that 

 fewer may be killed through ignorance concerning their true 

 worth. 



Syrphus-flies 



Besides the little beetles described above there is a family 

 of flies, the Syrphidce, many of whose larvae feed upon plant- 

 lice. This family is a very large one, and thus the habits of its 

 different members vary considerably. One of them, the drone- 

 fly, so closely resembles a honey- 

 bee as to be almost indistin- 

 guishable from it. The larva of 

 this fly (Eristalis tenax) is one 

 of the common rat-tailed mag- 

 gots which are found in putrid 

 matter. It is thought that the 

 old " bugonia " superstition of 

 the ancients that bees came from 



maggots in dead animals, etc., was due to the confusion of this 

 fly with honey-bee. 



In another group of the family, the adult flies of which also 

 quite closely resembles bees, the larvae are parasitic in the nests 

 of honey- and bumble-bees, feeding upon their larvae. 



FIG. 6. Syrphus ribesii; enlarged. 



