TREES AND SHRUBS 



In the great family of Muscidce, to which the House-fly and Blow-fly 

 belong, we have a genus which consists of flies in some respects resembling 

 the Ichneumons. Nearly two hundred British species have been described. 



One of the best known is Tacltina ferox. This species has the head 

 tinged with grey : and the abdomen is yellowish, shining like horn, and 

 black along the middle. The female lays her eggs upon the bodies of 

 various caterpillars, and the young larva 1 penetrate into the body of the 

 caterpillar, and feed upon the fatty tissues. Not only are the caterpillars 

 of Butterflies and Moths attacked, but various species are known to infest 

 the larva 1 of some Coleoptera. Hymenoptera. and even the bodies of spiders. 



The species Tachina grossa is so large and hairy that it might be easily 

 mistaken for a black humble-bee. Its body measures J in. in length, and 

 the wings have an expanse of 1| in. 



"We will conclude this brief review of some of the gardener's friends with 

 a mere reference to one which he would scarcely care to encourage, but which, 

 nevertheless, does him good service in keeping down the number of his enemies. 

 It is the Hornet (J^espa crabro), the largest and most formidable of British 

 wasps. The queen may measure 11 in. in length, and the wings may expand 

 over 2 ins., but many of the workers are no bigger than the common wasp. 

 The nest is usually built in outhouses or the hollows of trees. The food of 

 the Hornet consists of other insects, and is largely composed of wasps. 



/ 



