198 OTHER DENIZENS OF THE WOODS 



hind-border a large ringed velvet-black spot, with an inner lining of rusty red. It 

 deposits its eggs in the eyes of young apples, one only in each, by inserting its long 

 ovipositor between the divisions of the calyx ; and, on emerging from the egg, the 

 larva bores into the crown of the apple where the rind is always thinnest. The 

 flesh of the apple is first attacked, then the pips, until the fruit falls, when the larva 

 creeps out by the hole it made on entering, and, climbing a tree, chooses a crevice 

 in the bark, which it gnaws and smoothens, and, weaving in it a white silken case, 

 goes to sleep there for the winter, not becoming a pupa until the following May. 

 In short, the larva of the codlin moth is the " fruit-maggot," which causes " worm- 

 eaten " fruit, and brings about at least as many " windfalls " as the wind. 



The great group of flies (Diptera) are characterised — in so far 

 as they are not entirely wingless — by possessing only one pair of 

 membranous wings, behind which are the club-like organs known as balancers or 

 " halteres," representing the hind-pair of wings in the Hymenoptera and other 

 orders. The larvae — mostly known as maggots — have no legs, and, as a rule, are 

 cylindrical or thread - like, and long and flexible, though differing in details of 

 structure. The pupa? are generally barrel-shaped, being longish oval in form, and 

 permitting the escape of the fully developed insect, either by the fore-part of the 

 envelope springing open like a lid, or by splitting longitudinally. Most flies 

 require but a short time to develop, and hence, as they find food the whole summer, 

 produce several generations in a year. Their numbers, and their taste for blood 

 make them the most troublesome of all insects ; while many of them, in one way 

 or another, are the propagators of various diseases. 



Among the Orthorrhapha, or section with straight-seamed wings, perhaps the 

 most important group is that of the gall-midges {Cecidomyidce), small insects, re- 

 stricted as larvae to certain plants, on which they produce singular malformations, 

 while as adults they lay their eggs on certain parts of the same plant, often far 

 away from the malformation caused by the larvae : indeed, no part of the plant 

 may remain free from attack. 



Another group of importance is that of the fungus-midges, among which are 

 the army-worm, the yellow-fever fly, and the pear-midges. The small pear-midge 

 (Sciara pyri), Like its larger namesake, deposits its eggs in the blossom of the pear 

 as soon as it opens, and the larva eats its way into the core of the growing fruit, 

 drops with it to the ground, and gnaws its way out when the time arrives to 

 1 lury itself in the earth, and pass into the pupa-stage. These pupae develop into fine- 

 haired gnats only -j 1 ^ of an inch in length, with black head, thorax, and antennae, 

 white stems to their balancers, and black rings round the lead-coloured abdomen. 



„ „. The brilliantly coloured hover-flies are to be met with in the 



Hover-Flies. « 



haunts of plant-lice. Like buzzards, they hover for a long time at 

 the same height, and then in a series of short jerks dart off and deposit their eggs 

 on some leaf or twig. Here the emerging larvae, like leeches, fasten on the plant- 

 lice, which may often be observed creeping carelessly about as their enemies suck 

 their comrades dry. Among the commonest species of the family is the gooseberry 

 hover-fly (Syrphiis ribesii), living as a larva on currant and gooseberry bushes. It 

 is over a quarter of an inch long, and has a greenish thorax, yellow shield, reddish 



