04 NATURAL HISTORY. 



and consist of one joint ; the wings show no trace of the false vein which characterizes the Syrphidae ; 

 the tarsi have two pulvilli ; and the abdomen consists of five segments. There is no doubt that this 

 is not only the most varied but also the most extensive family of the Diptera. It includes some 

 thousands of species distributed over all parts of the world, and the species are probably nearly as 



numerous as those of all other families of the order taken together. 

 Of such a multitude it is scarcely possible to make any general state- 

 ments, but it may be remarked that of many species the individuals 

 are excessively numerous, and that in consequence their influence for 

 good or for evil is very great. The larvae are for the most part of 

 the kind known in common parlance as "maggots," and they present 

 a great variety of habits. Many are parasitic not only on other insects, 

 but even on vertebrate animals ; others reside in living plants, and 

 feed upon their substance ; others again seek dead and decomposing 

 CONOPS FLAVIPES. animal and vegetable matter and even the excrements of animals ; 



whilst a few are found in water. Of the latter the most remarkable 



are the Ephydrce, several of which occcur in salt water, and even in the condensed brine of salt 

 works. These have a long breathing tube something after the fashion of the rat-tailed larva of 

 Kristalis tenax. The number of species whose habits render them directly injurious to man and 

 his possessions is not very great when compared with that of those whose action in the economy of 

 nature must be regarded as beneficial, such as the parasites upon the larvae of injurious insects and 

 the consumers of carrion and other impurities. 



In the exceptional genus Conops, already referred to, the antennae spring from a projection of the 

 forehead, and are prominent and longer than the head ; their first joint is short, the second very long 

 and thickened towards the apex, and the third short, stout, and conical, with a short, jointed style at 

 the apex. They are handsome flies, generally black, banded with yellow, and frequent flowers after 

 the manner of the Syrphidae. Their larvae are parasitic in Bees, Wasps, and Grasshoppers. 



Another group of parasitic Muscidae consists of the great genus Tachiiia and its allies, forming 

 the sub-family TACHINARI^;. These have the scales behind the base of the wings very large, entirely con- 

 cealing the halteres, and the bristles projecting from the third joint of the antennae either entirely 

 naked, or hairy or plumose only at the base. Of this group there are several hundred species in 

 Europe alone, and they are abundant in all parts of the world. In the larva state they are parasitic 

 upon other insects of various orders, chiefly, however, the caterpillars of the Lepidoptera, although 

 Beetles, Field Bugs, Earwigs, Grasshoppers, and other Orthoptera, and the larvae of Saw Flies, are 

 commonly attacked by them, and some species live in the nests of Bees and Wasps, while others even 

 attack Spiders. The flies themselves are generally moderately stout and rather roughly hairy. They 

 fly with great rapidity. One of the largest and finest species, which is abundant in many parts of 

 Europe, and not uncommon in Britain, is the Tachina, grossa (see PI. 62, K), which measures two- 

 thirds of an inch in length, and is of a black colour, clothed with bristles rather than hairs, and with 

 the head and base of the wings reddish-yellow. The antennae in this insect are of peculiar structure ; 

 they have the second joint much longer than the third, which is broad and somewhat quadrangular. 



Gymnosoma rotundata is distinguished from the rest of the group by its inflated, nearly spherical 

 abdomen and the absence of the strong hairs which most of them possess. It is leather more than a 

 quarter of an inch long, black, with the abdomen yellowish-red, banded and spotted with black. The 

 larva of this insect is parasitic upon a Field Bug (Rliapldy aster piinctipennis). In Prosena siberita the 

 proboscis is very long and slender, and the bristle of the antennae is feathered, thus indicating a 

 transition towards the next group. Many of the exotic species are adorned with beautiful colours. 

 One of the finest is the Australian Rutilia splendida, which has the upper surface adorned with 

 golden green spots, with blue superficial reflections. 



The MusCAKl^E form a second group having the halteres concealed by the wing scales, but in 

 them these organs are generally smaller than in the Tachinariae, and the bristles of the antennae are 

 feathered or hairy to the apex. This group includes the commonest and best known species of the 

 family, such as the Common House Fly (Musca domestica) and the Bluebottle (Musca vomitoria). 

 The larvae live either upon dead flesh or excrements, and the attacks of some of them iipon meat 



