DIPTERA. 



7i 



spiny fly (Echini 



1. WITH LARVA 



AND PurA (nat. size). 



representative of the family found in Britain, It is about two-thirds of an inch 

 long, with a short, broad, oval abdomen ; the shining- black of its body being 

 relieved by the reddish yellow colour of the head and the base of the wings. The 

 allied species (E. ferox) represented in the illustration is brownish, with the 

 abdomen tinted with red at the sides. Belonging to the same subfamily is 

 the Australian fly Rutilia, remarkable among the order for 

 being ornamented with bright metallic green spots. By rea- 

 son of their external form and general colouring the flies of 

 the subfamily Anthomyince appear to the casual observer 

 to be nothing but ordinary house-flies ; but they may be 

 distinguished from the latter by the absence of the apical 

 transverse vein on the wing (marked d on the figure of the 

 fly's wing on p. 48). The scales, moreover, which cover the 

 halteres are very small, and lead up to the condition found 

 in those flies in which they are absent. The larva3, which 



differ from those of the house and blow-flies in being covered with spines, live on 

 plants of various kinds, those that have attracted the most attention being the 

 species that attack cultivated vegetables, such as onions, cabbages, lettuces, radishes, 

 and the like. Those members of the family having no scales covering the balancers 

 and assigned to the subfamily Trypetince are generally of small size, many 

 being very obnoxious on account of the damage inflicted by their larva) on 

 various marketable vegetables. Of the numerous species it is only possible to 

 a notice a few. The first is the painted-winged as- 



paragus-fly (Platyparea pceciloptera), which, as its 

 name indicates, has variegated wings, and attacks 

 asparagus. The male is smaller than the female, ;is 

 shown by the length of the lines in the figure, and 

 the latter sex may be recognised by the possession 

 of a long ovipositor, by means of which she deposits 

 her eggs between the scales of the head of the 

 asparagus. The laying takes place about the begin- 

 ning of May, and in two or three weeks, according 

 to the season, the eggs hatch, and the larvae burrow 

 into the stalk of the plant. In a fortnight or so 

 the latter reach maturity, and, after passing through the pupa stage, develop 

 into flies towards the end of June. Many more or less nearly allied species are 

 found in England and other countries, but it will suffice to indicate a few of the 

 more important. Of these the cherry-fly (Spilographia cerasi) and the olive-fly 

 (Dacus olece) devour in their larval stages the fruits after which they are named ; 

 while the various species of the genus Ceratitis similarly attack the orange. 

 Recently G. cwpitata was very destructive to the mandarin oranges in Malta, and 

 seems to have been first introduced into the island about twenty years ago. This 

 fly is lively and hardy, as shown by the fact that a specimen kept under a glass 

 shade without food maintained its activity for twelve days When egg-laying, the 

 female chooses the side of the fruit exposed to the sun. where it perforates the rind 

 so that the larvse upon hatching start at once to devour the nutritious Eood. I he' 



asparagus fly, $ male ; $ , female. 

 («) Front view of head. 



