GADFLIES AND BOTFLIES 3033 



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

 toward 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 

 C. capitata 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 larvae upon hatching start at once to devour the nutritious 

 food. The infected fruit drops to the ground, and the larvae when mature pass out 

 to become pupae beneath the earth. Besides oranges and other acid fruits, peaches 

 and melons are attacked by this fly. The annexed figure represents another of 

 these injurious little insects (Chlorops tceniopus}, a shining yellow fly variegated 

 with black bands. This species and its allies, which 

 are most destructive in the larval stage to cereals and 

 grass, much resemble in the cycle of their development 

 the before-mentioned Hessian fly. Allied to the pre- 

 ceding in structure and habits are the members of the 

 subfamily Ortalincz, containing the genus Ortalis and 



others. A curious representative from the Malay Arch- chiorops taniopus, with figure show- 

 ing side view of head. 



ipelago, known as the stag-horn fly {Elaphomyia) , takes (Much enlarged.) 



its name from the development of the sides of the head 



into large branching horns. This, however, is only a sexual characteristic, and con- 

 fined to the male. Finally, the small black fly {Piophila case?), known in the grub 

 stage as the cheese hopper, belongs to that group of Muscidce in which there are 

 no scales to cover the balancers. 



GADFLIES AND BOTFLIES Family 



The flies of this family are mostly of large size, and many present superficial 

 resemblance to various kinds of bees. In structural characteristics they are nearly 

 allied to house flies, but the head is larger and broader and the mouth parts are 

 reduced. In the larval stage gadflies infest, either as internal or external parasites, 

 various mammals, but since those that attack domestic cattle have been more 

 thoroughly studied than the others, attention will mainly be directed to three of the 

 best-known forms, namely, those that infest respectively horses, oxen, and sheep. 

 The horse botfly {Gastrophilus equi}, which resembles the honeybee in size, color, 

 and form, lays its eggs on the skin of horses, asses, and mules, which seem to 

 have an instinctive dread of the insect. It has been noticed, moreover, that the 

 gadfly instinctively selects for the purpose a spot that is well within reach of the 



