94 



CALIFORNIA STATE COMMISSION OF HORTICULTURE. 



into the body of their host, where they remain until they have attained 

 their growth. We have often been disappointed when, after caring for 

 a choice specimen of caterpillar, until it passed into the chrysalis state, 

 and were watching anxiously for it to come out, to have a small hand- 

 ful of Tachnid flies reward us for our pains. 



In California one species of Tachininas is a most effective check upon 

 the locust pest. This is the Masicera pachytyli Sk., and where there is 

 a flight of grasshoppers these flies will be found in countless numbers, 

 and the grasshopper which escapes them is rare. It is the natural 

 enemy of the grasshopper, feeding most voraciously on the adipose 

 tissues of its victim, but avoiding the vital parts. It feeds in the 

 thorax and abdomen, and frequently three or four may be found in a 

 single grasshopper. A grasshopper infested by these maggots soon 

 shows signs of feebleness, ceases feeding, and dies in a short time, the 

 maggots escaping often before the death of the host insect. The 

 maggots, after extricating themselves from the grasshopper, enter the 

 ground to pupate, and emerge in five or six days as perfect flies. 



There is no more effective check upon cutworms and other lepidop- 

 terous pests than the Tachina flies. 



The subfamilies Sareophaginse, the flesh-flies, and Dexiinse, the 

 nimble-flies, are of less importance to us. 



The subfamily Museinse, however, embracing the house-flies, and 

 other species equally obnoxious, forces itself more upon our consider- 

 ation. The house-fly 

 (Musca domestica) is 

 known by every one 

 the world over. It is 

 a highly sociable in- 

 sect, and clings to 

 mankind with a te- 

 nacity more to be 

 repudiated than ad- 

 mired. Its breeding 

 places are around 

 stables, and a female 

 will lay from 120 to 

 1BO eggs. The larvae 

 attain their growth in 

 from five to seven 

 days, pass through 

 their changes in an- 

 other five to seven, 

 and then make a line 

 for our houses. Keep- 



FIG. 82. Screw-worm fly (Compsomyia maceltaria), enlarged, 

 a, adult fly; b, larva. (After Francis.) 



