The Currant Fruit Fly. 217 



tents of the alimentary canal of toads captured during the period 

 that the currant fruit Hies issued in 1915, for it was believed 

 that the trypetids which emerged from the soil with wings not 

 expanded, would be devoured in larger numbers by these nat- 

 ural enemies. One toad was caught on June 4, and three on 

 June 7, during the early mornings while hopping about under 

 gooseberry bushes ; whereas, two were captured on June 7, and 

 one on June 11, during cloudy afternoons after light showers 

 of the mornings had aroused them to activity. A glance at 

 table 9, shows the number of adults which emerged on the dates 

 that the toads were captured, and table 18, indicates the number 

 of specimens taken in shady localities. Dissections of the toads 

 did not show a single trypetid in any part of the digestive canal. 



Fungus Disease. 



Ninety fruit flies captured in the field on June 17, 1914, 

 were "confined in a breeding jar, and of this number one male 

 died of a fungus disease on the following day. A successful 

 attempt was made to spread this disease to healthy specimens 

 under laboratory conditions. Trypetids were confined with the 

 diseased insect for several hours in a vial plugged with moist 

 cotton. These flies were then transferred to a breeding jar con- 

 taining about an inch of moist sand. The disease was contracted 

 by a number of the adults. Healthy individuals were now placed 

 in the jar and numerous specimens succumbed to the effects of 

 the fungus. The dead flies were found glued with the end of 

 the proboscis to the sides of the jar, and the legs were usually 

 bent beneath the body. We attempted to remove one of the 

 imagoes from the glass jar by seizing the abdomen with a pair 

 of forceps and gently pulling, but the mouth-parts were glued 

 so tightly to the glass that the body was torn in two parts. 



Diseased trypetids were scattered in shady localities of a 

 currant and gooseberry garden. A single fruit fly which died 

 of the fungus, was found attached to a currant leaf (Fig. 16, A.), 

 but this specimen may not have contracted the disease from the 

 dead infected insects introduced in this garden. 



An attempt was made to transfer the fungus to other species 

 of fruit flies confined in breeding jars with diseased currant 

 fruit flies. Four sun-flower flies (Straussia longipcnnis Wied.) 

 died of the fungus (Fig. 16, B.) at the end of 10 to 12 days. The 



