INSECT PESTS 105 



shipped from Suva, although no specimens have ever been 

 actually found in Fiji.* This is a handsome dark yellow 

 and black fruit fly, 6 mm. in length, head yellow, eyes 

 purplish black, the dorsal surface of the mid-body covered 

 with a dark shield-shaped black patch, the centre with an 

 elongate double bar of silvery white. 



NEMATODE (FLASK-WORM) DISEASE 



Dr. Joseph Bancroft investigated ( a disease of the banana 

 in Queensland in the year 1879. In the course of the 

 rootlets, and also of the main roots from which these 

 spring, are formed gall-like swellings that ultimately are the 

 sites of decay. The symptoms are the yellowing and death 

 of the older leaves while the suckers are stunted, with a 

 tendency for their leaves to be small and crowded together 

 instead of being large and widely expanding. This disease 

 is due to the development in the root -galls of certain 

 minute worms, and the subsequent decay of the galls and 

 of the roots themselves. Dr. Bancroft named the disease 

 the "Flask-worm Disease" from the form of the worm 

 when mature. The worm is a species of nematode J which 

 was also found attacking the China banana at Cairo, as 

 well as other species of plants. The disease may be 

 combated by ploughing up the fields and leaving them 

 fallow for some time. But the disease is very insidious, as 

 it may be brought from surrounding districts by various 

 agencies, and it is very difficult to eradicate when once 

 started. 



A black smut fungus (Glceosporium musarum) was also 

 reported. It covered the leaves and spread rapidly. 

 Burning the plants and liming the soil are effective 

 remedies. 



* " Report on Parasitic and Injurious Insects," Dept. of Agric., N.S.W., 

 1909, p. 93. 



t H. Tryon in Queensland Agric. Journ,, xxviii. 178 (1912). 

 J Tylenchu* radicicola. 



