148 



FuLLAWAY (D. T.). Division of Entomology. — Hawaiian Forester and 

 Agriculturist, xiii, no. 11, November 1916, pp. 401-402. [Received 

 24th January 1917.] 



During the month, 1,615 females and 1,015 males of Opius Jletcheri, 

 1,800 Tetrastichus, 400 Chalcids and 387 Diachasma tryoni were 

 Uberated. The corn leaf-hopper egg-parasite is being propagated in 

 the open and small numbers have been distributed. 



Pests of Sugar-Cane in British Guiana. — Agric. News, Barbados, xv, 

 nos. 382-383, 16th and 30th December 1916, pp. 410-411 & 

 426-427. 



These notes review the reports for the years 1914 and 1915 by 

 Mr. H. W. B. Moore, and deal with many of the same pests as those noted 

 in a previous one [see this Review, Ser. A, ii, p. 57]. The small, black 

 hard-back {Dyscinetus bidentatus) came into prominence in 1914, 

 after the heavy rains, and caused 75 per cent, of the damage in the 

 fields examined. This outbreak lasted into August ; a second 

 outbreak in December did only a small amount of damage. Two 

 attacks occurred in 1915, the first in January on two estates, on one 

 of which it was severe, and the second from April to the end of July, 

 which was generally slight. Some details of the life-history and 

 habits of this beetle are given. The larvae live in the earth about 

 the cane stools, feeding almost entirely on soil containing decayed 

 vegetable matter. They must be destroyed before they can develop 

 into the destructive adults. The beetles are active at night, but 

 hide in the day time. Two things are essential for the growth and 

 development of this beetle, viz. : an abundant and long-continued 

 supply of moisture and decaying vegetable matter. Where the 

 larvae find the cane stools decayed or in poor condition, and the 

 moisture conditions suitable, they are almost certain to cause serious 

 damage to crops. The larva of the large moth borer [Casttiia licus) 

 is primarily the cause of the bad state of the cane stools, but poor 

 or unsuitable soil and bad weather are also responsible. Among 

 the decaying stools, besides the hard-back, may be found weevil 

 borer larvae, stool moth larvae {Acrolophus sacchari), root scale 

 (Aspidiotus sacchari) and wood ants. 



The best protection against D. bidentatus lies in a vigorous condition 

 of the cane stools and the control of stool-eating insects, such as Castnia, 

 and more frequent replanting, as ratoons suffer most from this pest, 

 are advised. Digging out of dead stools enables grubs to be collected 

 in large numbers, and their exposure to sun and wind causes the 

 destruction of many eggs. Replanting should not be carried out 

 on land previously occupied by such grasses as arrow-grass {Anatherum 

 bicorne) or razor-grass, the shoots of which are attacked by the hard- 

 back in the same way as sugar-cane. Trap lights were tried in 1915, 

 but were not successful ; nor was the night collection of the adults 

 with lanterns. D. bidentatus was parasitised in 1914 and 1915 by 

 Tiphia parallela. Another Scoliid, Dielis dorsata, was also observed, 

 though it is uncertain which species of hard-back it parasitises. 



The smaller moth borers {Diatraea saccharalis and D. canella) are 

 still the most important sugar-cane pests, in spite of the great collection 



