84 



A. antiqua, Gyl. {aerea, Perty) ; Brahmina fumila, Sharp ; Lepadoretus 

 cmnpressus, Web. ; Adoretus sciuiinus, Burm. ; Holotrichia leucop- 

 thalma, Wied. ; H. helleri, Brsk. ; Popillia higuttata, Wied. ; and 

 several undetermined species of Serica. 



The underground habits of the larvae protect them very considerably 

 from the attack of insect parasites. The adults are destroyed by owls 

 and bats, as well as by crows and starlings, which follow the plough 

 and pick up the grubs. The following Scoliid wasps are known to 

 parasitise the larvae : Dielis anmdata, F. ; D. luctuosa, Smith ; 

 D. tristis, Sauss. ; D.javana, Lap. ; D. thomcica, F. ; D.formosa, Guer., 

 Triscolia rubiginosa, F., as well as two undescribed species of Dielis 

 and an undetermined species of Tiphia. The bionomics of these 

 insects is given at length, and it is stated that about 26 percent, of the 

 beetle larvae are parasitised by D. thoracica. A species of Sarcophaga 

 and a Tachinid parasitise Leucopholis and Euchlora, but there is no 

 evidence of effective control. Attempts have been made to obtain 

 beneficial parasites from the United States and from Porto Rico, 

 but these have been unsuccessful, as have trials of various fungi. 

 Observations are in progress on parasites of the useful Scoliids with a 

 view to their destruction ; large numbers of Dielis tJioracica hi.Wd 

 been found dead and an undetermined Conopid fly is suspected of 

 being the cause. Apparently the only practicable method of getting 

 at the larvae is by ploughing and cross ploughing the land, collecting 

 all the larvae possible by hand and allowing crows and other birds 

 to assist in their destruction ; this method is, however, costly both 

 in time and money, amounting to more than £2 10s. per acre. The 

 results are given of experiments with a number of chemical poisons, but 

 the author comes to the conclusion that none of them were of any 

 use against grubs attacking the roots of the living plants, though 

 carbon bisulphide proved the best. As the grubs of Leucopholis 

 absolutely refuse to eat Agave it is suggested that this plant should 

 be used in rotation and that, in this way, a given area of ground might 

 be cleared of the pests by a process of starvation. 



Hall (C. J. J. van), Rutgers (A. A. L.) & Dammermann (K. W.). 

 Bestrijdingsmiddelen tegen Plantenziekten en schadelijke Dieren. 



[Methods of combating plant diseases and injurious animals.] — 

 Dep. Landbouw, Nijverheiden Handel. — Med. van het Lab. v. Planten- 

 ziekten, Buitenzorg, 1915, 42 pp., 13 figs. [Received 16th 

 December 1915.] 



This is a general review of the methods now employed for the 

 control of insects and fungi attacking cultivated plants. These are 

 classified under the following heads : Indirect methods include the 

 cultivation of crops so as to secure a maximum of power of resistance ; 

 the results of the use of stable manure for Coffea robusta is cited as an 

 example, and the fact that feeble plants are specially attacked by 

 scale-insects and Aphids. The choice of disease-resisting varieties is 

 exemplified in the good results obtained in Java coffee cultivation, 

 which formerly suffered very seriously from leaf disease ; sugar 

 cultivation in the Antilles has been similarly helped by replacing the 

 highly susceptible Bourbon variety of cane by other sorts, and in Java 



