85 



Chiari (M.). Due Vermi delle Castagne. |Two Larvae injurious to 

 Chestnuts.] — Riv. Agric, Parma, xxvi, no. 50, 10th December 

 1920, p. 631. 



The larvae of Cydia {Carpocapsa) splendana, Hb. (chestnut tortrix) 

 and Balaninus elephas, Gyll. (chestnut weevil) are briefly described. 



In Italy C. splendana oviposits in June on chestnut, walnut, and 

 hazel, and the caterpillars mine the fruit. Nuts thus injured are 

 distasteful to cattle. B. elephas oviposits in June ; its larva attacks 

 chestnuts and acorns. When the infested fruits fall, the larvae enter 

 the ground and hibernate there. The only measure advised is the 

 collection of infested fruits and their destruction by feeding to cattle. 



MjoBERG (E.). De Rupsenvraat in de Tabakscultuur ter Oostkust van 

 Sumatra. Caterpillar Injury to Tobacco Cultivation on the East 

 Coast of Sumatra.] — Meded. Deli Proefst., Medan, Ser. 2, no. xv, 

 1920, 54 pp., 4 figs. 



The development of tobacco cultivation on the East Coast of 

 Sumatra has destroyed the balance of nature there, and during recent 

 \'ears there has been such a steady increase in leaf injury as to con- 

 stitute a serious menace to tobacco, now the chief crop in Sumatra. 

 The injury is due mainly to the caterpillars of Heliothis {Chloridea) 

 obsoleta, F., Prodenia littira, F., and Phytometra {Pliisia) sp. In the 

 higher-lying plantations Orthoptera occur and are quite as harmful. 



In 1918 the average of leaf injury from 80 estates amounted to 

 33 per cent., equivalent to a loss of about ;^750,000 at par. Handhng, 

 heav}' rains, storms, and scorching by insecticides are responsible for 

 10 per cent, of this loss ; 90 per cent, may be ascribed to insect attack, 

 60 per cent, occurring in the field and 30 per cent, in the drying sheds. 



Radical measures are now needed, and the author suggests that 

 attention should be chiefly directed to suppressing the first generation 

 in the fields. Severe damage is done during the first five weeks after 

 the seedlings are planted out, and after harvesting the caterpillars of 

 Prodenia and Phytometra are carried in large numbers into the drying 

 sheds, where thej^ continue feeding. 



The seed-beds must be kept absolutely free from the caterpillars so 

 that they can never act as foci of infestation. This is attained by 

 spraying with a solution containing 2 per cent, lead arsenate and 3 

 per mille soap. The latter is best added in the form of a concentrated 

 solution. The addition of soap is very advantageous, as the poison is 

 better distributed and the spray adheres better and longer to the foliage. 

 Repeated applications must be made as the protection onh' lasts for 

 4 to 6 days. The beds should not be watered on the same day after 

 spraying, but the application should be particularly abundant either 

 on the day of planting or on the day before ; the seedlings must be 

 quite white with the poison when they are planted out, and will remain 

 so for 7 to 10 days. The adhesive power of the spray is such that eight 

 waterings are needed to wash it off completely. It can also withstand 

 rain if it is not \'ery heavy. This method renders superfluous the 

 expensive cloth coverings for the seed-beds, estimated to cost on an 

 average o^•er ;^"400 per estate per annum. Furthermore the cost of 

 searching for caterpillars in the beds is saved. 



This method was tried on a large scale in March and April 1920 

 on one estate with 7,000 seed-beds, and proved entireh" successful, 

 Paris green does not, however, give satisfactory' results. 



