424 



numbers each year, destroying an average of 25 per cent, of the crop. 

 The various stages of both moths are described. Their hfe-history 

 and the injury they cause are so nearly identical that it is almost 

 impossible to tell which insect is responsible for the damage. 



The first moths appear in the potato fields about the middle of 

 September, being active at night and remaining hidden by day. Eggs 

 are laid on the leaves or tender shoots of potato plants, or directly 

 on the tubers if these are exposed. The young larvae first feed on the 

 green part of the plant and then descend to the tubers, in which the}' 

 construct galleries, from which they issue when mature to pupate 

 under some slit in the skin of the tuber, the adults appearing about 

 20 days later. In the southern and central Provinces there are as many 

 as three generations during the spring and summer, but in the north, 

 where the climate is warmer, all stages of the insect may be found 

 at any time. The injury is two-fold, in the field, and in storage, 

 where breeding and destruction of the tubers continues. 



There is no one decisive remedy for these insects, and several methods 

 have to be used in conjunction to reduce the infestation within reason- 

 able limits. Land that is required for potatoes should be cleared of all 

 weeds, especially wild Solanaceous plants that might harbour the insects, 

 and should be kept clear for as long as possible before planting with 

 potatoes. During the growth of the plants the soil should be kept 

 cultivated and free from weeds, and any plants that show signs of 

 infestation should be at once taken up and burnt. In places where 

 potatoes have been cultivated for a number of years and where the 

 moths have been breeding unchecked, rotation of crops should be 

 practised, all Solanaceous plants being dug up, and cereals, beans, 

 melons, lucerne, clover, etc., substituted for a 3/ear or two. The 

 soil should be kept very fine and without lumps, as neither larvae 

 nor adults can make their way easily through such ground to the 

 tubers. The plants should be well hilled up so that the tubers are 

 not exposed. Before taking up the crop, all dried-up plants should 

 be pulled out and laid in piles along the lines. A day or two later, 

 early in the morning, these piles should be burnt. Larvae, pupae 

 and adults all shelter under these piles and may thus be destro^^ed. 

 After the crop is up, it should be removed as quickly as possible in 

 order to avoid infestation by the adults that have survived. Before 

 storage, any affected tubers should be separated and either destroyed 

 or boiled at once and used as food for stock. When the crop is to be 

 kept during the winter or to be used as seed it should be inspected 

 again two weeks after gathering and should be sjtored in a well ventilated 

 building, all openings being screened by fine wire mesh. Storehouses 

 that are found to be infested should be disinfected uith carbon 

 bisulphide used at the rate of 2 lb. per 20 cu. ft. of space. This 

 process should be repeated at least once after a two weeks' interval. 

 As the moths are attracted to lights, an acetylene lamp set in a 

 wide, open receptacle makes an excellent trap either in the field or' 

 storehouse. 



Las Cuncunillas. — Serv. Policia Sanit. Vej., Santiago de Chile, 1921, 

 8 pp., 12 figs. [Received 4th July 1921.] 



Cutworms occur ever}' year in the gardens, fields and orchards 

 of Chile, but it is only under unusual circumstances that they become 

 serious pests. The most important species are Cirphis {Leucania) 

 unipuncla and C. (L.) impunda, on lucerne and pasture grasses : 



