422 



Camacho (C). EI Gusano del Poroto {Pegomyia chilensis). — Serv. 

 Policia Sanit. Vej., Santiago de Chile, 1918, 7 pp., 3 figs. [Received 

 4th July 1921]. ' 



Growers of beans in Chile frequently find it necessary to re-sow 

 a large part of their crop, on account of infestation by Pegomyia 

 chilensis, which destroys many of the seeds, preventing them from 

 germinating, or causing the young plants to wilt and die as soon as 

 they appear above ground. Eggs are laid either on the seed or on the 

 seedlings, which are then attacked by the larvae. The destruction 

 of these subterranean insects is difficult ; substances used to sterilise 

 the soil are very expensive and are apt to injure the plant more than 

 the insect. Plants that show signs of infestation should be pulled up 

 carefully, so that the larvae come with them and can be destroyed. 

 As a preventive measure, a bucketful of fine sand should be well 

 shaken up with a cupful of paraffin and spread around the base of 

 the plants. Another method is to prepare a phenic acid emulsion by 

 dissolving 1 lb. of soap in 2 gals, of water and then adding 5 lb. of 

 crude phenic acid until an emulsion is formed. This must be diluted 

 with 25 parts of water before use. It has been observed that infestation 

 is worse in soil in which organic manure is used, as the flies are attracted 

 by the decomposing matter, while minerals act as repellents — 

 particularly saltpetre and potassium salts. The use of a roller over 

 the ground just after sowing would probably prevent ovaposition 

 to some extent. 



Algunos Insectos perjudiciales a las Arvejas, Frejoles, Lentejas y otras 

 Legumbres y Brucos del Trebol. [Some Insects injurious to 

 Vetch, Beans, Lentils and other Vegetables, and Clover Bruchids.j — 

 Serv. Policia Sanit. Vej., Santiago de Chile, 1919, 28 pp., 13 figs. 

 [Received 4th July 192i .] 



An account is given of the Bruchids commonly found attacking 

 vetch, beans, lentils, etc., both when growing and in storage. Bruchns 

 pisonmi, L., is the only one as yet recorded from Chile, where 14 per cent, 

 of germination has been found to be the rule in large varieties of 

 vetch and per cent, among the small varieties of seed, such as the 

 petit-pois, which are chiefly used for preserving. There is only one 

 generation in a year. As breeding does not take place in the granary, 

 infestation in a second year arises from insects surviving in the seeds, 

 or that have remained in the field or escaped from a granar}' where 

 infested seed has been stored. A simple rem'edy is to keep the seed 

 in a tightly closed vessel ; the insects die in this, and the damage 

 is limited to that of the larvae in the first year. Late sowing con- 

 siderably reduces the damage. If seed must be sown early and in the 

 first year after gathering it should be fumigated with carbon bisulphide, 

 or the storehouse heated during the winter, as explained below. It 

 is suggested that the parasite, Pteromahis varians, should be introduced 

 from France. 



Clover Bruchids occurring in Chile include Bntchus leguminarius, 

 Schoenh., B. leucogaster, Blanch., and B. elegans, Blanch. There is 

 one generation of these in a year, infestation occurring in the field, 

 where the females oviposit on the flowers The larvae penetrate the 

 seed, and the insect remains within until harvest-time, when the adults 

 begin to appear, and generally survive in the storehouses until the 

 following spring, when they continue reproduction in new clover. 



