Since 1939 an Erradieation Campaign against the common bean weevil, Acanthoscelídes obtectus (Say ), has been held in the valley of Limache. The need of a more detailed knowledge on the host plants of the insect was early noticed. A particularly interesting aspect of such investigation was the search for native seeds suitables to the weevil development.
The first experiments weremade with material eoming from various sources, but gathered all through 1939. As a result, it was possible to find out A. obtectus living on seeds of:
-16 varieties of Phaseolus vulgaris L.;
-two varieties of P. multiflorus Willd. (albiflorus Lam. and coccineus Lam.);
-Dolichos Lablab. L., var. albiflorus DC.;
-Vigna sinensis Savi ex Hassk.;
-Vicia Faba L., f. Megalosperma Beck. and
-Cicer arietinum L.
D. Lablab is apparently a new host plant to A. obtectus.
Then, an ex profeso picking up of suspicious seeds was started.
It was thus possible to gather seeds of 25 species which were latter used in the investigation. Over groups oi these seeds, weevil eggs were "sowed" and the whole stuff was placed under optimum environment conditions (30°C., R. H., 75-89% and in full darkness).
From a total of nearly 28.860 migratory larvae placed under direct contact with the investigated seeds, a heavy death of larva was detected before they were able to enter the seed. The rest of the larva penetrated into the seed in a variable grade depending on the species of seed. Seeds of Lathyrus odoratus L., Lens esculenta Moench and Pisum sativum L., were perforated and insects developed safely in them reaching the adult stage. L. odoratus appears also to be a new host to the comon bean weevil, since this seed has not been listed by previous authors. The rest of the seed were damaged in different grade of penetr

1 Ing. Agrs. Entomólogo-Jefe y Entomólogo, Sección Zoología Agrícola, DVS