none. Studies were conducted on the infestation of cones on the larches of various species and provenances, on the IUFRO plantation at Kolanow (District Forest Inspectorate at Krakow). On the above-mentioned plantation established by Prof. E. Chodzicki in 1949 Larix decidua Mill. is represented by 3 groups of provenances, viz., a Polish-Sudetic-Carpathian group (PSK0, a lower Alpine group (AD) and an upper Alpine group (AG). In addition of L. decidua Mill. were planted Larix sukaczewii Dylis*, Larix leptolepis Gord. and Larix eurolepis (Henry). In October 1982 a total of 463 cones were collected from 15 larches, which number included all the cones growing on the studied larches. A special count was made of ocnes with external injuries. Each batch of cones was in turn divided into two groups. From the first one seeds were hulled while the cones of the second group (together with the cones after removing seeds) were designed for establishing mass cultures. From every portion 100 hulled seeds were randomly taken to be analyzed by cutting. Counts were made of fertile and infertile seeds, seeds infested by insect-larvae and those externally eaten out. The results of analyses are presented. From the set cultures and analyses 313 insects were obtained which were represented by 16 species (Dasytes coeruleus, Megastigmus pictus, Habrocytus sp., Angomus laricis, Mesopolobus zetterstedtii, M. subfumatus, Eupelmus pullus, Elachertus geniculatus, Scambus calobatus, S. strobilorum, Bracon pineti, Spilonata laricina, Lycoriella sp., Asynapta strobi, Dasyneura sp. and Gaurax fascipes). The dominant species was Megasligmus pictus (Forst.) (Hym., Torymidae). It was found in the seeds originating from the cones of all the studied species and provenances of larches, except Larix eurolepis (Henry) (Swedish provenance 55/2). It mostly affected the seeds of L. decidua the group of PSK provenances (52/1 from Czechoslovakia); a calculated mean was 2 larvae per cone. The lowest mean, 0.5, was found for Larix leptolepis Gord. (provenance 56/3 from East Germany, West Germany). A mean value for the groups of provenances and species of the studied larches was also highest for Larix decidua Mill. of PSK group and amounted to 11 (0.65 per cone). The lowest one for Larix leptolepis Gord. was 2 (0.02 per cone). Among the pests of cones and seeds the only caterpillar of Spilonota laricina (Hein.) (Lep., Tortricidae) was found in a cone of Larix decidua Mill., AG (provenance 18/2).