In years 1919-2007 on domestic onion plantations 37 phytophagous species taxons belonging to 7 insect orders: Thysanoptera, Homoptera, Heteroptera, Lepidoptera, Coleoptera, Diptera and Orthoptera were noted. Among these groups 22 species were stated as phytophagous, additional taxons were indentified to 5 genus (Thrips, Mamestra, Polia, Agrotis, Agriotes) and 3 families: fungus gnats (Sciaridae), march flies (Bibionidae), crane flies (Tipulidae). Furthermore 7 species of saprophagous Diptera were collected from damaged onions during harvest.
The most common dominant species occurring in all regions of onion production were: onion fly (Delia antiqua Meig.), onion thrips (Thrips tabaci Lind.), onion weevil (Ceutorhynchus suturalis Fabr.), leek moth (Acrolepiospis assectella Zell.) and cutworms (Noctuidae). The population density of: onion beetle (Lilioceris merdigera L.), garlic fly (Suillia lurida Meig.) and leek miner fly (Napomyza gymnostoma Loew) were only a seasonal danger, especially in southern regions of Poland. On wet and rich in organic matter soils some soil dwelling insects such as larvae of Melolontha species (Scarabaeidae), larvae of Agriotes (Elateridae), flies (Diptera) from Tipulidae and Bibionidae families were also occurring periodically.
The species and population changes of above mentioned pests allowed to elaborate effective pest control methods of onion plantations. The pest control was performed after field monitoring on the basis of constantly updated short - and long-term forecasting.
