none The tomato leafminer, Liriomyza bryoniae Kalt. (Diptera: Agromyzidae), has been causing problems in Swedish glasshouses during the last decade. Apart from tomato, it attacks cucumber, melon and sweet pepper. Lettuce is also a host plant, but this crop is never seriously damaged. Three parasitoids are kept in culture at present: Dacnusa sibirica Telenga, Diglyphus isaea (Walker) and Cyrtogaster vulgaris Walker. L. bryoniae is generally used as a host, but C. vulgaris can also be reared on Drosophila melanogaster Meigen. Biological control of L. bryoniae with D. sibirica has been successful in many cases, especially in cucumber. This species is more difficult to rear, but could possibly be introduced in combination with D. sibirica , a system which is now being evaluated. Yellow traps are used as an aid in timing introductions into glasshouses and in checking spontaneous occurrence of hibernating parasitoids. Experimental methods are discussed briefly. Animals and man; Control; Biological control; Parasites diseases and disorders; Parasites; Insect parasites; Hosts; Insect hosts; Habitat; Land and freshwater zones; Palaearctic region; Europe Liriomyza bryoniae (Agromyzidae); Control by; Dacnusa & Diglyphus (Hymenoptera); Evaluation for use in glasshouses; Hymenopteran parasites; Cyrtogaster; Dacnusa & Diglyphus; Control evaluation in glasshouses; Man made habitat; Glasshouses, control by hymenopteran parasites; Sweden; Control in glasshouses by hymenopteran parasites, evaluation Dacnusa sibirica (Braconidae ); Diglyphus isaea (Eulophidae ); Cyrtogaster vulgaris (Pteromalidae ); Control of; Liriomyza bryoniae (Diptera); Evaluation for use in glasshouses; Dipteran hosts; Liriomyza bryoniae; Control evaluation in glasshouses; Man made habitat; Glasshouses, control of dipteran host; Sweden; Control of dipteran host in glasshouses, evaluation