title: Unusual occurrence of cocoons in population of Haplodiplosis marginata (Diptera: Cecidomyiidae) in Belgium.
abstract: The saddle gall midge, Haplodiplosis marginata (von Roser) (Diptera: Cecidomyiidae), is a phytophagous species that develops in saddle-shaped galls on stems of wheat Triticum vulgare, barley Hordeum sativum, rye Secale cereale, and some other species of Poaceae. Only one generation develops per year. Full-grown larvae leave galls and drop onto the soil where they remain up to the springtime of the following year. Larvae do not usually spin cocoons. However, formation of cocoons by larvae was observed in populations developing in western Europe: in England in 1954, in the Netherlands in the 1960s, and in Belgium in 2011. On the basis of our analysis, a part of the larval population forms cocoons as protection against unfavorable weather conditions, especially drought.
authors.affiliation: Crops Management Unit, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, BE-5030 Gembloux, Belgium fcensier@doct.ulg.ac.be.
authors.forename: F
authors.initials: F
authors.lastname: Censier
authors.affiliation: Life Sciences Department, Plant Protection and Ecotoxicology Unit, Walloon Agricultural Research Center, Balachowsky Bldg., Chemin de Liroux 2, BE-5030 Gembloux, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: Chavalle
authors.affiliation: Department of Zoology, Faculty of Science, Charles University, Viničná 7, CZ-128 44 Praha 2, Czech Republic.
authors.forename: S
authors.initials: S
authors.lastname: Knor
authors.affiliation: Life Sciences Department, Plant Protection and Ecotoxicology Unit, Walloon Agricultural Research Center, Balachowsky Bldg., Chemin de Liroux 2, BE-5030 Gembloux, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: De Proft
authors.affiliation: Crops Management Unit, Gembloux Agro-Bio Tech, University of Liege, Passage des Déportés 2, BE-5030 Gembloux, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Bodson
authors.affiliation: Bítovská 1227/9, CZ-140 00 Praha 4, Czech Republic.
authors.forename: M
authors.initials: M
authors.lastname: Skuhravá
mesh_terms: D000818:Animals; D001530:Belgium; D018556:Crops, Agricultural / Q000469:parasitology; D004175:Diptera / Q000254:growth & development*; D007814:Larva / Q000254:growth & development; D006109:Poaceae / Q000469:parasitology*; D012987:Soil; D014887:Weather
chemical_list: D012987:Soil
keywords: Europe; development; life cycle; salivary gland