Infestation by Delia fabricii Holmgren (Diptera: Anthomyiidae) in Smooth Meadow-grass ( Poa pratensis L.) Grown for Seed Production in Northern Norway
1990; Taylor & Francis; Volume: 40; Issue: 1 Linguagem: Inglês
10.1080/00015129009438546
ISSN0001-5121
Autores Tópico(s)Fire effects on ecosystems
ResumoAbstract Delia fabricii larvae infested about 20% of the shoots of Poa pratensis grown in sparse stands for seed production at Bardu (69° N). Infestations originated from overwintering eggs, beginning when grass growth started in the spring. Each larva fed on several shoots. At pupation about 50% of the shoots were damaged. Early symptoms of infestation were red and wilting central leaves followed by dying shoots. At the lowest infestation rate in the laboratory, i.e. about 15% of the shoots infested, the number of generative shoots, vegetative shoots, and the seed yield were reduced by 67%, 22% and 40%, respectively, as compared with the uninfested plant material. At the highest infestation rate, i.e. about 77% of the shoots infested, the corresponding reductions were 95%, 83% and 92%. The number of emerged adults decreased at the highest infestations, probably due to larval intraspecific competition. Key Words: dead-heartsDelia fabriciispring infestationstem-boring
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