Environmental Entomology (1980) 9, 241-244

Kathleen J.R. Johnson, Edgar L. Sorensen and Ernst K. Horber (1980)
Resistance of glandular-haired Medicago species to oviposition by alfalfa weevils (Hypera postica)
Environmental Entomology 9 (2), 241-244
Abstract: We evaluated annual glandular-haired diploids (Medicago blancheana Boiss., and M. disciformis DC.) and tetraploids (M. rugosa Desr. and M. scutellata (L.) Mill.) for resistance to adult alfalfa weevils, Hypera postica (Gyllenhal) in growth chambers.
In no-choice and free-choice tests, adult weevils reared on M. sativa L. laid fewer eggs in stems of M. blancheana, M. rugosa and M. scutellata than in stems of M. sativa. Similar results were obtained in no-choice tests when weevils were reared from eclosion on the test species (M. blancheana, M. rugosa, and M. sativa). Stem size was not related to oviposition resistance in the annual species.
Adults preferred M. sativa to the glandular-haired species for feeding; adults confined to the glandular-haired species preferred stems to leaves. In contrast, leaves were readily accepted when the adults were confined to M. sativa.
In no-choice tests, total adult mortality at 45 days was 65, 20, and 5%, respectively, for M. rugosa, M. blancheana, and M. sativa.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)

Research topic(s) for pests/diseases/weeds:
resistance/tolerance/defence of host

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Hypera postica	Alfalfa/lucerne (Medicago sativa)