Leaf Disk Method of Testing Alfalfa Plants for Resistance to Feeding by Adult Alfalfa Weevils1
Authors: BARNEN, D. K.; RATCLIFFE, R. H.
Source: Journal of Economic Entomology, Volume 60, Number 6, December 1967 , pp. 1561-1565(5)
Publisher: Entomological Society of America
Abstract:Several methods of testing adult alfalfa weevils, Hypera postica (Gyllenhal), feeding on detached leaves were evaluated under forced conditions. Dry-weight comparisons of damaged and undamaged pairs of lateral leaflets were time consuming and imprecise. Evaluations comparing leaf areas eaten from leaf disks were rapid, but were influenced by leaf thickness. Leaf area, eaten from leaf disks and then adjusted according to dry weight of the sample, was the most critical measurement of feeding.
Adult feeding was influenced by light and by moisture levels used during testing of excised leaf disks. Weevils ate more when tested under constant light than under constant darkness. However, feeding was more erratic in light. Test conditions of constant darkness and uniform moisture levels were recommended.
Effects of adult size, sex, and age on feeding were studied. Adult feeding was in direct proportion to body size. Differences in feeding rate (mg leaf material eaten per mg body weight) between large and small weevils as well as between male and female weevils were insignificant. However, because differences in body size exist in most weevil populations, the use of sized adults in feeding tests was recommended. Studies on feeding behavior of nondiapausing adults ranging from I to 49 days old showed that freshly emerged adults ate 5-6 times more leaf material than did 4- to 5-week-old adults.
Information obtained was used to develop a rapid procedure for classifying alfalfa plants for differential feeding by adult weevils. Data obtained from using the leaf disk test on surviving seedlings from adult feeding preference test arc presented.
Document Type: Research Article
Publication date: December 1, 1967
- Journal of Economic Entomology is published bimonthly in February, April, June, August, October, and December. The journal publishes articles on the economic significance of insects and is divided into the following sections: apiculture & social insects; arthropods in relation to plant disease; forum; insecticide resistance and resistance management; ecotoxicology; biological and microbial control; ecology and behavior; sampling and biostatistics; household and structural insects; medical entomology; molecular entomology; veterinary entomology; forest entomology; horticultural entomology; field and forage crops, and small grains; stored-product; commodity treatment and quarantine entomology; and plant resistance. In addition to research papers, Journal of Economic Entomology publishes Letters to the Editor, interpretive articles in a Forum section, Short Communications, Rapid Communications, and Book Reviews.
- Editorial Board
- Submit a Paper
- Subscribe to this Title
- Information for Advertisers
- Visit this journal's homepage
- ingentaconnect is not responsible for the content or availability of external websites