Oviposition and Larval Survival of the Clover Head Weevil on Crimson Clover1

Autor: Smith, C. M., Knight, W. E., Frazier, J. L.
Zdroj: Crop Science; January 1977, Vol. 17 Issue: 1 p162-164, 3p
Abstrakt: Seed damage caused by the clover head weevil (Hypera melesF.) on crimson clover (Trifolium incarnatumL.) limits the utilization of this forage species. In laboratory studies weevil oviposition was greater in the second basal internode of clover stems than in any other internode. Of eight crimson clover inbred lines and five cultivars tested in the field for larval seed feeding damage, one inbred line showed decreased larval survival and decreased seed damage. An estimate of actual seed damage was obtained from five seed head samples harvested from each of 40 plants. Numbers of seeds damaged by larval calyx boring were positively correlated (P<0.05) with seed damage estimates based on numbers of pupae per seed head for the cultivars ‘Chief’ (r=0.65) and ‘Tibbee’ (r=0.61), but estimates were attained in approximately onesixth the time required to visually count bored seed. Estimating seed damage in this manner will greatly increase the amount of germplasm which can be evaluated for weevil resistance.
Databáze: Supplemental Index