Effect of greenbugs (Homoptera: Aphididae) on yield loss of winter wheat.

Development and validation of a binomial sequential sampling plan for the greenbug (Homoptera: Aphididae) infesting winter wheat in the southern plains.

From 1997 to 1999, Schizaphis graminum (Rondani), intensity (number per tiller) was estimated on 115 occasions from hard red winter wheat fields located throughout the major wheat growing regions of Oklahoma. A total of 32 and 83 fields was sampled during the fall and spring, respectively. The parameters of linear regressions relating the mean number of greenbugs per tiller (m) and the proporti...

Physiological modification of the host feeding site by cereal aphids (Homoptera: Aphididae).

Indole-3-acetic acid-l-14C and 14C-sucrose labels were used to study the effects of greenbugs, Schizaphis graminum (Rondani), and Russian wheat aphids, Diuraphis noxia (Mordvilko), on phloem function of wheat (Triticum aesticum L.). Greenbug feeding significantly reduced translocation from the immediate feeding site; however, phloem integrity was not impeded. In contrast, Russian wheat aphids h...

Use of Rubidium to Label Lysiphlebus testaceipes (Hymenoptera: Braconidae), a Parasitoid of Greenbugs (Homoptera: Aphididae), for Dispersal Studies

Fixed precision sequential sampling plans for the greenbug and bird cherry-oat aphid (Homoptera: Aphididae) in winter wheat.

The numbers of greenbugs, Schizaphis graminum (Rondani), and bird cherry-oat aphids, Rhopalosiphum padi L., per wheat tiller (stem) were estimated in 189 production winter wheat (Triticum aestivum L.) fields located throughout Oklahoma. Taylor's power law regressions were calculated from these data and used to construct fixed precision sequential sampling schemes for each species. An evaluation...

Efficacy of Beauveria bassiana (Hyphomycetes) for control of Russian wheat aphid (Homoptera: Aphididae) on resistant wheat under field conditions

Efficacy of Beauveria bassiana (Hyphomycetes) for control of Russian wheat aphid (Homoptera: Aphididae) on resistant wheat under field conditions Justin L. Hatting a; Stephen P. Wraight b;Ray M. Miller c a Agricultural Research Council Small Grain Institute, Bethlehem, South Africa b Plant Protection Research Unit, USDA-ARS, Ithaca, NY, USA c Pietermaritzburg, University of Kwa Zulu-Natal, Scot...