Marking Gypsy Moth (Lepidoptera, Lymantriidae) Life Stages and Products with Low Doses of Rubidium Injected or Implanted into Pin Oak

1990

S. 2343-2348

1 Abb., 2 Tab., 13 Lit. Ang.

Unselbständiges Werk

200091761

Systemic introduction of rubidium into pin oaks (Quercus palustris Muenchh.) at low doses (25 and 50 g RbCl per tree) and water volumes was tested by four techniques: injection into flare roots with a pressurized cylinder, injection into flare roots with a syringe, injection into tree boles with a syringe, and implants into flare roots. Injection of solutions resulted in faster uptake into foliage than implantation of a crystalline solid. Foliar rubidium concentrations peaked in 1-3 wk after treatment. Flare root injection with a syringe of a 50% RbCl solution resulted in higher foliar rubidium concentrations that did not decline as quickly as with other techniques. Gypsy moth, Lymantria dispar (L.), larvae were allowed to feed on foliage from treated trees. All gypsy moth life stages, frass, and pupal exuviae collected from all but the 25-g RbCl pressurized cylinder treatment held rubidium concentrations significantly higher than controls. Nearly 90% of the samples from all but the 25-g RbCl treatment were marked.