STUDIES ON INSECTICIDES USED IN STRUCTURAL PEST CONTROL. I. EFFECT OF FIVE DIFFERENT SURFACES ON DIAZINON WHEN USED TO CONTROL THE GERMAN COCKROACH (BLATTELLA GERMANICA L.). II. SAMPLING EFFICIENCY OF FIVE SOLID SORBENTS FOR TRAPPING AIRBORNE INSECTICIDES

Squares of five different building surfaces (0.8 cm plywood, plate glass, plasterboard, enamel and latex paint on glass) were treated with distilled water or a 0.5% or 1.0% diazinon emulsion. Adult male German cockroaches (Blattella germanica L.) were caged on the treated surfaces and mortality after a 48-h exposure was compared to the diazinon detected by chemical analysis of the treated surfaces at 9 sampling times over a 4-week period.Five solid materials, polyurethane foam, Carbowax GC resin, Tenax GC resin, Chromosorb 102 and C(,18) Porasil were tested as sorbents for vapors of propoxur, chlordane, chlorpyrifos, diazinon and resmethrin. Insecticide vapors were generated and sampled in a closed system. Chromosorb 102 was the best sampling material. However, it gave interferences on GLC analysis of chlordane and a constant rate of air flow through this sorbent was more difficult to maintain. Polyurethane foam, though not quite as effective a sorbent as Chromosorb 102 or C(,18) Porasil, was selected as the sorbent of choice for future air sampling because of its low cost, ease of handling, and ability to be cleaned and reused.Mortality was 100% for both concentrations on painted and plywood surfaces for the entire study. Diazinon residues on these surfaces decreased an average of 57% over the 4 weeks. Diazinon on treated glass declined to near the limit of detection, with 0% mortality at 4 weeks for both concentrations. Decreased mortality on glass is explained by the decline of pesticide residues on treated surfaces perhaps due to volatilization of abrasion. Residues decreased by only 35% on plasterboard at 4 weeks. However, mortality was reduced to 11% at 4 weeks on plasterboard treated at the 0.5% rate and 44% at the 1.0% rate. Loss of cockroach mortality on plasterboard may have been due to absorption or binding of diazinon to the paper covering on the treated surface.