Evaluation of Vinyl Garment Bags as Chambers for Paradichlorobenzene Fumigation of Fabric-Insect Pests

Abstract

Twelve brands of vinyl garment bags were evaluated for effectiveness as chambers for paradichlorobenzene (PDB) fumigation of larvae of the webbing clothes moth, Tineola bisselliella (Hummel), and the black carpet beetle, Attagenus megatoma (F.), by using 340.2 g of PDB in every test bag for each fumigation. Mortality of the webbing clothes moth larvae within the bags was 100% in 10-28 days at 26.6±1.1°C and 50± 5% RH and was dependent upon type of bag. Under similar conditions, 100% kill of the black carpet beetle larvae occurred in 14-28 days only in 4 samples in some tests, whereas in the rest of the samples ca. 11-67% kill occurred during the 28-day period. A similar PDB fumigation of both species in an airtight metal box gave 100% kill within 3-6 days. Lower temperatures greatly reduced the efficacy of the bags as fumigation chambers, especially for black carpet beetle larvae. At 21.1±1.6°C and 35±5% RH, 100% kill of the webbing clothes moth larvae was not achieved in any of the bags earlier than 21 days. In a 28-day period, mortality of the black carpet hectic larvae ranged from 13 to 90%, dependent upon the type of bag. Under similar conditions, in an airtight box 100% kill of t he larvae of the webbing clothes moth and black carpet beetle larvae was achieved in 10 and 6 days, respectively. Permeability of representative vinyl films to PDB vapors was not proportionate to their thickness. Use of 680.4 g of PDB /bag improved the percent kill of test insects, whereas use of different floor liners, presence or absence of garments in the bags, and different schedules for opening and closing the bags during exposure did not alter effectiveness. However, when 340.2 g of PDB were used in a widerthan-normal receptacle in the bag, initial percent kill was improved. Of 340.2 g of PDB placed in a medium-quality bag, only 27.38 g remained at the end of the 28-day testing period. At lower temperatures of 21.1±1.6°C, buildup of PDB vapor concentration in the bags inhibited feeding activity but did not kill all insects.