LAUSR

BACKGROUND The fumigant phosphine is used all over the world for disinfestation of stored grains and commodities. Adults of 23 different populations of Tribolium castaneum from 10 different countries, were evaluated for phosphine resistance using a modification of Detia Degesch Phosphine Tolerance Test Kit (DDPTTK). Adults were exposed to 3,000 ppm and recorded for 5 to 270 min for their mobility. RESULTS Among the tested populations, high level of phosphine resistance was recorded from populations of Brazil, Serbia, and Spain. No survivals were recorded after 7 days post exposure for 8 out of 23 population tested. CONCLUSIONS Our work showed four scenarios: 1. quick knockdown - low (or no) recovery; 2. Slow knockdown - high recovery; 3. Quick knockdown - high recovery and 4. Slow knockdown - low recovery. Our data indicate that post exposure period is critical for the evaluation and characterization of phosphine resistance. This article is protected by copyright. All rights reserved.