Assessment of donor/recipient ratios in permethrin transfer studies with Reticulitermes virginicus Banks
Crowding of termites may influence observed recipient mortality in donor-recipient toxicant transfer studies. It was hypothesized that if crowding were important, any termiticide (particularly repellent termiticides, which were not thought to transfer) could be transferred by contact among termites when the donor complement was sufficient. Termiticide transfer donor-recipient studies were performed with 5 ppm permethrin (a repellent termiticide; 30 min exposure time) in donor: recipient ratios of 10:90, 20:80, 30:70, 40:60, and 50:50 using 4 colonies of Reticulitermes virginicus Banks. Recipient mortality at 14 d was significantly different between treatments and controls in the 30:70 ratio for 3 colonies. Treatments and controls were significantly different for recipient mortality of one colony each in the 40:60 and 50:50 donor: recipient ratios. These results demonstrated that a repellent termiticide could be transferred by contact among termites with high donor percentages; they suggest that the phenomenon of toxicant transfer by contact may be influenced by crowding in these studies.