|Publication Type:||Journal Article|
|Year of Publication:||1961|
|Authors:||M. M. Cole, Clark P. H.|
|Journal:||Journal of Economic Entomology|
|Pagination:||649 - 651|
A strain of body lice maintained in the laboratory for 14 years without exposure to any insecticides was subjected to progressively increased concentrations of pyrethrins plus sulfoxide for 56 generations. Resistance to the synergized pyrethrins gradually developed to about seven or eight times that of the parent colony. Cross resistance to DDT developed slowly at first, but in later generations increased rapidly until the lice could no longer be killed by exposure to doth treated with 10% of DDT in an acetone solution. There was little or no resistance to lindane, two- to four-fold resistance to synergized allethrin, and none to malathion.