@article{Richard Gorham_1962, title={Insecticide Resistance-Susceptibility Tests with German Cockroaches (Blattella germanica Linnaeus) in Puerto Rico}, volume={46}, url={https://revistas.upr.edu/index.php/jaupr/article/view/12338}, DOI={10.46429/jaupr.v46i3.12338}, abstractNote={Adult males and females of a strain of <em>Blattella germanica</em> cultured from collections made in the School of Medicine, San Juan, P.R., were tested for insecticide resistance-susceptibility. According to the LT50 test these cockroaches demonstrated resistance to chlordane (â™, and ♀ LT50 > 72), lindane (â™, LT50 = 7); ♀, 6), and dieldrin (â™, and ♀ LT50 > 72), but were susceptible to malathion (â™, LT50 = 1.75; ♀, 1.25). Lethal concentrations at the 50- and 90-percent levels, estimated on the basis of combined counts of "dead" and "moribund" insects, indicated that the cockroaches are susceptible to the following insecticides, listed in decreasing order of effectiveness: Bayer 29493 (â™, LC50 = 0.007; ♀, 0.012; â™, LC90 = 0.016; ♀, 0.024), diazinon (â™, LC50 = 0.02; ♀, 0.01; â™, LC90 = 0.05; ♀, 0.02), synergized malathion (â™, LC50 = 0.07; ♀, 0.1; â™, LC90 = 0.12; ♀, 0.15), and malathion (â™, LC50 = 0.13; ♀, 0.08; â™, LC90 = 0.35; ♀, 0.2).}, number={3}, journal={The Journal of Agriculture of the University of Puerto Rico}, author={Richard Gorham, J.}, year={1962}, month={Jul.}, pages={219–225} }