This is real data that I received from Terry Speed, UC Berkeley. Here's his explanation of the data:
The western predatory mite Metaseiulus occidentalis is an effective native biological control agent of spider mites in deciduous orchards and vineyards in Western North America. It is being used in integrated pest management programs on applies in Washington, and on graps, strawberries and almonds in California.
Since resistance to some organophosphorous (OP) insecticides was found to develop naturally in M occidentalis, and the species was documented to be an acarine predator of economic importance, it was selected as a candidate for genetic improvement.
The data for this lab involve a carbaryl-OP-sulfur (COS) resistant strain of M occidentalis developed by crossing colonies with field (OP and sulfur) developed resistances with a laboratory-selected carbaryl-OP resistant colony. It is being mass-reared commercially and released in almond orchards in California. Our data come from an experiment aimed at elucidating the genetic basis for susceptibility to the insecticide permethrin.
The experiment was carried out in a lab at the Department of Entomology, UCB. Mites were exposed in 11-14 groups of ten to a given dose of permethrin for a fixed interval of time, and the number of mites dead in each group of ten at the end of the interval was recorded. This was done for each of seven doses, expressed in grams of active ingredient per 100 liters.