@article{shaffer_1983, title={PREDICTION OF VARIATION IN DEVELOPMENT PERIOD OF INSECTS AND MITES REARED AT CONSTANT TEMPERATURES}, volume={12}, ISSN={["0046-225X"]}, DOI={10.1093/ee/12.4.1012}, abstractNote={The relationship of standard deviation (SD) of developmental period at constant temperatures to mean developmental period (|$\bar x$|) was examined based on data for 113 species of insects and mites. The regression equation SD = 0.209 |$\bar x$|0.730 explained 65% of the variance of SD; this relationship differed little between insects and mites, and varied little among the orders of insects. This relationship is useful for designing constant-temperature rearing experiments for insects and mites. A standard protocol for presenting results of these experiments is suggested. The regression equation is also useful in developing stochastic models of insect development at varying temperatures. Transformations are presented for converting statistics based on developmental period to statistics for developmental rate. Statistics on rate of development computed from these transformations were used to test the prediction that coefficient of variation of developmental rate should be constant. This prediction did not hold for about 20% of the 194 cases for which it was tested, so the underlying hypothesis, that variation in concentration of rate-controlling enzymes among individuals explains variation in developmental rate, must be rejected.}, number={4}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={SHAFFER, PL}, year={1983}, pages={1012–1019} }
@article{shaffer_rock_1983, title={TUFTED APPLE BUDMOTH (LEPIDOPTERA, TORTRICIDAE) - EFFECTS OF CONSTANT DAYLENGTHS AND TEMPERATURES ON LARVAL GROWTH-RATE AND DETERMINATION OF LARVAL-PUPAL ECDYSIS}, volume={12}, ISSN={["1938-2936"]}, DOI={10.1093/ee/12.1.76}, abstractNote={The relationship of head capsule width (HCW) to instar number in larvae of tufted apple budmoth, Platynota idaeusalis (Walker), was determined under different conditions of constant daylength and temperature. Growth rate (increase in HCW with instar) decreased markedly under the short-daylength, low-temperature condition, which has previously been shown to induce larval diapause. Variation in both growth rate and number of instars increased under diapause conditions. Under all conditions, growth rate was lower in larvae which experienced more instars before larval-pupal ecdysis, yet mean size of final-instar larvae increased with total number of larval instars. The hypothesis of constancy of growth ratio was rejected for all conditions. There was not an absolute threshold of larval size at which larvae metamorphosed, but discriminant analysis demonstrated that larval size was more important to form determination than was instar number. Field-collected overwintering tufted apple budmoth larvae, which experienced short-daylength, low-temperature conditions, did not have discrete size classes representing specific instars.}, number={1}, journal={ENVIRONMENTAL ENTOMOLOGY}, author={SHAFFER, PL and ROCK, GC}, year={1983}, pages={76–80} }