Developmental Rate Isomorphy in Insects and Mites

Abstract

When the proportion of total developmental time spent in a particular developmental stage does not change with temperature, an organism shows "rate isomorphy." This is the case only if the lower developmental threshold is the same for all developmental stages. In this study, the incidence of rate isomorphy in seven species of mites and 342 species from 11 insect orders (some represented by several populations) was determined. Whether a species shows rate isomorphy or not was determined over a range of temperatures where the relationship between the rate of development and temperature is linear. Proportion of total developmental time spent in a particular stage was plotted against temperature and the existence of rate isomorphy inferred from a zero change in proportion. Rate isomorphy was detected in 243 (57%) of 426 populations. In the rest of the cases, rate isomorphy was violated by deviations in the proportion of time spent in a stage by an average of 0.2% (range 4.5E-06% to 2.8%) at the mean of the range of temperatures of all the data sets (11 degrees C). The violations occurred most frequently at the extremes of the linear phase, which is attributed to methodical biases, mortality at low temperatures, or too coarse an estimate of developmental time at high temperatures. Similarly, a meta-analysis also revealed an overall prevalence of rate isomorphy. Consequently, in insect and mite species, all the developmental stages appear to have the same population-specific lower developmental threshold. The existence of rate isomorphy could be of great practical importance, for example, in the timing of life-history events and in determining preadult thermal requirements. There are also indications that it may act as a phylogenetic constraint.

Temperature-dependent development of the predatory mite Cheyletus malaccensis (Acari: Cheyletidae)

“…Therefore, we applied the Logan type I model to study the adverse effect of extreme temperatures on developmental rate. The data from the juvenile developmental rates may also be used for the investigation of the isomorphy hypothesis, which is of great practical importance (Jarosik et al 2002).…”

Common-intersection hypothesis of development rate lines of ectotherms within a taxon revisited

“…If both the RIH (Jarošík et al, 2002(Jarošík et al, , 2004 and CIH hold true for two developmental stages of two species belonging to the same taxon, two common temperatures could be estimated (Fig. 3).…”

“…van Rijn et al (1995) hypothesized that the lower developmental thresholds of the different stages of an insect or mite species are equal. Thus, Jarošík et al (2002Jarošík et al ( , 2004 developed the rate isomorphy hypothesis (RIH, Fig. 1) using the published mean development rate data for insects and mites.…”

Bridging meta-analysis and the comparative method: a test of seed size effect on germination after frugivores’ gut passage

“…Criticisms of metaanalysis have mainly focused on the problems of (1) publication bias (Jennions and Møller 2001;Kotiaho and Tomkins 2002), and (2) non-independence among observations (taxa) due to phylogenetic relatedness . So far, although a large number of studies using meta-analysis have tried to establish relationships between traits across taxa from interspecific databases, these meta-analyses have not been "phylogenetically corrected" by means of any of the available methods (Poulin 2000;Jarosik et al 2002;Traveset and Verdú 2002; but see Møller and Thornhill 1998).…”