Testing the rate isomorphy hypothesis using five statistical methods

Abstract

Organisms are said to be in developmental rate isomorphy when the proportions of developmental stage durations are unaffected by temperature. Comprehensive stage‐specific developmental data were generated on the cabbage beetle, Colaphellus bowringi Baly (Coleoptera: Chrysomelidae), at eight temperatures ranging from 16°C to 30°C (in 2°C increments) and five analytical methods were used to test the rate isomorphy hypothesis, including: (i) direct comparison of lower developmental thresholds with standard errors based on the traditional linear equation describing developmental rate as the linear function of temperature; (ii) analysis of covariance to compare the lower developmental thresholds of different stages based on the Ikemoto‐Takai linear equation; (iii) testing the significance of the slope item in the regression line of versus temperature, where p is the ratio of the developmental duration of a particular developmental stage to the entire pre‐imaginal developmental duration for one insect or mite species; (iv) analysis of variance to test for significant differences between the ratios of developmental stage durations to that of pre‐imaginal development; and (v) checking whether there is an element less than a given level of significance in the p‐value matrix of rotating regression line. The results revealed no significant difference among the lower developmental thresholds or among the aforementioned ratios, and thus convincingly confirmed the rate isomorphy hypothesis.

Bioclimatic Thresholds, Thermal Constants and Survival of Mealybug, Phenacoccus solenopsis (Hemiptera: Pseudococcidae) in Response to Constant Temperatures on Hibiscus

“…Outside this range, developmental rate deviates from the straight line and hence some data points are to be excluded in the linear fit [17,28,35]. We selected the linear range of 18-30°C (Table 3) after taking into account higher R 2 values, lower survival of crawlers to adulthood at 15°C, and rapid development of instars at 32°C.…”

“…Therefore, we adopted equation 6 to recalculate the lower developmental threshold (LDT, same as T min ) and sum of effective temperature (SET, same as k ) for different populations for a meaningful comparison. In one case, we could obtain replicate data sets of development duration at different temperatures from our previous study on cotton from the same laboratory [26] and hence it was possible to test the equality of LDTs and SETs for the local Warangal population on the two hosts: hibiscus in this study with those on cotton using equation 2 through analysis of covariance (ANCOVA) [33-35]. …”

Cascade effects of crop species richness on the diversity of pest insects and their natural enemies

“…We used the arcsine square root transformation of the abundance ratio in the analysis of variance following Kuang et al [19] and Xiao et al [20].…”

How to Compare the Lower Developmental Thresholds

“…Analysis of covariance (ANCOVA) was performed using the arcsin square root of proportion as a response variable and temperature as a covariate. A significant (p < 0.05) increase or decrease in the proportion was considered as violation of the assumption of rate isomorphy (Kuang et al 2012). A life table was of average eggs laid by females; and P ♀ is the female proportion of adults.…”