In this paper, the generalized potential function, the stationary probability distribution function (SPDF), the mean development time and the mean shrinking time of a time-delayed vegetation growth system induced by cross-correlated internal and external noises are investigated.
Pre-oviposition period, mean development time and body weight were transformed by a square root transformation prior to the analysis.
Mean development time of the immature stages was not affected by whitefly biotype, but was significantly affected by plant status as well as by biotype*plant interaction (Table 2).
For analysis of the percentage survival or mean development time for the two whitefly biotypes and three types of plants, a two-factor ANOVA was conducted as described above.
One-way analysis of variance (ANOVA) and Student-Newman-Keuls (S-N-K) multiple comparisons test (p<0.05) were performed to assess the differences in adult performance (pre-oviposition period and realized fecundity) and offspring performance (mean development time, body weight, survival and sex ratio) of S. harmandi from two colonies.
However, despite the absence of differences in their mean development time, flies from the selected populations showed lower inter-individual variance in development time.
We regressed the inverse of the mean development time in days (=the development rate) on temperature, assuming a linear model, and estimated the slope and X-axis intercept.
Post-hoc multiple comparisons using Tukey's test revealed that although the mean development time of the selected and control populations did not differ, selected flies showed reduced variation in development time compared to the controls (Fig. 1).
The same effect was observed when the performance of F3-families was correlated with their mean development time: Early-flowering families performed better than late-flowering lines (Table 3).
Moreover, circadian period and development time are usually positively correlated, with short period individuals developing faster than those with long period (Kyriacou et al., 1990; Yadav and Sharma, 2013; Miyatake, 1997), therefore, the lack of change in the mean development time of the selected populations (Fig. 1b) despite shortening of period (Kannan et al., 2012) is counterintuitive.
