Age‐stage, two‐sex life tables of Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae) with a discussion on the problem of applying female age‐specific life tables to insect populations

Abstract

Age‐stage, two‐sex life tables of the melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), reared on cucumber (Cucumis sativus L.), sponge gourd (Luffa cylindrica Roem) and a carrot medium (mashed Daucus carota L. mixed with sucrose and yeast hydrolysate) were constructed under laboratory conditions at 25 ± 1°C, 65%± 0.5% relative humidity, and a photoperiod 12 : 12 h (L : D). The intrinsic rates of increase of B. cucurbitae were 0.144 6, 0.141 2 and 0.068 8 days on cucumber, sponge gourd, and carrot medium, respectively. The highest net reproduction rate was 172 offspring per fly reared on sponge gourd. The mean generation times of B. cucurbitae ranged from 34 days reared on cucumber to 56 days reared on carrot medium. The life history raw data was analyzed using the traditional female age‐specific life table and compared to results obtained using the age‐stage, two‐sex life table. When the age‐specific female life table is applied to an age‐stage‐structured two‐sex population, survival and fecundity curves will be improperly manipulated due to an inability to include variation in preadult development time. We discussed different interpretations of the relationship between the net reproductive rate and the intrinsic rate of increase to clarify possible misunderstanding in the literature.

Development of insect life tables: comparison of two demographic methods of Delia antiqua (Diptera: Anthomyiidae) on different hosts

“…Chi 14 showed the relationship between the net reproductive rate ( R 0 ) and mean female fecundity ( F ) as R 0  =  F  × ( N f / N ), where N is the total number of eggs used at the beginning of the life table study, and N f is the number of female adults that emerged. In this study, the values of R 0 and F on each host plant are consistent with this relationship and this formula can be used to detect errors in life table analysis 16 .…”

Demographic Analysis, a Comparison of the Jackknife and Bootstrap Methods, and Predation Projection: A Case Study of <I>Chrysopa pallens</I> (Neuroptera: Chrysopidae)

“…If the bootstrap is used, the omission of any individual will not produce identical extreme values because the bootstrap is performed with random sampling with replacement. Although the jackknife method has been widely used in many demographic studies (e.g., Chi and Getz 1988, Tsai and Wang 2001, Huang and Chi 2012 during past several decades, according to the above discussion and the detailed mathematical invalidation of Huang and Chi (2013) we suggest that the jackknife technique not be used for the estimation of the variance of population parameters. Chi (1990) and Huang and Chi (2012) demonstrated the effectiveness of population projection based on the age-stage, two-sex life table in revealing changes in stage structure during population growth.…”

Treatment by glyphosate-based herbicide alters life history parameters of the rose-grain aphid Metopolophium dirhodum

“…The second problem that limits the use of available literature data for comparison is that thermal conditions differ among studies, and as a consequence, temperature notably influences development43 and life table parameters394445. The third problem is that a comparison of life table parameters calculated by using the age-stage, two-sex life table to parameters from the traditional female age-specific life table is inappropriate; Huang and Chi46 demonstrated earlier the problems associated with the application of female age-specific life tables to insect populations. The limited literature on life tables of cereal aphids therefore suggests that more investigations using proper methods should be conducted for a better understanding of which conditions are important for population build-up of these important pests in the field.…”