Dynamics of experimental populations of native and introduced blowflies (Diptera: Calliphoridae): mathematical modelling and the transition from asymptotic equilibrium to bounded oscillations

The equilibrium dynamics of native and introduced blowflies is modelled using a density-dependent model of population growth that takes into account important features of the life-history in these flies. A theoretical analysis indicates that the product of maximum fecundity and survival is the primary determinant of the dynamics. Cochliomyia macellaria, a blowfly native to the Americas and the introduced Chrysomya megacephala and Chrysomya putoria, differ in their dynamics in that the first species shows a damping oscillatory behavior leading to a one-point equilibrium, whereas in the last two species population numbers show a two-point limit cycle. Simulations showed that variation in fecundity has a marked effect on the dynamics and indicates the possibility of transitions from one-point equilibrium to bounded oscillations and aperiodic behavior. Variation in survival has much less influence on the dynamics

Post-embriononic development of Chrysomya putoria(Diptera: Calliphoridae) on a diet containing ampicillin in different concentrations

Here we evaluate the effects of different concentrations of the antibiotic ampicillin on the growth and development of Chrysomya putoria. Third-generation, first instar larvae (L1) reared on 60 grams of homogenate+agar 65% were treated with ampicillin sodium. The experiment consisted of four replicates (40 larvae/replicate) of each antibiotic concentration tested (T1: 466µg/mL ; T2: 81.33 mg/mL and T3: 166.66mg/mL) and a T4: control. The body mass of the mature larvae, after they abandoned the diet, were recorded in batches of five. The variation between the mean body mass of larvae and the duration of larval and pupal stages, and overall duration of the development, viability and normal rates were analyzed by ANOVA. There were no significant differences between the four treatments in the following parameters: body mass of larvae that discontinued the diet as well as the duration of larval, pupal, and total development. The sex ratios found in the four treatments did not differ from those expected. Normality rates were 100% for all treatments. There were no significant differences between treatments for larval and overall viability, but pupal viability differed significantly between T1 and the control, T1 and T2, and between the control and T3. The antibiotic did not appear to significantly alter the development of C. putoria