تغییر پایداری سطح تعادل جمعیت به عنوان راهبردی اکولوژیک در مدیریت کرم گلوگاه انار

Carob moth, Apomyelois ceratoniae, is the most important pest of pomegranate, and its control is only plausible using ecological pest management. In the present study, the stability of population equilibrium of carob moth was examined. An experiment with four treatments (perturbation using an adult density increase (ADI), perturbation using an adult density reduction (ADR), perturbation using a larval density reduction (LDR) and no perturbation or control) was carried out, where all treatments were replicated four time using a randomized complete block design. To start the experiment, 10 pairs of newly emerged moths were released on cages (40 × 40 × 40) containing pomegranate fruits (Shahraza subacid variety) and honey solution (10%). The extra pomegranate fruits were then provided for adult oviposition and larva food. Adult moths were fed on honey solution. After 3 generations, the perturbation was implemented as adding 50 moths to cages in ADI, removing all adult moths from cages in ADR and removing all larvae from cages in LDR. The experiment was then continued for 3 more generations. The number of moths was weekly recorded and used for data analyses. Data were analyzed using log-linear models to determine whether it equilibrium was stable, and if there was any shift in equilibrium level. The results showed that when there was no perturbation, it equilibrium does not go under any changes. It was the same for perturbation using density increase. However, perturbation using adult density reduction caused instability (a trend) in three populations. In one population there was no trend, but ADR resulted in shifting population equilibrium to a lower level (neutral stability). Perturbation using larval density reduction resulted in instability (a trend) in two populations. Other two populations did not show any trends (stable), such that LDR either shifted the population equilibrium to a lower level (neutral stability in one population) or had no effect on equilibrium level (stability in one population). Our findings indicate that the perturbation using a density reduction either caused an instability or shifted population equilibrium to a lower level. This indicate that creating a perturbation in the population of carob moth may significantly change its population dynamics, which can be applied to sustainable pest management programs.