ارزیابی اثرات ارقام مختلف گوجه‌فرنگی روی پارامترهای پارازیتیسم زنبور پارازیتوئید Habrobracon hebetor (Hym.: Braconidae) در برنامه‌های مدیریتی شب‌پره‌ی Tuta absoluta (Lep.: Gelechiidae)

The South American tomato leaf miner, Tuta absoluta (Meyrick), is considered as one of the most important pests of tomato cropping systems worldwide. High reliance on chemical insecticides in management programs of this Gelechiid pest has resulted in undesirable effects on non-target organisms and hence, search for alternative methods are urgently needed. The parasitoid wasp Habrobracon hebetor Say is one the most important natural enemies which parasitized larval stages of different pests and its potential in control of T. absoluta could be considered. However, regarding undeniable effects of host plant on biological performance of natural enemies (bottom-up effects), in the present study, parasitism parameters of H. hebetor on the last instars of T. absoluta reared on susceptible (King ston) and resistant (Atrak) tomato cultivars to this pest was investigated. In addition, the last instars of Mediterranean flour moth, Anagasta kuehniella Zeller, were applied as control. Experiments were performed under laboratory conditions with 25 ± 1 ºC, relative humidity of 65 ± 5 % and a light period of 16 h. In each treatment, 100 individuals were evaluated. Data analyzing was performed using Age-Stage Two Sex Consumption Rate theory. According to results obtained, the highest (100.44 ± 12.65 host) and lowest (52.89 ± 10.42 host) values of net parasitism rate (C0) was obtained on resistant cultivar (Atrak) and last instars of A. kuehniella, respectively. The values of stable parasitism rate (ψ) on the susceptible and resistant tomato cultivars and control were 0.230 ± 0.012, 0.216 ± 0.036 and 0.189 ± 0.034 (host/parasitoid), respectively. The highest recorded value for finite parasitism rate (ω) was obtained on the cultivar King ston (0.275 ± 0.014 day-1) and the value of this parameter on the Atrak and last instars of A. kuehniella was calculated as 0.259 ± 0.046 and 0.223 ± 0.043 (day-1), respectively. Calculated value of transformation rate of host population to parasitoid offspring (Qp) was equal to 1 at all treatments. Our findings confirmed significant effects of different treatments tested on the biological performance of H. hebetor at laboratory conditions. However, more attention should be devoted for further investigations at greenhouse and field conditions. Finally, regarding the results obtained in the present study, partially resistance of the cultivar Atrak had a relative compatibility with parasitoid wasp H. hebetor and therefore, integrated management of T. absoluta using these two control procedures should be discussed with more emphasis.