Background The two-spotted spider mite, Tetranychus urticae (Koch) (Acari: Tetranychidae), is a widely distributed plant-feeding pest that causes significant yield losses in a wide range of crops. Newly developed or improved environmentally friendly biocontrol agents serve as an alternative to traditional pest control tools. Experiment of the effects of 2 local fungal isolates of Beauveria bassiana (BGF14 and BCA32) was carried out against T. urticae under laboratory conditions. Results Both tested isolates had lethal effect in a short time after application, and this effect increased as time progressed. BGF14 and BCA32 isolates caused T. urticae mortality rates ranging from 25.88 to 61.92 and 32.36 to 62.03% when applied at the concentrations between 1×105 and 1×108 conidia/ml, respectively. According to the Probit analysis performed on the effect of fungi on T. urticae adults, the LC50 values of BGF14 and BCA32 isolates on the 7th day after inoculation were 2.6×106 and 6.3×104 conidia/ml, respectively, and the LT50 values for both fungi applied at a concentration of 108 conidia/ml were 2.14 and 2.23 days, respectively. Conclusions The 2 isolates of B. bassiana (BGF14 and BCA32) had the potentials to suppress T. urticae population and can be recommended as promising biocontrol agent candidates for control of T. urticae.

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Background Potato tuber worm (PTM) [Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae)] is one of the most significant and widespread pests of potato. PTM damages potatoes both in the field and in potato storage areas. Control of the pest is getting harder as it is developing resistance to pesticides. Several entomopathogenic nematode (EPN) species have been reported to successfully control numerous agricultural pests worldwide. The main aim of the study was to isolate native nematode/s as a biological control agent against P. operculella. Morphometric measurements of the infective juvenile (IJ) and sequencing and characterization of the internal transcribed spacer (ITS) region was used to identify the nematode isolate to species level. The efficacy of EPN isolate Z-1 obtained from Zonguldak province, Turkey was tested against different life stages of the pest. Experiments were conducted in 150 ml plastic pots containing sterile soil mixture. Four EPN concentrations (i.e., 0, 250, 500 and 1000 IJs/ml) were applied to the soil. Data relating to the mortality of different life stages were collected daily till 6 days after inoculation. Results Molecular analyses based on the ITS sequence and morphometric data revealed that isolate Z-1 was Heterorhabditis bacteriophora. Mortality rates of PTM larvae exposed to 250, 500, and 1000 IJs/ml concentrations of native EPN were 62.9 ± 9.8, 74.0 ± 3.7, and 92.5 ± 3.7%, respectively. There were non-significant differences among tested EPN concentrations for pupal mortality and the highest concentration (i.e., 1000 IJs/ml) caused 25.6% mortality. Conclusions The results revealed that the native H. bacteriophora isolate was effective against late-stage larvae of PTM under laboratory conditions. Therefore, it can be used as an alternative management option of the pest.

The potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), is an important pest of potato that causes yield losses in potato producing countries all over the world. Many management methods are available for reducing this pest populations. Chemical control methods are at the top of these. However, Entomopathogenic nematode (EPNs), can be used as a potential alternative to chemical insecticides to control potato tuber moth larvae as an eco-friendly management method. We aimed in this study to examine the efficacy of Turkish isolates of Heterorhabditis bacteriophora against the last instar larvae (fourth stage) of the potato tuber moth under laboratory conditions. Experiments were conducted in 150 milliliter plastic cups with sterile soil mixture. Four nematode concentrations (0, 250, 500 and 1000 IJs) were applied directly to the soil. Potato tuber moth was susceptible to different concentrations of the H. bacteriophora isolate. All doses were more effective than the control (water). The most effective was the 1000 IJs concentratio, providing a high mortality rate of the last instar larvae of potato tuber moth. No statistically significant difference was observed among temperatures. These results indicated that this H. bacteriophora isolate is very efficient and could be used against potato tuber moth in biological control programs.

Bu çalışma, Rize iline ait ilçelerdeki çay bahçelerinde bulunan akar türlerini tespit etmek amacıyla 2017-2019 yılları arasında gerçekleştirilmiştir. Çalışma süresince, 9 ilçede tesadüfi örnekleme yöntemi ile çay bitkisinin 1., 2. ve 3. sürgün dönemine denk gelecek şekilde Mayıs-Eylül ayları arasında sürvey çalışmaları yürütülmüştür. Çalışma süresince, 1. sürgün döneminde 9 ilçede toplam 73 çay bahçesinde, 2. sürgün döneminde 107 çay bahçesinde ve 3. sürgün döneminde ise 97 çay bahçesinde arazi çalışmaları yapılmış ve çay örnekleri toplanmıştır. Çalışma sonunda en yaygın ve en yüksek sayıda tespit edilen tür Sarı çay akarı olmuştur. Belirlenen diğer akarlar ise; Calacarus carinatus, Brevipalpus phoenicis, Tydeus californicus, Neoseiulus californicus, Czenspinskia transversostriata, Tuckerella sp., ve Oribatida türleridir. Bu çalışmada bulunan akarlar, farklı fenolojik dönemler hakkında bilgi eksikliğini giderecek nitelikte olup, daha önceki yıllarda yapılan çalışmalarla bütünleşecek şekilde tamamlanmıştır.