ارزیابی اثر رهاسازی کنترل‌شده نانو‌اسانس‌های پوست پرتقال و نارنگی بر سمیت تدخینی آن‌ها علیه شپشه‌ آرد Tribolium confusum (Col.: Tenebrionidea) و شپشه برنج Sitophilus oryzae (Col: Curculionidae)

نوع مقاله : مقاله پژوهشی

نویسندگان

• مسلم بسیج ¹
• فریده گنجوی ²
• ایمان شریفیان ³
• راضیه رضوی ⁴

¹ گروه گیاهپزشکی، دانشکده کشاورزی، دانتشگاه جیرفت، جیرفت، ایران

² اداره کل استاندارد استان کرمان، کرمان، ایران

³ بخش فنی و فروش شرکت سینجنتا، خوزستان، ایران

⁴ گروه شیمی، دانشکده علوم پایه، دانشگاه جیرفت، جیرفت، ایران

چکیده

کلیدواژه‌ها

• اسانس‌های گیاهی
• نانوامولسیون
• آفات انباری
• سمیت تنفسی
• رهاسازی کنترل‌شده

عنوان مقاله [English]

Investigation on the effect of orange and tangerine peel nanoemulsion controlled release on their fumigant toxicity against Tribolium confusum (Col.: Tenebrionidea) and Sitophilus oryzae (Col: Curculionidae)

نویسندگان [English]

• moslem basij ¹
• Farideh Ganjavi ²
• Iman Sharifian ³
• Razieh Razavi ⁴

کلیدواژه‌ها [English]

• plant essential oils
• nanoemulsion
• stored product pests
• fumigant toxicity
• controlled release

Extended Abstract

Introduction

Essential oils as biopesticides have gained significant attention in recent years due to their potential for eco-friendly and sustainable pest management. They don't have any residue on stored products. One of the key challenges in effectively utilizing essential oils is their controlled release and targeted delivery to the target pests. Nanoemulsion formulation has emerged as a promising approach to achieve this goal, as it can enhance essential oils' stability, solubility, and bioavailability. In this study, the fumigant toxicity of essential oils and their nanoemulsion formulations derived from orange and tangerine peels were investigated against two important storage pests, Tribolium confusum (confused flour beetle) and Sitophilus oryzae (rice weevil). The objectives were to evaluate the impact of nanoemulsion formulation on the controlled release and efficacy of the essential oils compared to the non-formulated oils.

Materials and Methods

The essential oils were extracted from dried orange and tangerine peels using a hydrodistillation method, from shed-dried orange and tangerine peels. Their chemical composition was analyzed by gas chromatography-mass spectrometry (GC-MS) with a 30-meter capillary column, 0.25 mm internal diameter, and 0.25 μm film thickness. The temperature program of the column was initially set at 70 °C with a 2-minute hold, then increased to 220°C at a rate of 15 °C per minute, and finally increased to 300 °C and held for 2 minutes. The nanoemulsions were synthesized using 5% v/v of the pure essential oils, Tween 80, and water were mixed, and 1% v/v of ethylene glycol was also added to the mixture. Subsequently, the emulsion solution was subjected to ultrasonic waves using an ultrasonic device (USH650, Max power: 650W) at a frequency of 25 kHz for various durations. This step revealed that the samples became completely transparent after 15 minutes of exposure to the ultrasonic waves. The particle sizes of the nanoemulsions were determined using a dynamic light scattering (DLS) instrument. The fumigant toxicity of the essential oils and their nanoemulsion formulations was evaluated under controlled laboratory conditions (temperature of 27±1 °C, relative humidity of 65±5%) against 1-day-old mature beetles in 125 ml glass containers. Trials were performed using eight different concentrations based on primary tests (5, 10, 15, 20, 25, 50, 75, and 95 microliters) and three independent replicates. The mortality rates of the target pests, T. confusum and S. oryzae, were recorded at 24 and 48 hours. Data were analyzed using SPSS 22.0 software.

Results and Discussion

The results of the study revealed that the fumigant toxicity of essential oils was higher at 24 hours compared to the nanoemulsion formulations. It is probably related to their release rate which is higher than nanoemulsions in 24 h. Also, essential oil and nanoemulsion of orange were more efficient than tangerine in both 24 and 48 h. level of Limonene (an active ingredient in their essential oil) as an efficient insecticide was higher in orange oil (94.8%) compared with tangerine (91.7%). Results showed that the average size of nanoemulsion particles was 65 nanometers for both orange and tangerine nanoemulsions. Smaller particle sizes result in better fumigant toxicity because they can more efficiently penetrate the spiracles and cuticles of insects. The nanoemulsion formulations demonstrated higher efficacy at 48 hours, with the highest observed mortality percentage recorded for the orange nanoemulsion at a concentration of 95 µl. The enhanced performance of the nanoemulsions at 48 hours was attributed to their better-controlled release properties, which allowed for a sustained and prolonged exposure of the target pests to the active compounds. The essential oils were more effective in the short term (24 hours), while the nanoemulsions exhibited superior performance in the longer term (48 hours), suggesting that the nanoemulsion formulation can provide better control and management of the target pests. The findings of this study highlight the potential of nanoemulsion formulation to enhance the controlled release and efficacy of essential oils as biopesticides.

Conclusion

The improved performance of the nanoemulsions at 48 hours, compared to the non-formulated essential oils, underscores the advantages of using nanoemulsion technology for the delivery and sustained release of active compounds in pest management applications. Further studies are suggested to evaluate the efficacy of nanoemulsions in penetrating and distributing within stored crop depths in silos and storages.