Phytochemical and Insecticidal Activity of Some Thyme Plants’ Essential Oils Against Cryptoblabes gnidiella and Scirtothrips mangiferae on Mango Inflorescences
by
, , , ,
Mohammad M. Aljameeli
1,*,
Nawal Abdulaziz Alfuhaid
2,
Ahmed Ramadan El-Rokh
3,
Samira A. El-Salam
3,
May A. Elhefni
4,
Amira S. El-Rahman
5,
Esraa M. Hussein
6,
Jazem A. Mahyoub
7,
Hayam Elshazly
8,
Hanan S. Alyahya
7,
Shatha I. Alqurashi
9,
Mohamed A. Abdein
10,*
,
EL-Sayed M. Qaoud
11 and
Marwa M. Mosallam
12 1
Department of Biological Sciences, College of Science, Northern Border University, Arar 73213, Saudi Arabia
2
Department of Biology, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia
3
Plant Protection Research Institute, Agricultural Research Center, Giza 12618, Egypt
4
Agricultural Chemistry Department, Faculty of Agriculture, Mansoura University, Mansoura 35516, Egypt
5
Horticulture Department, Faculty of Agriculture, Benha University, Moshtohor, Toukh 13736, Egypt
6
Horticulture Department, Faculty of Agriculture, Sohag University, Sohag 82524, Egypt
7
Department of Biological Sciences, Faculty of Science, King Abdulaziz University, Jeddah 21589, Saudi Arabia
8
Department of Biology, Faculty of Sciences & Arts-Scientific, Qassim University, Buraidah 52571, Saudi Arabia
9
Department of Biological Sciences, Collage of Science, University of Jeddah, Jeddah 23218, Saudi Arabia
10
Seeds Development Department, El-Nada Misr Scientific Research and Development Projects, Turrell, Mansoura 35511, Egypt
11
Horticultural Department, Faculty of Agriculture, Suez Canal University, Ismailia 41522, Egypt
12
Department of Plant Production, Faculty of Environmental Agricultural Science, Arish University, Al Arish 45516, Egypt
*
Authors to whom correspondence should be addressed.
Insects 2025, 16(9), 922; https://doi.org/10.3390/insects16090922
Submission received: 10 May 2025
/
Revised: 23 August 2025
/
Accepted: 28 August 2025
/
Published: 2 September 2025
(This article belongs to the Special Issue Advanced Pest Control Strategies of Fruit Crops)
Simple Summary
Mango crops face significant threats from pests such as Cryptoblabes gnidiella and Scirtothrips mangiferae. This study investigated the potential of using essential oils from five thyme plants—Thymus vulgaris, Origanum vulgare, Thymus argenteus, Thymus citriodorus, and Origanum syriacum—as natural insecticides. Essential oils were extracted and analyzed using hydrodistillation, revealing high concentrations of thymol and carvacrol, especially in T. vulgaris and O. vulgare oils. The insecticidal effects of these oils and the compounds isolated from them were tested on the target pests. The results indicated that T. vulgaris and O. vulgare oils were the most effective, with low lethal concentrations (LC50 values) being potent against both pests. This study also measured biochemical changes in pest enzymes at these concentrations. Overall, thymol and carvacrol show promise as natural insecticides, offering an alternative to synthetic options for protecting agricultural crops.
Abstract
Mango fruits are one of the strategic fruit crops in different countries that are attacked by several serious pests such as Cryptoblabes gnidiella and Scirtothrips mangiferae. Natural extracts, especially essential oils, provide several promising insecticide agents to control different insects as an alternative to synthetic insecticides. Using Clevenger-type hydrodistillation, the essential oils of five thyme plants—Thymus vulgaris, Origanum vulgare, Thymus argenteus, Thymus citriodorus, and Origanum syriacum—from Saudi Arabia and Egypt were extracted, and GC/MS analysis was performed. In addition, some chemical parameters of the five species were determined, such as chlorophyll a, chlorophyll b, β-carotene, total antioxidant capacity, total phenols, and total flavonoids. Two compounds, thymol and carvacrol, were identified in T. vulgaris and O. vulgare at ratios of 69.45 and 64.82%, respectively. These major compounds were isolated and identified using 1H NMR analysis. The insecticidal potentials of the five essential oils and their pure isolated compounds were evaluated on C. gnidiella and S. mangiferae on mango inflorescences. The results showed that T. vulgaris and O. vulgare oils were the most potent against C. gnidiella (LC50, 183.33 and 164.68 ppm, respectively) and S. mangiferae (18.93 and 16.93 ppm, respectively). Thymol and carvacrol had the highest effect on both insects. Furthermore, the effect of thymol and carvacrol at LC50 values on some biochemical parameters of C. gnidiella was determined. Therefore, thymol and carvacrol from Thymus species are promising compounds that could be used as insecticides against the harmful insects C. gnidiella and S. mangiferae on mango inflorescences.
