scholarly journals Study of potential activity of clove oil 10 % emulsifiable concentrate formulation on Two-spotted spider Mite Tetranychus urticae Koch (Acari: Tetranychidae)

2021 ◽  
Vol 13 (4) ◽  
pp. 1414-1419
Author(s):  
Hisham I. Abd-Alla ◽  
Saad E. S. Hamouda

Clove oil is reported to have a great range of biological activities against many species of pests; termites, cockroaches, aphids, weevils and moths, and many different usages such as perfume and food flavoring agent. This study aimed to determine the acaricidal activity of clove oil emulsifiable concentrate new formulation against two-spotted spider mites Tetranychus urticae. Clove oil was formulated as 10 % emulsifiable concentrate (EC). The new formula passed successfully all physical and chemical tests reported for emulsifiable concentrates. It was then tested biologically on the individuals of two-spotted spider mite T. urticae Koch (Acari: Tetranychidae) on two host plants beans and squash under laboratory conditions. In both cases, there were a direct relationship between the increase in the concentration of the formulation and the percentage of inhibition on the individuals of the two-spotted spider mite, after 72 hours of treatment, at concentrations of 20, 40, and 80 mg/ml the new formulation showed 10.30, 44.8, and 75 percent inhibition, respectively in case of beans, while squash at the same concentrations and for the same period of treatment showed 33.3, 40.7, and 51.9 percent inhibition, but the effect in case of beans was greater than that in case of squash as its EC50 value was lower than that in case of squash. In the case of the former, it was 39.81 mg/ml, whereas in the case of the latter, it was 79.43 mg/ml. Therefore, the new clove oil formulation can be used to combat the two-spotted spider mite.

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Kyeongnam Kim ◽  
Yong Ho Lee ◽  
Gayoung Kim ◽  
Byung-Ho Lee ◽  
Jeong-Oh Yang ◽  
...  

Abstract Two spotted spider mite, Tetranychus urticae, is a polyphagous pest to a variety of plants and they are hard to be controlled due to occurrence of resistance to acaricides. In this study, biochemical evaluation after ethyl formate (EF) and phosphine (PH3) fumigation towards T. urticae might help officials to control them in quarantine purposes. PH3 fumigation controlled eggs (LC50; 0.158 mg/L), nymphs (LC50; 0.030 mg/L), and adults (LC50; 0.059 mg/L) of T. urticae, and EF effectively affected nymphs (LC50; 2.826 mg/L) rather than eggs (LC50; 6.797 mg/L) and adults (LC50; 5.836 mg/L). In a longer exposure time of 20 h, PH3 fumigation was 94.2-fold more effective tool for control of T. urticae than EF fumigant. EF and PH3 inhibited cytochrome c oxidase (COX) activity differently in both nymphs and adults of T. urticae. It confirmed COX is one of target sites of these fumigants in T. urticae and COX is involved in the respiratory chain as complex IV. Molecular approaches showed that EF fumigation completely down-regulated the expression of cox11 gene at the concentration of LC10 value, while PH3 up-regulated several genes greater than twofold in T. urticae nymphs treated with the concentration of LC50 value. These increased genes by PH3 fumigation are ndufv1, atpB, para, and ace, responsible for the expression of NADH dehydrogenase [ubiquinone] flavoprotein 1, ATP synthase, and acetylcholinesterase in insects, respectively. Lipidomic analyses exhibited a significant difference between two fumigants-exposed groups and the control, especially an ion with 815.46 m/z was analyzed less than twofold in the fumigants-treated group. It was identified as PI(15:1/18:3) and it may be used as a biomarker to EF and PH3 toxicity. These findings may contribute to set an effective control strategy on T. urticae by methyl bromide alternatives such as EF and PH3 because they have shared target sites on the respiratory chain in the pest.


2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Cenk Yucel

Abstract 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.


2012 ◽  
Vol 68 (7) ◽  
pp. 1069-1076 ◽  
Author(s):  
Sabrine Attia ◽  
Kaouthar L Grissa ◽  
Anne C Mailleux ◽  
Stéphanie Heuskin ◽  
Georges Lognay ◽  
...  

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