Lethal and sublethal effects of fenazaquin and acequinocyl on demographic and some biochemical parameters of Panonychus citri (McGregor) (Acari: Tetranychidae)

Author(s):  
Hava Raoufi ◽  
Shahriar Jafari ◽  
Mohammad Ghadamyari ◽  
Masoud Arbabi
Bio-Research ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 1185-1191
Author(s):  
Christian Chinonso Ugwu ◽  
Rasheed Olatunji Moruf ◽  
Aderonke Omolara Lawal-Are

Low insecticide exposure has been shown to cause profound effects on non-target organisms, including crabs. Therefore, the changes in hematological parameters, serum biochemistry and antioxidant enzymes in the Gercacinid crab, Cardiosoma armatum were assessed during 28-day exposure to four concentrations of organophosphate chlorpyrifos (0.003, 0.006, 0.03 and 0.06 mg/l). The results showed a significant (P= 0.0) decrease in packed cell volume and total haemocyte count of the exposure crabs (except in 0.003 mg/l concentration) compared to control group. There were no significant changes in hemocyte sedimentation rate, granulocyte and agranulocyte, although all exposure groups increased in hemocyte sedimentation rate and agranulocyte with respective ranges of 3.00-3.02 mm/hr and 64.00-67.00 %. Except for alkaline phosphatase, there were no significant variation in the biochemical profile of both the control crabs and exposure crabs, although organophosphate chlorpyrifos exposure induced increase in all the measured biochemical parameters. The serum protein level and the activities of the enzymes (superoxide dismutase, catalase and malondialdehyde) were inhibited in exposure groups. The changes in these hemato-immunological parameters of the crabs were suitable biomarkers of a sub-lethal exposure to chlorpyrifos at the concentrations tested, and this will be useful in biomonitoring of aquatic environment.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hongyan Wang ◽  
Tianrong Xin ◽  
Jing Wang ◽  
Zhiwen Zou ◽  
Ling Zhong ◽  
...  

AbstractPanonychus citri, a major citrus pest. In pest management, bifenazate is a novel acaricide with high biological activity against red mites, such as Tetranychus urticae Koch. However, in the field, pests are frequently exposed to sublethal or lethal concentrations of pesticides. At present, its sublethal effects on P. citri have not been reported. Therefore, in order to investigate sublethal effect of bifenazate on biological traits and enzymatic properties of P. citri. The newly emerged females were treated with two concentrations of bifenazate: LC10 and LC30, the development and fecundity were observed. The results showed that female adult duration, fecundity, oviposition days, longevity were decrease compared with control, but pre-oviposition period was longer, net reproductive rate (R0), mean generation (T) were decreased, intrinsic rate of increase (rm), finite rate (λ) were decreased in LC30, however, doubling time was increased. Enzymatic tests showed that CAT, POD, CarE activities were higher in treatments than control. The SOD and GST activities were lower in LC30 than control and LC10, the CYP450 activity was decreased with the increasing concentrations. This study demonstrated that low lethal concentrations of bifenazate adversely affected life table parameters, enzymatic properties in P. citri. Therefore, bifenazate has the potential to control this pest.


2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Everaldo Batista Alves ◽  
Nádia Fernanda Bertan Casarin ◽  
Celso Omoto

ABSTRACT: Pesticides have been blamed as the principal factor responsible for biological disequilibrium favoring the population increase of Panonychus citri (McGregor) in Brazilian citrus groves. In order to generate subsidies for the integrated management of this pest, we evaluated the lethal and sublethal effects of pesticides used in citrus on P. citri. We tested 18 pesticides by evaluating mortality of adult female, egg viability and adult avoidance. For imidacloprid, pyriproxyfen, dimethoate, deltamethrin, lambda-cyhalothrin and lime sulfur, the principal insecticides used in Brazilian orchards, the oviposition behavior and the incidence of adult females on discontinuous pesticide residues were evaluated. The pesticides which caused adult P. citri mortality were: abamectin (94%), dimethoate (86%), lime sulfur (69%), fenpropathrin (44%), diafenthiuron (25%) and lambda-cyhalothrin (23%). The pesticides affecting egg viability were: fenpropathrin (53%), dimethoate (30%) and lime sulfur (22%). Fenpropathrin, lambda-cyhalothrin and lime sulfur caused repellent effects of 55, 45 and 22%, respectively. P. citri preferred areas untreated with deltamethrin, lambda-cyhalothrin and lime sulfur for oviposition and permanence, but the species could not distinguish areas treated with imidacloprid, pyriproxyfen and dimethoate. The insecticides abamectin, dimethoate and diafenthiuron affected survival and did not cause changes in P. citri behavior. These pesticides should be used mainly in periods P. citri occurs. On the other hand, fenpropathrin, lambda-cyhalothrin, lime sulfur and deltamethrin affect dispersal behavior, oviposition and P. citri incidence and their use should be avoided.


1984 ◽  
Vol 116 (7) ◽  
pp. 1033-1040 ◽  
Author(s):  
Vincent P. Jones ◽  
Michael P. Parrella

AbstractPopulations of the citrus red mite, Panonychus citri (McGregor), reared on “rough lemon” seedlings (Citrus limon (L.) Burm.) in a greenhouse and treated with malathion or permethrin were significantly higher than those on untreated seedlings. Significant increases were demonstrated in age-specific fecundity (mx), mortality corrected mx (lx mx), and net reproductive rate (Ro) values for mites reared in the laboratory on leaves treated with malathion or permethrin when compared with those reared on untreated leaves. Mites reared on oxamyl-treated leaves exhibited significant reductions in age-specific survivorship (% lx), mx, lxmx, and Ro values compared with those reared on untreated leaves. The importance of reproductive stimulation in relation to other causes of pest resurgence is discussed.


2021 ◽  
Author(s):  
Hongyan Wang ◽  
Tianrong Xin ◽  
Jing Wang ◽  
Zhiwen Zou ◽  
Ling Zhong ◽  
...  

Abstract Panonychus citri, is a major citrus pest with a global distribution. But in Pest Management, the extensive use of insecticides has resulted in insecticide tolerance. Bifenazate, a novel acaricides with high biological activity against red mites, such as the T.urticae, P. citri. However, its sublethal effects on P. citri have not been reported. Therefore, in present study, P. citri exposed to sublethal concentration of bifenazate shows high biological activity, and causes great changes of population parameters and enzymatic activity. Life table technology was used to demonstrate sublethal effects on the growth and reproduction of P. citri. The results showed that the developmental duration of immature stage used sublethal concentration of bifenazate (LC10, LC30) were no difference than control. Nevertheless, compared with control group, the female adult duration, the fecundity and longevity were significantly decrease, but the pre-oviposition period was longer; In addition, the net reproductive rate (R0), the mean generation(T) were significantly decreased compared to those of the control, but the intrinsic rate of increase(r), the finite rate(λ) were decreased in LC30 group, however, the doubling time was increased with the increasing concentrations of bifenazate. Furthermore, Enzymatic tests showed that CAT, POD, and CarE activities were higher in LC10 and LC30 treatments than control. The SOD and GST activities were lower in LC30 treatment than control and LC10 treatment. Moreover, the CYP450 activity was decreased with the increasing concentrations of bifenazate. Based on these results, the sublethal concentration of bifenazate may have adverse effects on population growth of P. citri. This result provides certain significant guidance for the Pest Management. As well as that, further studies should be done to explore resistance mechanisms of P. citri exposure to a sublethal concentrations of bifenazate.


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