scholarly journals Detection of Amitraz Resistance inRhipicephalus (Boophilus) microplusfrom SBS Nagar, Punjab, India

2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
N. K. Singh ◽  
Abhijit Nandi ◽  
Jyoti ◽  
S. S. Rath

The resistance status ofRhipicephalus (Boophilus) micropluscollected from SBS Nagar, Punjab, was evaluated against amitraz by Adult Immersion Test (AIT). The regression graph of probit mortality of ticks plotted against log values of progressively increasing concentrations of amitraz revealed the slope of mortality (95% CI) as2.36±0.61(0.38 to 4.33). The LC50(95% CI) and LC95(95% CI) values were recorded as 332.52 ppm (305.06–362.44) and 1646.93 ppm (1383.97–1959.84), respectively, and the resistance factor (RF) was 13.17 which indicated level II resistance status. The dose response curves for egg mass weight, reproductive index, and percentage inhibition of oviposition were also validated by AIT and the slopes (95% CI) were-7.17±2.41(−14.85 to 0.50),-0.009±0.02(−0.16 to −0.031), and19.99±4.77(4.81 to 35.17), respectively. The current study reports the development of resistance inR. (B.) microplusto amitraz from Punjab state and the data generated would be useful in formulation of effective control strategies against ticks of this region.

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
M. Haque ◽  
Jyoti ◽  
N. K. Singh ◽  
S. S. Rath

The effect of commonly used acaricides (amitraz, cypermethrin, deltamethrin, fenvalerate, and flumethrin) on the eggs ofRhipicephalus (Boophilus) micropluscollected from Ludhiana, Punjab, was evaluated by egg hatch assay (EHA). The regression graph of probit hatchability and per cent inhibition of hatching (IH%) of eggs was plotted against log values of concentration of various acaricides. All concentrations of flumethrin and amitraz caused complete inhibition of hatching, whereas a hatchability of31.0±6.1,40.0±5.2and19.3±1.7% was only recorded at the highest concentration of cypermethrin, deltamethrin, and fenvalerate, respectively. An increase in the concentration of the acaricide showed a significant effect on the IH% of eggs for cypermethrinP<0.01and deltamethrinP<0.05but was nonsignificant for fenvalerate. The slope of the regression curve of IH% was utilized for the calculation of the dose of various acaricides causing inhibition of hatching for 95% eggs (LC95) and the discriminating dose (DD). Results indicated that maximum DD was recorded for fenvalerate (2.136%), followed by cypermethrin (0.214%) and deltamethrin (0.118%). The results of the current study will be helpful in formulating effective control strategies against ticks.


2015 ◽  
Vol 46 (3) ◽  
pp. 536-541 ◽  
Author(s):  
Anne Caroline dos Santos Dantas ◽  
Andreina de Carvalho Araujo ◽  
Alessandra Gomes Marques Pacheco ◽  
Alexsandro Branco ◽  
Luis Antônio Sangioni ◽  
...  

ABSTRACT: This experiment was carried out to study the bioacaricidal activity of Amburana cearensis against engorged females of Rhipicephalus (Boophilus) microplus. The crude ethanolic extract from the leaves of A. cearensis was submitted to partition with organic solvents (hexane, chloroform and ethyl acetate) in order of increasing polarity; and evaluated using three treatments at concentrations of 5, 10 and 25mg ml-1. To evaluate the acaricidal activity, engorged females were submitted to the adult immersion test. Parameters analyzed were the weight of females; weight of egg mass; percentage of hatch; reproductive efficiency; expected rate of reproduction; and efficacy. For each extract and concentrating fraction, tests were performed in triplicate. Among all fractions, the hexane (2.5%) achieved the best results in all parameters analyzed: 52.7% of inhibition of oviposition; 39% of hatching rate; 3,271 index of reproductive efficiency; and 67.0% effectiveness. The extract obtained gradual dose response with increasing concentration; and could be used as an aid in the control of R. (B.) microplus therapy.


EDIS ◽  
2020 ◽  
Vol 2020 (2) ◽  
Author(s):  
Pratap Devkota ◽  
Ramon Leon

Palmer amaranth has become one of the most troublesome weeds in the southeastern US due to its vigorous growth rate, high seed production, and development of resistance to herbicides from multiple modes of action. This 4-page publication illustrates characteristics of this weed to assist in accurate identification, proper management, and development of effective control strategies. Written by Sergio Morichetti, Jason Ferrell, and Pratap Devkota, and published by the UF/IFAS Agronomy Department, revised April 2020.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
R. Godara ◽  
M. Katoch ◽  
R. Katoch ◽  
Anish Yadav ◽  
S. Parveen ◽  
...  

In vitro efficacy of methanolic extract ofAtropa belladonnaand its components scopolamine and atropine was assessed againstRhipicephalus(Boophilus)microplus. Five concentrations of the extract (1.25%, 2.5%, 5%, 10%, and 20%) were used whereas scopolamine and atropine were each tested at 0.1%. In adult immersion test, the extract was lethal to ticks at 20% concentration. The LC50 and LC95 values were determined as 6.875% and 17.306%, respectively. The extract caused a significant reduction (P<0.05) in egg mass production at 10% concentration. In larval packet test, the extract was lethal to larvae in the concentrations of 10% and 20% after 24 h, with LC50 and LC95 values of 1.321% and 4.935%, respectively. Scopolamine and atropine showed 93.3% and 60.0% mortality of adult ticks, respectively, but they caused complete (100%) blocking of hatching as well as 100% larval mortality. Scopolamine and atropine were observed to be more potent than the crude extract at an equivalent concentration in both the bioassays.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
K. P. Shyma ◽  
Jay Prakash Gupta ◽  
Veer Singh ◽  
K. K. Patel

Rhipicephalus (Boophilus) microplusis the most common tick species in India infesting cattle and buffaloes and causing significant economic losses to dairy and leather industries by adversely affecting the milk production and quality of hides. A study to evaluate the acaricide resistance status ofRhipicephalus (Boophilus) microplusto deltamethrin, flumethrin, and fipronil was conducted on the samples collected from organized and unorganized farms of North Gujarat state, where treatment failures were reported frequently. Adult Immersion Test (AIT) and Larval Packet Test (LPT) were conducted using field strain for determination of 50 and 95% lethal concentration of deltamethrin, flumethrin, and fipronil. Results obtained by the Adult Immersion Test showed low grade resistance (level I, RF > 5) has been developed against both deltamethrin and fipronil. However, deltamethrin by performing Larval Packet Test showed moderate grade resistance (level II, RF > 25). Larval packet performed by flumethrin also revealed low grade resistance, level I. The data on field status of acaricide resistance from the area with diversified animal genetic resources will be helpful to adopt suitable strategy to overcome the process of development of resistance in ticks.


1974 ◽  
Vol 32 (02/03) ◽  
pp. 356-365 ◽  
Author(s):  
F Haverkate ◽  
D. W Traas

SummaryIn the fibrin plate assay different types of relationships between the dose of applied proteolytic enzyme and the response have been previously reported. This study was undertaken to determine whether a generally valid relationship might exist.Trypsin, chymotrypsin, papain, the plasminogen activator urokinase and all of the microbial proteases investigated, including brinase gave a linear relationship between the logarithm of the enzyme concentration and the diameter of the circular lysed zone. A similar linearity of dose-response curves has frequently been found by investigators who used enzyme plate assays with substrates different from fibrin incorporated in an agar gel. Consequently, it seems that this linearity of dose-response curves is generally valid for the fibrin plate assay as well as for other enzyme plate bioassays.Both human plasmin and porcine tissue activator of plasminogen showed deviations from linearity of semi-logarithmic dose-response curves in the fibrin plate assay.


1991 ◽  
Vol 65 (02) ◽  
pp. 160-164 ◽  
Author(s):  
Marina Poggio ◽  
Armando Tripodi ◽  
Guglielmo Mariani ◽  
Pier Mannuccio Mannucci ◽  

SummaryBeing a putative predictor of ischemic heart disease, the measurement of factor VII (FVTI) coagulant activity will be presumably requested to clinical laboratories with increasing frequency. To assess the influence on FVII assays of different thromboplastins and FVII-deficient plasmas we compared performances of all possible combinations of 5 thromboplastins and 6 deficient plasmas. The reproducibility of the clotting times of the dose-response curves for human and rabbit thromboplastins were acceptable (CV lower than 7%), whereas bovine thromboplastin had a higher CV. Reproducibility was very similar for all deficient plasmas when they were used in combination with a given thromboplastin. Responsiveness of the dose-response curve did not depend on the deficient plasma but rather on the thromboplastin: one rabbit thromboplastin was the least responsive, the bovine thromboplastin the most responsive, the human and the remaining two rabbit thromboplastins had intermediate responsiveness. Assay sensitivity to cold-activated FVII varied according to the thromboplastin: the bovine thromboplastin was the most sensitive, the human thromboplastin the least sensitive, of the three rabbit thromboplastins two were relatively sensitive, one was almost insensitive. In conclusion, our results indicate that thromboplastin rather than deficient plasma is the crucial factor in the standardization of FVII assay.


1967 ◽  
Vol 56 (4) ◽  
pp. 619-625 ◽  
Author(s):  
Hans Jacob Koed ◽  
Christian Hamburger

ABSTRACT Comparison of the dose-response curves for LH of ovine origin (NIH-LH-S8) and of human origin (IRP-HMG-2) using the OAAD test showed a small, though statistically significant difference, the dose-response curve for LH of human origin being a little flatter. Two standard curves for ovine LH obtained with 14 months' interval, were parallel but at different levels of ovarian ascorbic acid. When the mean ascorbic acid depletions were calculated as percentages of the control levels, the two curves for NIH-LH-S8 were identical. The use of standards of human origin in the OAAD test for LH activity of human preparations is recommended.


1962 ◽  
Vol 41 (1) ◽  
pp. 143-153 ◽  
Author(s):  
U. Henriques

ABSTRACT A bioassay of thyroid hormone has been developed using Xenopus larvae made hypothyroid by the administration of thiourea. Only tadpoles of uniform developmental rate were used. Thiourea was given just before the metamorphotic climax in concentrations that produced neoteni in an early metamorphotic stage. During maintained thiourea neotoni, 1-thyroxine and 1-triiodothyronine were added as sodium salts to the water for three days and at the end of one week the stage of metamorphosis produced was determined. In this way identical dose-response curves were obtained for the two compounds. No qualitative differences between their effects were noted except that triiodothyronine seemed more toxic than thyroxine in equivalent doses. Triiodothyronine was found to be 7–12 times as active as thyroxine.


1963 ◽  
Vol 42 (1) ◽  
pp. 29-38 ◽  
Author(s):  
L. Ther ◽  
H. Schramm ◽  
G. Vogel

ABSTRACT Longitudinal tension exerted on a killed rat's femur results always in rupture on the same place viz: the distal epiphyseal line. The power required to produce this effect can be measured with a simple dynamometer. The tensile strength increases with advancing age and during exsiccation (thirst). In untreated rats (weight range 100–120 g) this value amounts to about 1.5–1.8 kg. Tensile strength of the femoral epiphyseal line may be influenced by hormones. Corticosteroids such as prednisolone acetate and cortisol acetate increase the level of maximal load to more than 2.0 kg. In general the effect of a single injection reaches a climax after 48 hours. Dose-response-curves can be established and relative effectiveness may be gathered therefrom. Deoxycorticosterone acetate likewise increases tensile strength in spite of the fact that contrary to prednisolone exhibiting diuretic action this compound has a water retaining effect. Triiodothyronine and progesterone when given alone produce a slight decrease in tensile strength. The effect of prednisolone when given simultaneously with one of these two compounds is antagonized: this phenomenon is more pronounced in the case of triiodothyronine.


Sign in / Sign up

Export Citation Format

Share Document