History of Deer Herd Reduction for Tick Control on Maine’s Offshore Islands

Susan P Elias; Benjamin Stone; Peter Rand; Charles Lubelczyk; Robert Smith

doi:10.53558/oywu2247

First Report of Cattle Tick Rhipicephalus (Boophilus) annulatus in Egypt Resistant to Ivermectin

Insects ◽

10.3390/insects10110404 ◽

2019 ◽

Vol 10 (11) ◽

pp. 404 ◽

Cited By ~ 4

Author(s):

Saeed El-Ashram ◽

Shawky M. Aboelhadid ◽

Asmaa A. Kamel ◽

Lilian N. Mahrous ◽

Magdy M. Fahmy

Keyword(s):

Immersion Test ◽

Tick Control ◽

Cattle Tick ◽

First Report ◽

Significant Difference ◽

History Of ◽

Rhipicephalus Annulatus ◽

Almost All ◽

Lower Slope ◽

Egg Fertility

Tick control is mainly dependent on the application of acaricides, but resistance has developed to almost all classes of acaricides, including macrolactones. Therefore, we aimed to investigate ivermectin resistance among tick populations in middle Egypt. The larval immersion test was conducted using a commercial formulation of ivermectin (1%). Different concentrations of the immersion solution (0.0000625% (625 × 10−7%), 0.000125% (125 × 10−6%), 0.0005% (5 × 10−4%), 0.001% (1 × 10−3%), 0.0025% (2.5 × 10−3%), 0.005% (5 × 10−3), and 0.01% (1 × 10−2%)) were prepared by diluting a commercial ivermectin (1%) with distilled water containing 1% (v/v) ethanol and 2% (v/v) TritonX-100. Field populations of Rhipicephalus annulatus were collected from five different localities in Beni-Suef province, Egypt. Adult engorged female ticks were collected and assessed for oviposition and egg fertility. Eggs were collected, and hatched larvae were then used in the experiment. Application of acaricides was conducted on 10-day-old larvae. There was a significant difference in the LC50 (50% lethal concentration) among the examined localities on the log dose-response plot, where, the LC50 of tick populations from two localities (Emin elaros and Aldiabia) was higher than the other localities (Alhalabia, Alkom, and Beshnna). Besides, tick populations from Emin elaros and Aldiabia showed higher LC90 values with lower slope values compared to those from Alhalabia, Alkom, and Beshnna. According to these values (LC50, LC90, and slope values), as well as a history of acaricide failure to ticks in these areas, R. annulatus developed resistance to ivermectin. This study documents the first report of field populations of R. annulatus resistant to ivermectin in Egypt.

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Factors associated with the efficiency of acaricides on different populations of Rhipicephalus microplus

Brazilian Journal of Veterinary Research and Animal Science ◽

10.11606/issn.1678-4456.bjvras.2019.157595 ◽

2019 ◽

Vol 56 (3) ◽

pp. e157595

Author(s):

Michel Menin ◽

Carolain Xavier ◽

Mauricio Francisco Grigolo ◽

Kaio Fernando Molosse ◽

Michele Helena Weirich ◽

...

Keyword(s):

Ixodid Tick ◽

Tick Control ◽

Economic Losses ◽

Cattle Tick ◽

Sample Collection ◽

Contributing Factors ◽

Santa Catarina ◽

History Of ◽

Different Populations ◽

Control And Management

Tick infestation causes major problems in cattle. Tick parasitism accounts for significant economic losses in many beef and dairy herds in the vast majority of the states in the Brazilian territory including the State of Santa Catarina in the southern region of the country. Tick resistance to several active principles occurs due to a number of factors including the indiscriminate, injudicious and inadequate use of tick insecticides. Considering the great importance of fighting off tick infestations in cattle, we evaluated the efficiency of 8 different topical active principles against the ixodid tick R. microplus and identified the main factors that contribute to the development of ticks that are resistant to acaricides in the farms and bovine herds studied. For such purpose, R. microplus telegionae were collected in 39 farms locates in different municipalities of the West of Santa Catarina, south Brazil. At the time of sample collection, information about the management, the history of the acar used in the herd, the number of annual applications of these pesticides, the frequency of acaricide rotation, and the frequency of technical monitoring for strategic tick control were retrieved. We collected this data in order determine contributing factors to the development resistant R. microplus populations. For the sensitivity profile of these ticks to a number of different acaricides tested, 10 engorged females for each principle and a control were used. The results of our study show that most associations between pyrethroids and organophosphates had an efficiency between 96.6% and 100% in the control of R. microplus except for the combination of Alfacipermetrine 15%, Ethion 16%, and Chlorpyrifos 8.5% that had 93.4% of efficiency. Among the chemicals not associated with any other type of compound, Amitraz 12.5% was effective in 98.3% of the cases. In contrast, Cypermethrin 15% had an efficiency in only 25.8% of the farms/herds analyzed. Based on the results of the present study, we may infer that the methods of control and management used by producers may be related to the low indexes of resistance to topical acaricides in the different populations of ticks in the study area.

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