Observations on infestations of undipped cattle of British breeds with the cattle tick, Boophilus microplus (Canestrini).

1955 ◽  
Vol 6 (4) ◽  
pp. 655 ◽  
Author(s):  
PR Wilkinson
Keyword(s):  
Tick Infestation ◽  
Adult Tick ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Skin Thickness ◽  
Small Areas ◽  
Thickness Measurements ◽  
Tick Resistance

A small herd of cattle infested with the cattle tick, Boophilus microplus (Canestrini) was kept in a previously unstocked paddock for 11 months without treatment for tick infestation. Frequent examinations showed that widely differing numbers of ticks developed on the cattle. The "tick resistance" of one animal, which showed no adult ticks during the summer months, could only be accounted for by mortality of the larvae and nymphs on the animal, since as many larvae were seen on selected small areas of this animal as on some animals carrying many adult ticks. The animals grazed together and thus would encounter similar numbers of tick larvae. The degree of susceptibility to adult tick infestation showed negligible correlation with skin thickness measurements and was not related to coat length. Larvae reappeared on the cattle 6 weeks after the first stocking of the paddock in March. The animals became almost free of ticks for 2 weeks in August. Although larvae were most numerous in November-December, they gave rise to fewer adults than the earlier wave of larvae in September- October. Some of the cattle suffered from "tick-worry'' in October, but thereafter their condition improved without treatment.

Selection of cattle for tick resistance, and the effect of herds of different susceptibility on Boophilus populations

1962 ◽  
Vol 13 (5) ◽  
pp. 974 ◽  
Author(s):  
PR Wilkinson
Keyword(s):  
Tick Infestation ◽  
Tick Control ◽  
Boophilus Microplus ◽  
Skin Thickness ◽  
Adult Females ◽  
Cattle Ticks ◽  
In Parenthesis ◽  
Tick Counts ◽  
Tick Resistance ◽  
Selection Of

Weekly counts of Boophilus microplus (Canestrini) on 30 Australian Illawarra Shorthorn heifers enabled the cattle to be ranked in order of tick infestation, with highly significant correlations between counts of two observers and between counts of one observer on different occasions. In May 1960, when the heifers were 1½–2 years old, 12 were selected as relatively tick-resistant and 12 as relatively tick-susceptible. Each of these groups was divided at random into herds of six, and the four herds were then allotted randomly to separate paddocks, each onequarter of the area previously grazed. A herd was sprayed with 0.5% DDT emulsion when its average count of ticks (adult females over 5 mm in length) on one side of the animals exceeded 40. During the ensuing tick season, from October 5, 1960, to June 7, 1961, the sums of average weekly tick counts, and the numbers of sprayings (in parenthesis) were: susceptible herds 4853 (5) and 5962 (6): resistant herds 718 (0) and 1073 (1). Counts of tick larvae on defined body areas showed that, in the summer after segregation, resistant herds carried fewer larvae than the susceptible herds, apparently because fewer mature ticks fell from the resistant cattle in the preceding spring and winter. As a consequence of this, counts of adult ticks were comparatively lower after than before segregation. There was little or no 'spring rise' of tick infestation on the resistant herds. There was no significant correlation between tick resistance and coat score, sweat gland dimensions, or total skin thickness, but a correlation of -0.53 with follicle depth was significant at the 1% level. There was no evidence of adaptation of cattle ticks to the resistant animals, either in the field experiment or in observations on stalled cattle. The experiment draws attention to the appreciable proportion of tick-resistant animals within the Australian Illawarra Shorthorn breed, which has largely been overlooked in past discussions on tick-resistant breeds of cattle. It also suggests a technique for estimating the improvement in tick control that may be obtained by a given degree of selection within any breed, for any given environment.

The structure of the Spiracles of the cattle tick, Boophilus microplus

1967 ◽  
Vol 15 (5) ◽  
pp. 941 ◽  
Author(s):  
HE Hinton
Keyword(s):  
Electron Microscope ◽  
Ambient Air ◽  
Adult Tick ◽  
Boophilus Microplus ◽  
Ixodid Ticks ◽  
Cattle Tick ◽  
Serial Sections ◽  
Peripheral Part ◽  
Gas Exchanges ◽  
Spiracular Plate

The structures of the nymphal and adult spiracles of the tick, Boophilus microplus, have been examined by means of serial sections and a stereoscan electron microscope. Contrary to the views of recent writers, the functional openings of the spiracle have been found to be holes or aeropyles in the peripheral part of the spiracular plate of the adult tick. The ostium of previous writers is shown to be the ecdysial tube, which is present only in the spiracles of adult ixodid ticks. After the nymphal-adult ecdysis, the ecdysial tube is closed. There is thus no ostium in this stage, as has been claimed by previous writers who supposed that the chief or only route for gas exchanges between the atrium of the spiracle and the ambient air was through the so-called ostium. The ecdysial process of the spiracles of ticks is shown to be basically similar to the ecdysial process of the spiracles of certain insects such as scarabaeid larvae and the larvae of some Diptera-Cyclorrhapha.

Resistance to the cattle tick, Boophilus microplus in a herd of Australian Illawarra Shorthorn cattle: Its assessment and heritability

1970 ◽  
Vol 21 (1) ◽  
pp. 163 ◽  
Author(s):  
RH Wharton ◽  
KBW Utech ◽  
HG Turner
Keyword(s):  
Reference Value ◽  
Mature Female ◽  
Boophilus Microplus ◽  
Supplementary Information ◽  
Cattle Tick ◽  
The Mean ◽  
Tick Counts ◽  
The Right ◽  
High Level ◽  
Tick Resistance

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.

The spelling of pasture in cattle tick control

1957 ◽  
Vol 8 (4) ◽  
pp. 414 ◽  
Author(s):  
PR Wilkinson
Keyword(s):  
Field Trial ◽  
Tick Infestation ◽  
Tick Control ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Frequent Use ◽  
Cattle Tick Control

When two comparable herds of cattle were kept continuously in adjoining paddocks, frequent acaricidal treatment was necessary to control ticks (Boophilus microplus (Canestrini) ). Thereafter, one of the two herds was grazed alternately in its own and an adjacent paddock, the intervals between each transfer being sufficient to ensure that most of the ticks in the unoccupied paddock had died. Tick infestations on this herd were greatly reduced, and less frequent use of acaricides was necessary. The herd remaining in the continuously stocked pasture continued to need acaricidal treatment for recurring tick infestation. In a field trial with 350–400 cattle moved a t intervals to each of three formerly heavily infested paddocks, tick infestations remained very light, although the herd was dipped only In January, September, and the following January. A control herd on continuously stocked pasture, treated at the owner's discretion, required eight dippings in this period. This procedure of "pasture spelling" seems likely to be widely applicable in central Queensland.

scholarly journals Alterations in Host Metabolism by the Specific and Anorectic Effects of the Cattle Tick (Boophilus Microplus) I. Food Intake and Body Weight Growth

1971 ◽  
Vol 24 (2) ◽  
pp. 373 ◽  
Author(s):  
RM Seebeck ◽  
PH Springell ◽  
JC O'kelly
Keyword(s):  
Food Intake ◽  
Tick Infestation ◽  
Specific Effect ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Weight Growth ◽  
Hereford Cattle ◽  
Anorectic Effect ◽  
Quality Diet ◽  
Host Metabolism

This experiment was designed to measure the effects of infestation by B. microplus on cattle and to separate the effects of reduced food intake ("anorectic effect") from those due to the remaining factors of tick infestation ("specific effect"). Hereford cattle kept on a high-quality diet were studied over a treatment period of 11 weeks with the tick-infested animals being infested regularly with equal larval doses for each animal.

Heritability estimates from correlations in intra-sire data. Appendix I. from - Resistance to the cattle tick, Boophilus microplus in a herd of Australian Illawarra Shorthorn cattle: Its assessment and heritability

1970 ◽  
Vol 21 (1) ◽  
pp. 181
Author(s):  
HG Turner
Keyword(s):  
Reference Value ◽  
Mature Female ◽  
Boophilus Microplus ◽  
Supplementary Information ◽  
Cattle Tick ◽  
The Mean ◽  
Tick Counts ◽  
The Right ◽  
High Level ◽  
Tick Resistance

An Australian Illawarra Shorthorn herd of 24 cows was mated in three consecutive years with an AIS bull. The cows and their progeny were rated for tick resistance at frequent intervals from August 1959 to December 1965 by counting the numbers of semiengorged female ticks on the right side. The mean of log counts for all counts on a particular animal was adopted as the reference value for its degree of susceptibility. The ranking of cattle generally showed a high level of consistency with mean repeatability of counts (r = 0.47, P < 0.01). Discrimination between animals was more reliable (P < 0.01) in summer (r = 0.52) than in winter (r = 0.27). The repeatability of tick counts increased with mean count, from r = 0.27 when the mean count was 3 to r = 0.67 when it was 100. The reliability of counts on the cows decreased with age and with lactation. Supplementary information on a larger herd showed no effect of pregnancy on mean count or on discrimination between susceptible and resistant animals, but showed that there was a partial breakdown of resistance during lactation. In calves infested naturally, no effects of age or sex on tick counts or their repeatability were detected, though male calves yielded significantly larger numbers of ticks than females when infested artificially. The mean yield of mature female ticks on the cows following two artificial infestations with known numbers of larvae ranged from 0.2 to 27.4% of the potential. Natural and artificial assessments of susceptibility were closely correlated. The rank of the bull was similar to that of the more resistant cows. Mean estimates of the heritability of tick resistance based on single counts were 39 % from dam-calf correlations and 49 % from full-sib correlations. Estimates based on summer counts only were 42 and 64% respectively. These results provide strong encouragement for selecting for tick resistance.

Natural occurrence of lethal aspergillosis in the cattle tickRhipicephalus (Boophilus) microplus(Acari:Ixodidae)

Parasitology ◽  
2011 ◽  
Vol 139 (2) ◽  
pp. 259-263 ◽  
Author(s):  
E. MIRANDA-MIRANDA ◽  
R. COSSIO-BAYUGAR ◽  
F. MARTÍNEZ-IBAÑEZ ◽  
R. CASASANERO-ORDUÑA ◽  
J. FOLCH-MALLOL
Keyword(s):  
Aspergillus Flavus ◽  
Experimental Infection ◽  
Entomopathogenic Fungus ◽  
18S Rrna ◽  
Tick Infestation ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Natural Occurrence ◽  
Dark Colour ◽  
Microscopic Morphology

SUMMARYThe purpose of this study was to describe an unreported entomopathogenic fungus that naturally infects the cattle tickRhipicephalus (Boophilus) microplus(Acari: Ixodidae). Engorged female ticks, showed symptoms of fungal infection after controlled tick infestation of cattle. Infected ticks developed a distinctive dark colour, a pale mould grew over the cuticle and the ticks eventually died covered with fungal conidiophores. The responsible fungus was isolated and cultured on mycological medium and submitted to microscopic morphology, biochemical phenotyping and 18S rRNA ribotyping analyses, which identified it as aflatoxin-producingAspergillus flavus. Spores from the cultured fungus were experimentally sprayed over healthy engorged female ticks, obtaining an 80% prevalence of experimental infection of healthy ticks and their egg masses, the larval progeny after incubation under laboratory conditions was also infected. These results demonstrate thatA. flavusis the causative agent of the natural fungal disease of the cattle tickR. microplusdescribed here.

Ecology of the cattle tick (Boophilus microplus) in subtropical Australia. I. Introduction and free-living stages

1988 ◽  
Vol 39 (2) ◽  
pp. 285 ◽  
Author(s):  
RW Sutherst ◽  
ID Sutherland ◽  
AS Bourne ◽  
GF Maywald ◽  
DA Stegeman
Keyword(s):  
Host Resistance ◽  
Bos Indicus ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Climatic Effects ◽  
Free Living ◽  
Tick Reproduction ◽  
The Relationship ◽  
Tick Resistance ◽  
Subtropical Australia

An experiment is described which compared the fluctuations in the numbers of cattle tick, Boophilus miicroplus, that resulted from direct climatic effects or from changes in host resistance. Four herds of cattle, matched for tick resistance and with different Bos indicus (zebu) content, were grazed at each of two locations, one in central Queensland (23� S.) and one in southern Queensland (28� S.), from November 1977 to May 1982. Natural tick populations were counted regularly, and host resistance was measured using artificial infestations, either twice or six times a year. Concurrent exposures of engorged ticks in pastures were used to measure the success of the ticks in producing larvae and to partition mortality during development. Two later papers report other aspccts of the experiment. These include observations on the resistance of cattle to ticks and on the relationship between tick numbers on the cattle on one hand, and the availability of larvae on pasture and survival of parasitic stages on the other. Engorged ticks produced more larvae throughout the year in central Queensland, despite laying fewer eggs. The colder and longer winter in southern Queensland greatly reduced tick reproduction. Failure of engorged ticks to survive predation and find a favourable oviposition site, egg mortality and loss of larvae in the pasture accounted for most of the reduction in the potential number of larvae produced. Reduced oviposition was also important in wintcr.

scholarly journals Alterations in Host Metabolism by the Specific and Anorectic Effects of the Cattle Tick (Boophilus Microplus) II. Changes in Blood Composition

1971 ◽  
Vol 24 (2) ◽  
pp. 381 ◽  
Author(s):  
JC O'kelly ◽  
RM Seebeck ◽  
PH Springell
Keyword(s):  
Feed Intake ◽  
Tick Infestation ◽  
Specific Effect ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Blood Composition ◽  
High Quality ◽  
Anorectic Effect ◽  
Quality Diet ◽  
Host Metabolism

Changes in the blood composition of Hereford steers kept on a high. quality diet and infested with B. microplus were studied. The experiment was designed so that the effects on blood composition due to reduced feed intake ("anorectic effect") and those due to the remaining factors of tick infestation ("specific effect") could be independently estimated.

Long-term population studies on the cattle tick (Boophilus microplus) on untreated cattle selected for different levels of tick resistance

1979 ◽  
Vol 30 (2) ◽  
pp. 353 ◽  
Author(s):  
RW Sutherst ◽  
RH Wharton ◽  
IM Cook ◽  
ID Sutherland ◽  
AS Bourne
Keyword(s):  
Census Data ◽  
Seasonal Pattern ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Tick Population ◽  
Population Sizes ◽  
The Mean ◽  
Highly Correlated ◽  
Tick Counts ◽  
Tick Resistance

Census data were collected at weekly intervals on tick populations on untreated cattle over a period of 6 years in central Queensland, near Rockhampton. Hereford x Shorthorn (British; HS) heifers and two herds of Africander (Zebu) x [Hereford and Shorthorn] (AX) heifers, one with animals of high resistance (AXH) and the other of medium (AXM) tick resistance, were grazed in separate paddocks. A herd of AX steers was added to the trial when the heifers commenced calving in 1972–73. Data were collected from the heifers for three years prior to their first calving and then for a further three years whilst they were breeding. There were large differences between the numbers of ticks in different years and a consistent seasonal pattern, the numbers being lowest from July to September and highest in the April to June quarter. The AXH herd had fewest ticks for most of the experiment, but after the first year there was little difference between the infestations on the AXM and HS herds. The resistance of all herds, measured by artificial infestations with larvae, increased during the first 3 years but declined after the cattle began breeding, and fluctuated from year to year. The resistance of some heifers did not stabilize until the animals were more than a year old, and that of some animals drifted up or down over long periods. The loss of resistance of a small proportion of the cattle in the AXH herd was responsible for the advantage of that herd being substantially reduced. Both the ranking for resistance of animals and the mean resistance of the herds, assessed with artificial infestations, agreed with the rankings and tick population sizes observed from tick counts on the cattle in the field. Changes in the mean resistance of the herds in spring in different years were highly correlated with concurrent field infestations, which suggests that changes in host resistance have important effects on tick populations. Tick counts on the calves up to weaning showed no correlation with concurrent counts on their dams, but the ranking of the counts on the calves was consistent over the 6 month period.

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