Studies on age and trypanosome infection rate in females of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. in Uganda

1966 ◽  
Vol 57 (1) ◽  
pp. 23-37 ◽  
Author(s):  
J. M. B. Harley
Keyword(s):  
Infection Rate ◽  
Lake Victoria ◽  
Glossina Pallidipes ◽  
Physiological Age ◽  
Infection Rates ◽  
The North ◽  
Large Numbers ◽  
North Eastern ◽  
Food Animals ◽  
Trypanosome Infection Rate

During 1964–65, 1,646 newly emerged females of Glossina pallidipes Aust., 1,898 of G. palpalis fuscipes Newst. and 2,528 of G. brevipalpis Newst. were marked and released in an area on the north-eastern shore of Lake Victoria in Uganda so that, by examination of those subsequently recaptured, the relation between physiological and calendar age could be determined. In the light of the results, records of physiological age and trypanosome infections in large numbers of wild-caught females of the same three species caught in the same area in 1962–63 were examined, together with published observation on the animals on which they fed, and the effects of age and food-animals on the incidence of infections were investigated.Physiological age was determined by examination of the reproductive system and was expresses as the exact or approximate number of ovulations that had taken place. Infections with Trypanosoma were classified as brucei-type, vivax-type or congolense-type, and the last two as mature (infective) or immature, according to the sites in which trypanosomes were found in the flies. All brucei-type infections were regarded as mature.The relation between physiological and calender age indicated that the length of the ovulation cycle was 11 days in G. pallidipes, 11 1/2 in G. brevipalpis and about 15 in G. palpalis fuscipes, but from other evidence that the last figure should have been about 11 days it is considered that ovulation was retarded in the released females of G. palpalis fuscipes.The incidence of mature vivax- and congolense- type infections rose with age in all three species, beginning for the most part when flies were about a fortnight old. Brucei-type infections were rare and were found only in flies more than about 35 days old; nearly all flies with such infections also had one or both of the other types. The incidence of immature vivax-type infections rose with age up to about 25 days and then levelled off, which suggests that all eventually became mature. Immature congolense-type infections were rare.G. pallidipes had the highest total infection rate and G. brevipalpis the lowest. The percentage of order flies in the samples was, however, greater in the later than in G. palpalis fuscipes, which suggests that age is not the sole factor determining infection rate. Food-animals appeared to influence it, since the infection rates of the three species were proportional to the percentages of meals obtained from Bovids.The age at which females were inseminated was lowest in G. palpalis fuscipes, greatest in G. pallidipes and intermediate in G. brevipalpis. Abnormal ovulation cycles were rare in wild-caught flies, and few females that from their age should have been pregnant were found with an empty uterus.

Further studies on age and trypanosome infection rates in Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. in Uganda

1967 ◽  
Vol 57 (3) ◽  
pp. 459-477 ◽  
Author(s):  
J. M. B. Harley
Keyword(s):  
Infection Rate ◽  
Lake Victoria ◽  
Age Determination ◽  
Glossina Pallidipes ◽  
Physiological Age ◽  
Developmental Cycle ◽  
Seasonal Fluctuations ◽  
The North ◽  
North Eastern ◽  
The Mean

Between June 1964 and May 1965, samples of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. were caught in an area on the north-eastern shore of Lake Victoria in Uganda. Both males and females were classified into age-categories according to the degree of wear of the wings. Females were also classified into ovarian age-categories according to the exact or approximate number of ovulations that had taken place. All were examined for presence of infections with Trypanosoma, which were classified as vivax-type, congolense-type or brucei-type according to their location in the flies.The percentage compositions of the samples by wing-fray category are compared. The mean wing-fray category of females of G. palpalis fuscipes and G. brevipalpis was somewhat lower, and that of females of G. pallidipes somewhat higher, than that of the corresponding males. However, the figures for infection rate in females of all three species were higher than in the corresponding males, significantly so in G. pallidipes and G. palpalis fuscipes, and it seems probable that the mean age of females, at least of the two latter species, was greater than that of males. Among females, the range of calendar ages of flies in the various fray categories was wide.The physiological age-determination method, in which females older than about 42 days are classified iDto four age-categories, does not extend sufficiently far to give a reasonable pattern for the age-composition of any of the species at Lugala, and many of the individuals caught must have been more than about 80 days old.Seasonal fluctuations in mean wing-fray and in the proportion of old flies in the population were correlated with changes in infection rate of females of G. palpalis fuscipes but not of females of G. pallidipes. Among males of neither species were seasonal fluctuations in mean fray correlated with changes in infection rate, though among those of G. palpalis fuscipes the two varied similarly between June and February.Females of G. pallidipes and G. palpalis fuscipes about 31–42 days old had significantly fewer brucei-type infections than those over 42 days old, and either the developmental cycle in the field must normally be longer than that recorded in laboratory investigations or many of the flies must become infected when more than just a few days old.

Seasonal and diurnal variations in physiological age and trypanosome infection rate of females of Glossina pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst

1966 ◽  
Vol 56 (4) ◽  
pp. 595-614 ◽  
Author(s):  
J. M. B. Harley
Keyword(s):  
Infection Rate ◽  
Glossina Pallidipes ◽  
Early Morning ◽  
Physiological Age ◽  
Infection Rates ◽  
Age Composition ◽  
Seasonal And Diurnal Variations ◽  
Late Evening ◽  
The Mean ◽  
Trypanosome Infection Rate

A series of 24-hr. catches of Glossina from bait-oxen was carried out during 16 months in 1962–63 at Lugala, Uganda, where G. pallidipes Aust., G. palpalis fuscipes Newst. and G. brevipalpis Newst. occur. Female flies were dissected to determine their physiological age and the presence or absence of trypanosomes. Five age-categories were distinguished, depending on whether a fly had ovulated 0, 1, 2, 3 or more (4 + ) times. Flies remained in each of the first four categories for about 11 days and the fifth therefore comprised those over 40–50 days old. Trypanosome infections were classified as brucei-type, vivax-iype or congolense-type (i.e., attributable to trypanosomes of the groups of Trypanosoma brucei, T. vivax and T. congolense) according to the sites in which they were found.In all three species of Glossina, vivax-tjpe infections were commonest and alone showed seasonal fluctuations in incidence. Infections of the brucei-type were rare. The total infection rate (all types) in G. pallidipes and G. palpalis fuscipes was highest in or immediately after months of greatest rainfall and relatively lower in dry months; the highest infection rates in G. brevipalpis occurred a month later than those of the other two species. Over 80 per cent, of infections in all three were found in category 4+ flies, the percentage of which in the catches varied in much the same way as the total infection rate, suggesting not only that the flies live longest during wet periods but also that fluctuations of infection rate are largely due to changes in mean age. The regression of total infection rate on percentage of category 4 + flies was significant for G. palpalis fuscipes over 14 months, and for G. pallidipes over 12 months, but insignificant for G. brevipalpis.The age-composition of catches of G. pallidipes and G. brevipalpis but not G. palpalis fuscipes varied during the day. In G. pallidipes, the percentage of older flies was higher in the middle of the day than in the early morning and late evening, and these contrasts were reflected in the infection rate, which was highest in samples taken in the middle of the day. In G. brevipalpis, the percentage of oldier flies and also the infection rate were lower during the night than during the day.Estimates were made of the mean number of bites by infected females that would be received by one ox in one day. The number varied from month to month, with peaks shortly after periods of high rainfall, mainly as a result of changes in fly density and relatively little as a result of changes in infection rate. G. pallidipes, the most numerous species, was responsible for most of the potentially infective bites.

Age grades and infection rates of Rhipicephalus appendiculatus Neumann (Acari: Ixodidae) to assess theileriosis challenge in the field

1985 ◽  
Vol 75 (4) ◽  
pp. 653-660 ◽  
Author(s):  
Alan R. Walker ◽  
June D. Fletcher
Keyword(s):  
Salivary Glands ◽  
Infection Rate ◽  
Rhipicephalus Appendiculatus ◽  
Physiological Age ◽  
Methyl Green ◽  
Infection Rates ◽  
A Value ◽  
Type 3

AbstractData are presented from five series of 240 adults of Rhipicephalus appendiculatus Neumann kept in the laboratory, in which a steady decline in the numbers of granules in e cells of type 3 acini of the salivary glands occurred. This was readily detected in whole gland preparations of the salivary glands stained with methyl green and pyronin, and the same specimens could be used for detecting Theileria parasites in the salivary glands. Characteristics for grading these ticks into three physiological age grades are given, and a formula is provided for incorporating the age grade with infection rate. This gives a value for comparative estimates of the challenge posed by field populations of ticks for the transmission of Theileria to cattle.

Phylogeography and species delimitation in the New Zealand endemic, genetically hypervariable harvestman species, Aoraki denticulata (Arachnida, Opiliones, Cyphophthalmi)

2014 ◽  
Vol 28 (4) ◽  
pp. 401 ◽  
Author(s):  
Rosa Fernández ◽  
Gonzalo Giribet
Keyword(s):  
New Zealand ◽  
Species Delimitation ◽  
Northern Region ◽  
Genetic Connectivity ◽  
The North ◽  
Geographic Structure ◽  
Large Numbers ◽  
North Eastern ◽  
History Of ◽  
Complex Scenario

Aoraki denticulata, a widespread mite harvestman endemic to the NW South Island of New Zealand, was postulated to constitute an old lineage with deep genetic history. Expanding on previous studies, we explored its genetic diversity and population structure, phylogeography and diversification patterns. We also examined the systematic implications of such a complex scenario through species delimitation analyses under coalescent-based and barcoding gap discovery methodologies. Our results depict the deep evolutionary history of the A. denticulata lineage, which shows high geographic structure and low genetic connectivity among modern populations. Aoraki denticulata is further subdivided into three lineages: a lineage presently inhabiting the northern region of the Southern Alps (and including the subspecies A. d. major), a second lineage in the north-eastern part of the sampled land, and a third one occupying the south-eastern localities. When using species delimitation methods based on coalescence approaches, large numbers of cryptic species were estimated. Based on morphological and biological evidence, we thus argue that these methods may overestimate species in cases in which genetic divergence is unusually large and discuss the systematic implications of our findings.

scholarly journals Hosts, seasonality and geographic distribution of the South African tortoise tick, Amblyomma marmoreum

2006 ◽  
Vol 73 (1) ◽  
Author(s):  
I.G. Horak ◽  
I.J. McKay ◽  
Heloise Heyne ◽  
A.M. Spickett
Keyword(s):  
South African ◽  
Adult Tick ◽  
Eastern Cape ◽  
Large Herbivores ◽  
Mpumalanga Province ◽  
The North ◽  
Numida Meleagris ◽  
Large Numbers ◽  
North Eastern ◽  
Northern Cape

The tortoise tick Amblyomma marmoreum was collected from large numbers of reptiles and other animals during the course of numerous surveys conducted in South Africa. A total of 1 229 ticks, of which 550 were adults, were recovered from 309 reptiles belonging to 13 species, with leopard tortoises, Geochelone pardalis being the most heavily infested. The 269 birds sampled harboured 4 901 larvae, 217 nymphs and no adult ticks, and the prevalence of infestation was greatest on hel meted guinea fowls, Numida meleagris. Only two larvae were recovered from 610 rodents, including 31 spring hares, Pedetes capensis, whereas 1 144 other small mammals yielded 1 835 immature ticks, of which 1 655 were collected from 623 scrub hares, Lepus saxatilis. The 213 carnivores examined harboured 2 459 ticks of which none were adult. A single adult tick and 6 684 larvae and 62 nymphs were recovered from 656 large herbivores, and a total of 4 081 immature ticks and three adults were collected from 1 543 domestic animals and 194 humans. Adult male and female A. marmoreum were most numerous on reptiles during January and February, and larvae during March. The largest numbers of larvae were present on domestic cattle and helmeted guineafowls in the Eastern Cape Province during March or April respectively, whereas larvae were most numerous on helmeted guineafowls, scrub hares and the vegetation in north-eastern Mpumalanga Province during May. In both provinces nymphs were most numerous between October and December. Amblyomma marmoreum appears to be most prevalent in the western regions of the Western and Eastern Cape and Free State provinces, and the north-eastern regions of the Northern Cape, KwaZulu- Natal, Mpumulanga and Limpopo provinces.

scholarly journals Traditions in Transition: Some Thoughts on Late Bronze Age and Early Iron Age Burial Costumes from the Northern Caucasus

2003 ◽  
Vol 6 (1) ◽  
pp. 25-54 ◽  
Author(s):  
Sabine Reinhold
Keyword(s):  
Bronze Age ◽  
Iron Age ◽  
Social Identities ◽  
Northern Caucasus ◽  
Early Iron Age ◽  
Late Bronze Age ◽  
North Caucasus ◽  
The North ◽  
Large Numbers ◽  
North Eastern

Ornaments, jewellery, personal equipment and weapons in graves can be defined as relicts of ancient costumes and weapon assemblages which are connected to the social identities of the buried persons. At several late Bronze Age and early Iron Age sites in the north Caucasus (Koban culture) large numbers of richly furnished graves allow the reconstruction of specific costume and armour groups. These can be related to factors which structured these communities into a ranked society. This article is based on the investigation of two cemeteries in Chechenia (north-eastern Caucasus) which demonstrate the change in social differentiation during the developed Iron Age. The article also includes a general discussion about the concepts of costumes and their potential for reconstructing social identities.

Cycles of change in Jomon settlement: a case study from eastern Tokyo Bay

Antiquity ◽  
2013 ◽  
Vol 87 (338) ◽  
pp. 1169-1181 ◽  
Author(s):  
Enrico R. Crema
Keyword(s):  
Detailed Analysis ◽  
Settlement Patterns ◽  
Tokyo Bay ◽  
Archaeological Sites ◽  
The North ◽  
Large Numbers ◽  
Regular Cycle ◽  
Residential Units ◽  
North Eastern

Japanese archaeology benefits from the large number of rescue excavations conducted during recent decades that have led to an unparalleled record of archaeological sites. That record is here put to use to interrogate changing settlement patterns in the north-eastern corner of Tokyo Bay during several millennia of the Jomon period (Early, Middle and Late Jomon: 7000–3220 cal BP). Jomon hunter-gatherer occupation is characterised by large numbers of settlements, some of them substantial in size, containing hundreds of individual pit-house residential units. Detailed analysis of the rank-size distribution of these settlements reveals a pattern in which periods of settlement clumping, with few large settlements, alternate with more dispersed settlement patterns on a regular cycle of approximately 600 years. The regularity of this cycle might suggest a correlation with cycles of climatic change, such as Bond events. Closer scrutiny shows, however, that such a correlation is unconvincing and suggests that cyclical change in Jomon settlement patterns may instead be due to other factors.

Activity Cycles ofGlossina pallidipesAust.,G. palpalis fuscipesNewst. andG. brevipalpisNewst

1965 ◽  
Vol 56 (1) ◽  
pp. 141-160 ◽  
Author(s):  
J. M. B. Harley
Keyword(s):  
Lake Victoria ◽  
Glossina Pallidipes ◽  
Physical Factor ◽  
Dry Season ◽  
Physical Factors ◽  
Wet Season ◽  
North East ◽  
The North ◽  
Morning Peak ◽  
Hot Dry Season

A series of 24-hr catches ofGlossina pallidipesAust.,G. palpalis fuscipesNewst. andG. brevipalpisNewst. was carried out on the north-east shore of Lake Victoria over a period of 11 months in 1962–63. The object was to define and compare the daily pattern of activity of the three species as indicated by the numbers caught hourly on three black cattle that were used as bait. Catching during the hours of darkness was done by the light of dimmed hurricane lamps. The period of observation covered successively a dry season, a wet season, a cool dry season and a hot dry season.At all seasons, males ofG. pallidipeswere caught in gradually increasing numbers from just before dawn until shortly before sunset, after which a rapid decrease took place. Females ofG. pallidipesexhibited a different pattern, with a gradual rise in activity in the morning until about midday, after which activity remained more or less constant until shortly before sunset, when a rapid fall occurred. There was never any indication of a morning peak in activity such as has been described for this species elsewhere. Activity during the night was at an extremely low level.Activity of both males and females ofG. p. fuscipesstarted about dawn, increased to a peak in the middle hours of the day, and then fell fairly rapidly in the evening; the exact time of the peak was variable. None was caught during the night.There was some activity ofG. brevipalpisthroughout the diel, but marked peaks of activity were exhibited by both sexes. In the open, these took place immediately after sunset and immediately before sunrise, the latter being the smaller. In the shade, the morning peak in both sexes was an hour later than in the open, and the evening peak in males alone was an hour earlier.These results are compared with those of other workers, and the influence of physical factors is discussed. Particular values of temperature and saturation deficit were not closely associated with particular levels of activity of any of the three species, and light intensity is probably the physical factor that is most consistently the same at times of particular levels of activity at all seasons.

A diurnal and seasonal study of the feeding activity of Glossina pallidipes Aust.

1962 ◽  
Vol 53 (3) ◽  
pp. 541-550 ◽  
Author(s):  
R. D. Pilson ◽  
B. M. Leggate
Keyword(s):  
Infection Rate ◽  
Rainy Season ◽  
Feeding Activity ◽  
Glossina Pallidipes ◽  
The Other ◽  
Diurnal Pattern ◽  
Trypanosome Infection ◽  
Experimental Site ◽  
Southern Rhodesia ◽  
Trypanosome Infection Rate

In a continuation of studies of diurnal and seasonal feeding activity of Glossina pallidipes Aust. in thick riverine vegetation at Rekomitjie, in the Zambezi Valley, Southern Rhodesia, flies attracted to a stationary black ox were allowed to become engorged, then caught, marked and released. More flies fed per day in the late dry season (November), and fewer during the rainy season (February), than at other times of the year. The proportions of females amongst flies feeding, and of marked flies recaptured, were greatest in May (77·6 and 20·0 per cent., respectively) and least in November (59·2 and 7·7 per cent., respectively). The diurnal pattern of feeding activity was similar in all seasons, there being a well-marked peak of activity at or shortly before sunset.The trypanosome infection rate was obtained by dissecting flies caught near the experimental site and was combined with figures for the number of flies attacking the ox to give an estimate of the seasonal trypanosome risk (mean number of infected flies that fed on the ox per day); this was greatest in November and smallest in February.From comparison of catches off a moving and a stationary ox, two stationary oxen standing together, and two standing out of sight of one another, in each case one being red and the other black, it appears that colour of the bait-animal is not of great importance as an attractant to G. pallidipes unless a definite choice is presented, when flies show preference for feeding on a dark surface.

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