We will review some of the major results in random graphs and some of the more challenging open problems. We will cover algorithmic and structural questions. We will touch on newer models, including those related to the WWW.

Random graphs

Manuscript in preparation

The body encloses a complex antioxidant defence grid that relies on endogenous enzymatic and non-enzymatic antioxidants. These molecules collectively act against free radicals to resist their damag...

https://www.ajol.info/index.php/bafm/article/download/182149/171529

First line defence antioxidants-superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX): Their fundamental role in the entire antioxidant defence grid

We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

A new species

Ticks and tick-borne diseases affect animal and human health worldwide and are the cause of significant economic losses. Approximately 10% of the currently known 867 tick species act as vectors of a broad range of pathogens of domestic animals and humans and are also responsible for damage directly due to their feeding behaviour. The most important tick species and the effects they cause are listed. The impact on the global economy is considered to be high and although some estimates are given, there is a lack of reliable data. The impact of ticks and tick-borne diseases on animal production and public health and their control are discussed.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/2CCD9EAD34FA5E2FB3CD37DAAFFF7F56/S0031182004005967a.pdf/div-class-title-the-global-importance-of-ticks-div.pdf

The global importance of ticks.

Several studies on ticks infesting small mammals, including elephant shrews, have been conducted in South Africa; however, these studies have included only a single four-toed elephant shrew and no hedgehogs. This study thus aimed to identify and quantify the ixodid ticks infesting four-toed elephant shrews and Southern African hedgehogs. Four-toed elephant shrews (Petrodromus tetradactylus) were trapped in dense shrub undergrowth in a nature reserve in north-eastern KwaZulu-Natal. They were separately housed, first in cages and later in glass terraria fitted with wire-mesh bases to allow detached ticks to fall through for collection. Southern African hedgehogs (Atelerix frontalis) were hand caught on a farm in the eastern region of the Northern Cape Province and all visible ticks were collected by means of tweezers while the animals were anaesthetised. The ticks from each animal were preserved separately in 70% ethanol for later identification and counting. The immature stages of five ixodid tick species were collected from the elephant shrews, of which Rhipicephalus muehlensi was the most common. It has not been recorded previously on any species of elephant shrew. Three ixodid tick species were collected from the hedgehogs. Large numbers of adult Haemaphysalis colesbergensis, which has not been encountered previously on hedgehogs, were collected from these animals. Four-toed elephant shrews are good hosts of the larvae and nymphs of R. muehlensi, and Southern African hedgehogs are good hosts of adult H. colesbergensis.

Ticks of four-toed elephant shrews and Southern African hedgehogs : original research

Three isolates of an Aegyptianella sp. were established in young guineafowls experimentally infected with blood collected from wild helmeted guineafowls in the Skukuza area of the Kruger National Park. The parasite was unable to infect turkeys and domestic fowls. In addition to ring and spherical forms typical of Aegyptianella pullorum, the organism also exhibited numerous irregularly shaped forms. Because of its inability to infect domestic fowls and morphological differences the organism is considered to be a species distinct from A. pullorum. Argasid larvae found on the wild guineafowls were not Argas walkerae.
Drie isolate van 'n Aegyptianella sp. is in jong tarentale wat eksperimenteel met die bloed van wilde tarentale vanaf die Skukuza-gebied van die Nasionale Kruger-Wildtuin ingespuit is, gevestig. Dit was nie moontlik om kalkoene of hoenders met die parasiet te besmet nie. Bykomstig tot die ring- en sfeerfatsoene wat tipies is van Aegyptianella pullorum, het die organisme ook as veelvuldige onreelmatige vorms voorgekom. Omdat die organisme nie hoenders kon besmet nie en weens morfologiese verskille, blyk dit 'n spesie anders as A. pullorum te wees. Tampanlarwes op die wilde tarentale was nie die van Argas walkerae nie.

Isolation of Aegyptianella sp. (Rickettsiales: Anaplasmataceae) from helmeted guineafowls in the Kruger National Park

Mortality due to Karoo paralysis amongst livestock is of considerable economic importance in South Africa. Indications are that the extent of vertical migration of adult ticks, to reach questing positions on grasses, is influenced by sudden climatic chages. Such influences as well as selection of questing substrates were investigated under controlled conditions. Vertical migration of adult Ixodes rubicundus on copper rods was determined in a square metal arena within a closed glass container in a room in which temperature and light could be controlled. Significantly more female and male ticks migrated vertically on 1.5 mm diameter rods than on 4.0 mm rods and on 450 mm long rods than on 100 mm rods. More ticks of both sexes migrated vertically at RH>80% than at RH<50% and at 12°C than at 21°C. More female than male and more older than younger ticks migrated vertically in all experiments. The results of this study contribute towards an understanding of the epidemiology of Karoo paralysis.

Vertical migration of adult Ixodes rubicundus, the Karoo paralysis tick (Acari: Ixodidae)

A new species of nematode. Cooperia connochaeti, was collected from cross-bred blue and black wildebeest at Krugersdorp (Transvaal), blue wildebeest Connochaetes taurinus (Burchell, 1823) from the Kruger National Park (Transvaal) and Lake Xhau (Botswana), as well as from impala Aepyceros melampus (Lichtenstein, 1812) at Malelane (Transvaal) and Pafuri (Kruger National Park). These nematodes are smaller than Cooperia pectinata Ransom, 1907, and their spicules, which are bifid in the distal third, are shorter (145-166 micron) than those of C. pectinata (240-280 micron). In addition, the lateral branches of the dorsal ray of C. connochaeti are directed ventrally and slightly anteriorly, while those of C. pectinata are directed posteriorly.

Cooperia connochaeti sp. nov. (Nematoda, Trichostrongylidae) from the blue wildebeest, Connochaetes taurinus (Burchell, 1823).

Eight ixodid tick species were collected from 173 African savanna elephants ( Loxodonta africana ) in Kenya, northern Mozambique and Zimbabwe, and two species were collected from six African forest elephants ( Loxodonta cyclotis ) in the Republic of Congo. A new host record is reported for Amblyomma eburneum . A list of ticks collected from elephants in various African countries, and stored in the United States National Tick Collection, is supplied as well as an annotated checklist of the 27 ixodid tick species that have been collected from African elephants. The geographic distributions and alternative hosts of the various tick species collected from elephants are briefly discussed.

/pdf/ixodid-ticks-acari-ixodidae-collected-from-african-savanna-52u75m7zs5.pdf

Ivan Gerard Horak

Papers

Ticks of four-toed elephant shrews and Southern African hedgehogs : original research

Isolation of Aegyptianella sp. (Rickettsiales: Anaplasmataceae) from helmeted guineafowls in the Kruger National Park

Vertical migration of adult Ixodes rubicundus, the Karoo paralysis tick (Acari: Ixodidae)

Cooperia connochaeti sp. nov. (Nematoda, Trichostrongylidae) from the blue wildebeest, Connochaetes taurinus (Burchell, 1823).

Ixodid ticks (Acari: Ixodidae) collected from African savanna elephants (Loxodonta africana) and African forest elephants (Loxodonta cyclotis)