Fertilization capacity of Boophilus decoloratus (Koch, 1844) (Acarina : Ixodidae)

Thirty individual Boophilus decoloratus (Koch, 1844) males were studied daily, some during the whole observation period of 37 days. Newly moulted males spent a mean of 3, 8 days (range 3- 6) on the host before mating. Males mated w1th between 1- 8 females (mean 4, 6), spending 2,6 days (range 1- 10) with each and 0,5 days (range 0-4) in between females. The time spent by adult males on the host was from 9-37 days. The ability for males to produce viable offspring remained fairly constant with each successive female fertilized. Development took place in eggs produced by unfertilized female ticks but only a very small percentage (mean 0, 008 %) of these eggs hatched.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentyation PDF-Format

A rapid spectrophotometric method for the monitoring of embryonic development in ticks (Acarina : Ixodoidea)

A rapid spectrophotometric method for the monitoring of embryonic development in Boophilus decoloratus (Koch, 1844) is described. The method is based on a quantitative assessment of guanine, the principal end-product of nitrogenous metabolism in ticks, which is gradually built up and stored in the rectal sac during embryonic development of the larvae. A study of the growth of tick embryos under constant temperature conditions and 6 different humidity conditions demonstrated that embryonic development was dependent on the water content of the eggs at the time of oviposition. When eggs lost more than 35% of their initial mass through evaporation, nitrogenous metabolism (as indicated by guanine production) was seriously affected and embryos died.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acroabt XI was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Oviposition and incubation in Boophilus decoloratus (Koch, 1844) (Acarina : Ixodidae)

Studies on the duration of the oviposition and incubation periods of Boophilus decoloratus (Koch, 1844) revealed that these non-parasitic periods are temperature dependent, increase in temperature causing shortening of the periods. Humidity had no effect on the duration of either the oviposition or the incubation periods. The relation between the mass of engorged female ticks and that of the eggs they produced was found to be linear. The viability of eggs produced during the first 13 days of oviposition (at 26 °C) was greater than that of eggs laid subsequently. The critical temperature for B. decoloratus eggs was found to be 42 °C and they were shown to be unable to take up water vapour from damp atmospheres. Both temperature and humidity affected the hatch of eggs. A simple model of the relations between the physical factors of the environment and the various biological phenomena studied has been given.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Gonad development and gametogenesis in Boophilus decoloratus (Koch, 1844) (Acarina : Metastriata : Ixodidae)

Phases in the growth of the reproductive organs and gametogenesis were followed in both males and females of Boophilus decoloratus (Koch, 1844). Special attention was given to the timing of meiosis, the production of mature spermiophores, mating and spermiophore relocation in the female. The main growth phase of the male testes takes place during the nymphal stage while that of the accessory gland complex takes place during the 4 days after moulting and before mating. The main growth phase of female ovaries and oviducts takes place during the post-mating period on the ho5t and the preoviposition period. Meiosis in males takes place only after the attachment of the newly-moulted ticks; spermatogenesis and spermiogenesis occur within a period of 4 days, after which pairing and spermatophore transfer take place. Meiosis was not observed in female ticks and it is concluded that this reduction division takes place only after spermiophore penetration of the oocytes and egg shell formation. Female ticks may be impregnated more than once, a maximum of 5 matings being deduced from counts of spermiophore capsules in the female seminal receptacle. Each spermatophore produced by male ticks yields either I but more commonly 2 spermiophore capsules. The reproduction of B. decoloratus is briefly discussed and compared with other Ixodoidea.The articles have been scanned in colour with a HP scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to final presentyation PDF-Format

The life cycle of the two-host tick Rhipicephalus evertsi evertsi Neumann, 1897, under laboratory conditions (Acarina : Ixodidae)

The life cycle of Rhipicephalus evertsi evertsi Neumann, 1897, is discussed under the following headings: larval feeding; larval drop; nymphal feeding; nymphal drop; nymphal moulting; adult feeding; adult drop; preoviposition period; oviposition period and incubation. Special attention has also been given to the development of both male and female reproductive organs, gametogenesis and mating.The articles have been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format

Parasites of domestic and wild animals in South Africa. XIII. The seasonal incidence of adult ticks (Acarina : Ixodidae) on cattle in the northern Transvaal

Ticks were collected over a period of 13 months, at approximately fortnightly intervals, from 6 Africaner oxen kept on the farm Nylsvley in the Naboomspruit District. The 8 species of Ixodidae collected were, in order of abundance, Rhipicephalus appendiculatus, R. evertsi evertsi, Hyalomma marginatum rufipes, H. truncatum, Amblyomma hebraeum, R. simus, Boophilus decoloratus and Ixodes cavipalpus. The relative abundance of adult ticks of these species, their predilection feeding sites and seasonal fluctuations in numbers are discussed.This article has been scanned in colour with a HP Scanjet 5590; 300dpi. Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-Format

Atividade biológica de extratos acetato de etila, etanólico e aquoso de timbó (Lonchocarpus floribundus) sobre carrapato bovino

Os extratos acetato de etila, etanólico e aquoso de raízes de Lonchocarpus floribundus foram utilizados, a fim de avaliar a atividade biológica sobre carrapato bovino. Carrapatos adultos foram coletados em bovinos infestados artificialmente, separados em grupos de dez indivíduos, pesados e imersos, separadamente, nos extratos de raízes de L. Floribundus, nas concentrações de 5, 25, 50, 75 e 100 mg mL-1. Para a avaliação em larvas, foram utilizados indivíduos de 14 a 21 dias, os quais foram imersos nos extratos nas concentrações de 1, 5, 10, 15 e 20 mg mL-1. Após o tratamento, cada grupo foi colocado em placa de Petri e incubado a 27 ± 1 ºC e umidade relativa de 80 ± 5%. Os extratos avaliados não foram eficazes para induzir, acima de 50%, a mortalidade de fêmeas ingurgitadas. Os extratos acetato de etila e etanólico induziram 100% de mortalidade de larvas. Entretanto, quanto aos valores de concentração letal mediana (CL50), o extrato etanólico (CL50 = 2,1 mg mL-1) foi mais tóxico que o extrato acetato de etila (CL50 = 4,1 mg mL-1). O extrato etanólico estimou concentração inibitória mediana (CI50) de 3,0 mg mL-1 e foi mais tóxico que os demais extratos quanto a este parâmetro de avaliação. Entre os três extratos avaliados, os extratos acetato de etila e etanólico apresentaram os melhores resultados quanto ao controle de reprodução de R. (B.) microplus, atingindo 100% na concentração de 5 mg mL-1. Os extratos de raízes de L. Floribundus apresentaram atividade biológica sobre carrapato bovino

Ear-invading Arthropoda: Results of a preliminary South African survey

[No abstract available]Short Surve