[One of the developmental dead ends or a method of dispersal of the pasture tick Dermacentor marginatus]. / Odin iz tupikov razvitiia ili sposob rasseleniia pastbishchnogo kleshcha Dermacentor marginatus.

Accumulation of pasture ticks Dermacentor marginatus has been discovered in the wool of sheep, 5-6 cm from the skin surface, the temperature in those sites being permanent 18-20 degrees C. The ticks died either in the course or following ovipositor. It may be assumed that this was followed by the appearance of larvae from oocysts. It is suggested that the above phenomenon is one of the deadlines in Dermacentor marginatus development or one of the unusual ways of their larvae habitation on pastures.

[The possible role of the salivary gland substrate in ixodid ticks as an adjuvant enhancing arbovirus transmission]. / Vozmozhnaia rol' substrata sliunnykh zhelez iksodid v kachestve ad''iuvanta, usilivaiushchego peredachu arbovirusov.

Using a model: salivary glands of Dermacentor ticks--tick-borne encephalitis virus--guinea pig--D. marginatus ticks, it became possible to confirm the data of Jones et al. (1989) on the role of a substrate of Rhipicephalus appendiculatus glands as a strong enhancer of orthomyxovirus Togoto transmission during subcutaneous administration of a moderate virus dose to virus-resistant guinea pig. A tendency was only noticed towards better infectivity of ticks with the administration of sub- or supraoptimal virus doses together with the adjuvant (salivary gland substrate), as well as enhanced sensitivity of male individuals to a combination of virus with adjuvant. The latter fact can be explained by a transptyal way of infection typical for male individuals, which was noted earlier during joint nutrition with infected female individuals. A lower level of virus reproducibility in ticks who got it together with the adjuvant, as compared to the control, has been established. Low titer in female individuals after nutrition reduces the likelihood of transovarial transmission of virus with adjuvant.

[Vertical migrations of hungry imagoes of the tick Dermacentor marginatus]. / Vertikal'nye peremeshcheniia golodnykh imago kleshcha Dermacentor marginatus.

The ticks of D. marginatus display activity at a temperature of 3 to 16 C and relative humidity of 20 to 75%. At a low temperature higher than 19 C their activity is inhibited throughout the whole autumn period at any time of the day. Active appearance of ticks on the stems of vegetation was recorded at 8C and higher in August and the first decade of September (in the morning 16%, in the day time 7.5% and in the evening 74% of ticks become active). As a rule the most high percentage of ticks (56 to 85%) recorded from upper parts of stems was observed in August and first decade of September at evening hours at 12 to 17 C and relative humidity of 50 to 70%.

[Hibernation of Dermacentor marginatus ticks in alpine Armenia]. / Zimovka kleshchei Dermacentor marginatus v usloviiakh gornoi Armenii.

Only mature ticks, engorged females and hungry imago hibernate in mountain regions of Armenia. According to the author's observations eggs of ticks as well as their larvae are not capable of hibernating. In females of spring satiation the development of eggs proceeds in most short periods from May to October. The longest period before the beginning of egg laying is observed in ticks of summer and autumn satiation. It becomes prolonged, in general, on account of hibernation of satiated females. Females of August-September satiation hibernate more successfully than females satiated in June and July.