How do ticks feed

Eggs laid oviposited by gravid females will typically incubate and hatch over several weeks to months depending on temperature and concurrent weather conditions. Depending on the influence of environmental cues and host availability, larvae will ascend surrounding vegetation to quest for a passing host and renew the cycle of parasitism.

Most Ixodid ticks produce one generation per year univoltine , but some species require 2 years to complete a life cycle e. Host-originated odors provide specific and, when carried on wind currents, also directional information. Among the most important host-originated odorants are carbon dioxide, a component of animal breath and ammonia, common in urine and other animal wastes.

They bring hungry ticks into close proximity to potential hosts, whereupon other, shorter range stimuli become effective. Close range stimuli include radiant heat, such as body heat from the host, odorants characteristic of sweat and other body odors e. Some species respond to sounds within a particular range of frequencies. Boophilus microplus larvae are highly responsive to sounds in the Hz range, frequencies commonly emitted by feeding cattle, while Rhipicephalus sanguineus are attracted to the sounds made by barking dogs Waladde and Rice, Other stimuli in host-finding activities, like visual cues and vibrations have been little studied.

Visual images are probably more important in hunter ticks, which are believed to discriminate dark shapes against the bright background of the sky. However also questing ticks of many species will respond to distinct shadows. Vibrations are also excitatory; rustling the grassy or weedy stems on which ticks are perched in ambush will provoke the characteristic "questing" behavior, with the forelegs outstretched to cling to a passing host. Finally, tactile stimuli come into play only upon host contact, contributing, along with short-range odorants and body heat, to the selection of the feeding site and the commencement of blood-sucking activity.

In some instances, tick-originated rather than host-originated stimuli are of critical importance in tick host-seeking behavior. Thus, Amblyomma variegatum and Amblyomma hebraeum are excited by CO 2 from cattle but select tick-infested animals when they detect the aggregation-attachment pheromone emitted by previously attached, feeding ticks Norval et al.

There are two different host finding strategies in ticks, an endophilic nidicolous — from nidis, Latin for nest - strategy, where ticks live in burrows, nests, hollows or cracks near resting or breeding places of hosts, and an exophilic non-nidicolous strategy in which ticks must search for their hosts.

Due to this diverging host seeking behavior, endophilic and exophilic ticks differ in their exposure to environmental conditions. While endophilic ticks remain better protected from environmental changes and hosts are easily accessible, exophilic ticks are highly exposed to environmental conditions and the accessibility to the host is also dependent on host ecology and population dynamics Ruiz-Fons and Gilbert, Appetence initiates the series of behavioral responses that leads to host contact and successful parasitism.

Appetence is the "locomotory hunting for a host or seeking one from a vantage point" Waladde and Rice, Appetence is preceded by hunger, which in turn is influenced by the tick's physiological condition; appetence does not occur in diapausing ticks. Non-nidicolous or exophilic ticks are species that occupy open, exposed habitats. Most occur in forest, savannah, scrub, brush, or meadow vegetation; others remain buried in sand or sandy soils, under stones, crevices, and elsewhere in the open environment.

Most non-nidicolous ticks use a passive host-finding strategy, i. Such questing ticks living in grass, herb, or brush covered habitats climb the vegetation, clinging to the tips of stems or branches waiting in a typical pose - with the front legs extended, especially in response to a host passing by - for direct contact with hosts that brush against these vegetative supports. Vibrations caused by animal movements as well as odors, body heat, and shadows from such hosts excite tick responses, causing extension and rapid waving of the forelegs.

If contact is made, questing ticks cling to the bodies of animals as they brush past. The height at which ticks quest also plays an important role in the types of hosts they acquire. Generally, tick questing height is strongly correlated with the specific life stage and size of the most common hosts of each species or life stage Loye and Lane, ; Fourie et al. During the colder months, nymphs will sit dormant under leaf litter, snow cover and shaded areas. When the weather warms, nymphs will begin questing behavior in order to locate their next host.

If already infected, nymphs can transmit Lyme disease to their new host, or nymphs may become infected with a tick-borne disease by feeding on an infected reservoir host, or even contract a second tick-borne disease making them co-infected with various pathogens.

In fact, since April , 7, Nymph Blacklegged Ticks were tested for Lyme disease and a total of Once attached to their host, nymphs will feed for four to five days before dropping off to start transitioning into their final life stage — an adult. During the fall, when the nymph falls off its host and transitions into an adult, it will look for its third and final host. During the nymph and adult phases, ticks can seek out humans as their hosts and possibly transmit disease s.

Most ticks go through four life stages: egg, six-legged larva, eight-legged nymph, and adult. After hatching from the eggs, ticks must eat blood at every stage to survive. The lifecycle of Ixodes scapularis ticks generally lasts two years. During this time, they go through four life stages: egg, larva, nymph, and adult. After the eggs hatch, the ticks must have a blood meal at every stage to survive.

Blacklegged ticks can feed from mammals, birds, reptiles, and amphibians. The ticks need a new host at each stage of their life.

The lifecycle of Ixodes pacificus ticks generally lasts three years.