Ecology of host defence

A host is not a passive victim of a parasite but rather defends itself actively against the detrimental effects of parasitism. I have already mentioned two strategies of defence that can be implemented by a host (a) it may attempt to avoid the parasite by choosing an appropriate habitat or patch and (b) it may attempt to kill the parasite (Combes, 2001, 2005). The first strategy is purely behavioural, whereas the second strategy comprises behavioural, physiological and immunological defence...

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13.3.1 Flea antigens and host response Ectoparasitic arthropods are often thought of as crawling or flying hypodermic needles that suck blood and inject disease causing agents. However, the saliva of blood-feeding arthropods contains factors that not only help them evade host haemostatic defences (Ribeiro, 1995 Wikel, 1996) but also have potent immunogens that influence the immune responses of the host (e.g. Roehrig et al., 1992). The development of immune responses to ectoparasitic arthropods...

Ecology of reproduction and preimaginal development

The main evolutionary motivation of every species is to increase its reproductive success, a goal that is achieved via various adaptations to specific ecological conditions, biotic and abiotic. Consequently, investigating reproductive patterns in different situations and disentangling factors that affect reproduction traits is an integral part of any ecological and evolutionary study. We already know that a flea life cycle is typical for a holometabolous insect. Consequently, individuals at...

Fleas and humanity

Humans have always coexisted with fleas. This coexistence is asymmetric, usually being favourable for fleas, but unfavourable for humans. Fleas can cause direct medical damage to humans and can serve as vectors for some diseases. They can also cause indirect damage to humans by parasitizing poultry and livestock and, thus, causing economic loss e.g. Yeruham et al., 1989 . Flea damage to human pets mainly dogs and cats also represents a serious veterinary problem. The ubiquity of the negative...

Flea species richnessBody mass and complexity of burrow

Figure 16.7 Relationship between mean C a, b and mean A c, d of a flea assemblage and scores of composite variables positively correlated with infra- and xenocommunity flea species richness a, c or positively correlated with host body mass and burrow complexity b, d . Redrawn after Krasnov et al. 2006f reprinted with permission from Blackwell Publishing . intra- to interspecific aggregation and taxonomic distinctness of xenocommu-nity suggests that aggregation may be important for coexistence...

Ecology of haematophagy

Leptopsylla

Adult fleas are obligatory haematophages. Among arthropods, haematophagy has evolved independently in at least six lineages Ribeiro, 1995, 1996 Lehane, 2005 . Two routes for the evolutionary transition to a parasitic lifestyle have been suggested Waage, 1979 . In the first type, known as type A routes, associations with hosts preceded adaptations for parasitic feeding. This is presumed to be the evolutionary pathway for, among others, psoroptoid acariforms Fain amp Hyland, 1985 and anopluran...

Patterns of flea diversity

The search for patterns of biodiversity across locations and through time and the explanation of these patterns is one of the most popular themes in ecology. Understanding of biodiversity patterns in application to parasites is especially important because parasites play important roles in the regulation of populations and communities of their hosts e.g. Combes, 2001 Poulin, 2007a and because this understanding is crucial for successful control of diseases that hit humans as well as wild and...