Ectoparasite fitness in auxiliary hosts: phylogenetic distance from a principal host matters

Abstract

We studied reproductive performance in two flea species (Parapulex chephrenis and Xenopsylla ramesis) exploiting either a principal or one of eight auxiliary host species. We predicted that fleas would produce more eggs and adult offspring when exploiting (i) a principal host than an auxiliary host and (ii) an auxiliary host phylogenetically close to a principal host than an auxiliary host phylogenetically distant from a principal host. In both flea species, egg production per female after one feeding and production of new imago after a timed period of an uninterrupted stay on a host differed significantly between host species. In general, egg and/or new imago production in fleas feeding on an auxiliary host was lower than in fleas feeding on the principal host, except for the auxiliary host that was the closest relative of the principal host. When all auxiliary host species were considered, we did not find any significant relationship between either egg or new imago production in fleas exploiting an auxiliary host and phylogenetic distance between this host and the principal host. However, when the analyses were restricted to auxiliary hosts belonging to the same family as the principal host (Muridae), new imago production (for P. chephrenis) or both egg and new imago production (for X. ramesis) in an auxiliary host decreased significantly with an increase in phylogenetic distance between the auxiliary and principal host. Our results demonstrated that a parasite achieves higher fitness in auxiliary hosts that are either the most closely related to or the most distant from its principal host. This may affect host associations of a parasite invading new areas.

A trade‐off between quantity and quality of offspring in haematophagous ectoparasites: the effect of the level of specialization

“…In addition, we predicted that if the trade‐off between quantity and quality of the offspring occurs, then the quality of the new fleas would increase with an increase in phylogenetic distance between the maternal host and principal host of a flea because their quantity has been shown to decrease (Khokhlova et al . ). Finally, given the difference in the degree of host specificity between the two fleas, we predicted that the negative relationships between the quality of the new imagos and either maternal egg production effort or phylogenetic distance between the maternal host and the principal host or both would be manifested stronger in the host‐opportunistic X. ramesis than in the host‐specific P. chephrenis .…”

Reproductive consequences of female size in haematophagous ectoparasites

“…Details on origin, rearing and maintenance of colonies have been described in earlier publications (e.g. Krasnov et al, 2001Krasnov et al, , 2003Khokhlova et al, 2012). Fleas were reared and maintained on their natural rodent hosts, namely X. ramesis on Meriones crassus and Gerbillus dasyurus, S. cleopatrae on Gerbillus andersoni and Gerbillus pyramidum, and P. chephrenis on Acomys cahirinus and Acomys russatus.…”

“…Thirty male and 70 female fleas were released into the cage and allowed to feed for two (X. ramesis and S. cleopatrae) or three (P. chephrenis) days. Under these conditions, fleas take more than one blood meal and start to oviposit no sooner than the second day on a host (Khokhlova et al, 2012). We allowed P. chephrenis to stay on a host longer than the other two species because it requires more time for engorgement (Khokhlova et al, 2008b).…”

Flea fitness is reduced by high fractional concentrations of CO2 that simulate levels found in their hosts' burrows

“…Details on breeding and maintenance of fleas can be found elsewhere (Krasnov et al, , 2003bKhokhlova et al, 2009Khokhlova et al, , 2010Khokhlova et al, , 2012. In brief, fleas were maintained on rodents that were kept individually in plastic cages with a wire mesh floor over a pan with a mixture of sand and dried bovine blood (larval nutrient medium) at 25°C air temperature with a photoperiod of 12 h:12 h (light:dark).…”

“…Details on rodent maintenance in colonies can be found elsewhere (Krasnov et al, , 2003aKhokhlova et al, 2009Khokhlova et al, , 2012Liberman et al, 2011). In short, rodents were maintained in plastic cages (35×25 cm and 15 cm high) at 25°C ambient temperature and 12 h:12 h (light:dark) light regime.…”