Consumption of blood-feeding ectoparasites: A comparison with
terrestrial systems
By comparison, Buphagid birds (oxpeckers) are the only terrestrial
analog to dedicated cleaner fishes and the ticks they consume are the
primary terrestrial analogs of gnathiids. Ticks are commonly removed
from mammals by the Buphagid birds in mutualistic interactions
(Bezuidenhout and Stutterheim 1980). However, like gnathiids, ticks
spend a significant portion of their life cycle not associated with a
host. In addition to the specialist oxpeckers, ticks are consumed by
over forty species of birds across multiple orders of classification
(Milne 1950, Mooring and Hart 1999, Samish and Rehacek 1999). Ticks are
also susceptible to consumption by many arthropods, amphibians,
reptiles, and mammals as well as infection by several pathogens
(reviewed by Samish and Rehacek 1999). In fact, in some areas/habitats
tick predation can be so high that populations become unsustainable
(Krivolutsky 1963, Wilkinson 1970).
Culicid mosquitoes are biting flies that, like gnathiids, obtain blood
meals by puncturing the external surfaces of their hosts. Due to
negative impacts on human health via disease transmission, a significant
amount of effort has been dedicated to researching ways to control
mosquito populations (Eba et al. 2021). To our knowledge, there are no
mosquito “cleaners”, which may be one reason why many hosts have
developed fly-repelling behaviors (Hart 1994). Elephus maximus(Asian elephants) even use branches as a tool to keep biting flies away
(Hart and Hart 1994). While consumption of adults seems insufficient to
control mosquito populations, it is the larvae which are aquatic, that
are highly susceptible to pathogens and predation. In fact, entire
mosquito populations can be biologically controlled by consumption of
larval stages (Reddya Naik 2018). Predators of mosquitoes found to be
useful in biocontrol include macroinverebrates such as Odonates (Mandal
et al. 2008), Dysticids (Aditya and Saha 2006), and Nonectids (Eba et
al. 2021), as well as many larvivorous fishes (Brahman and Chandra 2016,
Ghosh et al. 2005) and amphibians (Lee 1967). Thus, for both ticks and
mosquitoes there exists a robust functional redundancy of consumers that
can lessen the ectoparasite burden of terrestrial organisms.