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.