Table 1.

Currently recognised genera of the family Trypanosomatidae

Genus	Invertebrate host	Description
Monoxenous
Angomononas	Zelus leucogrammus, Ornidia obesa, Chrysomya putoria, Chrysomya megacephala, Lucilia cuprina	Genus within the subfamily Strigomonadiae. Members of this genus harbour an obligate intra-cytoplasmic beta-proteobacterial symbiont [57]. Angomonoas deanei (formerly Crithidia deanei), the type-species, has a small, rounded choanomastigote with truncated anterior ends.
Blastocrithidia	Gerris remiges, Euschistus servus	The genus is characterised by the epimastigote form with its pointed ends and the anterior location of the kinetoplast [56]. Blastocrithidia triatome infects reduviid bugs (the vector of T. cruzi), reducing their life span and reproduction rate [134]. Other species include Blastocrithidia gerridis, commonly found in Gerris remigis “water striders” and Blastocrithidia euschisti in the Euschistus servus “milkweed” bug [56].
Blechomonas	Pulex irritans, Chaetopsylla spp. Ctenophthalmus spp., Monopsyllus sciurorum, Paraceras melis, Ceratophyllus spp., Nosopsyllus fasciatus, Ctenocephalides spp., Nycteridopsylla spp., Archeopsylla erinacei	A relatively new genus reserved for species that are strictly found in fleas (Siphonaptera) [135]. Morphologically, Blechomonas is a diverse genus, comprising of extremely pleomorphic cells including promastigotes, choanomastigotes and amastigotes.
Crithidia	Bombus hortorum, Bombus muscorum, Bombus terrestris, Culex spp.	This genus includes common parasites of the insect alimentary canal. They possess small, wide cell bodies with a truncated anterior end and broad posterior end [56]. Crithidia bombi is the most extensively studied species given its potential role in the reduction of bumblebee reproductive fitness. It infects several bee species: Bombus terrestris, Bombus muscorum and Bombus hortorum [136]. Crithidia mellificae is a honeybee pathogen associated with colony losses and Crithidia fasciculate infects mosquitoes.
Herpetomonas	Musca domestica	A genus that includes a variety of morphological types including promastigote and opisthomastigote forms. Herpetomonas is predominately found in dipterans, with Herpetomonas muscae domesticae, the type-species, found in the common housefly [95]. Members of the Herpetomonas genus have also been detected in hemipterans, plants and a rat [95].
Kentomonas	Sarcophaga (sensu lato) sp.	Another novel endosymbiont-harbouring trypanosomatid genus within the subfamily Strigomonadiae [133].
Leptomonas	Proba sallei, Collaria oleosa, Neotropicomiris nordicus, Hyalymenus sp., Jadera aeola aeola, Camptischium clavipes, Dysdercus spp., Calocorisca altiplana, Stenodema andina, Prepops cf. accinctus	Trypanosomatids with a life-cycle containing both promastigote- and amastigote stages [76], parasitic only in invertebrates and generally considered of no medical importance [77–79]. However, several reports of Leptomonas seymouri infection in vertebrates have emerged [53].
Lotmaria	Apis mellifera	A novel clade in the subfamily Leishmaniinae that infects the honey bee, Apis mellifera [137]. Crithidia mellificae was once considered the predominant trypanosomatid of the honey bee. Phylogenetics facilitated reassignment of some Crithidia parasites to the newly described Lotmaria passim. While C. mellificae is still extant in bee populations Lotmaria passim is the most prevalent trypanosomatid in A. mellifera [137].
Novymonas	Niesthrea vincentii	A newly established genus accommodating a novel endosymbiont-bearing trypanosomatid that exist aspredominantly as promastigotes and choanomastigotes [87].
Paratrypanosoma	Culex pipiens	This genus represents the missing link between the free-living bodonid family and the parasitic trypanosomatids [83]. Paratrypanosoma confusum, predominately exists as an elongated promastigote in the intestine of female mosquitoes (Diptera: Nematocera: Culicidae).
Sergeia	Culicoides festivipennis, Culicoides truncorum	This genus is represented by the novel endosymbiont-free Sergeia podlipaevi [138]. In the midgut of their hosts, they exist as promastigotes with the nucleus located in the centre or proximal to the posterior portion of the cell.
Strigonomonas	Aedes vexans, Oncopeltus sp., Lutzomya almerioi	This genus is comprised of endosymbiont-bearing trypanosomatids also of the Strigomonadiae subfamily characterised by flagellates of diverse shapes and length. Strigomonas oncopelti (syns Herpetomonas oncopelti, Leptomonas (Strigomonas) oncopelti, Crithidia oncopelti), the type-species, harbour an obligate intra-cytoplasmic betaproteobacterial symbiont [57].
Wallaceina	Nabis brevis, Nabis flavomarginatus, Calocoris sexguttatus	This genus was established to incorporate trypanosomatids that produce endomastigotes. The taxonomy of this genus is somewhat confusing as upon its establishment to accommodate the newly discovered Wallaceina inconstans, Crithidia brevicula was moved into this genus. Few isolates have been discovered that possess phylogenetic affinity to Wallaceina [139].
Zelonia	Simulium (Morops) dycei, Ricolla simillima	A genus created to accommodate the trypanosomatid previously named Leptomonas costaricensis [28]. Along with the newly described Zelonia australiensis, this genus includes parasites that are immediately basal to the dixenous clade occupied by Leishmania, Endotrypanum and Porcisia.
Dixenous
Endotrypanum	Phlebotomus spp.	A genus comprised of species that infect the erythrocytes of their mammalian hosts, which include the Neotropical tree sloths (genera Choloepus and Bradypus). Endotrypanum is comprised of the species E. schaudinni and E. monterogeil as well as three species previously placed in the genus Leishmania including E. herreri, E. colombiensis and E. equatorensis [28].
Leishmania	Phlebotomus spp., Lutzomyia spp., Forcipomyia (Lasiohelea) spp.	Leishmania species were once differentiated by their respective proliferative stages [18]. Female phlebotomine sand flies are the natural vectors for Leishmania transmission, and roughly 70 known animal species serve as reservoirs for human pathogenic Leishmania species, including rodents [20], dogs [21] and other mammals [22]. Approximately 20 species of Leishmania act as the aetiological agents of human leishmaniasis.
Phytomonas	Phthia picta, Nezara viridula, Oncopeltus fasciatus	Phytomonas is a dixenous genus that includes several plant pathogens transmitted by phytophagous insects [140]. They predominately exist as promastigotes and less frequently as choanomastigotes [47]. Phytomonas spp. have been isolated from a wide-range of plant tissues including the fruit, flower, seeds and the phloem [51].
Porcisia	Vector unknown	A new genus recently established to accommodate the Neotropical porcupine-infecting parasites previously known as Leishmania hertigi and Leishmania deanei [28].
Trypanosoma	Triatoma infestans, Rhodnius prolixus, Glossina spp.	Trypanosoma species infect reptiles, fish, birds and mammals, including humans, and are transmitted by hematophagous insects and aquatic leeches [141, 142]. Certain members of this genus cause devastating human diseases including Human African Trypanosomiasis (aetiology: Trypanosoma brucei) and Chagas disease (aetiology: T. cruzi) [13].