RESUMO

In host-symbiont systems, interspecific transmissions create opportunities for host switches, potentially leading to cophylogenetic incongruence. In contrast, conspecific transmissions often result in high host specificity and congruent cophylogenies. In most bird-feather mite systems, conspecific transmission is considered dominant, while interspecific transmission is supposedly rare. However, while mites typically maintain high host specificity, incongruent cophylogenies are common. To explain this conundrum, we quantify the magnitude of conspecific vs. interspecific transmission in the brood parasitic shiny cowbird (Molothrus bonariensis). M. bonariensis lacks parental care, allowing the assessment of the role of horizontal transmission alone in maintaining host specificity. We found that despite frequent interspecific interactions via foster parental care, mite species dispersing via conspecific horizontal contacts are three times more likely to colonize M. bonariensis than mites transmitted vertically via foster parents. The results highlight the previously underappreciated rate of transmission via horizontal contacts in maintaining host specificity on a microevolutionary scale. On a macroevolutionary scale, however, host switches were estimated to have occurred as frequently as codivergences. This suggests that macroevolutionary patterns resulting from rare events cannot be easily generalized from short-term evolutionary trends.

Assuntos

RESUMO

Two new feather mite species of the family Analgidae are described from the Rufous-collared Sparrow, Zonotrichia capensis (Müller, 1776) (Passeriformes: Passerellidae), from Brazil: Analges ticotico sp. nov. (Analginae) and Strelkoviacarus brasiliensis sp. nov. (Anomalginae). Analges ticotico sp. nov. is characterized by the heteromorphic males having three short and rounded spines on the inner margin of femur III, the anterior margin of adanal shield convex, the hysteronotal shield with the anterior margin sinuous, and the terminal lamella rectangular. Strelkoviacarus brasiliensis sp. nov. is characterized by the anterior ends of the adanal shields being convergent and encompassing the bases of setae ps3 in males, and by the strongly convex median extension of the prodorsal shield and short dorsal setae vi, c2, d2 and e2 in females. These species represent the first records of corresponding feather mite genera in Brazil.

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RESUMO

Five new species of feather mites (Proctophyllodidae: Pterodectinae) are described from passerines and hummingbirds of Brazil: Amerodectes longifuscus sp. nov. from Poospiza lateralis (Nordmann, 1835) (Passeriformes: Emberizidae), A. vireonis sp. nov. from Vireo olivaceus (Linnaeus, 1766) (Passeriformes: Vireonidae), Tyrannidectes synallaxis sp. nov. from Synallaxis ruficapilla Vieillot, 1819 (Passeriformes: Furnariidae), Trochilodectes willisi sp. nov. from Phaethornis eurynome (Lesson, 1832) (Apodiformes: Trochilidae), and Xynonodectes phaethornis sp. nov. from Ph. pretrei (Lesson & Delattre, 1839) (Apodiformes: Trochilidae).

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RESUMO

Five new species of the family Pterolichidae are described from two common non-parasitic cuckoo species of the subfamily Crotophaginae (Cuculiformes: Cuculidae) in Brazil: Aniacarus ani sp. n. from the Smooth-billed Ani, Crotophaga ani Linnaeus, A. simplex sp. n., A. robustus sp. n., A. coronatus sp. n. and Aniibius guirae sp. n. from the Guira Cuckoo, Guira guira (Gmelin). A key to all known species of Aniacarus is provided. All four pterolichid species associated with the G. guira can occur simultaneously on one host individual. A brief review of studies of feather mites associated with Cuculidae is given.

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RESUMO

Carcinopodacarus polymorphus gen. n. et sp. n. (Acariformes: Dermationidae: Dermationinae) is described from the guira cuckoo Guira guira (Gmelin) (Cuculiformes: Cuculidae) in Brazil. The new genus differs from the closest genus, Psittophagoides Fain, 1964, by the following features: in both sexes, the anterior spines of trochanters I and II are absent (vs present in Psittophagoides), setae d2 are distinctly developed (vs only alveoli), and genual setae mGI are absent (vs present); in males, the hysteronotal shield is split transversally at the level of trochanters III (vs hysteronotal shield entire); in females, the platelets situated posterior to the propodonotal shield are absent (vs present), the metapodosomal sclerites are present (vs absent), and the adanal shields are fused anteriorly to each other (vs separated from each other). In this species, andropolymorphism is detected for the first time for the family. It involves various characters but the most impressive feature is the structure of legs III. In hetero- and mesomorphic males, these legs are strongly hypertrophied and have a distinct ventral spur on femora III; in homeomorphic males, legs III are not modified and subequal to legs IV.

RESUMO

Feather mites are highly specialized permanent ectosymbionts recorded from all recently recognized bird orders. These mites, specialized to live in the plumage of their hosts, rarely cause any visible damage to their specific hosts. Recently described feather mite Allopsoroptoides galli Mironov (Acariformes: Psoroptoididae) was reported to cause severe mange in chickens in Brazil, leading to unprecedented economic losses. Until now, the natural host of A. galli remained unknown. In this paper, we report its true wild host, the Guira cuckoo Guira guira (Cuculiformes: Cuculidae). In addition, a previously unknown heteromorphic form of males is described from the mite population distributed on its natural host. We also speculate a possible scenario by which this mite species could have been horizontally transferred from the wild populations of the natural host to the secondary hosts.

Assuntos