Three New Species of Subgenus Parasecia Loomis (Genus Fonsecia) from Northeastern Brazil and a Key to the Included Species (Acarina: Trombiculidae)

Abstract

New species and their type hosts are: Parasecia fundata off Caluromys philander, P. thalurania off Thalurania furcata, and P. valida off Oryzomys capito. The subgenus is briefly redefined, condensed data are given for nine other assigned species, and a key to species is included. Loomis (1966) erected the subgenus Parasecia (genus Fonsecia Radford, 1942) for Western Hemisphere species differing from subgenus Fonsecia in having normal AL scutal setae (peglike in Fonsecia). He referred all species listed here except Trombicula soucouyanti and the new ones to Parasecia. Parasecia is further distinguished from Fonsecia, whose four species are also restricted to the New World, by a sinuous posterior scutal margin (convex in Fonsecia) and a wide host range (Fonsecia species apparently confined to reptiles). The three new species described add support to the compactness and validity of the group. They were collected by Dr. Thomas H. G. Aitken, Rockefeller Foundation, Belem, Para, Brazil. A key to the 12 included species and condensed host and distributional data are given as an aid to identification and to fix relationships. Fonsecia (Parasecia) Loomis, 1966 Type species: Trombicula gurneyi Ewing, 1937. Ectoparasitic trombiculine larvae with leg segmentation 7-7-7. Scutum rectangular usually with sinuous margins, sensilla flagelliform, branched, PL>AM>AL, anterior setae postmarginal, the AL's conspicuously so and not peglike as in subgenus Fonsecia. Palpal tarsus with 7 branched setae, a subterminalia, and a tarsala. Galeal seta nude except in P. chara. Cheliceral blade with tricuspid cap. Three genualae I, microtarsala I distad of tarsala I, mastitarsala III present or absent. Principally neotropical and on a wide variety of hosts including reptiles, birds, and mammals. Key to species of Parasecia Loomis 1. Mastitarsala III present -2 Mastitarsala III absent 5 Received for publication 13 December 1968. 2. Two mastitarsalae III, palpal setae B/ B/NNN, DS 56 ?, beginning 2-10 -psittaci Floch and Abonnenc One mastitarsala III 3 3. Palpal dorsoand ventrotibial setae branched 4 Palpal dorsoand ventrotibial setae nude, palpal setae B/B/NNNb, DF 2-6-6-4-2 = 20 valida sp. n. 4. Galeal seta branched, palpal setae B/B/ BBB, DS 38 +, beginning 2-10 --chara Wharton Galeal seta nude, palpal setae B/B/ BNB, DF 2-6-6-4-2-2-2 = 24 soucouyanti Brennan and Yunker 5. (1) Palpal tibial claw bifurcate, palpal genual seta nude 6 Palpal tibial claw trifurcate, palpal genual seta branched 7 6. Eyes 2/2, palpal setae B/N/NNN, DF 2-6-6-4-2-2 = 22 gurneyi Ewing Scutum small -gurneyi gurneyi Ewing Scutum large gurneyi campestris Loomis Eyes 1/1, palpal setae B/N/NNN, DF 2-6-6-4-2-2 = 22 -kansasensis Loomis 7. (5) Dorsal formula begins 2-6 8 Dorsal formula begins 2-8 10 8. Palpal ventrotibial seta branched, palpal setae B/B/NNbB, DF 2-6-6-4-4-2 = 24 fundata sp. n. Palpal ventrotibial seta nude 9 9. Palpal tarsala ca. 20 /, dorsal setae less than 50 /u, palpal setae B/B/NNN, DF 2-6-6-2-6-2-2 = 26 (variable) -longicalcar Brennan and Jones Palpal tarsala ca. 12 A, dorsal setae 50 / or more, palpal setae B/B/NNNb, DF 2-6-6-4-2-2 = 22 (variable) manueli Brennan and Jones 10. (7) Palpal ventrotibial seta branched, palpal setae B/B/NNbB, DF 2-8-6-8-6-4-4 =-36 universitatis Hoffmann Palpal ventrotibial seta nude 11 11. Dorsal setal formula 2-8-8-8-6-4 = 36, length of dorsal setae 35 to 44 ,, ventrals (2-2) + 20, palpal setae B/B/ NNNb aitkeni Brennan and Jones Dorsal setal formula 2-8-10-10-10-8-6-4