New species records of Culicoides biting midges (Diptera: Ceratopogonidae) for the state of Rondônia in Brazilian Amazon

Abstract Background Culicoides biting midges are small insects that are proven vectors of pathogens that cause disease in animals and humans. There are 1,368 species of Culicoides in the world, including 149 species in Brazil and 122 species in the Brazilian Amazon Basin. This study documents specimens that were collected between 2013 and 2015 in the municipalities of Alvorada d’Oeste, Buritis, Cacoal, Costa Marques, Espigão d’Oeste, Guajará-Mirim, Pimenta Bueno, Porto Velho and São Francisco Guaporé. Collections were performed using HP light traps in forest, pasture and peridomicilie environments. New information Species newly recorded in Rondônia State include Culicoides carpenteri Wirth & Blanton, 1953; C. dasyophrus Macfie, 1940; C. eublepharus Macfie, 1948; C. galindoi Wirth & Blanton, 1953; C. heliconiae Fox & Hoffman, 1944; and C. ignacioi Forattini, 1957. This is the first record in Brazil of C. darlingtonae Wirth & Blanton, 1971.


Introduction
The biting midges Culicoides Latreille, 1809 (Diptera, Ceratopogonidae) are small insects; their blood-feeding females bite birds and mammals, including humans, and they sometimes feed in large swarms. The bites are painful and can cause severe reactions. These insects can also transmit pathogens that cause disease in humans and domestic animals of economic importance (Ronderos et al. 2003, Borkent andSpinelli 2007). The diverse species of Culicoides are distributed around the world; currently, 1,368 species have been described worldwide; 149 species have been recorded in Brazil and 122 species have been recorded in the Brazilian Amazon Basin (Borkent 2016a, Carvalho et al. 2016, Farias et al. 2016a, Farias et al. 2016b, Santarém and Felippe-Bauer 2017. Despite evidence of high species diversity of Culicoides, only a few surveys have been conducted in the Brazilian Amazon Basin, primarily in the states of Amazonas and Pará. Recently, Carvalho et al. (2016) made collections of Culicoides species near Porto Velho, the capital of Rondônia State; they recorded 28 species, thereby increasing the number of species recorded in Rondônia to 33. Herein, we provide seven new records of Culicoides species collected in Rondônia State, in the western Amazon Basin of Brazil.
Culicoides specimens were preserved in 70% ethanol, and then dissected and slidemounted in phenol-balsam as described by Wirth and Marston (1968). The specimens were identified using the identification keys of Wirth and Blanton (1959), Spinelli et al. (1993), Felippe-Bauer et al. (2013). Subgeneric classification of Culicoides species was based on Borkent and Spinelli (2007) and Borkent (2016b

Diagnosis
Third palpal segment with scattered sensilla; apical pale band on mid femur, hind femur dark to tip; wing with distal pale spot in r which is narrow and transverse, r with pale spot present anterior to base of M , a single pale spot crosses the second radial cell, apices of CuA and CuA pale; spermathecae with short, slender necks (Felippe-Bauer et al. 2009).

Notes
This species was here recorded for the first time in Rondônia State.

Diagnosis
Eyes contiguous, separated by a distance equal to the diameter of 1.5 ommatidial facets; third palpus segment broad in middle, with conspicuous irregular pit; wing as shown in figure; halter knob dark brown, pedicel pale. This species is similar to C. fernandoi, but can be distinguished by the mandible which has 20-22 teeth (14-15 in C. fernandoi), vein R pale (infuscated on lower portion with a very small dark spot behind apex in C. fernandoi), distal pale spot in cell r large, transverse (crescentshaped or subdivided in C. fernandoi) (Spinelli et al. 1993).

Notes
This species was here recorded for the first time in Rondônia State.

Diagnosis
Third palpal segment scarcely swollen, with a broad, shallow sensory pit; second radial cell very dark, large pale area over r-m crossvein, extensive distal pale spot in cell r broadly extending across cell near apex from anterior wing margin to vein M ; apices of veins M , M and CuA dark; subapical pale spot in cell m , distal pale spot in cell m broadly meeting wing margin; two pale spots in distal part of cell m , the distal one broadly meeting wing margin; the proximal one connected by a pale area extending to 3 3 3 1 1 2 1 2 1 2 base of cell and including the pale spots lying in front of mediocubital fork and behind medial fork; pale area in cell CuA nearly filling entire cell; anal cell pale except for a large dark area centering on middle of stem of mediocubital vein; halter pale (Wirth and Blanton 1959).

Notes
This species was here recorded for the first time in Rondônia State.

Diagnosis
Eyes narrowly separated above, with long interfacetal hairs; third palpal segments swollen, with a broad, shallow, sensory pit; wing with poststigmatie pale spots in cell r more or less fused, the posterior one located slightly proximad of the anterior one, distal pale spot in cell r small, only one small pale spot in distal part of anal cell and one pale spot in distal part of cell m ; halter whitish; spermatheca one, pyriform (Wirth and Blanton 1956).

Notes
This species was here recorded for the first time in Rondônia State. New species records of Culicoides biting midges (Diptera: Ceratopogonidae) ...

Diagnosis
Eyes narrowly separated, with long interfacetal hairs; third palpal segment moderately swollen, with a broad, shallow, sensory pit; wing with four pale spots in a rhomboid in cell r , the distal pair usually fused and broadly attaining wing margin anteriorly; two pale spots each in cells m and apices of cells m and anal cell; pale spots present behind medial fork and in front of mediocubital fork; halter yellowish; spermatheca one, oval with a short portion of the duct sclerotized (Wirth and Blanton 1959).

Notes
This species was here recorded for the first time in Rondônia State.

Diagnosis
Eyes contiguous, bare; third segment slightly swollen, with a small, shallow, sensory pit; pale distal spot in cell r rounded distally, leaving a small dark area in apex of cell; halter pale; spermathecae two, pyriform, subequal (Wirth and Blanton 1959).

Notes
This species was here recorded for the first time in Rondônia State.

Diagnosis
Eyes narrowly separated, with short interfacetal hairs; third palpal segment considerably swollen its full length, with shallow and round sensory pit; proboscis short; thorax dark brown; legs brown, knee spots blackish; second radial cell included in a dark spot to its apex, cell r with contiguous poststigmatic pale spots, cell m with two pale spots, cell m with small pale spot; two spermathecae and rudimentary third, with sclerotized ring (Wirth and Blanton 1971).

Notes
This species was here recorded for the first time in Brazil.

Discussion
The major Culicoides species collected in this study are distributed throughout the Brazilian Amazon (Farias et al. 2016a, Santarém andFelippe-Bauer 2017); C. dasyophrus, C. eublepharus, C. galindoi and C. ignacioi are found from Acre State to Maranhão State (Santarém and Felippe-Bauer 2017). The specimens of C. heliconiae herein were collected in a forest environment, which is the same habitat as the specimens collected by Fittkau in 1970 in APEG Forest, Pará State (Wirth and Blanton 1973). The main breeding sites this species are water-holding plants, rotting parts or fruits of plants .
Culicoides ignacioi is distributed throughout Paraguay and Brazil (Borkent and Spinelli 2007). In Brazil, this species has been recorded in the states of Acre, Amazonas, Pará, Roraima, Maranhão, Minas Gerais, Rio de Janeiro and São Paulo (Santarém and Felippe-Bauer 2017). The specimens herein were collected in a forest environment. Silva and Carvalho (2013), sampled Culicoides from many points of collection and this species was captured in highest abundance in Cerrado forest, in the State of Maranhão.
Culicoides eublepharus has been recorded in Mexico, Costa Rica, Venezuela, Ecuador and Brazil. It has been found in the Brazilian Amazon in states of Amazonas, Pará and Roraima Spinelli 2007, Farias et al. 2016a). The specimens herein were collected in forest fragments. Veras and Castellon (1998) collected this species in forests on the Adolpho Ducke Forest Reserve, in Amazonas State.
This study increases the number of species recorded in Rondônia State to 40. Of the seven species here recorded, all are new records in Rondônia state, and one is also a new record in Brazil; underlining how poorly the distribution of even medically important insects such as Culicoides still is understood in Brazil. This study shows that species diversity is high among Amazonian Culicoides. Furthermore, this study will be helpful in knowledge of Culicoides fauna in the Amazon, and may contribute to a better understanding of the medical importance and vector epidemiology these insects.