Abstracts

ARTIGOS

The female of Ichthyocladius kronichticola Mendes, Andersen et Sæther, 2004 (Diptera: Chironomidae: Orthocladiinae)

Fêmea de Ichthyocladius kronichticola Mendes, Andersen et Sæther, 2004 (Diptera: Chironomidae: Orthocladiinae)

Humberto F. Mendes^I,1 1 Correspondence author: Humberto F. Mendes, e-mail: humberto.mendes@zmb.uib.no ; Trond Andersen^I; Luiz C. de Pinho^II

^IThe Natural History Collections, Bergen Museum, University of Bergen, Muséplass 3, N-5020 Bergen, Norway e-mail: trond.andersen@zmb.uib.no, http://www.uib.no/

^IIDepartamento de Biologia da FFCLRP, Universidade de São Paulo – USP, Ribeirão Preto, Brazil e-mail, lcpinho@pg.ffclrp.usp.br, http://www.ffclrp.usp.br/

ABSTRACT

The female of Ichthyocladius kronichticola Mendes, Andersen et Sæther is described and figured. The female genitalia shows characters like a large, apparently undivided gonapophysis VIII; large oval seminal capsules; and fused, fully sclerotized labia, that strengthen the placement of the genus in the Corynoneura-group of genera.

Keywords: Ichthyocladius, Corynoneura-group, Orthocladiinae, Chironomidae, female, Brazil.

RESUMO

A fêmea de Ichthyocladius kronichticola Mendes, Andersen et Sæther é descrita e ilustrada pela primeira vez. A genitália feminina apresenta caracteres como gonapófise VIII bem desenvolvida, aparentemente não-dividida; cápsulas seminais grandes e ovais e lábios fundidos, completamente esclerosados, estreitando o posicionamento do gênero no grupo Corynoneura.

Palavras-chave: Ichthyocladius, grupo Corynoneura, Orthocladiinae, Chironomidae, fêmea, Brasil.

Introduction

The genus Ichthyocladius was erected by Fittkau (1974) for two species from Peru and Ecuador. The larvae live on catfishes, attaching themselves to the skin and scales of the fish. Mendes et al. (2004) reviewed the genus and described two new species and two additional pupal types. The genus thus includes three named species: I. neotropicus Fittkau, 1974 from Peru, I. kronichticola Mendes, Andersen et Sæther, 2004, and I. lilianae Mendes, Andersen et Sæther, 2004 from Brazil. In addition, immatures of other species are known from Trinidad, Venezuela, Guyana, Bolivia, Brazil, and Argentina (Fittkau 1974, Mendes et al. 2004).

The female of I. neotropicus was described by Fittkau (1974), based on pharate pupae. When reviewing the genus (Mendes et al. 2004), no new material of females was available. Several details, especially concerning the female genitalia, have thus not been described. However, recently we received more material of I. kronichticola including several females. Below we describe and figure these females in detail.

Material and Methods

The material was reared from catfishes by E. N. F. Moura and F. O. Roque (see Ipeúna material in Roque et al. 2004). Rearing techniques consisted of keeping the catfishes in an aquarium covered with a net, and collect the emerging midges. The pupal exuviae were then collected on the water surface, as mentioned by Mendes (2002). The material was later mounted on slides in Euparal following the procedure outlined in Sæther (1969). The general terminology follows Sæther (1980). Measurements are given as ranges followed by mean when four specimens are measured.

The material is deposited at the Museu de Zoologia da Universidade de São Paulo, Brazil (MZUSP), The Natural History Collections, Bergen Museum, University of Bergen, Norway (ZMBN), Laboratório de Entomologia Aquática da Universidade Federal de São Carlos (LEA-UFSCar) and Museu de História Natural "Professor Adão José Cardoso", Universidade Estadual de Campinas (ZUEC).

Ichthyocladius Fittkau

Ichthyocladius Fittkau, 1974: 91; Spies & Reiss (1996: 76); Mendes et al. (2004: 15)

Type species: Ichthyocladius neotropicus Fittkau, 1974: 101

Other included species:Ichthyocladius kronichticola Mendes, Andersen et Sæther, 2004: 18; Ichthyocladius lilianae Mendes, Andersen et Sæther, 2004: 21; Ichthyocladius sp. Ecuador (Fittkau 1974); Ichthyocladius sp. Rio Marauiá (Mendes et al. 2004); Ichthyocladius sp. Argentina (Mendes et al. 2004).

Diagnosis as in Mendes et al. (2004) with the following additions: female AR lower than 0.5; tergites II–VIII with median group of setae on low to strong protuberance. Apodeme lobe covered by gonapophysis VIII, coxosternapodeme without sclerotized lamellae, labia fused and sclerotized. Fittkau (1974) stated that the female of I. neotropicus was lacking temporal setae. We are not able to observe any temporal setae in the female of I. kronichticola either, although the male has several minute temporals (Mendes et al. 2004).

Ichthyocladius kronichticola Mendes, Andersen et Sæther

Ichthyocladius kronichticola Mendes, Andersen et Sæther, 2004: 18

Material examined: BRAZIL, São Paulo, Ipeúna, córrego da Lapa, 22° 22’ 42" S, 47° 46’ 40" W, 6.i.2003, 2 males, 4 females, 3 pupal skins, E. N. F. Moura leg.; as previous except for 30.xi.2003, 1 male, 1 larva; as previous except for vii.2002, 18 larvae. BRAZIL, Minas Gerais, Bocaina de Minas, Maringá, Rio Preto, 10.iv.2003, 1 larva (pre-pupa) ZUEC 6189, I. Sazima leg., chironomids attached to Trichomycterus mirissumba Costa, 1992; as previous except for ZUEC 6189, 1 larva (pre-pupa); as previous except for ZUEC 6179, 1 larva; as previous except for ZUEC 6190, 1 larva.

Diagnostic characters: The female of I. kronichticola differs from I. neotropicus by having median setae on tergites II–VIII on strong protuberances, and by having tergite IX completely covering the cerci.

Female (n = 3-4): Total length 2.6-3.17 mm. Wing length 1.57-1.88 mm. Total length / wing length 1.63-1.74. Wing length / length of profemur 2.80-2.88. Thorax and head dark brown; abdomen dark brown with posterior 1/4 of segment VI and posterior 1/2 of segment VII pale; coxa, trochanter, femur, and tibiae dark brown with setae on foretibia in pale spots; tarsi pale; wing darkened.

Head (Figure 1). Antenna with 6 flagellomeres, length / width of segments (in µm): 53-59 / 25-29, 43-53 / 21-30, 53-64 / 18-23, 59-64 / 14-16, 64-74 / 14-16, 123-135 / 16-21. AR 0.41-0.48. No temporal setae visible. Clypeus with 12-17, 14 setae. Tentorium, stipes and cibarial pump as in Figure 2. Tentorium 98-113 µm long, 45-54 µm wide; stipes 86-92 µm long. Palpomere 43-49 µm long, 35-39 µm wide.

Thorax (Figure 3). Dorsocentrals 20-29, 25, in 1-3 rows; prealars 4-5, 5; supraalar 1. Scutellum with 6-12, 8 setae.

Wing (Figure 4). VR 1.04-1.10. Clavus 884-1096 µm long. Clavus length / wing length 0.54-0.58. Cu / wing length 0.42-0.44.

Legs. Spur of foretibia 17-21 µm long, spurs of midtibia 19 -26 µm and 11-15 µm long; spurs of hind tibia 40-48 µm and 23-30 µm long. Width at apex of foretibia 35-43 µm, of midtibia 49-55 µm, of hind tibia 48-53 µm. Comb with 3-5 setae, longest about 45 µm long. Pseudospurs each about 10 µm long. Tarsi 4 shorter than tarsi 5. Length and proportion of legs as in Table 1.

Abdomen (Figure 5). Tergites II–VIII with median group of setae on strong protuberance; number of setae on tergites I–VIII: 0-1, 0; 8-19, 14; 14-23, 18; 12-27, 20; 13-33, 24; 11-26, 20; 3-15, 9; 2-21, 10.

Genitalia (Figures 6-7). Gonocoxite IX 83-104, 95 µm long; with 8-13, 11 weak setae. Tergite IX large, with lateral margins down-turned, completely covering cerci, with 27-38 weak setae. Postgenital plate well developed. Cercus 65-90, 79 µm long; 11-18, 15 µm wide; with about 30 weak setae. Seminal capsule 133-154 µm long including 40-47 mm long neck; neck 7-14 µm wide at apex. Notum 184-205, 193 µm long; labia fused and sclerotized (Figure 8). Gonapophysis VIII apparently undivided, large (Figure 9); covering apodeme lobe (Figure 10).

Discussion

Mendes et al. (2004) performed a phylogenetic analysis of 34 genera, including genera near Eukiefferiella Thienemann and Corynoneura Winnertz. The Corynoneura group of genera appeared to be monophyletic and included Corynoneura, Ichthyocladius, Kaniwhaniwhanus Boothroyd, Onconeura Andersen et Sæther, Tempisquitoneura Epler, and Thienemanniella Kieffer.

The internal structures of the female genitalia of Ichthyocladius shows clear similarities to Corynoneura and Thienemanniella (see Sæther 1977), with large, apparently undivided gonapophysis VIII, covering the apodeme lobe; large oval seminal capsules; and fused, fully sclerotized labia.

The genus Ichthyocladius lives on catfishes of the families Austroblepidae, Loricariidae and Trichomycteridae (Roque et al. 2004, Nessimian et al. 2003). Ichthyocladius kronichticola was recorded as associated with Kronichthys sp. (Loricariidae) by Mendes et al. (2004). Now it has also been recorded on Trichomycterus mirissumba Costa, 1992 (Trichomycteridae).

Acknowledgments

We are indebted to Dr. Fabio de Oliveira Roque and Dr. Evelise Nunes Fragoso de Moura for providing us with material. L. C. Pinho received financial support from the Brazilian Research Council of the São Paulo State (FAPESP proc. 05/53026-0) within the BIOTA/FAPESP - The Biodiversity Virtual Institute Program (www.biota.org.br). Financial support was also given by the Programa de Pós-Graduação em Entomologia da FFCLRP-USP (CAPES-PROAP).

Recebido em 01/05/07

Versão Reformulada Recebida em 16/07/07

Publicado em 21/07/07

ISSN 1676-0603.

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