A new species of Caladomyia Säwedal, 1981, with description of the female and immature stages (Insecta, Diptera, Chironomidae) Susana Trivinho-Strixino & Giovanni Strixino Trivinho-Strixino, S. & G. Strixino (2000): A new species of Caladomyia Säwedal, 1981, with description of the female and immature stages (Insecta, Diptera, Chi- ronomidae). - In: Baehr, M. & M. Spies (eds): Contributions to chironomid research in memory of Dr. Friedrich Reiss. - Spixiana 23/2: 167-173. The immatures and adults of Caladomyia frieden, spec. nov. are described from the southeast of Brazil. Characterizations of the larva and adult female are the first for the genus. The larvae live on the aquatic macrophyte Mayaca fluviatilis Aublet. Phenology Information about adults and larvae is presented. Susana Trivinho-Strixino, Giovanni Strixino, Laboratörio de Entomologia Aquätica, Universidade Federal de Säo Carlos, C. P. 676; 13560-905 Säo Carlos SP, Brazil. E-mail: strixino@power.ufscar.br Introduction The genus Caladomyia was erected by Säwedal (1981) from material coUected by E. J. Fittkau and F. Reiss in the Amazon area. Säwedal proposed two species groups based on adult male morphology, but described 8 species from only the s;;fxf-group. Sublette & Sasa (1994) added another species from Central America. Reiff (2000), in a review of the entire genus, is reevaluating Säwedal's orellaimi-group. In the present paper a new species of the spixi-group is described, for the first time in Caladomyia including all life stages (larvae, pupae, male and female adults). Methods Larval and adult densities at the type locaUty were estimated from XII. 1992 through XII. 1993. Monthly, a pair of 150 ml samples of the aquatic macrophyte, Mayaca fluviatilis Aublet, 1775 were taken, chosen as similar in plant structure as possible. From the first sample of each pair, chironomid immatures were quantitatively removed under a stereoscope with transillumination. The second was maintained in a Container with pond water and enclosed in nylon mesh; all emerged adults were collected daily for 30 days. Eventually, each macrophyte sample was dried for 24 hs at 60 °C, and weighed according to Cyr & Downing (1988). In parallel, to obtain immature /adult associations, some larvae were isolated in small vials covered with nylon screen. AU material described below has been mounted on slides. Measurements are given as means followed by ranges in parentheses. The morphological terminology follows Ssether (1980) and Säwedal (1981). 167 Caladomyia frieden, spec. nov. Figs 1-16 Types. Holotype: d (in Euparal), Brazil, Säo Paulo, Säo Carlos, Federal University of Säo Carlos (UFSCar) Campus, Lagoa Mayaca, 21°59'S, 47°54'W, 20.X.1993, leg. S. Trivinho-Strixino. - Paratypes (mostly in Euparal, 299 and the pupa in Hoyer's): 4c? c?, 5??, all fully emerged; 1 pupal exuviae + assoc. S on same slide; 5 larvae; all as holotype. Holotype and most paratypes deposited in Laboratory of Aquatic Entomology collection at Federal University of Säo Carlos, Säo Paulo, Brazil; IS, 299, 1 larva in Zoologische Staatssammlung Munich, Germany. Etymology. The species is named after Friedrich ('Frieder') Reiss for his contributions to the knowledge of Neotropical Tanytarsini. Diagnosis. The male of Caladomyia frieden, spec. nov. resembles C. mulleri Säv^^edal, 1981, but differs by the coloration including distinctly darkened parts, by a lower AnPBR, a shorter ventromedian part of the anal point, and by the superior volsella lacking a pronounced distalmedian projection. The female keys to Stempellineila in Saether (1977), from which it is most easily separated by the nearly straight GcaVIII and the v-shaped, not rounded posteromedian contour of SVIII. The pupa differs from the only other described species, C. spixi Säv\^edal, by the absence of spinule fields on the abdominal tergites. Instead, C. frieden, spec. nov. presents widespread shagreenation on T II- VI and VIII-IX. Another difference is in the number of anal comb teeth. The larval characteristics approach Cladotany- tarsus, mainly in antenna design and the presence of serrate claw^s on the posterior parapods. In our genus guide to Chironomidae larvae of Säo Paulo State (Trivinho-Strixino & Strixino 1995), the larva described above was named "Cladotanytarsus (?)". How^ever, C. friederi, spec. nov. differs from Clado- tanytarsus larvae by the presence of a distinct apical tooth on the antennal pedestal, and by the lower numbers of teeth on the mandible and premandible. Description Adult male (n = 5) Size small, length about 2 mm. Head. Pale yellowish green. 5-7 uniserial temporal setae. Frontal tubercle length 8, basal width 4 ^m. Antennal flagellum yellowish, length 700 ^m (692-712); AR= 0.78 (0.73-0.82). Eye bare, without dorsomedian extension. About 10 clypeal setae. Palp yellowish, lengths Pm 2-5: 30(28-32), 55(52-64), 77(68-84), 129(116-136) ^m. Thorax. Greenish with dark brown mesonotal stripes and postnotum, preepistemum brown. acrostichal setae, 5-6 dorsocentrals, 1 prealar, 1-2 scutellars in central positions. Scutal tubercle absent. Wing (Fig. 1). Length 1203 ^m (1184-1216), width 339 }im (320-368); membrane transparent, veins yellowish; C ending close to R4+5, before wing apex; R2+3 ends halfway between R^ and R4+5. VR=1.20 (1.17-1.25). Membrane macrotrichia restricted to cells r4+5 and distal mj+j- Vein macrotrichia on R and Legs. Yellowish brown, without transverse bands. Fore tibia with short, light-colored spur. Mid and hind tlbiae each with two separate, dark combs; mid tibial spurs slightly, hind spurs strongly unequal in length (Fig. 2). Mid tarsus 1 with 2 sensilla chaetica. Segment lengths (in }im) and propor- tions: fe ti ta, ta, ta. ta. ta= LR Abdomen yellowish green. Hypopygium (Figs 3, 4): Anal tergite with 2 far distal setae. Anal tergal bands Y-shaped, fused part about 40 pim long. Anal point brown with slightly concave margins; dorso- lateral margin bearing 2 setae, vertical ventromedian part with 1 distal and 1 more proximal pair of setae. Anal point bars short, originating on anal point and not reaching beyond it (Figs 3, 4); 168 Figs 1-6. Caladomyia frieden, spec. nov. Adults. 1. Wing of male. 2. Hind (top) and mid tibial combs and spurs. 3. Hypopygium, dorsal; detail: tip of anal point, ventral. 4. Hypopygium, lateral. 5. Wing of female. 6. Female genitalia, ventral. Scales in ^m. 169 500 Figs 7-9. Caladomy ia fiiederi, spec.nov.Fupa. 7. Wing sheath. 8. Abdomen, dorsal. 9. Anal comb. Scales in ^m. ArLPBR = 1.8. Superior volsella with 4 dorsal setae and 2 on anterior part of median margin. Digitus long, reaching beyond posteromedian corner of superior volsella. Inferior volsella bent in an S-shape, tip slightly folded to dorsal, with 6 long and 3 shorter setae. Median volsella short, with 2 lamelliform and 4 simple setae. Adult female (n = 3) Total length about 1.5 mm. Coloration as male. Head. 5-7 uniserial temporals. Frontal tubercles absent. Antennal flagellum about as long as palp, Fm lengths 1-4: 70-72, 40-43, 50-60, 97-105 ^im; AR = 0.57-0.66. Eye bare, without dorsomedian exten- sion. 11-12 clypeals. Palpomere lengths 2-5=22-25, 42-68, 58-80, 104-130 ;/m. Thorax. 6-8 acrostichals, 4-6 dorsocentrals, 1 prealar, 4 scutellars (2 central, 2 lateral). Scutal tubercle absent. Wing (Fig. 5). Length 1208 ^m (1200-1216), width 412 ^^m (384-432); VR = 1.27 (1.17-1.35). Macro- trichia on all veins except M, on posterior false veins, and in all cells posterior to R4+5 and M except cu, macrotrichia in cells more numerous toward wing tip. Legs. Mid and hind tibiae each with two strongly unequal spurs. Mid tarsus 1 with 5-7 sensilla chaetica. Segment lengths (in fim) and proportions: LR fe ta: ta. ta. ta. ta, Genitalia (Fig. 6). Sternite VIII bearing 12-15 setae in an irregulär transverse row or band, and 2-5 slightly smaller setae at each side of posteromedian sternite emargination; floor under vagina large, posteromedian contour of SVIII more or less V-shaped, forming an angle medially. GpVIII simple, rounded, with long, lightly curved caudolateral microtrichia. Notum slightly longer than free rami, about 1.5 times as long as seminal capsule. 2 seminal capsules present, ovoid, length 35-45 ^m, with narrow neck (10-15 /^m); spermathecal duct with long loop. GcaVIII conspicuous, nearly straight, running diagonally to posteromedian corner of SVIII. GcIX with 1 seta. TIX with about 10 strong setae; 170 Figs 10-16. Caladoniyia frieden, spec. nov. Larva. 10. Antenna. 11. Pecten epipharyngis. 12. Premandible. 13. Mandible. 14. Mentum and ventromental plate. 15. Posterior abdominal segments. 16. Posterior parapod claw. Scales in ^m. near transition TIX to GcIX a projection often present appearing similar to lateral teeth known from many male Tanytarsini TIX. Postgenital plate triangulär. Cercus about as large as seminal capsule. Pupa (n = 1) Cephalothorax. Frontal setae elongate; cephalic tubercles absent. Thoracic hörn not discernible in slide mount. Weak granulation close to median suture; scutal tubercle absent. Wing sheath with prominent nose (Fig. 7), pearl row absent. 3 lateral antepronotals, LAps, situated in front of and at same level as precorneals, LApSj.s close together and more ventral; 3 precorneals, situated in front and ventral of thoracic hörn basal ring; 4 dorsocentrals in two widely separated pairs. Abdomen (Fig. 8). Length about 2.5 mm. Tergite I without shagreen; T II-IV with central field of fine shagreen; VII without shagreen; VIII and IX with central fields of shagreen. Hook row continuous, occupying Vz width of segment II. Pedes spurii B present on II. Segment VIII with posterolateral combs consisting of 4-5 marginal and 5-6 overlapping ventral teeth (Fig. 9). Abdominal setation. Segments II and III with 3 L setae; IV-VI with 3 LS setae; VII with 4, VIII with 5 LS setae. Anal lobe with 14-16 fringe setae and 2 dorsal setae, all lamelliform. 171 1000 £ 100 I 1 350 300 250 - E £ 200 5 150 100 50 -- ZZZIppt. ■■♦-■temp. H_.a_.a_.H-^ a a - 25 23 27 i I. 19 17 15 XI 1/92 I IV V VI VII VIII IX XI XI 1/93 Fig. 17. Densities of Caladoinyia frieden, spec. nov. on Mayaca fluviatüis from XIL1992 through XII.1993. Fourth instar larva (n =5) Size small, total length 3.74 mm (3.20-4.08). Head. Width 197 ^m (192-200), length 240 ^m (232-248); IC = 0.82. Antemia 5-segmented (Fig. 10), placed on pedestal bearing a distinct apical tooth; basal segment longer than flagellum, with basal ring organ and small seta in proximal Vi; segment 2 unsclerotized distally, shorter than segment 3; Lauter- born Organs large, pedicels 44 f