Erythemis credula ( Hagen, 1861 )

Rodríguez, Fredy Palacino, Sarmiento, Carlos E. & González-Soriano, Enrique, 2015, Morphological variability and evaluation of taxonomic characters in the genus Erythemis Hagen, 1861 (Odonata: Libellulidae: Sympetrinae), Insecta Mundi 2015 (428), pp. 1-68 : 15-16

Erythemis credula ( Hagen, 1861)

( Fig. 1a , 2a , 22, 24 , 32 )

Diplax credula Hagen, 1861: 184 .

Type material. (2 male). BRAZIL. Minas Gerais: St. Thomas, 1877, no more data, 1 male lectotype, 1 male paralectotype ( MCZ). We examined two adult specimens labeled as types ( MCZ), in the type 1 the abdomen is lost (from the mid region of second segment). The specimen labeled as type 2 is here designed as the lectotype because it has all its parts.

Diagnosis. Thorax, dorsum of abdomen, and dark basal spot ochreous or brown (in female and immature male), or black (mature male). Dorsum of the thorax pale with dark antehumeral stripes, the width of the three stripes is similar (female and sexually immature male). Dark basal spot on HW does not reach the first antenodal vein, but reaches the following regions: beyond the MP crossvein, the penultimate row of cells or the row of marginal cells, and maximum the supplementary anal vein. Posterior lobe of vesica spermalis not covered by lateral lobe ( Fig. 20 and 21 ), which extends more posteriorly than medial lobe is more extended into posterior region than the medial lobe. Hook not bilobed, instead two finger-shaped structures are oriented perpendicular to the longitudinal axis of the vesica spermalis ( Fig. 22 and 24 ). Cornua diagonal with respect to vesica spermalis transversal axis, with lobes separate to apex, and not covered by lateral lobes ( Fig. 20 ). Vulvar lamina suboval in ventral view, not projected to posterior region and with posterior border rounded ( Fig. 10 ). Lab ≤ 30mm, LcaS4/LclS4>2.1.

Morphometric ratios of males. AnptFW/LoptFW ratio on HW (AnptHW/LoptHW<0.19); LHW/ Lab>1.2; AnptFW/LoptFW>0.22; Acd/Lban> 4.10; And/Lban>4.10; Lban/Anb>1.90; LHW/Acd>3.60; LHW/LFW>0.97; LclS3/LcaS3>2.10; LclS3/Lecv-clS3>4.00; Lecv-clS3/LcaS3>1.50; Lab/LclS3<1.50; Lab/ LcaS3>3.00; Ansbt/Antr<2.70; LFW/Lnpt>3.00; Lnpt/Anb>1.50; Lba/Lban>2.00; Lban/Lasa-ca<3.00.

Head. Ll: 0.0009 –0.0011 mm (M); 0.0013mm (F). Lw: 0.0027 –0.0031 mm (M); 0.0031mm (F). Hwd: 0.0050 –0.0053 mm (M); 0.0055mm (F). Hl: 0.0026 –0.0028 mm (M); 0.0028mm (F).

Legs. Nsmf: 9–22 (M); 6–12 (F). Nshf: 21–54 (M); 7–17 (F). Hfl: 0.0056 –0.0060 mm (M); 0.0062mm (F). Fbsd: 0.0020 –0.0021 mm (M); 0.0023mm (F). Mfl: 0.0034 –0.0036 mm (M); 0.0038mm (F). Dshf (the conditions separated by commas are present in different specimens): short spines-3 long spines (MF), short spines-1 (F) or 2 median spines (MF)-3 long spines (M).

Wings. AvFW: 10–12 (M); 10–12 (F). AvHW: 8–10 (M); 8–9 (F). LoptFW: 0.0030 –0.0033 mm (M); 0.0031mm (F). AnptFW: 0.005 –0.007 mm (M); 0.006mm (F). LoptHW: 0.0031 –0.0033 mm (M); 0.0032mm (F). AnptHW: 0.0053 –0.0068 mm (M); 0.006mm (F). DfwHW: 0.004 –0.006 mm (M); 0.0053mm (F). LbanFW: 11.85–14.58mm (M); 13.24–14.58mm (F). LbanHW: 10.25–13.35mm (M); 10.91–12.89mm (F). AndFW: 5.33–6.74mm (M); 5.55–6.62mm (F). Wb: 6.38–8.16mm (M); 7.47–7.91mm (F). LFW: 24.19–30.35mm (M); 27.24–29.94mm (F). LHW: 24.46–29.00mm (M); 25.67–29.05mm (F). AnsbtFW: 0.0015 –0.0018 mm (M); 0.0013mm (F). AntrFW: 0.0062 –0.0075 mm (M); 0.007mm (F). LarFW: 0.000 – 0.0002 mm (M); 0.0006mm (F). LarHW: 0. 000– 0.002mm (M); 0.0006mm (F). LnptFW: 7.86–9.75mm (M); 8.30–9.81mm (F). LnptHW: 7.56–10.95mm (M); 9.00– 10.90mm (F). At-MP: 0.004 –0.008 mm (M); 0.009mm (F). LbaFW: 0.0025 –0.0029 mm (M); 0.002mm (F). LbaHW: 0.0025 –0.0029 mm (M); 0.0025mm (F). RP2-loptFW: 0.0009 –0.0015 mm (M); 0.008mm (F). RP2-loptHW: 0.0011 –0.0016 mm (M); 0.008 (F). Dat-lsbt: 0.0012 –0.0018 mm (M); 0.0018mm (F). Lasa-ca: 0.003 –0.008 mm (M); 0.006mm (F). Crp: 6–9 (FW), 5–10 (HW). Crp: 4–6 (FW), 5 (HWF). Cal: 2–4. PC-RA-RP1: 2–3 (FW), 1–3 (HW). CdfFW: only 2 rows, only 3 rows, 1–3 triple cells-2 rows, 1 double cell-1-2 triple cells-2 rows, 1 double cell-1 triple cell-2 rows. CdfHW: 1–4 individual cells-2 double cells, 1 cell-1 double cell-1 cell-2-3 rows. Vt: 0–1, in some cases 0 (left), 1(right). Csub: 2–3. FW arculus approaching or beyond the second antenodal vein.

Abdomen. Lab: 21.16–24.94mm (M); 22.97–24.65mm (F). LcaS3: 0.005 –0.008 mm (M); 0.008mm (F). LclS3: 0.0016 –0.0018 mm (M); 0.0019mm (F). Lecv-clS3: 0.0011 –0.0013 mm (M); 0.001mm (F).

Caudal appendages. Las: 0.0013 –0.0015 mm (M); 0.009mm (F). Poas: 0.001 –0.003 mm (M); 0.001mm (F). Anas: 0.003 –0.005 mm (M); 0.002mm (F). Ddas: 0.002 –0.004 mm (M). Epl: 0.0008 –0.0014 mm (M); 0.004mm (F).

Larva. Dias dos Santos (1969) provides the following characters for the last larval stage: larva ochre and spider-shaped, with white eyes and long metathoracic legs. Head short and wide. Total length 15 mm, width of the head 5 mm, head length 2 mm, ll 3 mm, lw 3.50 mm, thorax length 4 mm, wing teca 6.00 mm, femur anterior, medial and posterior length 2.30; 3.00 and 5.50 mm respectively. Tibia anterior, medial and posterior length 2.50; 3.50 and 7.00 mm respectively. Lab 9.00 mm, caudal appendage mid-dorsal 1.20 x 1.10 mm, lateral superior 0.70 mm, lateral inferior 1.20 mm. According to Costa and Pujol-Luz (1993), E. credula larvae show 11 premental setae, six palpal setae, cercus exceeds 1/2 the length of the epiproct.

Material examined. BRAZIL, Amapá, Ressurreição , ii.1964, J.C.M. Carvalho, Dirce leg., 1 male ( MNRJ) ; Espírito Santo, Reserva Nova Lombardia, 4 Km. do Sta. Tereza , 15.i.1967, N. Santos leg., 1 male ( MNRJ) ; Minas Gerais, Cataguases , 20.ii.1958, N. Santos leg., 2 males ( MNRJ) ; same, but Lagoa Santa, Lagoa olho d’ agua, 20.iv.1949, Machado e N. Dias dos Santos leg., 4 males, 6 females ( MNRJ) ; same data as before except collected on following dates: 23.x.1983, N. Santos, Ulisses leg., 1 male ; same, but ii.1942, Berla leg., 1 male ( MNRJ) ; same data as before except collected on following dates: ii.1947, Santos, Berla, Machado leg., 4 males, 1 female, 13.i.1951, N. Dias dos Santos e Machado leg. 2 males, 2 females ; same, but Pirapora , ii.1947, Santos, Machado leg., 1 male ( MNRJ) ; Pará, Belém, Utinga , 20.ii.1963, Roppa, Mielke leg., 4 males 1 female ( MNRJ) ; Pernambuco, Igaraçu, Usina S. José, 2 males ( MNRJ) ; same, but Recife, Reserva Florestal do Açude do Prata, Parque Dois irmãos, 08°- 09°S e 34°- 35°W, 08.ii.2001, 5 males ; same data as before except collected on following dates: 09.ii.2001, 1 male ; same, but Dois irmãos, 12.xii.1944, Berla leg., 1 male ( MNRJ) ; same data as before except collected on following dates: 27.vii.1944, 1 male ; same, but São Lourenço, Brejo dos Macacos , 18.ii.1963, N. Santos, Dardano Lima leg., 1 male ( MNRJ) ; Sem procedência, 2 males, 3 females ( MNRJ) ; São Paulo, Emas , i.1939, Santos leg., 1 male ( MNRJ) ; same, but Pirassununga, Ribeirão S. Vicente , 15.xii.1948, Machado, N. Dias dos Santos leg., 2 males ( MNRJ) ; same, but Laranja Azeda , iii.1944, N. Santos leg., 1 male, 2 females ( MNRJ) ; same, but E. E. Casa e Pesca , 09.xii.1948, Machado, N. Dias dos Santos leg., 2 males ( MNRJ) ; same, but Lagoa do Carrinho , xii.1948, Machado, N. Dias dos Santos leg., 1 male ( MNRJ). COLOMBIA, Amazonas, Leticia. km. 2 vía Tarapacá, 1 male ( ICN) ; Meta, San Juan de Arama, Hda. La Macarena, 1 male ( ICN). GUYANA, Demerara , Lama creek , tributary of Mahaica River , 6°48’ 58°10’, 0 m, T. W. and A. J. Donnelly leg., 1 female ( RWG). FRENCH GUYANA, small canal 17 km S of Tonate on route D5, 4°52’15” 52°31’9”, 18 m, 18.ii.1988, R. W. Garrison leg., 2 males ( RWG) ; marsh by Piste de Kaw, just E of N2, 4°23’53” 52°18’30”, 71 m, 17.ii.1988, R. W. Garrison leg., 1 male ( RWG). VENEZUELA, Bolívar State, Canaima at Río Carrao , 6°14’30” 62°50’53”, 415 m, 12-14.viii.1990, R. W. and J. A. Garrison, 1 male ( RWG) .

Remarks. The larva of E. credula was described by Calvert (1928) based on material from Antigua and Barbados, but Dias dos Santos (1969) remarks that both the description and the figures provided by Calvert (1928) do not correspond to this species, so he provided a new description.

Biology. Larvae of Erythemis credula show low mobility in water, but walk rapidly on dry surfaces ( Dias dos Santos 1969) and have been observed preying on larvae of Buenoa platycnemis Fieber (Heteroptera: Notonectidae ) in acidic water ponds with temperatures between 22 and 24°C (Nessimian and Ribeiro 2000). Likewise, larvae and adults have been found in swamps where the primary vegetation was Sphagnum (Sphagnaceae) ( Dias dos Santos 1969).

Distribution. From Belize to Argentina ( Fig. 32 ), between 0–1870 m. asl.

Figures

Figure 1. a) Plot showing continuous variation for the character distance between lateral and ventral carinae (dlvc), opposite to meeting point of lateral and medial transverse carinae on S3 (lmt). Numbers represent the following species: 1) E. attala, 2) E. carmelita, 3) E. collocata, 4) E. credula, 5) E. haematogastra, 6) E. mithroides, 7) E. peruviana, 8) E. plebeja, 9) E. simplicicollis, 10) E. vesiculosa. b) S1-3 E. carmelita males showing the measures from Williamson (1923): distance between lateral and ventral carinae (dlvc), divided by the measure of distance between meeting point of lateral and medial transverse carinae and ventral carinae (lmt).

Figure 2. Plots of the first two discriminant functions of the discriminant analysis. a) The first two discriminant functions explain 72.5% in males, the cases in where species are overlapped were analyzed by separated in b. b) The first two discriminant functions explain 88.3% in males, and c) The first two discriminant functions explain 83.7% in F. Polygons define the limits of proposed groups.

Figure 32. Erythemis credula distribution map.

Figures 18–25. Discrete characters of vesica spermalis. Numbers represent the following species:18) E. mithroides, dorsal view; 19) E. carmelita, left side view; 20) E. vesiculosa, left side view; 21) E. peruviana, left side view; 22) E. credula, dorsal wiew; 23) E. haematogastra, right side view; 24) E. credula, finger-shaped structures, dorsal view; 25) E. plebeja, dorsal view. Abbreviations indicate the following characters, C: Cornua; L: Lateral lobe; H: Hook; Pb: Posterior border; M: Medial lobe; P: Posterior lobe; NH: Hook not bilobed.

Figures 10–17. Discrete characters of vulvar lamina, abdominal appendages, thorax, and femur.Numbers represent the following species: 10) E. peruviana female; 11) E. plebeja female; 12) E. simplicicollis male; 13) E. mithroides male; 14) E. vesiculosa male; 15) E. peruviana female; 16) E. vesiculosa female, 17) E. attala male. Abbreviations indicate the following characters, S 8 -S 9: Abdominal segments 8-9; LV: Vulvar lamina; Pb: Posterior border; Vt: Teeth ventral; Ai: Inferior appendage; As: Antehumeral stripe.