Orthemis ferruginea (Fabricius, 1775)

Carrillo-Lara, Diana E. & Novelo-Gutiérrez, Rodolfo, 2018, Description of the larva of Orthemis ferruginea (Fabricius, 1775) (Odonata: Libellulidae), Zootaxa 4455 (3), pp. 547-554: 548-550

publication ID

https://doi.org/10.11646/zootaxa.4455.3.10

publication LSID

lsid:zoobank.org:pub:F02DA9E5-AE7F-429B-ABBC-93ECBD6B69E3

persistent identifier

http://treatment.plazi.org/id/4206187E-9D38-3106-FF22-FDB5FDE0FECF

treatment provided by

Plazi

scientific name

Orthemis ferruginea (Fabricius, 1775)
status

 

Orthemis ferruginea (Fabricius, 1775) 

( Figs. 1–5View FIGURES 1View FIGURES 2View FIGURES 3View FIGURES 4View FIGURES 5)

Material studied: 4 exuviae (1♂, 3♀♀, reared from eggs), 5 F-0 larvae (2♂♂, 3♀♀). MEXICO: Veracruz; Municipality of Paso de Ovejas, El Angostillo (19°12.916 N; 96°32.370 W), elevation 244m, pond at dry forest, 15 February 2016, D. Carrillo, R. Novelo leg.GoogleMaps 

Description. Larvae and exuviae dark brown dorsally ( Fig. 1a View Figure ), pale ventrally ( Fig. 1b View Figure ), body robust and hairy, legs hairy, caudal appendages long and sharply pointed.

Head ( Fig. 2a View Figure ). Subrectangular, 1.4 times as wide as long, wider than thorax. Labrum brown, 1.0 mm long, moderately granulose, anterior margin setose. Clypeus pale, anteclypeus bare, postclypeus with a transverse row of small setae; anterior surface of frons pale, bare, anterior border with abundant, very long, whitish setae directed forwardly, dorsal surface with short, dark, stiff and erect setae; vertex blackish-brown, with a tuft of long, dark brown setae, ocelli pale. Antenna 7-segmented, scape and pedicel cylindrical, scape mostly brown, pedicel and flagellomeres yellow ( Fig. 2a View Figure ), scape and pedicel with short, brown stiff setae, flagellomeres with sparse, short and long delicate setae, third antennomere the longest, scape and 4th antennomere the shortest, size proportions: 0.5, 0.6, 1.0, 0.5, 0.7, 0.7, 0.7. Compound eyes relatively small, protruding dorsally ( Fig. 2b View Figure ). Occiput large, with 11 oval, vertical, parallel, glabrous areas bordered and separated from each other by abundant, short, dark brown setae ( Fig. 2a View Figure ). Mandibles ( Fig. 2c, d View Figure ) without molar crest, with formula: L 1234 0 a b / R 123+ 4 x y a b d, b>d>a. Maxilla: Galeolacinia ( Fig. 2e View Figure ) with seven teeth, three dorsal teeth almost straight, of similar length but basal one more slender, four ventral teeth of different size and robustness, basal tooth shortest, apical one largest, maxillary palp a little longer than galeolacinia, ending in a robust blunt spine. Ventral pad of hypopharynx transversally enlarged ( Fig. 2f View Figure ), subrectangular, with abundant long setae on anterior margin, a row of stiff setae along posterior margin directed apically. Labium spoon-shaped; prementum-postmentum articulation reaching posterior margin of procoxae. Prementum subrhomboidal ( Figs. 3a, b View Figure ), 1.2 times as wide as long, lateral margins widely divergent apically with a subbasal, short row of small setae; large premental setae ( Fig. 3a View Figure ) 3–4, usually 4, additional smaller spiniform setae 7¯9 on each side of midline; a row of 13–15 short setae at the base of palp articulation; ligula moderately developed, anterior margin strongly crenate ( Figs. 2b View Figure , 3a View Figure ), crenations usually 22–23, central crenation largest, extended into the dorsal surface of ligula as a swollen area, a minute spiniform seta between each crenation ( Fig. 3a View Figure ). Labial palpi strongly developed, covering inferior part of face as a mask ( Fig. 2b View Figure ), each with 8–9 strong crenations on apical margin, internally each crenation with 3 claviform setae; 7–8 (usually 8) palpal setae on dorsal margin ( Fig. 3a View Figure ), internal margin almost straight with 7–8 regularly spaced spiniform setae; external surface of palp dotted, internal surface with a group of 12–13 minute spiniform setae close to palp’s base; movable hook short and slender, shorter than most of palpal setae, sharply pointed and smooth. Ventral surface of prementum ( Fig. 3b View Figure ) covered with sparse delicate setae, no central sulcus visible on ventral surface.

Thorax. Prothorax with a transversally enlarged, light brown pronotum ( Figs. 1a View Figure , 2a View Figure ); anterior margin of pronotal disc straight, posterior margin convex, lateral margin rounded, all margins beset with short, dark brown, stout setae; a large, subrectangular bare area on each side of midline ( Fig. 2a View Figure ); inferior margin of propleura with tufts of long, white setae. Mesospiracle well exposed ( Figs. 1a View Figure , 2a View Figure ), with its internal and external ends subequally raised. Side of pterothorax sloping down more or less steeply ( Fig. 1a View Figure ), dorsal border and most of lateral surface with abundant, short, stout dark setae; inferior margins of meso- and metathorax with long, white setae. Legs setose ( Figs. 1a View Figure , 2a View Figure ), coxae, trochanters and tarsi yellow, femora and tibiae dark brown; external (anterior) surface of tibiae with a comb of large, dark, stiff setae ( Fig. 2a View Figure ); internal (posterior) surface of protibia ( Fig. 4a View Figure ) with an internal row of tridentate setae, and an external row of large, stout, yellow setae, and with large spiniform setae at apex; internal surface of meso- and metatibia only with the row of large, stout, yellow setae ( Fig. 4b View Figure ); ventral surface of all tarsi with two rows of setae as follows: protarsomeres ( Fig. 4c View Figure ) with an internal row of tridentate setae, the external one with stout spiniform setae on basal and middle tarsomeres, and hair-like setae on distal tarsomere; ventral surface of basal and middle mesotarsomeres with strong spiniform setae in both rows ( Fig. 4d View Figure ), distal mesotarsomere with an internal row of tridentate setae and an external row of hair-like setae; all metatarsomeres ( Fig. 4e View Figure ) with an internal row of tridentate setae and an external row of stout spiniform setae; pretarsal claws simple with pulvilliform empodium. Anterior and posterior wing pads slightly divergent ( Fig. 1a View Figure ), reaching basal half and posterior margin of S5, respectively, both pairs setose mainly on borders.

Abdomen. Enlarged, fusiform ( Figs. 1 View Figure , 5a View Figure ), reaching its maximum width at S5–6, gradually tapering caudad, with S10 reduced and sunken into S9, S1–5 pale, S6–10 dark brown ( Figs. 1a View Figure , 5a View Figure ). Tergites 1–4 mostly bare, 5–9 with abundant, short, dark setae ( Fig. 5a View Figure ), posterior margins of S6–10 with a row of small spiniform setae; no dorsal protuberances at all, only a subapical, middorsal tuft of long, reddish-brown, bristle-like setae on S2–9 ( Fig. 5a View Figure ); lateral margins of S1–9 with abundant, long, delicate white setae, intermingled with a row of small spiniform setae on S2–10; lateral spines on S8–9 short and sharply pointed ( Fig. 5a View Figure ), those of S8 more or less parallel, those of S9 moderately incurved and longer, 0.15-0.3 and 0.4-0.5 the middorsal length of their respective segments. Sterna 1–7 creamy pale to grayish yellow, 8 yellowish-brown, 9 reddish-brown, 10 dark brown ( Fig. 1b View Figure ); posterior margins of sterna 1–6 with long, delicate setae, 7–10 with a row of spiniform setae which increase in size and robustness caudally; sternum 9 with a subapical tuft of long, white setae on each side of midline; sternum 5 divided into five sternites, sterna 2–4 and 6–9 divided into three sternites, that of 10 forming a continuous ring with respective tergum; sutures parallel on 2–4, slightly convergent caudally on 5–7, slightly divergent on 8–9. Gonapophyses lacking. Caudal appendages ( Figs. 5a, b View Figure ) pyramidal, long, sharply pointed, basal half dark brown, apical half yellow. Epiproct and paraprocts of same length, cerci 0.40 the length of epi- and paraprocts; epiproct with a row of spiniform setae intermingled with long, bristle-like setae on ventral border; cercus with a row of small spiniform setae on external surface of apical third; paraproct with a row of stout spiniform setae intermingled with bristle-like setae on dorsal and ventral borders.

Measurements: Larvae (in alcohol, N=5) [mean in brackets]: TL, 22–25 [23.3]; AL (ventral, incl. app) 13.5–

15 [14.4]; MWh, 4.9–5 [4.96]; HfL (lateral), 4.7–5 [4.86]; Ep and Pp, 2.2–2.5 [2.38]; Ce, 0.8–1 [0.94]. Remarks. The most frequent morphological variation we found was in the number of premental setae, in both the primary and secondary series. Also, but in a lesser extent, the number of palpal setae varied, even in the palps of the same specimen, which is common in larvae of Libellulidae  (2nd author, pers. obs.). Larvae usually inhabit the muddy bottom of lentic habitats such as ponds and temporary pools. We collected F-0 larvae in a highly eutrophized pond with a water temperature of 40°C close to the surface, and 35°C at 15cm depth in the muddy bottom, around 1400 h in a sunny day.

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Odonata

Family

Libellulidae

Genus

Orthemis