Brachygonia oculata

Eastcoast Gvt.: Deli (Karsch); Bengkalis. Pakanbaroe. Oct. 25. 1925. Fulmek leg. Westcoast Res.: Mt. Ophir distr. (Ris).

Sumber: A Synopsis of the Odonata (Dragonflies) of Sumatra

Habitat In Singapore B. oculata is found exclusively in the western part of the island within a restricted area. One population is found at a shady young secondary forest swampy pool while the other is in a more open pond at a mosaic of forest and scrubland habitats (Fig. 5). The tiny larva inhabits a substrate of submerged tangled leaves, twigs and branches. Throughout Sundaland, the species inhabits a wide range of alluvial forest, peat swamp forest and other forested marshy areas (Orr 2003), and can thrive in secondary and disturbed forests (Dow 2009).

Sumber: Description of the larva of Brachygonia oculata (Brauer, 1878) (Odonata Libellulidae) with notes on rearing technique

General: Very small, overall dark brown with long dark banded legs. Head with prominent bulging eyes and dark banded antennae. Abdomen oviform (Fig. 1). Head: Wider than long, somewhat pentangular. Eyes sloping rearwards. Long setae present on the posterior portion of occiput especially along occipital corner. A tuft of fine black setae on the postfrons centrally. Antennae sevensegmented with dark bands. Labium scoop-shaped (Fig. 2 A). Prementum triangular (Fig. 2 B and 4 A). A row of six long primary premental setae and four short secondary premental setae on either side of prementum. 12 to 14 short bristle-like setae present along the distal margin of prementum. Ligula pointed. Labial palps sub-triangular (Fig. 2 B). Eight long palpal setae along dorsal rim. Moveable hook slender and as long as palpal setae. Six palpal crenations, each with one long palpal seta and one or two shorter setae. 10 to 12 setae along proximal margin of labial palp. Thorax: Prothorax narrow with short bristle-like setae along posterior margin. Sparse short bristle spiny setae on pterothorax. Wings sheaths parallel, dark, extending onto S 6. Legs with distinctive dark bands on femur and tibia. Short spines throughout entire legs. Tarsus three segmented with sharp pretarsal claws. Abdomen: Abdomen oviform with dark mottled markings. Dorsal spines recurved, small from S 2 to S 5, becoming strongly prominent from S 6 to S 8 (Figs. 3 A and 4 B). Very small lateral spines from S 3 to S 7. Sharp protuberant lateral spines on S 8 and S 9. Lateral spine on S 9 reach end of epiproct. Average length (measured dorsally with inner margin of lateral spine) ratio of S 9 lateral spine to S 9 is 1: 0.84. Fine lateral setae present along abdomen. Measured dorsally, average length ratio of S 9 + S 10 to anal appendages (measured to distal end of paraprocts) 1: 1.67. Small spiny setae on anal appendages. Epiproct triangular (Figs. 3 B and 4 C), shorter than paraprocts, average length ratio 1: 1.4. Cerci slightly shorter than epiproct. Average length ratio of cerci to epiproct 1: 1.3, ceri to paraprocts 1: 1.9. Measurement ranges in examined specimens (n = 6) (mm): TL 9 – 10.8; head width measured across widest section of occiput below compound eyes 2.39 – 3.43; prementum length 1.54 – 1.7; prementum width 1.94 – 2.71; epiproct length 0.59 – 0.64; paraproct length 0.81 – 0.88.

Sumber: Description of the larva of Brachygonia oculata (Brauer, 1878) (Odonata Libellulidae) with notes on rearing technique