Dysphaea, Selys, 1853

Orr, Albert G. W., 2024, A review of present knowledge of larvae of the Calopterygoidea (Zygoptera) of the Oriental realm, including keys to families and known genera, Zootaxa 5497 (2), pp. 209-243 : 234

Dysphaea

The genus is represented by nine species distributed widely from Sundaland to southern China, including Hainan, Indochina. Thailand, Myanmar across north-west India, Bangladesh and the eastern Himalayas to the Western Ghats. Larva of this common genus have proved remarkably elusive. Lieftinck (1950) recorded larvae of D. dimidiata Selys from West Java and noted their ecology in general terms, but surprisingly provided no description or even a general comment of their unusual morphology, either in that publication or in any later paper. Recently larvae and exuviae of Dysphaea gloriosa Fraser ( Fig. 57 ) were discovered in Thailand and described ( Nguyen et al. 2024). The head is extremely large, much wider than the prothorax, with small eyes; the genae are swollen beyond the outer margin of the eyes and armed with rows of heavy spines The postocular lobes are bulbous and also bear strong marginal spines ( Fig. 61 ). The saccoid gills are elongate and tapered to a long fine filament. The genus perhaps has the most distinctive of all euphaeid larvae and it is expected that all species will be recognisable.

Dysphaea have been observed ovipositing in areas of torrential water flow ( Orr 2001). The larvae have been collected clinging under rocks in swift flowing rapids ( Lieftinck 1950, Nguyen et al. 2024).

Figures

FIGURES 57–60. 57. Dysphaea gloriosa, habitus (drawn from Nguyen et al. 2024). 58. Bayadera strigata, habitus (drawn from Yang & Orr 2024). 59. Euphaea decorata, habitus. (drawn from Xu 2017). 60. Anisopleura furcata, habitus (drawn from Keetapithchayakul et al. 2024).

FIGURES 61–66. 61. Dysphaea gloriosa: detail of spines on genae and postocular lobe; underside (left), upperside (right) (modified from Nguyen et al. 2024). 62. Heterophaea barbata: dorsal view of head, showing (a) outer mandibular spines (b) genal spines partially visible and (c) right antenna (from Orr & Hämäläinen 2024). 63. Anisopleura subplatystyla, dorsal view of head (original drawing). 64. Bayadera strigata, dorsal view of head (drawn from Yang & Orr 2024). 65. Euphaea decorata, dorsal view of head. (drawn from Xu 2017). 66. Bayadera strigata, left labial palp with detail showing wavy outer margin of outer process of palpal lobe (arrowed), (drawn from Yang & Orr 2024).