Dragonflies were in existence before the dinosaurs, almost 300 million years ago (Jenkins, 2002). Dragonflies belong to the order Odonata, which means ‘toothed one’. Up to now, around 6,000 species have been described worldwide, with the greatest numbers occurring in the tropics (Dijkstra et al., 2013). In Malaysia alone, there are over 400 species of Odonates, and there are more to be identified.
One of the most recognised and well-known Odonate species across the continents of the globe is Pantala flavescens whose common name is the Wandering Glider. The Wandering Glider can be found almost everywhere, except Antarctica. It can be found throughout Malaysia in habitats ranging from permanent running water and lakes, to small, temporary rain pools, especially, in open country (Low et al., 2017). As its common name suggests, this dragonfly has globetrotting capabilities, for instance, it can fly more than 3,500 km over open waters from India to East Africa and vice versa across the Indian Ocean (Troast et al., 2016). Also, this species can make multigenerational journeys of about 18,000 km with individual globe skimmers flying more than 6,000 km to complete the migration (Troast et al., 2016). This is because it has adapted to follow prevailing seasonal winds to the Intertropical Convergence Zone (ITCZ), a narrow zone near the equator that produces low atmospheric pressure. Wind-assisted passive dispersal and an enlarged hindwing base for gliding are other factors that allow this dragonfly to migrate long distances (Troast et al., 2016).
The Wandering Glider belongs to the family Libellulidae, the skimmer dragonflies. Its hindwing can measure up to 41 mm in length. Its species name, flavescens, is the Latin word meaning yellowish which refers to the yellowish colour of this dragonfly. The colour of its abdomen depends on its stage of maturity; younger individuals have a lighter ochre abdomen, while the abdomen of the female ranges from yellow ochre to umber brown (Orr, 2005). The eyes of the males are reddish-brown or bluish-grey, while in females, they are olivaceous-brown when seen from above (Husain, 2015).
Primarily, the female breeds on standing or slow flowing water. The larva of the Wandering Glider is quite similar to the larva of Hydrobasileus croceus, the Amber-winged Glider, but the former is more slender and lacks dorsal spines on the abdomen. The life cycle from an egg to an emerging adult can be completed in two months. Both larvae and adults are predators. The larvae feed on a wide variety of aquatic insects, including mosquito larvae, mayfly larvae, and freshwater shrimps. The adults prey on small flying insects like mosquitoes, flying ants and termites (Lung & Sommer, 2001). The adults can venture far from water, over the rainforest canopy and mountain tops, to migrate and hunt for food (Orr, 2005). Compared to other Libellulids, the Wandering Gilder usually perches vertically on low stems and twigs (Tang et al., 2010).
The Wandering Glider is categorised as a Least Concern (LC) species under the IUCN Red List (Boudot et al., 2016). This is due to its ability to live in a wide range of habitats, its widespread distribution throughout the tropics and its migratory habit.
Always remember that dragonflies existed before humans appeared. Forest development and changes in the urban environment will have some impact on the dragonflies too, for example, the dragonfly may not survive in polluted water. Further research should be carried out and conservation measures taken to ensure that dragonflies continue to exist.
