Dragonflies and Damselflies (Insecta: Odonata) of the Republic of the Marshall Islands

Seven species of Odonata are recorded from among the numerous atolls and midocean reef islands that make up the Republic of the Marshall Islands (RMI). They include two Zygoptera (damselflies: Tanymecosticta sp. and Ischnura aurora) and five Anisoptera (true dragonflies: Anax guttatus, Diplacodes bipunctata, Pantala flavescens, Tholymis tillarga, and Tramea transmarina). The damselfly Tanymecosticta sp. is known only from a single World War II–era extralimital record reported here for the first time. Breeding is confirmed for the six other species, which are widely distributed in the Pacific and often further afield. The frequently cited record of Pantala flavescens as being the first odonate and one of the first insects to colonize Bikini Atoll after cessation of nuclear testing requires verification. Additional surveys on many of the Marshall Islands not yet sampled for odonates will doubtless result in many new locality records. However, small island size, limited habitat diversity and water resources for breeding, and large distances from potential source populations contribute to an impoverished odonate fauna, and few, if any, species are likely to be added to the list. The six species known to inhabit the Marshall Islands make up the entire known odonate faunas of many other low, coralline islands in the West-central Pacific.