CPIE Aquatic Environments
Near Links: [ALGAE] | [HIGHER PLANTS] | [OTHER INVERTEBRATES] | [INSECTS] | [VERTEBRATES]

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Phylum ARTHROPODA, Class INSECTA


OrderO DONATA

The dragonflies (Anisoptera) and damselflies (Zygoptera) are represented in Hawaii by three families, 9 genera, and about 34 species (Nishida, 1992). The largest genus is Megalagrion with 23 species and 5 subspecies, all endemic to the Hawaiian Islands (Polhemus, 1995). Many of these are threatened with extinction and members of the genus are only rarely seen on O`ahu in lowland areas.

Odonate links:

• Odonata: Damselflies & dragonflies -- lots of links (Kansas)
• Phylogeny
• O.I.N - Odonata Information Network
• Digital Dragonflies -- Texas
• Damselflies of Texas
• CPIE species list - list of Hawaiian Odonata

	124a		Elongated insects with four wings, frequently observed near bodies of water. Adult damselflies and dragonflies	[125]
	124b		Aquatic insect nymphs: larval forms living in aquatic environments or in water within vegetation. Having compound eyes and jointed legs, but without wings (wing pads may be present)	[126]
			~~~~~ Adults (terrestrial) ~~~~~~~~~~~~~~~
	125a	(103) & (124)	Front and hind wings similar in shape and size, with a narrow section at base (see Fig. 1); wings held, at rest, together over body (see Fig. 3). { Body slender. Head broad, rectangular. Damselflies ~ Suborder ZYGOPTERA	[127]
	125b		Hind wings broader than front wings and held out horizontally (or somewhat up or down) at rest. { Body elongate, but stout. Head round. Dragonflies ~ Suborder ANISOPTERA	[135]
			~~~~~ Nymphs (aquatic) ~~~~~~~~~~~~~~~
	126a	(111) & (124)	Tip of abdomen with three gills, which may be leaf-like (foliate) or dagger-like (lanceolate). Movement by wriggling and sculling with gills. Damselfly naiad ~ Suborder ZYGOPTERA	[130]
	126b		Tip of abdomen with short spines or none, but lacking gills. Rapid movement by squirting water from anus ("jet propulsion"). Dragonfly naiad ~ Suborder ANISOPTERA	[136]
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¹ Couplets are part of Keys to the Aquatic Biota of the Hawaiian Islands . If uncertain whether the insect specimen to be identified is an odonate (dragonfly or damselfly), begin the key here.

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Suborder Zygoptera (damselflies)

Damselflies are generally smaller and weaker fliers than dragonflies, although some of our native damselflies are of pretty good size and strength (Megalagrion blackburni for example). All of the native and introduced species of damselflies in Hawai`i are in the Family COENAGRIONIDAE.

Family COENAGRIONIDAE

	127a	(125)	Front wings with 5 or usually more cross-veins between node and M1/M2 junction ~ Megalagrion spp.2
	127b		Front wings with 4 (rarely 5) or fewer postnodal crossveins (pn in Fig. 1) before M1/M2 junction. { Color usually a shade of blue or green; if thorax red or orange, then lacking lateral black stripes	[128]
			Figure 1. Wings of female Ischnura posita. Modified from picture obtained at Damselflies of Texas.
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	128a	(127)	Front wing with three crossveins (pn in Fig. 1) between node and M1/M2 junction. Males with small, paired projections posterodorsal on abdominal segment X (ten). Coloration blue, green, or orange. Forktails	[129]
	128b		Front wing with 4 (rarely 5) crossveins between node and M1/M2 junction. Without knob-like projections above anus. Males a striking, deep blue on thorax and abdomen. Bluet ~ Enallagma civile (Hagen)
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	129a	(128)	Males with an electric blue spot near tip of abdomen (Fig. 2); females green, orange, or even red, but without lateral black bands on thorax (Fig. 3). Common ~ Ischnura ramburi (Selys-Longchamps)
	129b		Small, rather weak appearing greenish, yellowish, or blue damselflies. Dorsal surface of thorax marked with light stripes resembling exclamation marks (Fig. 4) ~ Ischnura posita (Hagen)
	Figure 2 (left).  A male Ischnura ramburi is quite distinctive with its bright blue abdominal segment between two black segments at the tip of the "tail" Figure 3 (below).  This red-orange female I. ramburi might be mistaken for a native Megalagrion, but note there are no lateral black bands on thorax.
	Figure 4. Two views of an Ischnura posita showing the distinctive exclamation point markings on the top of the thorax.
			~~~~~ Nymphs (aquatic) ~~~~~~~~~~~~~~~

² The native Hawaiian genus, Megalagrion, is a diverse group of species for which excellent identification material exists in the form of a book by Dan Polhemus & Adam Asquith, titled: Hawaiian Damselflies. A field Identification Guide. Pictures of many species are available on the Internet as listed below.

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* Introduced damselflies
• Enallagma civile / photo / photo, Kansas, photos, Texas
• Ischnura posita / photo, male, Kauai, photos, Texas
• Ischnura ramburi / photos, Texas

* Native damselflies



Figure 5.  A Megalagrion xanthomelas photographed by Rodger Douglas
of AECOS in the Moanalua area of Honolulu.

• Megalagrion vagabundum (Perkins) / photo.
Hawaii Biological Survey / B. P. Bishop Museum

• Megalagrion Damselfly Page.
  • M. adytum (Perkins) / photo, male / photo, female / distribution.
  • M. blackburni McLachlan / photo, male / photo, female / distribution.
  • M. calliphya (McLachlan) / photo, male / photo, female / distribution.
  • M. eudytum (Perkins) / photo, male / photo, female / distribution.
  • M. koelense (Blackburn) /photo.
  • M. leptodemus (Perkins) /photo.
  • M. nigrohamatum nigrolineatum (Perkins) /photo.
  • M. oahuense (Blackburn) /photo.
  • M. oceanicum McLachlan /photo.
• Megalagrion Image Archive

Far Links: [AECOS] | [CPIE]


Last modified on May 26, 2003 by Guinther (guinther@hawaii.rr.com)