Hine's emerald (Somatochlora hineana)
|Size||Body length: 6 - 6.5 cm (2) (3)|
Wingspan: 9.0 - 9.5 cm (2) (3)
- As with all emerald dragonfly species, Hine’s emerald has bright emerald-green eyes.
- The larval stage of Hine’s emerald lasts for between two and four years, whereas the adult stage lasts for a maximum of five weeks.
- Hine’s emerald is locally extinct in Ohio, Alabama, Michigan and Missouri.
- Hine’s emerald is a habitat specialist and is very sensitive to environmental change.
Hine's emerald is classified as Near Threatened (NT) on the IUCN Red List (1).
Hine’s emerald (Somatochlora hineana) can be distinguished from other Stomatochlora dragonflies by the male’s distinctively shaped appendages and the unique-looking ovipositor of the female (2). The body is metallic green and there are yellow stripes running along each side (2) (3) (4). Similarly to all emerald dragonflies, this species has bright emerald-green eyes (2) (4).
Hine’s emerald is endemic to the United States (1), where it is found in Illinois, Wisconsin, Michigan and Missouri (1) (2) (3) (4). There were once populations in Ohio, Alabama and Indiana, although these are now thought to be locally extinct (1) (2).
The larval development of Hine’s emerald occurs in the shallow, cool, running water (2) of calcareous wetlands, including marshes, sedge meadows (3) (4) and fens (2) (3). Adults are only found around these areas when mating or laying eggs (3), and generally spend the majority of their time roosting and foraging around the neighbouring woodlands, fields and open areas (2) (3).
The male Hine’s emerald establishes a small breeding territory and will pursue and mate with any female that enters the area (3) (4). The female then deposits the fertilised eggs by repeatedly dipping its ovipositor into shallow water (3) (4), releasing up to 200 eggs at a time (3). The eggs hatch later in the breeding season or the following spring, releasing the larvae into the water (4). The aquatic larval stage of this species’ life cycle lasts for between two and four years (2) (4), during which time it undergoes many moults (4). Eventually, the larva crawls out of the water and sheds its skin a final time, emerging as an adult (4). The individual will then take refuge in nearby vegetation while its exoskeleton hardens and the reproductive organs develop (3). The short adult stage of the Hine’s emerald life cycle lasts for a maximum of five weeks (4), and this period usually runs between late June and mid-August (2).
In its larval stage, Hine’s emerald is an opportunistic, sit-and-wait predator which takes a variety of invertebrates, including isopods, dragonfly, mayfly, mosquito and caddisfly larvae, worms and snails (2) (3). As an adult, Hine’s emerald hunts for insects while it is in flight (2).
One of the most significant threats to Hine’s emerald is habitat loss (1) (2) (4). As a species with very specific habitat requirements, it is extremely vulnerable to habitat degradation, and many previously suitable areas no longer have the correct conditions to support populations of Hine’s emeralds (1). Many wetlands throughout the range of this species have been drained to allow the development of new commercial and residential areas (2) (4), as well as to create landfills, quarries, roads and railways (2). As this species relies on aquatic habitats to breed, water drainage can prevent any reproduction from occurring, leading to a drastic reduction in population size (4). Sections of habitat have also been fragmented, which can lead to genetic problems such as inbreeding depression (2).
Chemical contamination is also a major threat to Hine’s emerald and its habitat (2) (4). Good water quality is vital for the aquatic larval period of this species, and the presence of pesticides and other pollutants in the habitat can reduce the water quality and can have negative effects on organisms living in the area (4).
To a lesser extent, Hine’s emerald is also affected by the negative effects of invasive species, such as garlic mustard (Alliaria petiolata), purple loosestrife (Lythrum salicaria) and glossy buckthorn (Frangula alnus) (3).
Hine’s emerald is included in the United States List of Endangered and Threatened Wildlife and Plants, which means any harmful treatment, harassment, collection or killing of individuals is illegal without a permit (4). Eight of the sites known to support wild populations of Hine’s emerald are also protected nature reserves (1).
Recommended conservation measures for Hine’s emerald include the maintenance of suitable habitat (1) (2), reducing the amount of off-road vehicle use and controlling invasive species (2). A public awareness campaign has also been suggested (1) (2) (4), which will involve contacting residents who live close to populations of Hine’s emerald and providing them with information about the species (4).
Further research is required n the population size, range and habitat of Hine’s emerald, as well as the threats to its future survival to implement suitable conservation measures and ensure the future survival of this rare dragonfly (3).
Find out more about Hine’s emerald:
U.S. Fish and Wildlife Service - Hine’s emerald:
Michigan Department of Natural Resources - Hine’s emerald:
Find out more about dragonfly and damselfly conservation:
Moore, N.W. (1997) Dragonflies: Status Survey and Conservation Action Plan. IUCN/SSC Odonata Specialist Group, IUCN, Gland, Switzerland and Cambridge, UK. Available at:
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- Calcareous: containing calcium carbonate, chalky.
- Endemic: a species or taxonomic group that is only found in one particular country or geographic area.
- Exoskeleton: an external skeleton that supports and protects an animal’s body.
- Fen: wetland with alkaline, neutral or only slightly acidic peaty soil. The alkalinity arises due to ground water seeping through calcareous rocks (rocks containing calcium carbonate).
- Fertilisation: the fusion of gametes (male and female reproductive cells) to produce an embryo, which grows into a new individual.
- Inbreeding depression: the reduction in viability, birth weight, and fertility that occurs in a population after one or more generations of inbreeding (interbreeding among close relatives).
- Invasive: describes species introduced deliberately or unintentionally outside their natural habitats where they have the ability to establish themselves, invade, outcompete natives and take over the new environments.
- Invertebrates: animals with no backbone, such as insects, crustaceans, worms, molluscs, spiders, cnidarians (jellyfish, corals, sea anemones) and echinoderms.
- Isopods: a diverse group of crustaceans, with flattened, segmented bodies, that includes pill bugs and woodlice.
- Larva: immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.
- Larval: of or relating to the immature stage in an animal’s lifecycle, after it hatches from an egg and before it changes into the adult form. Larvae are typically very different in appearance to adults; they are able to feed and move around but are usually unable to reproduce.
- Metamorphosis: an abrupt physical change from the larval to the adult form.
- Moult: in insects and other arthropods, a stage of growth whereby the hard outer layer of the body (the exoskeleton) is shed and the body becomes larger.
- Ovipositor: the egg-laying organ of a female insect, consisting of a tube-like structure at the end of the abdomen. In worker bees and non-reproductive female wasps, it is modified into a sting.
- Territory: an area occupied and defended by an animal, a pair of animals or a group.
IUCN Red List (January, 2014)
Michigan Department of Natural Resources - Hine's emerald (January, 2014)
Ministry of Natural Resources - Hine’s emerald (January, 2014)
U.S. Fish and Wildlife Service - Hine’s emerald (January, 2014)