This page provides information about the dragonfly and damselfly species recently recorded in Hertfordshire. This includes locations, flight periods, key identification points (including potential confusion species) typical habitats and hints on where to find them.
Willow Emerald Damselfly Chalcolestes viridis
Hertfordshire status:
Likely to be found at any suitable habitat in the county. Potentially now the most widespread ‘emerald damselfly’ species in the county despite first being recorded in 2014.
Flight period:
Typically from mid-July until late October, but has the potential to be flying earlier or later (photographs or descriptions may be requested for verification of early or late records).
Identification and potential confusion species:
A large, but slim, damselfly that tends to perch with its wings half open. Metallic green on the upperside, pale below. Larger than Emerald Damselfly, both sexes have pale pterostigma on the wings even when mature and have a obvious spur of green extending forwards on the side of the thorax. Males have white appendages at the end of the abdomen.
Widespread species that confusion may occur with: Emerald Damselfly (particularly when recently emerged as the pterostigma may be pale), and potentially Banded Demoiselle.
Typical habitat and finding tips:
Found in any freshwater habitats where there are trees, or woody shrubs, overhanging the water.
Eggs are laid into overhanging shrubs and leave distinctive scars that can be looked for during the winter months. The adult damselflies can be unobtrusive and often perch fairly high up in overhanging trees – they can often be found by scanning bankside trees and shrubs carefully with binoculars.
2022 records
Scarce Emerald Damselfly Lestes dryas
Hertfordshire status:
Recently recorded from a few sites in south-east and central Hertfordshire after a long absence, but remains very scarce and only found in low numbers.
Photographs or detailed descriptions will usually be required for confirmation of records.
Flight period:
Typically from mid-June until late August.
Identification and potential confusion species:
A relatively large, and moderately robust, damselfly that tends to perch with its wings half open. Metallic green on the upperside, pale below. Extremely similar to Emerald Damselfly, Lestes sponsa, with very close examination required to confirm identification, particularly for females and immature males.
Widespread species that confusion may occur with: Emerald Damselfly – an extremely similar species, Willow Emerald Damselfly, and potentially Banded Demoiselle.
Typical habitat and finding tips:
Typically found breeding in shallow ponds and ditches with plenty of emergent vegetation, particularly sedges/rushes, including ponds that may completely dry out by late summer.
They often remain low in the emergent vegetation, but can be found by walking slowly along the banks and/or scanning vegetation close to the water’s edge with binoculars.
2022 records
Emerald Damselfly Lestes sponsa
Hertfordshire status:
A widespread breeding species which may be found anywhere in the county, but which seems to have a fairly patchy distribution. It may be overlooked at some sites.
Flight period:
Typically from mid-June until early September, but has the potential to be flying earlier or later (photographs or descriptions may be requested for verification of early or late records).
Identification and potential confusion species:
A relatively large, but slim, damselfly that tends to perch with its wings half open. Metallic green on the upperside, with a pale underside. Mature individuals have dark pterostigmas on the wings and males become pale blue on the sides of the thorax and at either end of the abdomen.
Widespread species that confusion may occur with: Willow Emerald Damselfly and Banded Demoiselle.
Typical habitat and finding tips:
Typically found breeding in shallow ponds and ditches with plenty of emergent vegetation, particularly sedges/rushes, including ponds that may completely dry out by late summer.
They often remain low in the emergent vegetation, but can be found by walking slowly along the banks and/or scanning vegetation close to the water’s edge with binoculars.
2022 Records
Banded Demoiselle Calopteryx splendens
Hertfordshire status:
A widespread breeding species that is likely to be found on any moderately sized, largely unshaded rivers, streams or canals in the county.
Flight period:
Mainly from mid-May until mid-September, but has the potential to be flying from late April and into early-September.
Identification and potential confusion species:
A large, robust damselfly with coloured wings that will typically be active and easily seen. Males have a large patch in the centre of each wing that appears black, females usually have a distinct green tinge to the whole wing. Almost the whole of the body on both sexes is a metallic green, or metallic blue, including the underside.
Widespread species that confusion may occur with: Potentially Willow Emerald Damselfly and Emerald Damselfly.
Typical habitat and finding tips:
Breeds mainly in flowing water, seemingly preferring a silty substrate, relatively little shading, and a moderate flow (in Hertfordshire they are often found in good numbers below weirs). Sometimes found at ponds, lakes and even well away from water.
Where present this species will usually be very obvious, perching openly on bankside vegetation in the sun, or actively flying over the open water.
2022 Records
Beautiful Demoiselle Calopteryx virgo
Hertfordshire status:
In recent years there have been reports of this potential colonist from a number of locations, but usually only involving a very small number of individuals. Due to the scarcity of the species in the county, and the likelihood of confusion with Banded Demoiselle, photographs or detailed descriptions will usually be required for verification.
Flight period:
Likely from mid-May until late August.
Identification and potential confusion species:
A large, robust species with coloured wings that will typically be active, but which can be unobtrusive in its preferred habitat. Males have almost completely dark wings, females have orange/brown toned wings – but care needs to be taken because the dark patches in the wings of Banded Demoiselles can sometimes look surprisingly extensive, and female Banded Demoiselles occasionally have somewhat brown toned wings.
Widespread species that confusion may occur with: Banded Demoiselle.
Typical habitat and finding tips:
Flowing water, with a preference towards smaller rivers and streams and more of a gravel substrate those preferred by Banded Demoiselle. They are also far more tolerant of shade and may be found along small, quite heavily shaded streams. Although they tend to perch openly along their chosen streams, they can be easily overlooked if they are in the shade.
2022 Records
White-legged Damselfly Platycnemis pennipes
Hertfordshire status:
A scarce species in the county, with a restricted distribution.
Photographs or descriptions may be required for confirmation of records away from known sites.
Flight period:
Typically from mid-May until mid/late August.
Identification and potential confusion species:
Easily identified if attention is paid to the pattern of dark markings on the abdomen and thorax, with narrow dark lines running along the length of the body. Widespread species that confusion may occur with: Azure Damselfly and Common Blue Damselfly are often mistakenly identified as this species because individuals of these species can sometimes have quite white legs.
Typical habitat and finding tips:
The preferred habitat is relatively slow flowing rivers and canals with extensive herbaceous vegetation along the banks, although they can sometimes be found breeding at still water sites. Best looked for by walking slowly along the banks and looking for them on the bankside vegetation.
2022 Records
Azure Damselfly Coenagrion puella
Hertfordshire status:
A very common and widespread species that is likely to be found breeding in most freshwater habitats across Hertfordshire.
Flight period:
Mainly from early May until late August, but a few may be flying earlier or later.
Identification and potential confusion species:
Very similar to the equally widespread Common Blue Damselfly, but separable with a close view and/or a bit of experience. Markings on the thorax, and either end of the dorsal side of the abdomen can be used to confirm the identification. Widespread species that confusion may occur with: Common Blue Damselfly and potentially Blue-tailed Damselfly.
Typical habitat and finding tips:
May be found in any freshwater habitats but particularly favours well vegetated smaller ponds. Will also breed in larger lakes/gravel pits, and streams and rivers, where they will tend to be found in the parts with the most extensive emergent vegetation. Usually found in, or close to, emergent vegetation near the water’s edge. May also be found away from water in long grass and along hedgerows.
2022 Records
Common Blue Damselfly Enallagma cyathigerum
Hertfordshire status:
A very common and widespread species that is likely to be found breeding in most freshwater habitats across Hertfordshire
Flight period:
Mainly starts to emerge from early-May and can be flying into October.
Identification and potential confusion species:
Very similar to the equally widespread Azure Damselfly, and separable with a good view of the markings on the thorax, and either end of the dorsal side of the abdomen. Widespread species that confusion may occur with: Azure Damselfly and potentially Blue-tailed Damselfly.
Typical habitat and finding tips:
May be found in any freshwater habitats, including smaller ponds, but typically occurs in the largest numbers on larger lakes and gravel pits where large swarms may be seen over open water on sunny days. May also be found on rivers/streams and away from water in long grass and along hedgerows.
2022 Records
Red-eyed Damselfly Erythromma najas
Hertfordshire status:
A relatively widespread species that might be found at any suitable habitat across the county but which can sometimes be easy to overlook.
Flight period:
From early May until mid-September.
Identification and potential confusion species:
Very similar to the Small Red-eyed Damselfly, which is now likely to be just as widespread. Males are best separated using the less extensive blue at both ends of the abdomen. Females of the two species are usually trickier to separate without experience. Widespread species that confusion may occur with: Small Red-eyed Damselfly and potentially Blue-tailed Damselfly.
Typical habitat and finding tips:
Typically found at larger ponds, lakes and gravel pits and on slow flowing canals and rivers, where there are lilies or other floating vegetation. Although they may be found in bankside vegetation they are best looked for by scanning with binoculars for males sitting on floating vegetation, or flying low over the surface of the water.
2022 Records
Small Red-eyed Damselfly Erythromma viridulum
Hertfordshire status:
Beginning to colonise at the time of the previous atlas survey, with the first Hertfordshire record in 2002. Now probably breeding at most suitable habitat across the county
Flight period:
Typically from mid-June until at mid-September, but has the potential to be flying earlier or later.
Identification and potential confusion species:
Males can be distinguished from the similar Red-eyed Damselfly by looking for the noticeably more extensive blue at both ends of the abdomen. Females require more experience to identify but tend to have complete antehumeral stripes. Widespread species that confusion may occur with: Red-eyed Damselfly and potentially Blue-tailed Damselfly.
Typical habitat and finding tips:
Mostly found at ponds, lakes and gravel pits and on slow flowing canals and rivers, where there is floating vegetation, perhaps favouring habitats with smaller leaved floating plants than Red-eyed Damselflies seem to prefer – although there is considerable overlap and both species are often found together. Males will often bend the end of their abdomen upwards when perched on floating vegetation, which is something that Red-eyed Damselflies don’t tend to do. Best looked for by scanning with binoculars to look for males sitting on floating vegetation, or flying low over the surface of the water, in the same way as for Red-eyed Damselflies.
2022 Records
Blue-tailed Damselfly Ischnura elegans
Hertfordshire status:
A common and widespread species, potentially the most widespread damselfly species in the county due to the variety of habitats they can breed in.
Flight period:
Mainly from early May until late September, but may be flying earlier or later.
Identification and potential confusion species:
A very variable species, particularly females which can show a variety of different colour forms. The dorsal side of the abdomen of most forms is dark with the only blue on the 8th abdomen segment – near the tip of the abdomen but not actually at the tip. The pterostigma on all forms is roughly diamond-shaped and is black & white. Widespread species that confusion may occur with: potentially Red-eyed Damselfly and Small Red-eyed Damselfly, and perhaps females of Azure Damselfly and Common Blue Damselfly. There is a small possibility of one colour form being mistaken for Large Red Damselfly.
Typical habitat and finding tips:
Blue-tailed Damselflies are able to breed in almost any freshwater habitat that isn’t completely shaded, and seemingly have a greater tolerance of some pollution than many other species. They do seem to prefer to remain in emergent vegetation, and will often stay fairly low down within this, so are best looked for by slowly walking along the banks and peering into emergent vegetation.
2022 Records
Scarce Blue-tailed Damselfly Ischnura pumilio
Hertfordshire status:
Until recently the only Hertfordshire record of this species was of a single male in 1948, but in late summer 2022 small numbers were found at a site near Hertford in circumstances that suggest probable breeding, and perhaps a new species beginning to colonise.
Due to the rarity of the species in the county, and the likelihood of confusion with Blue-tailed Damselfly, photographs or detailed descriptions will usually be required for verification.
Flight period:
Potentially mid-May to early September, but so far only recorded in Herts in August.
Identification and potential confusion species:
Mature males closely resemble [Common] Blue-tailed Damselflies, but the blue ‘tail’ is nearer the tip of the abdomen, covering the distal half of segment 8 and segement 9, rather than being confined to segment 8. Females are very plain when mature, lacking any obvious identification features but have a distinctive orange immature stage when they have recently emerged. They average slightly smaller than [Common] Blue-tailed Damselflies.
Typical habitat and finding tips:
The typical breeding habitat for Scarce Blue-tailed Damselflies is shallow pools and streams, often in boggy areas. They have sometimes been known to breed in flooded tyre tracks in old quarry sites, or other habitat that may only be temporary. Although they are capable of dispersing over large distances, they usually appear to be very weak fliers and, like their more widespread relative, [Common] Blue-tailed Damselfly, will typically remain low down in emergent vegetation, so are best looked for in the same way by slowly walking along the banks and peering into emergent vegetation.
2022 records:
Large Red Damselfly Pyrrhosoma nymphula
Hertfordshire status:
Widespread, relatively common, and likely to be present across the whole county.
Flight period:
The earliest flying species, mostly flying from early April until mid-July, but seems to fly later at some sites and may potentially be flying well into August (photographs or brief descriptions may be requested for verification of early or late records).
Identification and potential confusion species:
No other damselfly species that has been recorded in Hertfordshire is red, so most Large Red Damselflies should be easy to identify. There is a dark form of the female that needs some experience to identify, but this form is rare. Widespread species that confusion may occur with: There is a small potential for darker individuals of a pink/reddish form of Blue-tailed Damselfly to be misidentified as Large Red Damselflies, and later in the year it is possible that inexperienced observers may mistake Ruddy Darter, or Common Darter, dragonflies for Large Red Damselflies, as these can be far smaller than might be expected.
Typical habitat and finding tips:
This species is typically found in, and around, well vegetated ponds and ditches, and shallow edges of larger lakes, streams and rivers. They can tolerate relatively stagnant ponds, such as woodland ponds, and it is in the latter type of habitat where they seem to be most likely to be found flying later in the year.
2022 Records
Southern Migrant Hawker Aeshna affinis
Hertfordshire status:
Recorded on just a handful of occasions since 2018, but increasing in south-east England and likely to become more frequent in Hertfordshire.. Due to the scarcity of the species in the county, and the potential for confusion with Migrant Hawker, photographs or detailed descriptions will usually be required for verification.
Flight period: Most likely from late-June until late August.
Identification and potential confusion species:
With experience, identification of mature males is relatively straightforward if seen well but care is needed with the identification of all hawker species. The plain thorax sides and large spots on the abdomen are key features. This is one of the smaller hawker species, and one of the few species of ‘hawker type’ dragonfly that lays eggs while still in tandem. Widespread species that confusion may occur with: Southern Migrant Hawker is very similar to the far more common Migrant Hawker and there is also a potential for Southern Hawker, Emperor Dragonfly and Hairy Dragonfly to be misidentified as this species.
Typical habitat and finding tips:
For breeding habitat this species favours ponds and ditches that have a tendency to dry up, or largely dry up by late summer, and elsewhere in the UK are most commonly found breeding in habitat favoured by emerald damselfly species. Migrant individuals may turn up at sites that are not particularly well suited for breeding and there is a potential for them to be found away from water, for example, along hedgerows and woodland edges.This species remains in tandem while laying their eggs, like most damselfly species, but unlike most of the more regular hawker type dragonfly species in the UK. Any hawkers that appear to be remaining paired while the female is laying eggs are worth checking closely.
2022 Records
Southern Hawker Aeshna cyanea
Hertfordshire status:
A common species, widespread across the county. Although common, large numbers are not usually seen together.
Flight period:
Typically from mid-June until late October, but has the potential to be flying earlier and later (photographs or descriptions may be requested for verification of early or late records).
Identification and potential confusion species:
In the UK this species is the only one of the hawker type dragonflies to have a bar of colour on the last abdomen segments rather than separated spots. The broad antehumeral stripes on top of the thorax and the relatively plain thorax sides are additional features. Widespread species that confusion may occur with: In the spring and early summer confusion with Hairy Dragonfly and perhaps Emperor Dragonfly is possible, while later in the year Migrant Hawker needs to be considered.
Typical habitat and finding tips:
Although Southern Hawkers can be found breeding in a wide variety of habitats, they seem to show a preference for ponds and are tolerant of a fair amount of shading. They are frequently found breeding in small woodland ponds and garden ponds, and often feed by flying up and down woodland rides at a very low height.
2022 Records
Brown Hawker Aeshna grandis
Hertfordshire status:
Widespread in Hertfordshire with the potential to be recorded anywhere in the county.
Flight period:
Typically from mid-June until late September, but has the potential to be flying earlier and later (photographs or descriptions may be requested for verification of early or late records).
Identification and potential confusion species:
This is the largest of the two largely brown hawkers found in the UK and is by far the most widespread of the two in Hertfordshire. Brown Hawkers usually have very obviously amber-tinged wings which can be very noticeable in flight. Widespread species that confusion may occur with: Brown females of other hawker species may be mistaken, especially older individuals that may have some colour in the wings, for this species but are smaller and have more clearly patterned abdomens. The most likely confusion species is the much scarcer Norfolk Hawker, a smaller, more orangey-brown hawker which has noticeable green eyes when mature.
Typical habitat and finding tips:
Most larger water bodies, including gravel pits, rivers and canals, are likely to have Brown Hawkers present and they will also breed in smaller ponds. They are easily seen when patrolling territories, or when feeding over meadows and along hedgerows. Females can often be found ovipositing around the edges of water bodies and seem to show a preference for ovipositing into dead wood.
2022 Records
Norfolk Hawker Aeshna isoceles
Hertfordshire status:
First recorded in the county in 2015, now fairly well established in the Lea Valley south of Hertford and starting to spread further. Photographs or descriptions will usually be requested for verification of records from new sites.
Flight period:
Mostly from mid-June until late August.
Identification and potential confusion species:
A fairly small hawker that is predominately orangey-brown with few markings. When mature the eyes are a noticeable green colour. Widespread species that confusion may occur with: Brown Hawkers are a similar plain brown colour but tend to be darker and less ‘orangey’. They also usually have a noticeable amber suffusion in the wings and, with experience, can be seen to be much larger. Females of other hawker species may also appear plain brown in some circumstances.
Typical habitat and finding tips:
Existing records in Hertfordshire have come from gravel pits, rivers and ditches with plenty of emergent vegetation, almost always sites where a good variety of other species have been recorded. If present at a site, males will usually be obvious, patrolling short sections of the bank and frequently stopping to hover. Ovipositing females will tend to be less obvious, but records of egg laying are particularly welcome for this species – especially if the plant being oviposited into can be identified.
2022 Records
Migrant Hawker Aeshna mixta
Hertfordshire status:
This is probably by far the most abundant hawker species in the county and can potentially be seen in large numbers anywhere in Hertfordshire at the peak of their flight season.
Flight period:
Mid-July until late October, but has the potential to be flying well into November.
Identification and potential confusion species:
A relatively small hawker with mature males showing a blue-spotted abdomen and obvious yellow and black stripes on the side of the thorax. Females, and immature males, lack the bright colours but still have an obvious dark stripe across the side of the thorax. Widespread species that confusion may occur with: Confusion is most likely with Southern Hawker, the only other hawker species that is widespread in the county and flying at the same time. Females may be confused with other hawker species but the pattern on the side of the thorax should be diagnostic.
Typical habitat and finding tips:
Migrant Hawkers will breed in practically any freshwater habitats and are easily seen both when at water and when feeding over meadows, along hedgerows and in woodland clearings. It is not unusual to find large numbers together, especially when feeding.
2022 Records
Emperor Dragonfly Anax imperator
Hertfordshire status:
A widespread species found at sites across the whole of Hertfordshire.
Flight period:
From late-May until August, occasionally later (photographs or descriptions may be requested for verification of early or late records).
Identification and potential confusion species:
The largest dragonfly in Hertfordshire. Males have a plain green thorax and a largely blue abdomen with black stripes along it’s length. Females have a plain green thorax and are usually green on the abdomen but may be blue or brownish. Widespread species that confusion may occur with: Confusion is most likely with Southern Hawker which has a largely green thorax and a lot of blue/green on the abdomen, and is also possible with other hawker species and Lesser Emperor. Look carefully at the patterns.
Typical habitat and finding tips:
May be found in any freshwater habitats, seemingly preferring those that have areas of open water, with males patrolling at least a metre above the water, but will breed in some fairly small garden ponds and also sometimes habitat covered with floating/emergent vegetation. Can also be found feeding over meadows and along woodland edge.
2022 Records
Lesser Emperor Anax parthenope
Hertfordshire status:
First recorded in Hertfordshire in July 2006, this species might now be maintaining a small breeding population at Hilfield Park Reservoir but this is yet to be proven. Records elsewhere in the county remain rare, but are becoming increasingly frequent. Due to the scarcity of the species in the county, and the potential for confusion with Emperor Dragonfly, photographs or detailed descriptions will usually be required for verification.
Flight period:
Typically from mid-June until early September.
Identification and potential confusion species:
A fairly large dragonfly that is typically relatively dull in colour with a brown thorax and abdomen and green eyes. Males have a bright blue ‘saddle’ at the base of the abdomen. Care needs to be taken to rule out Emperor Dragonflies, especially females, which may become duller with age and can sometimes show limited blue at the base of the abdomen. From late July some hawker species, particularly Migrant Hawker might potentially be mistaken for Lesser Emperor.
Typical habitat and finding tips:
This is a species that is becoming increasingly regular in the UK and which may be found at any freshwater habitat, particularly those with extensive emergent vegetation. Males will patrol a few metres from the bank and typically a metre or two above the water. Like Southern Migrant Hawker, Lesser Emperors remain in tandem while laying their eggs, while female Emperor Dragonflies always oviposit alone.
2022 Records
Hairy Dragonfly Brachytron pratense
Hertfordshire status:
At the time of the 2000-2006 survey Hairy Dragonflies had a relatively restricted distribution in the county, predominantly being found in the south-east part of the county around the Lee Valley Regional Park. In recent years there have been a few records from new sites so there seems to have been some expansion. As an early flying and fairly unobtrusive species they may be overlooked.
Flight period:
Mainly early May to late June, potentially late April to early July if conditions are suitable
Identification and potential confusion species:
A relatively small blue/green spotted hawker with obvious pale antehumeral stripes on top of the thorax. Male tends to stay low to the water and ‘patrol’ in and out of the vegetation at the water’s edge. Few other ‘hawker type’ dragonflies are flying during the spring, so the most likely confusion species is Southern Hawker which can overlap the later part of the Hairy Dragonflies flight period. Southern Hawkers tend to be larger, brighter, and behave differently.
Typical habitat and finding tips:
This is a species with a preference for clean water bodies with extensive emergent vegetation at the edges. Look for them in May and early June when males will be actively patrolling the emergent vegetation at the edge of streams, canals and lakes/gravel pits. Egg laying females can easily be overlooked among vegetation, but can sometimes give their presence away by the rustling sound their wings make.
2022 Records
Downy Emerald Cordulia aenea
Hertfordshire status:
The current status of Downy Emerald in Hertfordshire is uncertain. They have been a handful of records in recent years which may refer only to individuals wandering from elsewhere, but there is a slight possibility that they may be breeding in low numbers at Tyttenhanger Gravel Pits, or somewhere nearby. Photographs or descriptions will may be required for confirmation of records.
Flight period:
Mid-May to July, with some potentially continuing to fly into August.
Identification and potential confusion species:
A fairly small dragonfly which is mostly metallic green all over when recently emerged but which can become increasing ‘bronze’ as they age. Males will hover at the edge of lakes and ponds, often those with some shaded margins, and have a characteristic way of holding their abdomens angled 30° upwards while in flight. There are no other species that have been recorded in the county that are likely to be confused with Downy Emerald if seen well, but it is possible that Brilliant Emerald might reach the county in the future.
Typical habitat and finding tips:
In south-east England the typical habitat for the species is small to moderate sized ponds that are at least partially surrounded by deciduous woodland. The species is found at very few sites in counties around Hertfordshire.
2022 Records
Broad-bodied Chaser Libellula depressa
Hertfordshire status:
A widespread breeding species that is often one of the first to colonise garden ponds. The most common chaser species in the county.
Flight period:
Mainly mid-May to early August.
Identification and potential confusion species:
The broad abdomen that gives this species it’s English name is a distinctive feature of both sexes but other Libellula species also have fairly broad abdomens so confusion is possible with both Four-spotted Chaser and Scarce Chaser. A key feature of Broad-bodied Chaser that is not shared with the other two species is the broad pale ‘antehumeral stripes’ on top of the thorax, while the black patches at the base of all four wings are also particularly prominent in this species. Mature males have pale blue abdomens, while females and immature males are brown or yellowish. There may be prominent yellow spots on the side of the abdomen.
Typical habitat and finding tips:
Broad-bodied Chasers favour ponds with emergent vegetation, but can also be found at larger bodies of standing water, especially those with shallow margins and may also be found along slower flowing streams. Males tend to be easy to see when they are present as they select prominent perches at the edge of a pond and will fly circuits around the pond from these perches. Away from water they may be found in sheltered, sunny spots along hedgerows and similar.
2022 Records
Scarce Chaser Libellula fulva
Hertfordshire status:
Scarce but apparently increasing. Successful breeding has not yet been confirmed in the county but seems certain to be taking place in the Lea Valley and on the Grand Union Canal near Wilstone. Occasional reports from other sites are becoming more frequent, and they have the potential to colonise new sites in the near future. Photographs or descriptions may be required for confirmation of records.
Flight period:
Mainly May to July but some could potentially fly into early August.
Identification and potential confusion species:
This is the least likely of the chaser species to be encountered in Hertfordshire. When recently emerged, both sexes are a distinctive orange colour with a line of black triangles down the centre of the abdomen. Mature males have a pale blue abdomen with a black tip, mature females become dull brown or greyish. Like other chasers they have black at the base of the wings, but this is much reduced in comparison to other species. Males could be confused with Broad-bodied Chaser, but lack pale stripes on the thorax and have much less black at the wing bases. They can also be confused with the slimmer bodied Black-tailed Skimmer, from which they can be separated by the black wing bases and bluish (not greenish) eyes. Mature females might be confused for Four-spotted Chasers.
Typical habitat and finding tips:
This is typically thought of as a species of well vegetated, slow flowing rivers, but can sometimes be found at mature gravel pits and similar. In Hertfordshire they are probably most likely to become established along stretches of river or canal with extensive emergent vegetation, but lakes, gravel pits and large ditches with reeds and other vegetation are also worth searching.
2022 Records
Four-spotted Chaser Libellula quadrimaculata
Hertfordshire status:
A widespread breeding species, that seems to be relatively sparsely distributed – although they can be fairly numerous at sites where they do occur.
Flight period:
Mainly May to early August.
Identification and potential confusion species:
A relatively small, but ‘chunky’, brown dragonfly. single spots halfway along the front edge of each of the four wings give the species its name – no other dragonfly in the UK has black spots on the wings here. There are also large black patches at the wing bases. If the wing pattern can be seen this is diagnostic, but there may be a potential for confusion with females/immature males of the other chasers, particularly the widespread Broad-bodied Chaser, although this later species has noticeable pale stripes on top of the thorax and a noticeably broader, less wedge-shaped, abdomen.
Typical habitat and finding tips:
A species that is most frequently found at shallow ponds, particularly shallow ponds with plenty of reeds, rushes, sedges or other emergent vegetation around the edges, and often including heathland ponds.Like the other chasers, they readily use prominent perches at the water’s edge from which males will fly circuits over a pond, but unlike the other two species Four-spotted Chasers will regularly hover on the spot.
2022 Records
Black-tailed Skimmer Orthetrum cancellatum
Hertfordshire status:
A widespread breeding species but usually most common where there are large reservoirs, lakes and gravel pits.
Flight period:
Typically late May to August but may be flying later.
Identification and potential confusion species:
Females and immature males are initially bright yellow with two wavy black lines running down the abdomen. Mature males have a largely pale blue abdomen which is extensively black at the tail end, a plain dark thorax and greenish eyes. Both sexes have completely clear wing bases. Perching on the ground is very common and is something that isn’t seen in chaser species.
Potential confusion with Broad-bodied Chaser can be ruled out by the larger area of black at the end of the abdomen, the lack of pale stripes on the thorax and the lack of black at the base of the wings. Males of the more unusual Scarce Chaser are sometimes misidentified as Black-tailed Skimmer because of the similar abdomen colours, but are fatter bodied and have small black patches at the base of the hind wings – a key feature to look for is the eye colour, which is bluish. Females can potentially be confused with female darters but are larger and the thicker black lines on the abdomen are usually noticeable.
Typical habitat and finding tips:
Although they are occasionally found at smaller ponds, Black-tailed Skimmers show a preference for larger lakes and gravel pits, particularly those with areas of bare ground at the edges. They have a tendency to perch on the ground, rather than bank side vegetation, and will frequently fly well out from the banks, skimming low over the water surface.
2022 Records
Red-veined Darter Sympetrum fonscolombii
Hertfordshire status:
Usually a very scarce species, but occasionally reaches the county in increased numbers during influxes into the UK. Potentially breeds in at least some years. Due to the scarcity of the species in the county, and the potential for confusion with other darter species, photographs or descriptions will usually be required for verification.
Flight period:
Mainly May to July but can potentially be seen until October.
Identification and potential confusion species:
A small species. Yellow when immature with males turning deep red when mature and females usually becoming pale brown. Important features to look for are the blue undersides to the eyes and the thick bordered, pale centred pterostigmas on the wings.
Common Darter and Ruddy Darter are both more common and widespread in the county and are potential confusion species and can have red veins in the wings.
Typical habitat and finding tips:
Most Hertfordshire records have come from reservoirs and large gravel pits, but they could potentially turn up at any pond or lake. Care needs to be taken to eliminate the more common species of darter, but any particularly deep red darter is worth checking carefully – especially in May or early June as mature migrants may be seen earlier than locally emerged Common & Ruddy Darters
2022 Records
Ruddy Darter Sympetrum sanguineum
Hertfordshire status:
A widely but relatively sparsely distributed breeding species in the county that can be fairly common at some sites.
Flight period:
Mostly mid-June to early September. A few may remain on the wing into October.
Identification and potential confusion species:
Like the other darters that are regular in the county, this is a small species that is yellow when immature and red or brown when mature. Mature males are deeper red than Common Darters and the abdomen appears ‘pinched’ in the middle when viewed from above. A key identification feature is the all black legs (Common Darters have yellow stripes running down the legs).
Particular care needs to be taken with identification from late August onwards as Common Darters become redder, and their legs and thorax sides darken as they age.
Typical habitat and finding tips:
Ruddy Darters have a preference for smaller, shallow ponds and will even breed in ponds that dry out in late summer. They will also breed in larger lakes and rivers if they have shallow, well vegetated margins. Darters are usually obvious at ponds with fairly limited bankside vegetation, but can easily be overlooked if present in small numbers at larger ponds or lakes with extensive tall plants around the banks.
2022 Records
Common Darter Sympetrum striolatum
Hertfordshire status:
Very common and widespread, breeding in a variety of habitats including garden ponds.
Flight period:
Mainly mid-June until mid-October but some can continue flying much later, potentially until the beginning of December.
Identification and potential confusion species:
Recently matured males are an orangey-red colour with two obvious yellow stripes on the sides of the thorax. Immature males, and females, are mainly yellow, with females becoming brown and then sometimes red, as they age. The legs have yellow stripes running down their length, but can darken to almost black in older individuals.
The majority of darters seen in Hertfordshire will be this species, but there is the potential of confusion with Ruddy Darter and Red-veined Darter.
Typical habitat and finding tips:
Preferred breeding habitat is ponds and smaller lakes, but they are regularly found breeding in a variety of other habitats including rivers and reservoirs. They will happily perch on the ground as well as on vegetation, and may occasionally be found well away from water. Later in the year they tend to seek out pale stones or pale bark to perch on as this helps them to warm up by reflecting sunlight back on to them.
2022 Records
VAGRANT SPECIES
The species covered here have been recorded at least once in Hertfordshire but they are considered very unlikely to currently have any presence in the county other than as occasional wanderers from outside of the county.
Photographs or detailed descriptions will be required for verification of records of all the species listed below (and for any species that have not previously been recorded in Hertfordshire).
Southern Emerald Damselfly Lestes barbarus
Hertfordshire status:
One record, a female found in the observer’s St Albans garden on 21st July 2021
Flight period:
May be flying between mid-June and September in the UK.
Identification and potential confusion species:
A large ‘emerald damselfly’ which, like other emerald damselflies, habitually perches with the wings half spread. The metallic green is slightly more restricted than on other emerald damselfly species, and the pterostigmas on the wings are noticeably bicoloured.
Typical habitat and finding tips:
Like other emerald damselflies, the breeding habitat will tend to be ponds that have a tendency to dry up during the summer, and may be found in areas of rushes or long grass, even in dry areas.
Variable Damselfly Coenagrion pulchellum
Hertfordshire status:
There have been three verified records, in 1969, 1996 and 2020.
Flight period:
Mainly from May to August in England
Identification and potential confusion species:
Very similar to Azure Damselfly which is very widespread and common in Hertfordshire. With experience, males can be identified by looking at features such as the antehumeral stripes and the pattern on the dorsal side of the second abdomen segment, but care needs to be taken because some Azure Damselflies can show patterns similar to Variable Damselflies. Both males and females can be confirmed by looking at the shape of the pronotum at the front end of the thorax, a feature that can be seen in good photos taken from above.
Typical habitat and finding tips:
This is a species that favours ditches and ponds with clean water and extensive emergent vegetation. They are often found around grazing marshes and similar areas in south-east England. Check all Azure/Common Blue Damselflies carefully for a chance to find a Variable Damselfly – but don’t expect to get lucky in Hertfordshire!
Common Hawker Aeshna juncea
Hertfordshire status:
A handful of historic records with the most recent record that is considered to have sufficient detail to be considered verified coming from Bramsfield Forest on 7th September 1971. The majority of other records were considered to have insufficient detail when assessed in 1981, but it is possible that Common Hawkers once bred at some sites in the county.
Flight period:
Mainly late June to September in the UK.
Identification and potential confusion species:
Common Hawkers could potentially be confused with any of the other spotted Aeshna species, particularly with Migrant Hawker. If you suspect that you have found a Common Hawker in Hertfordshire, try and get photos that clearly shown the top of the thorax and the first abdomen segments.
Typical habitat and finding tips:
In south-east England, Common Hawkers tend to be restricted mainly to heathland sites, although they can also be found in other habitats such as pools in sand dunes.
Vagrant Emperor Anax ephippiger
Hertfordshire status:
One record, from Hilfield Park Reservoir on 6th October 2013
Flight period:
An African species that periodically reaches Europe. Most records tend to be in the spring or autumn, but they can reach the UK at any time of year, including mid-winter if there are suitable winds.
Identification and potential confusion species:
The most similar species likely to be seen in Hertfordshire is Lesser Emperor. Vagrant Emperor tends to be browner overall, with brown rather than green upper sides to the eyes and a smaller blue ‘saddle’ on males.
Typical habitat and finding tips:
Although records in the UK most commonly come from sites near the coasts, this species could potentially turn up anywhere. Influxes usually come during prolonged spells of southerly winds coming up from Africa, and any future records in Hertfordshire are likely to be associated with records elsewhere in the UK at around the same time.
Keeled Skimmer Orthetrum coerulescens
Hertfordshire status:
There are two verified records, from 2003 and 2018.
Flight period:
Mainly June to August in the UK.
Identification and potential confusion species:
Similar to Black-tailed Skimmer but slimmer. Males lack the black ‘tail’; both sexes have pale antehumeral stripes on top of the thorax. Females and immature males could potentially be confused with female/immature darters when immature.
Typical habitat and finding tips:
Mainly found on heathland sites in south-east England, breeding in bog pools and seepages. Most likely to be found on heathland type sites if the species reaches Hertfordshire, but a population has recently been found breeding in a quarry in Bedfordshire.
Black Darter Sympetrum danae
Hertfordshire status:
An occasional visitor that has seemingly become much rarer in recent years.
Single males at Symonshyde Great Wood on 31st August 2009 and 16th September 2021 are the only records since 2006.
Flight period:
Late June to October in southern England.
Identification and potential confusion species:
Mature males should be distinctive as no other small British dragonfly species will usually be largely black. Females and immature males can easily be confused with female/immature Ruddy Darters or Common Darters, and are best distinguished by looking for the black triangle marking on top of the thorax.
Typical habitat and finding tips:
Mostly found breeding on heathland in south-east England, but they occur in a wider variety of freshwater habitats in continental Europe. Remnant heathland in Hertfordshire probably gives the best chance of finding the species, but they could potentially turn up elsewhere, especially if there are influxes of other darter species from the continent.
Yellow-Winged Darter Sympetrum flaveolum
Hertfordshire status:
A rare visitor, with almost all records during a large influx into the UK in 1995.
Flight period:
Most likely to reach the UK between late July and early September.
Identification and potential confusion species:
The yellow patches in the wings will typically be the first clue, but should not be the only feature used for identification. There is a potential for confusion with any other darter species, particularly Ruddy Darter and Red-veined Darter which can both sometimes show fairly extensive yellow in the wings – check the facial pattern, leg colour and abdomen pattern.
Typical habitat and finding tips:
Could potentially be found in any freshwater habitat, but there have been virtually no records in the UK in recent years and the species has declined in western Europe.
Vagrant Darter Sympetrum vulgatum
Hertfordshire status:
Two records in 1995 during a large influx of Yellow-winged Darters.
Flight period:
Most likely to reach the UK between late July and early September.
Identification and potential confusion species:
There is a potential for confusion with any other darter species, particularly Common Darter, but potentially also Ruddy Darter. Suspected Vagrant Darter can be confirmed by looking at the pattern on the face and thorax, abdomen colour and shape, and the vulvar scale on females.
Typical habitat and finding tips:
Could potentially be found in any freshwater habitat, but there have been virtually no records in the UK in recent years and the species has declined in western Europe.