FAMILY PROTONEURIDAE

Last Updated on : Sunday, 04 June, 2017 01:59:44 PM
FAMILY PROTONEURIDAE


Protoneuridae includes some 240 species found throughout the world's tropics. In Borneo there are 18 species in two genera, Elattoneura and Prodasineura. All are small (S hw, 16-20 mm), of slender build, with narrow, hyaline, sometimes lightly tinted wings, rounded at the tip. Venation is reduced, with the anal vein entirely lacking or represented as a short anal bridge. The quadrilateral is long and rectangular.
The pterostigma is usually dark and never very long (at most about 1.5 times as long as broad), most commonly lozenge- or diamond-shaped. The male abdomen is of moderate length, about 1.5 times the length of the hind wing; the female abdomen is only a little shorter and more robust. Most species are marked in either red, orange or blue or are unmarked. The ground color is usually matt black, only occasionally with a bronzy sheen. Male anal appendages are robust and squat, typically about as long as the last abdominal segment. The upper pair usually have a strong ventral spine but this may be difficult to interpret when its inner margin is hidden behind the tenth segment. The short lower pair often terminate in a thin distal process curling inwards. Although male terminalia of the different species are similar in general form, slight differences can be very useful in diagnosis. Likewise the posterior lobe of the female prothorax varies considerably and can be a good character for separating close species.

Most protoneurids are found near slowly flowing water in swampy places, in sluggish streams or in backwaters of fast running rivers. They are almost confined to forested areas in the lowlands. Although they are often abundant, little is known of their biology. Females oviposit in root masses under banks, typically in tandem with the male erect in the 'sentinel' position, but sometimes alone. The larvae are short and stout with broad heads and proportionally long legs. The caudal lamellae are flattened, short, broad and rounded with the central gill shorter than the lateral ones. Mouthparts, including the mask and its arrangement of setae, are basically similar to those found in some Coenagrionidae and it may be difficult to separate larvae of these families. They are found in silty areas and among root masses.

Five species of Elattoneura are known from Borneo. E. analis (Plate 7d) is superficially like the common Prodasineura verticalis. The two species are sometimes found flying together, but they differ significantly in color and markings and have slightly different venation. In particular the male off. analis has a prominent orange spot at the tip of the abdomen which is lacking in P. verticalis, and the orange color is less intense. E. analis is sometimes quite common on backwaters of small clear streams in dipterocarp forest but it also occurs in alluvial and freshwater swamp forest, especially around Pamlcmus, where males are often found resting among the foliage. In immature the orange color is replaced by pale blue. Also locally common is E. aurantiaca (not illustrated). It is mainly golden yellow-orange with a broad metallic blue-green band on the dorsum of the synthorax. It looks superficially rather like the common coenagrionid Teinobasis rajah but it is more slightly built and has very different wing venation, notably the strong reduction of the anal vein. It is found locally in all types of swamp forest but is probably more common in the south. The three remaining species are seldom encountered and are more or less confined to swamp forest in the southern and western parts of the island. E. longispina is very similar to E. analis in its markings but the ventral spine on the superior anal appendage of the male is exceptionally long and thin . On average it is a little smaller than E. analis. E. coomansi is a very fine, mainly dark species from the west and E. erythromma is a small, fine insect with dark russet antehumeral bands from the south. In life, its eyes are red.
Of the many species of Prodasineura, one of the most widely encountered is the strongly orange-striped P. verticalis . Similar marking occurs in the female but is paler and somewhat reduced. It is found in a wide range of lowland forest but is most common on small to medium-sized streams in mixed dipterocarp forest. It often perches on riverside vegetation, including Pinanga and Pandanus, but when on the wing it can be extremely inconspicuous.

Females generally oviposit alone, typically in root masses in the riverbanks . Several other species have predominantly linear orange markings on the thorax including P. hosei and P. peramoena both recorded from peat swamp and dipterocarp forest streams in west and north-west Borneo.

INDEX OF DRAGONFLY



 

 

Genus Elattoneura Genus Prodasineura
 

Protoneuridae includes some 240 species found throughout the world's tropics. In Borneo there are 18 species in two genera, Elattoneura and Prodasineura.

All are small ( hw, 16-20 mm), of slender build, with narrow, hyaline, sometimes lightly tinted wings, rounded at the tip. Venation is reduced, with the anal vein entirely lacking or represented as a short anal bridge. The quadrilateral is long and rectangular.


Genus 1 :  Elattoneura

The 5 species of Genus Elattoneura in Borneo Island

Common Not Common (Endemic)
1 2 3 4 5
Elattoneura analis Elattoneura aurantiaca Elattoneura longispina Elattoneura coomansi Elattoneura erythromma
       

1) Elattoneura analis is superficially like the common Prodasineura verticalis. The two species are sometimes found flying together, but they differ significantly in color and markings and have slightly different venation. In particular the male of Elattoneura analis has a prominent orange spot at the tip of the abdomen which is lacking in Prodasineura verticalis, and the orange color is less intense. Elattoneura analis is sometimes quite common on backwaters of small clear streams in dipterocarp forest but it also occurs in alluvial and freshwater swamp forest. In immature the orange color is replaced by pale blue.

2) Elattoneura aurantiaca  is another common species. It is mainly golden yellow-orange with a broad metallic blue-green band on the dorsum of the synthorax. It looks superficially rather like the common coenagrionid Teinobasis rajah but it is more slightly built and has very different wing venation, notably the strong reduction of the anal vein. It is found locally in all types of swamp forest but is probably more common in the south.

3) Elattoneura longispina is very similar to Elattoneura analis in its markings but the ventral spine on the superior anal appendage of the male is exceptionally long and thin . On average it is a little smaller than Elattoneura analis.

4) Elattoneura coomansi is a very fine, mainly dark species from the west

5) Elattoneura erythromma is a small, fine insect with dark russet antehumeral bands from the south. In life, its eyes are red.


The pterostigma is usually dark and never very long (at most about 1.5 times as long as broad), most commonly lozenge- or diamond-shaped.

The male abdomen is 1.5 times the length of the hind wing; the female abdomen is only a little shorter and more robust.

Most species are marked in either red, orange or blue or are unmarked. The ground color is usually matt black, only occasionally with a bronzy sheen.

Male anal appendages are robust and squat, typically about as long as the last abdominal segment. The upper pair usually have a strong ventral spine but this may be difficult to interpret when its inner margin is hidden behind the tenth segment. The short lower pair often terminate in a thin distal process curling inwards. Although male terminalia of the different species are similar in general form, slight differences can be very useful in diagnosis. Likewise the posterior lobe of the female prothorax varies considerably and can be a good character for separating close species.

Most protoneurids are found near slowly flowing water in swampy places, in sluggish streams or in backwaters of fast running rivers. They are almost confined to forested areas in the lowlands. Although they are often abundant, little is known of their biology. Females oviposit in root masses under banks, typically in tandem with the male erect in the 'sentinel' position, but sometimes alone. The larvae are short and stout with broad heads and proportionally long legs. The caudal lamellae are flattened, short, broad and rounded with the central gill shorter than the lateral ones. Mouthparts, including the mask and its arrangement of setae, are basically similar to those found in some Coenagrionidae and it may be difficult to separate larvae of these families. They are found in silty areas and among root masses.


Genus 2 : Prodasineura


Prodasineura verticalis
Of the many species of Prodasineura, one of the most widely encountered is the strongly orange-striped Prodasineura verticalis . Similar marking occurs in the female but is paler and somewhat reduced. It is found in a wide range of lowland forest but is most common on small to medium-sized streams in mixed dipterocarp forest. It often perches on riverside vegetation, but when on the wing it can be extremely inconspicuous.

Females generally oviposit alone, typically in root masses in the riverbanks . Several other species have predominantly linear orange markings on the thorax including Prodasineura hosei and Prodasineura peramoena both recorded from peat swamp and dipterocarp forest streams in west and north-west Borneo.


 

Prodasineura dorsalis is a distinctive species recognized at once by the brilliant orange on the upper side of the male thorax. The female has quite reduced coloration as may be seen from the pair in tandem . It occurs in west and north-west Borneo and is locally common around rivulets in fresh-water swamp forest. In the east and south-east of the island is found the very similar species Prodasineura flammula in which the thorax is of a deeper colour.




Prodasineura hyperythra (Fig. 100) is a very finely built, inconspicuous species found in sluggish forest streams in the north, west and east of the island. It is local, but common where it occurs. Males are recognized by the fine red stripe running almost the length of the abdomen. Females are much darker. A very similar species which flies in the same habitat in west Borneo and Brunei is Prodasineura haematosoma, in which the seventh abdominal segment is black above (red in hyperythra) and the labrum is mostly black (white in hyperythra). It is generally much less common than Prodasineura hyperythra.
 



Prodasineura collaris is the most frequently encountered blue species. In the male, the antehumeral bands on the upper side of the synthorax are broad at the front. In the female they are reduced to a small spot. It is found throughout the lowlands in all types of forested swamp habitat, including peat swamp forest. The species is often abundant and is widely distributed elsewhere in south-east Asia.


Prodasineura interrupta  is found in sluggish streams and swamp forest in the west, south and south-east. The male is easily distinguished from Prodasineura collaris by the different shape of its blue antehumeral bands.


Other blue species, which all differ in the thoracic markings in the male, include Prodasineura abbreviate and Prodasineura quadristigma, both from the south-east and Prodasineura notostigma, from the west and north-west.



A final species, Prodasineura tenebricosa is found in swamp forest and on the banks of broad rivers in the south-west. It is a very dark, lightly built species, entirely unmarked above, paler beneath.

Most Prodasineura species are relatively easily observed and photographed. They commonly perch in sunlit patches in their forest habitats and generally occur at high densities. Nevertheless it is certain that extensive tracts of suitable habitat remain unexplored and new species are to be expected. Moreover in some species the degree of variation is not well understood, and more material is required to clarify the status of certain forms.


INDEX : Damselfly     June 12, 2017 01:02:06 PM