Male antenna weakly serrate in apical half; Labial palp long, S3 half length of S2, S2 densely clad, S3 more sparsely clad in appressed scales;
Forewing lanceolate, apex acute, fully veined; V7&8 arise from V6; Hindwing trapezoidal, dorsum straight, tornus bluntly angled, termen slightly sinuate, apex strongly produced, fully veined, cilia 1-1.5x width of wing
Male genitalia: uncus reduced, gnathos absent, valva beaked, sacculus flap-like, aedeagus stout, with cornuti
Female genitalia: ovipositor extensile, ostium ill-defined, bursa copulatrix membranous, without signum
Forewing lanceolate, apex acute, fully veined; V7&8 arise from V6; Hindwing trapezoidal, dorsum straight, tornus bluntly angled, termen slightly sinuate, apex strongly produced, fully veined, cilia 1-1.5x width of wing
Male genitalia: uncus reduced, gnathos absent, valva beaked, sacculus flap-like, aedeagus stout, with cornuti
Female genitalia: ovipositor extensile, ostium ill-defined, bursa copulatrix membranous, without signum
Identification of species
M.littorella has a greyish-white forewing with fairly prominent stigmata and is confined to the south coast of the Isle of Wight.
The other 5 species have an orange-brown forewing (fading to yellow-brown with wear) with brownish streaks.
M.lappella/metzneriella have forewing stigmata, often not particularly prominent and require genital dissection to distinguish
M.aprilella/neuropterella/aestivella all lack forewing stigmata and require genital dissection to distinguish; though M.aprilella may be suspected by having a more reddish than orange colouration to the forewing when fresh..
MBGBI4.2 uses a lack of thickening of S3 of the labial palp to identify M.aestivella, but I am not persuaded that this is a feature shown by M.aestivella and have certainly not found it to be a useable marker for this species.
M.littorella has a greyish-white forewing with fairly prominent stigmata and is confined to the south coast of the Isle of Wight.
The other 5 species have an orange-brown forewing (fading to yellow-brown with wear) with brownish streaks.
M.lappella/metzneriella have forewing stigmata, often not particularly prominent and require genital dissection to distinguish
M.aprilella/neuropterella/aestivella all lack forewing stigmata and require genital dissection to distinguish; though M.aprilella may be suspected by having a more reddish than orange colouration to the forewing when fresh..
MBGBI4.2 uses a lack of thickening of S3 of the labial palp to identify M.aestivella, but I am not persuaded that this is a feature shown by M.aestivella and have certainly not found it to be a useable marker for this species.
Male genitalia: All 6 species are illustrated in MBGBI4.2; and all are shown at Moth Dissection.
The genus can be segregated into two groups of three species on features of the aedeagus. M.lappella/metzneriella/aprilella have discrete large cornuti. On the evidence available to me so far these consistently appear to number 4 in the intact aedagus of M.lappella (but on extraction of the vesica I have found an additional 3 weak cornuti), may be 2 or 3 in M.metzneriella and 2 to 4 in M.aprilella. These three species can be distinguished on the shape of the sacculus which is angular in M.metzneriella, broadly rounded in M.lappella (about as long as broad) and narrowly rounded in M.aprilella (about twice as long as broad). M.aestivella/neuropterella/littorella have a bundle of numerous small cornuti. (There are probably distinct differences in the exact form of these cornutal bundles and in the shape of the aedeagus, but I have insufficient evidence for this so far). The genitalia of these species may be best distinguished on features of the valva. As in all Metzneria the valva gradually expands from base to apex and is produced into a more or less obvious 'beak' at the ventral/anterior edge of the apex. In M.neuropterella the beak is quite pronounced so that the ventral edge of the valva curves to bring the apex to almost 90 degrees from the base; in M.aestivella the beak is small and the ventral edge of the valva is almost straight; in M.littorella the valva expands more rapidly at the base so that the bulk of the valva is more oblong, the beak is a small hook and there is a small hump near the base of the dorsal margin of the valva.
The genus can be segregated into two groups of three species on features of the aedeagus. M.lappella/metzneriella/aprilella have discrete large cornuti. On the evidence available to me so far these consistently appear to number 4 in the intact aedagus of M.lappella (but on extraction of the vesica I have found an additional 3 weak cornuti), may be 2 or 3 in M.metzneriella and 2 to 4 in M.aprilella. These three species can be distinguished on the shape of the sacculus which is angular in M.metzneriella, broadly rounded in M.lappella (about as long as broad) and narrowly rounded in M.aprilella (about twice as long as broad). M.aestivella/neuropterella/littorella have a bundle of numerous small cornuti. (There are probably distinct differences in the exact form of these cornutal bundles and in the shape of the aedeagus, but I have insufficient evidence for this so far). The genitalia of these species may be best distinguished on features of the valva. As in all Metzneria the valva gradually expands from base to apex and is produced into a more or less obvious 'beak' at the ventral/anterior edge of the apex. In M.neuropterella the beak is quite pronounced so that the ventral edge of the valva curves to bring the apex to almost 90 degrees from the base; in M.aestivella the beak is small and the ventral edge of the valva is almost straight; in M.littorella the valva expands more rapidly at the base so that the bulk of the valva is more oblong, the beak is a small hook and there is a small hump near the base of the dorsal margin of the valva.
Key to male Metzneria |
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Forewing greyish-white |
M.littorella |
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Forewing with stigmata |
Sacculus broadly rounded at apex |
M.lappella |
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Sacculus angulate at apex |
M.metzneriella |
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Forewing without stigmata |
Aedeagus with discrete large cornuti |
Valva and sacculus narrow |
M.aprilella |
Aedeagus with a bundle of many small cornuti |
Valva with a curved ventral margin and a pronounced beak |
M.neuropterella |
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Valva with a straight ventral margin and a small beak |
M.aestivella |
|
Metzneria neuropterella
Aedeagus with a bundle of many small cornuti; valva with a pronounced beak and ventral margin curved to bring apex to ~ 90° from base; sacculus about as long as wide and rounded at apex. (No material) |
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Metzneria aestivella
Aedeagus with a bundle of many small cornuti; valva with a small beak and almost straight ventral margin; sacculus longer than wide and rounded at apex. |
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Metzneria lappella
Aedeagus with discrete (relatively) large cornuti; valva with a small beak; sacculus about as long as wide and rounded at apex |
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Metzneria littorella
Aedeagus with a bundle of many small cornuti; valva oblong with a small beak; sacculus slightly longer than wide and rounded at apex. |
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Metzneria metzneriella
Aedeagus with discrete (relatively) large cornuti; valva with a small beak; sacculus about as long as wide and angular at apex |
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Metzneria aprilella
Aedeagus with discrete (relatively) large cornuti; valva narrow, with a small beak; sacculus narrow about twice as long as wide and narrowly rounded at apex. (No material) |
Female genitalia: All 6 species are illustrated in MBGBI4.2; and all are shown at Moth Dissection.
The key below is largely based on the illustrations in MBGBI4.2 (Fig 21): 1) The "Apophysis ratio" takes the length of the anal papillae as 1 and gives the lengths of the posterior and anterior apophyses respectively relative to this (for example: in M.lappella the posterior apophysis is 1.8x the length of the anal papillae and the anterior apophysis is 1.6x the length of the anal papillae). 2) "JS" = "Junctional sclerotisation" and refers to the shape of a sclerotisation at the junction of the introitus vaginae and the ductus bursae. 3) "S8" refers to the shape of the sclerotised ventral plate of abdominal segment 8 - (but note that the shape of this plate may vary with degree of compression of the specimen). I use the terms "transverse" = wider than long, "quadrate" = about as wide as long, "elongate" = longer than wide.
To date I have experience of only M.lappella and M.metzneriella so the key devised below should be regarded as provisional. It seems to work for the two species mentioned and is consistent with the images at Moth Dissection for these two species; however, the apophysis ratio of M.aestivella derived from the drawings in MBGBI4.2 is significantly different from that demonstrated in the image labelled as this species at Moth Dissection.
The key below is largely based on the illustrations in MBGBI4.2 (Fig 21): 1) The "Apophysis ratio" takes the length of the anal papillae as 1 and gives the lengths of the posterior and anterior apophyses respectively relative to this (for example: in M.lappella the posterior apophysis is 1.8x the length of the anal papillae and the anterior apophysis is 1.6x the length of the anal papillae). 2) "JS" = "Junctional sclerotisation" and refers to the shape of a sclerotisation at the junction of the introitus vaginae and the ductus bursae. 3) "S8" refers to the shape of the sclerotised ventral plate of abdominal segment 8 - (but note that the shape of this plate may vary with degree of compression of the specimen). I use the terms "transverse" = wider than long, "quadrate" = about as wide as long, "elongate" = longer than wide.
To date I have experience of only M.lappella and M.metzneriella so the key devised below should be regarded as provisional. It seems to work for the two species mentioned and is consistent with the images at Moth Dissection for these two species; however, the apophysis ratio of M.aestivella derived from the drawings in MBGBI4.2 is significantly different from that demonstrated in the image labelled as this species at Moth Dissection.
Key to female Metzneria |
Apophysis ratio |
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Forewing greyish-white |
3.2 : 2.5 |
M.littorella |
|
Forewing with stigmata |
1.8 : 1.6 |
JS & S8 distinctly transverse |
M.lappella |
2.5 : 2.0 |
JS & S8 ~ quadrate |
M.metzneriella |
|
Forewing without stigmata |
2.2 : 2.0 |
JS quadrate, S8 transverse |
M.aprilella |
2.9 : 2.4 |
JS quadrate, S8 elongate |
M.neuropterella |
|
2.4 : 2.0 |
JS indistinct, S8 transverse |
M.aestivella |
Metzneria lappella
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Metzneria metzneriella
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