|
|
(Coleoptera, Diptera, Hymenoptera and Lepidoptera)
by
Brian Pitkin, Willem Ellis, Colin Plant and Rob Edmunds
|
|
|
URTICA.
Nettles. [Urticaceae]
|
Six
species of Urtica are recorded in Britain. These include
the native Common Nettle (U. dioica) and Small Nettle (U.
urens). The BSBI provide a downloadable plant crib for the two subspecies of Urtica dioica.
Three British miners are recorded on Urtica.
The
agromyzids Melanagromyza
aenea and Phytomyza
flavicornis are recorded boring the stems of Urtica
in Britain and elsewhere.
Elsewhere
the tephritid Philophylla
caesio is recorded as a miner in the petioles of Urtica sp. by Ferrar
(1987), Beiger (1968)
and White (1988), although
there are unconfirmed records on Caprifoliaceae and Asteraceae, which seems an odd combination of hosts.
A key to the European miners recorded on Urtica is provided in Bladmineerders van Europa. |
Common
Nettle
Urtica dioica
|
Key for the identification of the known mines of British
insects (Diptera and non-Diptera) recorded on Urtica
|
1a > Leaf-miner: Larva
forming linear-blotch mine between two veins, not adjoining margin
of leaf, frass in distinct black strips or pellets (Spencer, 1972b: 37 (fig. 111), 39; Spencer,
1976: 100 (fig. 146)).
Full
depth mine with indistinct primary and secondary feeding lines.
Generally the mines lie in the centre of the leaf. The mine starts
as a narrow corridor, strongly, 'intestine-like', wound (unless
the mine lies near the leaf margin, in which case the first part
of the corridor follows the leaf margin). Further on the corridor
widens into an elongated blotch. Part of the frass in a long fine
thread. In comparision with the other two Agromyza's on Nettle
the mine is much clearer, less green-cloudy. Pupation outside the
mine.
The
mine starts away from the leaf edge usually and has a coiled intestine-like
start; it has frass in long threads in the broader part of the mine. |
|
|
Agromyza
anthracina puparium
Image: © Willem Ellis (Bladmineerders van Europa) |
On Urtica dioica in Britain. On Parietaria officinalis,
Urtica dioica, Urtica pilulifera, Urtica radicans and Urtica urens elsewhere. Widespread in Britain.
Also recorded in the Republic of Ireland. Widespread in continental Europe.
|
Agromyza
anthracina Meigen, 1830 [Diptera: Agromyzidae]. |
1b > Leaf-miner: Larva forming linear-blotch, adjoining or following the margin of
the leaf. |
2 |
2a > Leaf-miner: Larva
forming an irregular elongate linear blotch mine, normally adjoining
margin of leaf (Spencer, 1976:
137).
Forms a long blotch mine, which is usually adjacent to the edge of the leaf, which turns black.
Full
depth corridor, mostly beginning at the leaf margin, and never starting
with a closely set, intestine-like, number of curves. Further on
the corridor considerably widens, mostly keeping close to the leaf
margin. Often several larvae in a mine. Frass in lumps or short
rods, never in long threads. Pupation outside the mine.
Puparium reddish brown |
|
Agromyza pseudoreptans puparium
Image: © Willem Ellis (Bladmineerders van Europa) |
On Urtica dioica in Britain. On Urtica dioica and Urtica ilulifera elsewhere. Widespread and common in Britain. Also recorded in
the Republic of Ireland. Widespread in continental Europe.
|
Agromyza
pseudoreptans Nowakowski, 1964 [Diptera: Agromyzidae]. |
2b > Leaf-miner: Mine
generally follows the leaf margin, widening from the initial linear
section into an irregular broad blotch; it is dark green when fresh
but quickly turns blackish (Spencer, 1972b: 34 (fig. 90); Spencer,
1976: 138-9, fig. 246).
Full
depth corridor that mostly starts near the leaf margin, and never
begins with a series in close, intestine-like curves. Further on
the corridor strongly widens, and usually remains close to the leaf
margin. Often several larvae in a mine. Frass in lumps or short
rods, never in long threads.
Puparium reddish brown |
On Urtica dioica in Britain. On Urtica dioica, Cannabis,
Humulus, Mentzelia and Parietaria elsewhere. Widespread
in Britain and continental Europe. Also recorded in Canada.
|
Agromyza
reptans Fallén, 1823 [Diptera: Agromyzidae]. |
|