Lycidae - Net winged beetles

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Please note: During a recent visit to the Australian National Insect Collection (ANIC) in Canberra, I discovered that specimens labelled by Lea as a synonym of Porrostoma rufipennis did not fit the features that  Lea 's published key (1909, 1921) referred to and upon which I based descriptions of Lycidae species.   It was the same story for P. simsoni. Therefore, please disregard descriptions of those species on this page while I sort it out. This dilemma may affect other species on this page.



Checklist of Tasmanian species

Xylobanus conquisitus

Xylobanus insignipennis

Xylobanus simplicornis

Stadenus obscuripennis

Porrostoma atratus

Porrostoma  disconiger

Porrostoma fuscolineatus

Porrostoma gracilis

Porrostoma moerens

Porrostoma rhipidium

Porrostoma rufipennis

Porrostoma simsoni

Calochromous scutellaris

 Trichalus bifurcatus

Trichalus discoideus

 

Ecology

Larvae are recognizeable by their lateral abdominal processes and live in fallen logs where they are usually found under bark feed on rotting wood and fungi. 

 

Adults are largely pollen feeders and are usually found on flowers, though some species never feed as adults.


Some Lycidae such as Porrostoma rhipidium use chemicals for protection, with 2-methoxy-3-alkylpyrazines as odour warnings along with bitter principles 1-methyl-2-quinolone and 3-phenylpropanamide as well as antifeedants (Moore and Brown, 1989). A number of species from other families mimic P. rhipidium, benefiting from protection due to their likeness to unpalateable Lycids.  Some, such as  Cantharids,  produce only the warning odour. Oedemeridae rely on their own protective chemical, Cantharidin.

Taxonomy

 The genus Metriorrhynchus  is no longer valid and species have been placed in Xylobanus, Porrostoma and Stadenus genera.

Each elytra usually has large punctures that create a honeycomb or net effect with 6 strong costae (ridges) and a flattened shield-shaped pronotum with pits.

Xylobanus

-Elytral punctures in single series (5 rows per elytra, though these may become double or irregular at the base and apex).

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Xylobanus insignipennis (Blackburn, 1900)

-Prothorax 7 aereolate (i.e. 7 distinct impressions) and entirely black.

-Elytra uniformly black.

 

 

 

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Xylobanus conquisitus Kleine, 1927

 

 

 

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Xylobanus simplicornis (Lea,  1909)

-Prothorax black and not 7-areolate

-third joint of antennae distinctly longer than fourth

-elytra opaque with basal 3/5 orange

-large eyes

-rostrum absent

-penultimate abdominal segment widely and semi-circularly , but not deeply, excised in the middle. 

 

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Stadenus

-Elytral punctures in double series (8 to 10 rows).

-Prothorax 5, not 7 aereolate.

 

 

Stadenus obscuripennis (Lea, 1909)

-Prothorax entirely black

-Rostrum very short 

-Apex of elytra orange and the rest not entirely black but infuscate.

 -Penultimate abdominal segment triangularly excised.

Collected by Lea on King Island and Hobart.

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Porrostoma

-Elytral punctures in double series (8 to 10 rows).

-Prothorax 7 aereolate.

 

Porrostoma moerens (Lea, 1909)

-Rostrum long, approximately equal to length of prothorax.

-All parts entirely black.

-Abdomen with penultimate segment excised almost to base.

Found on Leptospermum flowers. 

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Porrostoma rhipidium (Macleay, 1826) long-nosed lycid

-Rostrum long, approximately equal to length of prothorax.

-Third joint of antennae distinctly longer than fourth. 

-Prothorax black and elytra uniformly orange.

-Black scutellum contrasts strongly against surrounding orange elytra.

This species is the same as Porrostomus erythropterum Erichson, 1842. 

Found on Leptospermum, Kunzea, Eucalypts. 

 

Similar looking beetles i.e. mimics:

You may be looking at Calochromous scutellaris (Lycidae) if you have something similar to the above but :

-the pronotum is shield shaped yet the aereoli are less distinct, soft impressions,

-the scutellum is rectangular and the area of the elytra around it is blackish.

-punctures on the elytra are not visible.

This mimic produces a slightly different warning odour but in high concentrations in the mandibular glands to also act as a deterrent to predators (Moore and Brown, 1989).

 or: Stenoderus suturalis (Cerambycidae) which has:

-shiny black head and cylindrical pronotum,

-antennae inserted close together on top of the head,

-very small, irregular punctures between elytral costae (ridges) that are more than 2 puntures wide.

S. suturalis produces toluene and o-cresol which produce a creosote odour (Moore and Brown, 1989).

or: Pseudolycus haemorrhoidalis (Oedemeridae) which has:

-last four antennal segments cylindrical , unlike the previous large triangular segments.

-pronotum is cylindrical with soft impressions.

-elytra with many fine punctures and short setae (hairs) between costae.

 On the Australian mainland a jewel beetle, Castiarina erythroptera (Buprestidae) also mimics Porrostoma rhipidium.

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Porrostoma atratus (Fabricius, 1801)

- Rostrum short (much shorter than length of prothorax), almost absent.

-Prothorax and elytra entirely black.

-Penultimate abdominal segment triangularly excised at base. 

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Porrostoma simsoni (Lea, 1909)  7.5mm

- Rostrum short (much shorter than length of prothorax).

-Prothorax entirely black.

-Elytra black, with orange at shoulders and apex only.

 

 

 

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Porrostoma rufipennis (Fabricius, 1801) red-winged lycid

- Rostrum short (much shorter than length of prothorax).

-Prothorax entirely black.

-Elytra black with orange at apex only but markings can be variable and extend a distance along the elytral suture etc, but never as in P. simsoni.

See photo at the top of this page.

 

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Porrostoma fuscolineatus Waterhouse, 1879

- Rostrum short (much shorter than length of prothorax).

- Prothorax partly orange and wider than long.

- Elytra dark but the costae (ridges between pairs of punctures) are orange.

 Also described as Metriorhynchchus laetus  Blackburn, 1892; Porrostoma lineatum, Waterhouse, 1877.

 

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 Porrostoma disconiger (Lea,  1909) 

-prothorax black and 7-aereolate

-rostrum about as long as prothorax 

-elytra with orange edge  

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Porrostoma occidentalis (Blackburn, 1892) 

Lea (1921, 52) describes two males from Hobart as a variety of this species but since the location of Blackburn's species was Eyre's Sandy Patch, W.A., this may not be the same.   Lea also mentions that he thinks it is the same as a species he described as Metriorhynchus disconiger  from Victoria. 

 

 

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 Porrostoma gracilis

-Sooty brown

-Large eyes

-Rostrum absent

-Apical half of prothorax coarsely punctate

-Penultimate abdominal segment widely excised almost to base

 

 

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Key to Tasmanian Stadenus, Xylobanus and Porrostoma species

(after Lea 1909, 1921) Incomplete for species I have not yet seen. Lengths are approximate.

1. Elytral punctures in single series...........................................2

-  Elytral punctures in double series...........................................3

2. Prothorax 7-aereolate with prothorax and elytra entirely black,8mm...........................................Xylobanus  insignipennis

-  Prothorax not 7-aereolate, prothorax black, elytra black with basal 3/5 orange, no rostrum, 6mm........Xylobanus simplicornis

3. Prothorax black and not 7-aereolate, elytra infuscate with apex orange, 13mm.........................................Stadenus obscuripennis

-  Prothorax 7-aereolate............................................................4

4. Rostrum about as long as prothorax .....................................5

-  Rostrum shorter than length of prothorax..............................6

5. Entirely black., 13mm..............................................P. moerens

- Elytra uniformly orange, 10-14mm.........................P. rhipidium

- Elytra black with orange edge, 11mm....................P. disconiger

6. Prothorax black.....................................................................7

-  Prothorax partly or entirely orange.........................................8

7. Elytra entirely black, 11mm........................................P. atratus

-  Elytra black with orange only at apex and shoulders, 10mm..........................................................................P. simsoni

-  Elytra black with orange at apex only, sometimes extending along suture, 12mm.................................................. P. rufipennis

8. Prothorax entirely orange/sooty brown, elytra black with less than 1/6 of apex of elytra orange, male antennae flabellate, 9mm................................................................................ P. gracilis

-  Prothorax partly orange and wider than long, dark parts of elytra do not include costae.............................................P. fuscolineatus