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lesser auger beetle

Scientific Name
Heterobostrychus aequalis
Scientific Author
(Waterhouse, 1884)
(Coleoptera: Bostrichidae: Bostrichinae: Bostrichini)
Exotic species - absent from Australia

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Diagnostic Images

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Diagnostic Images (8)
Other Images (2)
Diagnostic Notes
This genus resides in the subfamily Bostrichinae which is defined by:

- First tarsal segment shorter than second and third also shorter than second

- Anterior margin of pronotum truncate, concave or deeply emarginate

- Lateral teeth more prominent than median teeth.

The genus Heterobostrychus is defined by:

- Body length: 5.0-16.0mm

- Head capsule not deeply and transversely constricted behind eyes

- Gena without a large tooth or lobe below each eye

- Antennal club segments with two unmargined and indistinct nearly circular sensory areas

- Pronotum excavated behind the middle of the anterior margin.

There are 5 known species in Heterobostrychus: H. aequalis, H. brunneus, H. hamatipennis, H. pileatus and H. unicornis.

Females differ from males as: pronotum smaller, teeth on anterior apical border of pronotum shorter; apical declivity of elytra without marginal tubercles.

Heterobostrychus aequalis is characterised by:

- Apical declivity and elytra bare

- Pronotum with obvious posterior angles, often lobed

- Frons without a distinct hairy gibbosity

- Pronotum middle of basal half sparsely punctured (females) or densely punctured (males)

- Second segment of hind tarsus noticeable shorter than the last segment.


Graham Goodyer (2008). Identification of Bostrichid Beetles to Genus and Species (unpublished)

Differentiation of males as follows:

1. Apical declivity of elytra unituberculate on each side ..

H. hammatipennis

- Apical declivity of elytra bituberculate on each side .. 2

2. Posterolateral angles of pronotum lobed; teeth on anterior border of pronotum broadly separated; apical declivity of elytra arcuately deflexed with inner two stout tubercles pointing obliquely upwards ..

H. aequalis

- Posterolateral angles of pronotum rounded; teeth on anterior border of pronotum narrowly separated; apical declivity of elytra obliquely deflexed with inner two stout tubercles pointing inwards ...

H. pileatus
More Information
Walker, K.
30/05/2005 05:19 AEST
Last Updated
21/10/2011 09:42 AEST
Walker, K. (2005) lesser auger beetle (Heterobostrychus aequalis) Updated on 10/21/2011 9:42:24 AM Available online: PaDIL -
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Free for use under the Creative Commons Attribution 3.0 Australia License