Buprestidae of South Australia
( Jewel beetles )
by Peter J. Lang
Merimna atrata   (Gory & Laporte, 1837)
subfamily  Buprestinae » tribe  Melanophilini » subtribe  none
Merimna atrata   Adult images
Merimna atrata, PL1890 Merimna atrata, PL1890 Merimna atrata, PL1890 Merimna atrata, PL1890
Actual
size¹:
23.2 mm
×
8.8 mm
Measurements (mm)
malefemale
L122.0
18.7 – 25.5
n = 424.4
19 – 27.2
n = 4
L224.9
n = 125.7
24.8 – 26.55
n = 2
W8.4
7.2 – 9.55
n = 49.2
7.25 – 10.2
n = 4
Legend  L1length from clypeus/frons to elytral apex (mean, range, sample size)
L2length from anterior of edge of eyes to elytral apex
Wmaximum width with elytra fully closed
Merimna atrata  Distinctive features

Dark charcoal-grey colouration; flattened pronotum narrower than the elytra; elytra with distinct raised 'veins' and weakly developed whitish fovae.

Notes

This remarkable species is known as Fire Beetle on account of is amazing adaptations to wildfires. It is a very common species found right across mainland Australia in all major climatic zones where fire-adapted and largely Eucalypt-dominated vegetation occurs. It is often attracted to night lights and campfires.

Tepper 1887 described his encounters with this species thus: 'Usually they are seldom seen, as they are in the habit of sitting on the dusky branches and trunks of various gum trees, or running and flying most actively about; but if approached by anyone they manage to keep to the opposite side. I have never, so far as I can remember, met them upon flowers, but on several occasions have seen them flying about in thousands an hour or two after stubble or bush fires in localities I had previously searched in vain for them'. In the Perth area, Peterson observed M. atrata laying eggs into smouldering bark at the base of a Eucalyptus calophylla (Marri) tree Hawkeswood & Peterson 1982.

The behaviour of Merimna was investigated in a detailed study by Schmitz, Schneider & Schmitz 2015 who visited over 35 freshly burnt areas in WA. They found that the beetles arrived at a burnt area and started to invade it as soon as it was safe enough for humans to enter it. The beetles were observed to gather around smouldering hot spots for mate-finding, copulation and oviposition. Schmitz et al. speculate that the heat and smoke provide protection for these activities, having frequently observed Magpies start to prey on the beetles once the area had cooled down. Beetles were only observed laying eggs into bark of Eucalyptus trees that had been burnt sufficiently to destroy the cambium, so ensuring dead wood (inactive and relatively chemical-free) for the larvae.

The ability of Merimna to hone in on burning areas is astounding. Schmitz, Schneider & Schmitz 2015 cite a number of studies which demonstrate that M. atrata can detect with high sensitivity a variety of chemicals released from heated and burning timber. There are also infra-red heat sensors on the underside of the abdomen but according to Schmitz et al. they are not sensitive enough to operate at long range, but may serve to prevent the beetle from landing directly on top of hot spots.

Another interesting aspect of this species' biology is that they were observed by Schmitz et al. to be omnivorous, devouring even the carcass of a small lizard.

Distribution
SA Regions¹:  NWLENUGTFREAEPNLMUSLKISE
Australian States:  WASANTVICNSWQLD
South Australia distribution
LegendP.J.Lang collection vouchered records
other private collection or museum specimens, or sightings
Satellite map
Terrain map
Enlarge map
Adult activity records for Merimna atrata  (total of 101 beetles)
6
9 6 7 9
3 5 16 10
15 1 2
1 7
3 1
Jul Aug Sep Oct Nov Dec Jan Feb Mar Apr May Jun
Legend
live emerged adults, count > median value of 6 per quarter month
live emerged adults, count <= median value of 6
live non-emerged adults only, for that quarter month
12
number of active beetles for that quarter month
Adult host plants
beetles sites SA regions¹ family position on host plant
Acacia pycnantha11SLF
Eucalyptus leucoxylon ssp. leucoxylon11SLM
Legendbeetlescount of beetles collected from, or sighted on, host plant taxon
sitescount of major sites (unique 10 km grid cells +/- some distinct approximate localities)
Plant family
Code beetles % host plant taxa
F Fabaceae 1 50% 1
M Myrtaceae 1 50% 1
Position on adult host
positionbeetlessites
other
  on burnt stems21
¹ LegendregionsSA State Herbarium regions (map)
EA: Eastern, EP: Eyre Peninsula, FR: Flinders Ranges, GT: Gairdner-Torrens, KI: Kangaroo Island, LE: Lake Eyre, MU: Murray, NL: Northern Lofty, NU: Nullarbor, NW: North-Western, SE: South-Eastern, SL: Southern Lofty, YP: Yorke Peninsula
sizeThe ellipse is the correct size when printed, indicative on a desktop screen, and likely to be wrong on a mobile device.