Horehound Bug
Feeding
Ellura
Acacia Shield Bug
S2, dorsal
 
                      
Acacia Shield Bug (Alcaeus lignicolor)Class: Animals (Animalia) - Jointed Legs (Arthropoda) - Insects (Insecta)
Order: True Bugs (Hemiptera)
Family: Stink Bug (Pentatomoidea, Pentatomidae)     iNaturalist Observation
Species: Acacia Shield Bug (Alcaeus lignicolor)
This Photo:     S1, dorsal

General Species Information:
Found on Ellura (in the Murray Mallee, SA) and elsewhere
~17mm long. Notice the side spines one the pronotum are very much reduced compared with A. varicornis.
It's surprisingly difficult to see, but the leading edges of the pronotum also have small spines/teeth (this occurs on both Alcaeus species we have depicted here). Note though the edges of the abdomen seem less serated compared to most pentatomids, looking almost smooth edged.
We have separated out our species based on the "shoulder" spines. However this could be gender based, so will need to revisit, as Danilo Lüdke said "A. uniformis & A. hermannsburgi lack any subdivision of the 2nd antennal segment. From Gross: "females with lateral angles of pronotum acute, angles in males generally less spinously produced". I usually consider the black lines on the head on either side of the midline. According to Gross, the lines are "usually" not continued forward onto jugum to the antennae in lignicolor, while angling exteriorly about halfway the length of the head and continued forward to the antennae in varicornis."

Copyright © 2015-2024 Brett & Marie Smith. All Rights Reserved. Photographed 04-Feb-2015
This species is an Australian Native Species, not listed in the SA Murray Mallee Survey of 2010.