Home
Hemiptera                    
 
 
  
 
 
Orange Black Stink Bug
 
 

                    

Gum Tree Shield Bug - Theseus modestus

Family Pentatomidae

This page contains pictures and information about Gum Tree Shield Bugs in genera Theseus that we found in the Brisbane area, Queensland, Australia.

Body length 15mm
 
This shield bug looks very similar to the Common Gum Tree Shield Bug but about half the body size. Both can be found on the gum tree trunk. However, this shield bug is a bit less common in Brisbane.
 
wpe13.jpg (46688 bytes)  DSCN2542.jpg (198715 bytes)
 
The antenna is clearly 5-segmented on the relatively long head. The juga do not surpassing apex of anteclypeus. the body colours are dark brown punctuations on creamy-white. There are five longitudinal lines on head.   
 
DSC_1156.jpg (150719 bytes) DSCN0419.jpg (189678 bytes)
 
They are usually found feeding on large gum tree trunks. Adults can be found on stems and leaves as well. 
 
DSC_2080.jpg (87548 bytes) DSCN0415.jpg (225033 bytes)  
 
DSC_2708.jpg (152665 bytes) DSC_2718.jpg (225174 bytes) DSC_2720.jpg (187928 bytes)
 
We believe they are on leaves for looking for their mates. 
 
DSC_2736.jpg (258327 bytes) DSC_3562.jpg (225795 bytes) PWC_9364.jpg (297588 bytes)
 
PWC_8036.jpg (216291 bytes) PWC_8816.jpg (167438 bytes) PWC_9019.jpg (184397 bytes)
 
Because those difference species of Gum Tree Shield Bugs look so similar and live in the same environments, we believe they may have form a Mullerian mimicry complexIn Mullerian mimicry, the model is not defined and several unpalatable species share warning colors or patterns to evade predation. Both models and mimics are toxic. Several species from several different orders may comprise a mimicry complex. The advantage is that the predators need only encounter one form to shun the entire complex.
 

Nymphs

PWC_9726.jpg (148172 bytes) PWC_9728.jpg (180590 bytes) PWC_9057.jpg (120997 bytes)
4th instars 
 
PWC_9076.jpg (182680 bytes)
4th instars 
 
wpe36.jpg (23758 bytes) DSC_4309.jpg (234475 bytes) DSC_4312.jpg (170867 bytes)
5th instars 
 
We believed they are the nymphs of this species.
 

Reference:
1. Insects of Australia, CSIRO, Division of Entomology, Melbourne University Press, 2nd Edition 1991, pp 509.
2. FaunaKeys - Stink Bugs of Australia,  Australian Museum online 2003.
3. Theseus modestus - Australian Biological Resources Study, Department of the Environment and Heritage, Commonwealth of Australia 2005.
4. Poecilometis modestus Stål, 1865 -  Types of Heteroptera, Swedish Museum of Natural History
5. Theseus Stål, 1867 - by Gerry Cassis, Emma Betts and Michael Elliott, Stink Bugs, Fauna Net, Australian Museum 2002. 
6. Plant-feeding and Other Bugs (Hemiptera) of South Australia. Heteroptera-Part II - Gross, G.F. (1976). Adelaide: A.B. James, p285.

Back to top

Up ] Alcaeus ] Dippilana ] [ Theseus ] Poecilometis ] Anchises ] Bathrus ] Austromalaya ] Platycoris ]

                                                

See us in our Home page. Download large pictures in our Wallpaper web page. Give us comments in our Guest Book, or send email to us. A great way to support us is to buy the CD from us.  
Last updated: August 10, 2010.