T.E.R:R.A.I.N - Taranaki Educational Resource: Research, Analysis and Information Network


Bug (Eucalyptus bronze bug) Thaumastocoris peregrinus

Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Hemiptera
Suborder: Heteroptera
Infraorder: Cimicomorpha
Superfamily: Thaumastocoroidea
Family: Thaumastocoridae
Subfamily: Thaumastocorinae
Genus: Thaumastocoris
Species: Thaumastocoris peregrinus
Common name: Eucalyptus Bronze bug

Thaumastocoris peregrinus is a serious, sap-sucking, pest bug native to Australia and Argentina that has become a serious global pest that has caused enormous, economic losses to the eucalypt forest industry. This invasive insect is established in Auckland, New Zealand, It was first detected in March 2012 on urban street trees in East Tamaki. It has been reported in Tauranga, Hastings and Hamilton. This insect has the potential to be a pest on eucalyptus trees in most of the North Island and in northern and eastern regions of the South Island. About 30 species and hybrids of eucalyptus are known to be the hosts of Thaumastocoris peregrinus.

Thaumastocoris peregrinus is a sapsucker bug with a flattened body with a length of > 3 mm. It has a broad head, pedicellate eyes, and elongate conspicuous mandibular plates. It is a light brown colour with darker areas. This bug and its nymphs feed together on the leaves of the eucalyptus species. The eggs are laid in black capsules on the leaves, often in a cluster that can be seen as a large black mark on the leaf (Button, 2007). The hatched nymphs are orange, with black spots on the thorax and on the first abdominal segment. They go through 5 instars.
Adults live for an average of 16 days and each female will produce about 60 eggs (Noack and Rose, 2007).

Typical symptoms of infestation include initial reddening of the canopy leaves which subsequently changes to a reddish-yellow or yellow-brown colour (Nadel et al., 2009). Some leaf loss can be observed as well as an abundance of adults, nymphs and black egg capsules usually clustered in high numbers (Nadel et al., 2009). During severe infestations, leaf loss leads to severe canopy thinning, and this sometimes results in branch dieback or tree mortality (Nadel et al., 2009; Wylie and Speight, 2012). 
It is thought that dispersal is by air and on the cloths of travellers.

 

Photo of eggs, larvae and adults


Wallangarra white gum (Eucalyptus scoparia), a common Sydney street tree, showing signs of Thaumastocoris infestation, producing the effect known as winter bronzing.
 

The initial reddening of the canopy leaves

Thanks to Wikipedia for text and information: https://creativecommons.org/licenses/by-sa/3.0/