Are hitchhiker pests an increasing threat to Australian biosecurity?
Have you ever considered how exotic pests make their way into Australia? One major pathway is through ‘hitch hiking’. Hitchhiker pests are a unique category of exotic pests that do not rely on natural pathways such as wind; and instead, pests are moved accidentally through global trade and transport systems. Some pests such as stinkbugs have an ability to survive hidden in crevices of shipping containers and imported goods such as vehicles, boats and caravans.
Unlike most agricultural pests that require specific host plant material on which to survive during transit, hitchhiker pests have biological traits that enable them to endure long voyages on dry goods and re-emerge when conditions are right. For example, the brown marmorated stink bug (BMSB) hibernates in protected areas of goods or containers during the cooler winter months, while khapra beetle can survive for several years in shipping containers without food by going into a dormant state.
BMSB: A hitchhiker pest on the move
One of the most well-known hitchhiker pests is the brown marmorated stink bug (BMSB) (Halyomorpha halys), an agricultural pest that is native to China, Korea, Taiwan and Japan. Accidental introductions into North America resulted in establishment, and it has since spread to parts of Africa, South America and Europe.
The risk of this pest entering Australia is significant. Both dead and live BMSB have been intercepted over the past decade, within imported cars and containerised non-food items, as part of border surveillance activities. However, Australia’s biosecurity system has so far been effective, preventing the pest from establishing past these interception points.
BMSB has a large host plant range including cotton. In addition to being an agricultural pest, it is also likely to be a significant nuisance to homeowners and businesses. Though BMSB do not bite or sting, the pest is known to aggregate and overwinter in homes, sheds and storage facilities, emitting an unpleasant odour when disturbed. Large aggregations can stain walls and floors with excrement.
Adults are 12–17 mm long, with a mottled brown body and distinctive black and white banding on their antennae and abdomen. Adult BMSB can be confused with native stink bugs, such as the brown shield bug and glossy shield bug, while the first instar nymphs also resemble green vegetable bug nymphs. To assist with identification, CottonInfo has developed an ID guide highlighting key differences between this exotic pest and native species.
Growing risk of hitchhiker pests
With increasing global trade and tourism, hitchhiker pests are at greater risk of being intercepted in sea containers, imported goods, and even luggage. Last year, a traveller returning from Asia discovered a BMSB in their luggage. They quickly contained the pest by freezing it in a jar before reporting it to biosecurity authorities. Similarly in 2020, khapra beetles were detected in a consignment of refrigerators, prompting extensive tracing, inspection and treatment of the goods, packaging and premises to mitigate the risk.
While Australia remains free of BMSB and other hitchhiker pest species, staying pest-free requires constant vigilance. In response, the myBMP biosecurity module has a Level 3 practice:
‘Staff are alert to hitchhiker pest species, such as the exotic BMSB and khapra beetle, that can be transported on non-agricultural and even household type goods”.
Cotton growers and industry stakeholders can play a role in preventing hitchhiker pest species in establishing in Australia. You can implement this myBMP practice by:
- Using the CottonInfo BMSB factsheet as a resource for staff training;
- Plant Health Australia also has resources available for other hitchhiker species such as Khapra beetle; and,
- Discussing biosecurity at toolbox meetings or shed talks, emphasising that on-farm biosecurity extends beyond the field – unusual insects, larvae or signs of contamination in imported shipping containers need to be reported.
By staying alert, inspecting goods, and reporting suspicious detections, we can all stop hitchhiker pests from calling Australia home.
For more information: www.cottoninfo.com.au/publications/
insect-id-guide-endemics-exotics-brown-marmorated-stink-bug
Sharna Holman, CottonInfo Biosecurity and Disease Technical Lead sharna.holman@daf.qld.gov.au
BMSB. (PHOTO:Gary Bernon, USDA APHIS, Bugwood.org)
CottonInfo has developed an ID guide for BMSB.
BMSB.
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