Updated: 10 August 2017
The Spur Throated Locust is readily distinguished from other pest species of locusts and grasshoppers by is large size and the presence of a spur, or throat-peg (2 – 3 mm long) between the front legs.
The adults are pale brown or grey in colour with white stripes and dark markings on the thorax. The hindwings are colourless or have a bluish tinge. The shanks of the hind legs are straw or mauve coloured and bear two rows of dark-tipped white spines. Adult males measure 55–65 mm long and females are 70–80 mm long. They are generally twice the size of the Australian Plague Locust.
Nymphs are very elusive; with any movement they burrow into pasture or hide on the underside of leaves. They will move into a crop/pasture from adjoining pasture or native habitat.
Adults can stay locally or migrate by day or night up to 1,000 kilometres. They can form high density swarms that are highly visible. Long distance migration usually takes place at night.
There is only one generation per year. Female adult STL lay eggs in batches, called pods, in the soil. STL can lay up to 130 eggs in a pod and can lay several times. Unlike the Australian Plague Locust, eggs are not laid in eggbeds, but are scattered. Eggs take 20 to 30 days to hatch. Eggs are laid between mid-October and December.
This locust species can cause significant devastation to both crops and pastures in a short period of time. In the nymphal stage, these locusts can do significant damage. As adult locusts they are highly mobile and can move through crops and pastures very quickly. In the early 1970's they ate the foliage off thousands of hectares of trees (particularly Belah) whilst also attacking winter crops. They also attack summer crops.
As with the Australian Plague Locust, all Spur Throated Locust activity must be reported to your local Local Land Services (LLS). It is important that farmers remain vigilant and continue checking for all signs of locust activity, including nymphs and adults. Whilst these locusts can be found in crop and pasture, they also roost in trees and shrubs. Therefore, it is important that farmers check crops, pastures and trees for their presence. Appropriate control measures, including the best techniques and timing for spraying, should be discussed with your Local Land Services.
As with the Australian Plague Locust, if you spot Spur Throated Locust activity on your land you should report this to your Local Land Services either by phone, via email or in person.
Farmers should remain vigilant in looking for signs of locust activity and maintain a continuous monitoring program throughout the entire season. Eggs are generally laid between October and December with hatching occurring some 20-30 days later. In January to March nymphs will be present. During autumn and into winter, these nymphs will have fledged and become immature adults. These immature adults start to congregate throughout autumn and into winter, forming dense swarms where numbers are sufficient. Adults will mature and start to mate during late spring.
Spur Throated Locusts do not lay eggs in dense patches (egg-beds) like the Australian Plague locust. They lay throughout pasture in a scattered manner.
Nymphs do not congregate or form dense bands like the Australian Plague Locust, therefore control during the nymphal stage is generally very difficult and inefficient. They cannot be observed as nymphs using aerial surveillance.
Up-to-date information is critical in the fight against any locust outbreak. Knowing where and when locusts are hatching and the movement of nymph and adult locusts equips us with the knowhow to ensure our control measures are targeted, effective and delivered at the best time. It also allows us to measure the effectiveness of our response, make any changes and step up our campaign to deal with any hot spots or serious outbreaks. Farmers may be supported by aerial control of adult swarms where strict criteria can be met.
Unlike Australian Plague Locust, where the optimal control time is when they are banding during the nymphal stage, it is better to wait until STL congregate as dense adult swarms. The best control of swarms is in the morning or evening when they return to their roosting sites. It must be remembered that swarms are highly mobile and pose difficulties when trying to treat, such as environmental and insecticide label constraints limiting treatment opportunities. In the nymphal stage, this species remains quite scattered. There are however occasions where nymphal densities are worthy of control. For example they may become quite dense in patches of green vegetation when conditions are drying out.
Your Local Land Services Biosecurity Officer can assist with assessing the best timing for control and other issues associated with insecticide use. Contact your Local Land Services to talk to a Biosecurity Officer.
The NSW Government allocates funding to support the NSW Plague Locust Emergency Preparedness Response Plan and the State's landholders to deal with locusts effectively and efficiently and minimise damage.
As part of the NSW Government's funding commitment, all farmers and public land managers with locusts of sufficient density can obtain free insecticide – and in some cases spraying equipment – from their Local Land Services to treat banding locusts. Land managers are responsible for applying the insecticide.
NSW DPI has adequate insecticide on hand to treat more than half a million hectares of locusts. For further information on insecticide please contact Local Land Services.
Spraying of Spur Throated Locusts in the nymphal stage is very difficult. They do not congregate into dense bands like the Australian Plague Locust, therefore remain very scattered. Spraying large areas of low density/scattered nymphs is very costly and time consuming. Nymphs will reinvade treated areas very quickly.
Aerial control of roosting adult swarms is the most effective and efficient method of controlling Spur Throated Locusts and will form a critical part of the NSW response. Control is most effective when large numbers of swarming adult locusts are roosting (mornings and evenings).
Aerial control is expensive and is only considered when all criteria such as target size, label requirements and environmental aspects can be met.
Yes. Biological controls are available in the form of a naturally occurring soil fungus called Metarhizium and marketed as Green Guard™. Specific to locusts and grasshoppers, it provides an environmentally friendly alternative to chemicals which does not harm other organisms. As this is a fungus, and will generally be applied to adults, Green Guard will take some period of time to take effect. The adults will continue to cause damage while the fungus takes effect.
While some Green Guard™ formulations may be acceptable to organic certifying bodies, organic growers should check with their certifying body before use.
Green Guard™ can also be used alongside sensitive areas such as wetlands.
In the first instance, liaise with your neighbour about the best control options. If the swarms are within 300 metres of an organic farm it may be that only Green Guard (Metarhizium) can be used. The other option is too wait for the swarm to move to a more suitable site. It is recommended that you do not use a conventional insecticide within 300 metre upwind of an organic property boundary. This will reduce any likelihood of drift or the movement of treated hoppers from your property into the neighbours.
While it is impossible to eliminate the Spur Throated Locust threat completely, a concerted and targeted campaign can minimise the impacts on valuable crops and pastures by reducing populations.
Apiarists can be affected in two ways. First through the direct impact locusts can have on foraging bees (which can forage up to 5km from their hives) and secondly from insecticides sprayed to control locusts.
While locusts prefer to feed on green vegetation, experience shows they are still capable of causing damage to maturing and mature crops and trees that may be prime bee foraging sites.
Bees are particularly sensitive to the insecticides used to control locusts. It is important that apiarists are advised, through NSW Department of Primary Industries and Local Land Services, when major on ground or aerial spraying is being undertaken. Landholders must also notify nearby apiarists prior to undertaking control. It is also important that apiarists alert agencies or landholders when placing hives in an area where a locust threat exists.
Bee hives need to be moved out of areas before spraying occurs.
The protection of environmentally sensitive areas is critical when controlling any locusts. All environmentally sensitive sites need to be identified prior to any control taking place.
Environmentally sensitive areas may include:
Aerial control forms part of the Government's campaign strategy for controlling the Spur Throated Locust. Any aerial control measures will be particularly focused on "roosting" swarming adult locusts.
Aerial control brings particular challenges due to the type of terrain, and aircraft, Work Health and Safety and environmental hazards. Significant buffers of up to 1.5 km need to be maintained from some hazards including bodies of water.
Very strict criteria will be applied to aerial spraying and must be approved by the Plague Locust Management Group, the state's locust coordinating body. Planes are more frequently used for surveillance instead of spraying operations.
Safety is the number one priority in any emergency operation. This applies to all locust control and strict procedures are in place to protect the safety of the general public, operators, staff and contractors or anyone else involved in locust operations.
NSW has a comprehensive plan to help farmers across the state protect crops and pastures from potential Spur Throated Locust plagues. The plan is overseen by the Plague Locust Management Group which includes NSW DPI, Local Land Services and NSW Farmers' Association.
Under the Local Land Services Act 2013, landholders are required to monitor their property for all locust species and report activity to their Local Land Services. Landholders are also required to treat locusts using appropriate measures.
Locusts do not respect property boundaries or state boundaries, so it's crucial that we all work together in controlling outbreaks.
Local Land Services lead the local coordination and outbreak monitoring and provide advice on locust activity and control. Local Land Services are the point of contact for locust reporting and work closely with landholders on local operations, including the supply of insecticide for on-farm control.
NSW DPI handles State-wide monitoring, surveillance and coordination as well as major control operations which present a major threat to state agriculture.
The state-wide campaign is coordinated through the Plague Locust Management Group which includes representatives from NSW DPI, Local Land Services and the NSW Farmers Association.