Targeted sprays to minimise bluetongue spread
The BTV8 serotype of the Bluetongue virus disease transmitted by midges (Culicoides) is already entrenched and potentially endemic across a wide swath of southern and middle England, infecting and killing sheep and cattle on the 127 farms so far affected. Being carried and spread by midges, and without any direct animal to animal transmission/infection, there are obvious practical limitations on control at source.
Vaccine custom-matched to the BTV8 serotype and ideally administered to all susceptible livestock is seen as the only way of managing this disease. That said there is a limited role for chemical control of midges using portable sprayers (lever-operated knapsacks, compression and shoulder-mounted mistblowers).
Defra recognises insecticide use against Culicoides on farms does not generally provide a practical and cost-effective control measure against Bluetongue. It does not recommend treatment of the general environment with insecticides, claiming little effect on midge populations but implications for the environmental.
However, highly targeted clean up and control by insecticide spraying of midge breeding grounds such as dung and manure heaps near animal houses has been suggested. Targeted sprays to potential midge breeding areas should help to reduce chance of infection without compromising environmental safety.
Defra supports insecticide application for short-term protection of animals transiting through BTV restricted zones, or where required for specific livestock movements (i.e. licensed moves). Animals and their vehicles must be treated prior to travel. The interior of the animal compartment must be treated shortly before despatch with a spray containing a synthetic pyrethroid insecticide that is licensed by the Health and Safety Executive for control of flying insects and is applied in accordance with manufacturers' instructions.
Treatment of animals (where required or appropriate) should be with a synthetic pyrethroid insecticide which has marketing approval in the United Kingdom, meaning the product must have approval for use on animals. All treatment must be in accordance with manufacturers' instructions with particular attention paid to stipulated withdrawal period.
Portable sprayers
At times like these 'humble' but highly versatile portable sprayers and especially lever-operated knapsack sprayers come into their own. E. Allman & Company which supplies a wide range of pesticide and disinfectant application equipment to the UK farming industry sold 2000 extra of their lever operated knapsack sprayers, and an equivalent number of pneumatic (pump-up) sprayers and shoulder-mounted mistblowers, during the FMD epidemic of 2001.
Lever operated knapsack sprayers are the workhorses for general on farm spraying offering versatile application with easy use, maintenance and repair. A wide range of nozzle types and various attachments including extension lances, double nozzle holders, horizontal booms and spray management valves improve versatility and safety of performance.
HD-16 manual knapsack sprayer
Centrepiece of the Allman range is the lightweight but robust and efficient HD-16 weighing just 3.4 kg empty but holding 16 litre of spray in an impact, corrosion and UV-resistant tank, ergonomically designed and contoured for maximum comfort.
The high-efficiency piston-pump operates with minimum effort, guarded by long-life chemical-resistant seals and protected against overloading by an integral safety valve. The pumping lever can be mounted for right and or left hand operation and is provided with a grip for more efficient and comfortable operation.
There is a wide filler opening and deep basket strainer to allow quick filling and easy cleaning and a one-way breather valve in the tank lid to prevent leaking. Continual mixing and blockage-free flow (through the sprayer its reinforced 500mm long lance and nozzle) is provided for by the built in agitator for the tank and strategically placed filters within the system.
The HD-16 features a heavy-duty trigger valve with in-line filter. The trigger features an easy to operate lever which locks for constant spraying. Carrying handle for easy transportation, flat bottom base for stability while sitting on the ground, easy and rapidly adjusted carry straps with shoulder pads and carrying handle for easy transportation complete what is the most efficient, comfortable to use and safe to operate sprayer.
On either side of the HD-16 are two more high volume knapsack sprayers, the X-15 lever operated (manual) 15 litre-capacity knapsack sprayer with bigger pump capacity and spray management valve. And the Allman 'Propack' (Model SRS-540) rechargeable electric backpack sprayer for those averse to pumping and wanting 'an easy life'.
Allman compression and air shear sprayers
Saturn compression sprayers (6 and 10 litre capacity models) from Allman offer a real alternative to the lever operated knapsack sprayer since they can be used free standing as well as back-carried.
For extra reach and spray droplet penetration the Allman L80A knapsack mistblower has vertical and horizontal spray throws of, respectively, 15 and 17 metres. Its air-shear operation generates smaller droplets with minimum run off and surface wetness to provide low volume spray application. The high performance fan has an air displacement of up to 20 cubic metres per minute (706 cubic feet per minute), at speeds up to 280 mph and a variable flow control from 0-4 litres per minute. The L80A can be fitted with custom-designed jets (nozzles) to reduce the volume applied to an absolute minimum and to carry out 'Ultra low volume (ULV) mistblowing'.