How it Works!
Biological Insect Pest Control:
Finally, there is a safe way to control insect pests – safe for the gardener, the consumer as well as for plants and animals. This is in contrast to chemical controls, which affect all adversely, including the soil microflora (beneficial fungi and bacterium).
How does it work?
Most insect pest damage is caused by the larval stage of the insect. Prior to pupation, the larvae feed voraciously in order to store the energy required to pupate and form the adult. Once adults are visible, much of the damage has been done and the life cycle is reaching its conclusion. By this time, the next generation is ‘in production’.
Nematode is a microscopic worm, and is a natural enemy of insect larvae. CSIRO scientists have found that nematodes are able to invade and kill a large number of insects which, left unchecked, are capable of causing large-scale crop damage. Although most nematodes are harmless, some are dangerous, including roundworms that affect livestock.
Usually found in soil, the nematode detects insect movement and then follows a trail of carbon dioxide to find the insect. Entomopathogenic Nematodes (ENs) enter through the insects natural body openings; mouth, anus or respiratory inlets (spiracles) and then penetrate the blood cavity from the gut or breathing tubes.
Once in the insects blood, the EN infective juvenile releases a bacterium, found only in ENs, which multiplies and kills the insect; usually in about a day. The bacteria then convert the insect into suitable food for the nematodes and produce a range of antibiotics and anti-feedants that preserve the dead insect while the nematodes feed and breed within it.
After about 10 days, a medium sized insect cadaver may produce up to 100,000 or more infective juvenile ENs that are released into the soil and seek out new insect pest hosts.
CSIRO Entomology research in Australia and overseas has shown ENs to be effective against a range of insect pests. These include:
Scarab beetles on amenity turf, ornamentals and blue berries;
Cutworms, webworms, billbugs and mole crickets on amenity turf; termites in houses and trees;
Fungus gnatson plant nurseries, hydroponics and mushroom houses;
Peach borer moth in apples in China;
Weevils on ornamentals, strawberries, cranberries, citrus and bananas;
Carpenter worm in shade trees in China and fig trees in the United States.
Perhaps the most spectacular use of this technique occurred in Australia almost 30 years ago. CSIRO successfully introduced a nematode that sterilises the Sirex wasp, the main pest of Australia’s one million hectares of pine forest. The total cost was approximately $1.5 million, and it has been estimated that the economic saving to the dollars over a single growing cycle.
CSIRO Entomology has continued to lead the world in the on-going development of the technology and was the first organization ever to use ENs commercially – against black vine weevil in ornamental plants from 1981 and against borer moth in black currants in 1983. Since then, various ENs have been introduced around the world to control a variety of pests, though control is usually in niche markets.
Production and UseTo use ENs in insect control, researchers select the best nematode species, the best strain of that species, produce it in vast quantities and apply it evenly so larger numbers of ENs can reach their insect pest. It takes around 2 billion nematodes to treat one hectare.
CSIRO has developed a patented process of mass producing required quantities of various nematode species.
ENs are living organisms which require both oxygen and water in order to survive. Although it would be possible to supply nematodes held in a water suspension, this has proved impracticable because the water would need to be constantly aerated and even then, the shelf life would be restricted to just a few days.
CSIRO Entomology has also patented better ways of formulating ENs, and this has resulted in a formulation that can be readily mixed in spray tanks and delivered without clogging spray nozzles. Further developments of this new technology are leading towards a ‘nematode mix’ which will survive comfortably for longer periods than currently available.
Even now, a longer shelf life has been achieved by manipulating the organism’s physiology and causing them to enter into a period of hibernation. In this state, the nematodes have only around 1% of the normal oxygen requirement, and it is important that no fungal contamination develops. It is also critical to ensure that a precise water content is maintained.
Ecogrow now supplies a range of nematode formulations aimed at specific insect pest types. These are packaged so as to ensure the continued viability of the nematodes for the duration of the stated shelf life. The shelf life, depending on the nematode type, can be as long as six months from date of formulation, however this is achieved only in highly controlled environments. To activate the mix prior to applying it, only water need be added.
The application of nematodes is similar to, but slightly more complex than applying standard insecticides. Because they are living organisms, they can be adversely affected by ultra-violet light and will only survive in moist environments. The also require a water film to move through on their way to their insect hosts. The mix will also sediment in spray tanks if these are not agitated regularly.
Key application requirements are:
Apply in the evening
Water thoroughly both prior to and after application - 500 - 1,000 litres per Hectare
Maintain moist soil conditions until pests are controlled
Apply the mix evenly to ensure consistent coverage
ENs cannot infect at temperatures below around 15C and become stressed at temperatures of above 30C
Avoid chemical contamination of spray tanks
Avoid drying winds
EoGrow has signed an exclusive agreement to develop and market the CSIRO Entomology technology, and is funding further research and development. This process will lead to the development of an ever-increasing range of host-specific treatments. Many such treatments are well advanced and are undergoing extensive field testing prior to release.
EcoGrow is now able to make available products suitable for use in domestic environments that do not require expensive equipment. Indeed, no special equipment is required!
The two initial products being offered are TURFNEM1 (for the control of beetles in lawns such as scarabs and billbugs) and GNATNEM (for the control of the fungus gnat which is a pest affecting seedlings, cuttings and ornamental crops in horticulture).
Each product is available in two sizes; 15 million and 50 million nematodes respectively. In terms of coverage, a 50 million container of TURFNEM1 is sufficient for 250 m2 for control of black beetle.
If you would like further information, please contact;
Telephone: +61 2 6284 3844