Gerhard Fraundorfer – pheromones against crop failures

Gerhard Fraundorfer

CornProtect – Protecting maize crops through pest control with sex pheromones

The Lower Austrian company “LITHOS Industrial Minerals GmbH”, run by Gerhard Fraundorfer, has developed CornProtect, an environmentally safe means of pest control. By using sex pheromones, the corn rootworm, which presents an increasing threat to maize crops, is prevented from reproducing.

The corn rootworm, a five millimetre-long, yellow-and-black beetle, is becoming an increasing danger for maize crops. In the US, it is already one of the most widespread pests. The severe reduction in harvest levels that it has caused have earned it the nickname “billion dollar beetle”. In some cases, the harvest was reduced by 80%. In the interim, losses of up to 50% have also been reported in Europe, while in Austria, the presence of the corn rootworm has been identified in the most important maize-growing regions in Lower Austria, Styria, Carinthia and Burgenland. The Lower Austrian company “LITHOS Industrial Minerals GmbH” has taken on the problem, which is now of global importance, of combating this pest. The company, which is run by Gerhard Fraundorfer, provides a creative solution. With CornProtect, an innovative form of pest control has been developed and patented – and it is environmentally friendly, sustainable and a far cry from harmful insecticides or genetic manipulations. Sex pheromones of female beetles are used in a systematic way in order to confuse the males and prevent reproduction. Since only the corn rootworm males react to the scents that are applied, CornProtect is entirely safe for other animals, plants or humans. To date, it has not been possible to use pheromones efficiently in agriculture, since their period of effectiveness was too short. Through the use of extremely finely ground zeolite (volcanic rock) as a carrier for the scents, “LITHOS Industrial Minerals GmbH” has succeeded in overcoming this problem in an effective way for the first time. As a result, Lithos was presented with the innovation prize of the federal state of Lower Austria in 2014.

Mating behaviour of the beetles as a model for pest control

Originally, the corn rootworm comes from Central America, and has now spread to North America and Europe. Its larvae feed almost exclusively on maize. Since the eggs are laid between five and twenty centimetres deep in the earth, it is mainly the roots that are affected. The young larvae eat the hair roots, while in later stages, the outer layers of larger roots serve as a food source for the young adults. Here, the beetle does full justice to its name and bores its way through the root system. This reduces the vertical stability of the maize plant, and leads to the typical “gooseneck symptom”: the plant hangs its head and becomes more vulnerable to fungal diseases, frequently breaking off during harvesting. However, the fully-formed beetle is also a threat to the crop. It causes feeding damage to leaves, cobs, ears and silk hairs. The latter in particular leads to fertilisation problems. Almost no maize kernels are formed on the cob. This defective overall situation leads in some cases to huge reductions in harvest levels.

The corn rootworm bores its way through the root system, why the stability of the corn plant is reduced.

An innovative method for more effective use of pheromones in agriculture

In order to bring this pest under control, “LITHOS Industrial Minerals GmbH” has based its solution on the mating behaviour of the beetle. The female only mates during a short period of time: at an age of 14 days, once to three times per week – and after that, never again. The sperm collected during this period is stored by the female in a type of reserve storage sac, the sperm sac. Over eight weeks, 50 to 60 eggs, which she lays week after week, are fertilised from this sac. In order to attract the male beetles, the female sprays special scents, or sex pheromones. It is precisely during this “flirt phase” that CornProtect intervenes with a somewhat different kind of pest control method. Following a complex procedure, extremely finely ground zeolite is infused with the artificially created pheromones of the female corn rootworm. Then, the powder is distributed five to eight meters outside the treated field and throughout the entire productive flight period of the beetle (eight to ten weeks). The high concentration of sex pheromones confuses the males. They no longer find their way to the female beetles, or lose interest in mating altogether. This reduces the reproduction rate and therefore the larvae formation in the following year. The population level decreases. The zeolite, the carrier substance for the pheromones, has a negative electrostatic charge. It remains easily visible, and is stuck to the maize leaves from the time it is applied through to harvesting. It also cannot be washed away by strong and frequent rain. The use of pheromones in the field of pest control offers a large number of benefits. Toxic insecticides or genetic modification measures are no longer required. At the same time, every animal and insect has very specific pheromones, which is why the application of CornProtect affects only the corn rootworm. Also, the beetle is not killed, but instead, the number of fertilised eggs is decimated as a result of gentle “birth control”. This makes CornProtect environmentally safe and conformant with all bee, animal and environmental protection standards.

Gerhard Fraundorfer
general manager of LITHOS
Industrial Minerals GmbH