Cornfields Have Predatory Bugs' Protection

The corn rootworm is one of the worst pests of corn in the world, and the fact that it is thriving and currently spreading across Europe is due to its larvas' foul, sticky blood.

Jonathan G. Lundgren is an entomologist at the US Department of Agriculture (USDA) and made this discovery recently, along with his colleagues, while they were working with CABI researchers in Delémont, Switzerland, and Hódmezővásárhely, Hungary.

This discovery could actually lead to a way of overcoming the rootworm's defenses and develop sustainable, ecologically based pest management methods.

The researchers carried out several experiments in lab and in the field in the US and abroad, and found that the rootworm larvae's sticky blood caused certain species of predators to back off for good.

When the predatory tried to eat the larva, the foul-tasting blood coagulated in their mouths, temporarily gluing them shut.

The interesting this is that this also worked for ground beetles and ants, but had no effect of wolf spiders, who even seem to like eating rootworms.

Their trick is that they do not chew their victims, but instead they suck their prey's fluids, thus avoiding the ability of the blood to stick and linger.

The research carried out with CABI included two years of field and lab experiments and it begun in 2007, in the United States and Hungary.

In the Brookings laboratory, Lundgren and colleagues gave hungry predators a smorgasbord of rootworm larvae and pupae, and tested an total of 10 different predator species from Europe and North America.

CABI is an international not-for-profit organization that tries to solve problems in agriculture and the environment.

They look for natural ways of controlling pests, and they have been helping to lead the effort against corn rootworm's European invasion.

Rootworms have been a pest for the past 100 years, but this is actually the first comprehensive research program conducted on corn rootworm predators.

The results determined Lundgren to research managing crop fields to encourage wide and diverse predator populations.

Lundgren works at the Agricultural Research Service (ARS) North Central Agricultural Research Laboratory in Brookings, South Dakota, ARS being USDA's main intramural scientific research agency.