Corn harvest is slowly ramping up, soybeans are turning color and dropping leaves, milo fields are all over the place and fields are being prepared for the 2018 wheat crop. Milo and wheat producers are considering potential insect and arachnid pest problems. We tend to only think of insects as a negative in food production and they certainly can be. However, let’s take a step back and consider the insects from a broader perspective.
The number of insect species is estimated to be somewhere north of six million. Of that number we have identified approximately 900,000 species. It is thought there are around 200,000,000 for every person on the planet and an acre will contain in the vicinity of 40,000,000 insects. They are members of the order Arthropoda which includes arachnids (spiders, mites, and ticks) and crustaceans. Insects, Hexapoda, are the most numerous class of arthropods. With over six million species it is fortunate that most are not pests. Of all insect species, approximately 3,500 are of real concern as pests and of that number six hundred or so are of concern in the continental U.S. Additionally, the major organisms controlling insect pests are other insects. This may be as predators or parasites. This week let’s discuss the negative impacts of insects in the environment. Next week discusses beneficial insects and the problem agricultural producers face in insect pest control.
• Direct injury to plants by feeding on plant tissue and reducing yield, quality or both. Feeding on seeds and seedlings can significantly reduce plant stands.
• Indirect plant injury includes feeding on unharvested parts that affects the quality and/or quantity of the harvested commodity. The most significant indirect loss is the transmission of diseases by feeding insects, normally those that feed on sap. And injury caused by feeding can leave tissue vulnerable to pathogens.
• After harvest, insects can feed on stored products such as grains and processed foods. They can feed on household items such as wood, wool, paper, and food stuffs.
• For livestock, they may simply be a nuisance making animals uncomfortable and stressed with a result in decreased productivity. The may parasitize livestock and weaken them. Typically, parasites won’t kill the host as it’s not smart for a parasite to kill its host outright but death may result from other causes with a severely weakened animal.
• Indirect damage to livestock is often more severe and is the result of disease transmission when the insect feeds. The outbreak of disease in horses currently in SW Kansas or West Nile in horses and raptors.
• Direct effects of insect pests of human are not typically lethal except in rare cases, think allergic reaction to bee stings or fire ants. Normally the direct effects are discomfort or minor allergic reactions.
• The most negative effects to humans are typically indirect, again disease transmission: West Nile, malaria, Rocky Mountain Spotted Fever, nematodes and so on.
• One last one, insect predators and parasites can attack beneficial insects.
We covered the red ink this week. Next week features the positive.

Dr. Victor L. Martin is the agriculture instructor/coordinator for Barton Community College. He can be reached at 620-792-9207, ext. 207.