Since the dawn of civilization, and thus the dawn of agriculture, man has battled bugs. Despite years of trying to eradicate bugs from our agricultural crops, they persist in their assaults. Our tactics in fighting back often lack finesse, including repeated applications of broad-spectrum insecticides that kill both bad and beneficial bugs.
Many farmers now implement integrated pest management systems that make use of beneficial bugs. Spraying a bunch of pesticides over every crop is easier compared to IPM, which requires more thought and analysis, including knowing not only which bugs are good or bad, but also what keeps the good guys hanging around in the garden.
The Rogue’s Gallery of Agriculture Pests
Certain critters garner universal hatred in agricultural circles. Consider the efforts of Sonoran farmer Gilberto Salazar Escoboza — on a regular basis, he must deal with a huge variety of insect pests in implementing his integrated pest management program. Because of the region in which he farms, at any time he (and other farmers in his region) may face the threat of a veritable rogue’s gallery of insects:
- Armyworms, cutworms, and wireworms
- Cucumber beetles, darkling beetles, dried fruit beetles, and flea beetles
- Melon aphids and earwigs
- Leaf hoppers and leaf miners
- Grasshoppers, crickets, and false chinch bugs
- Spider mites and thrips
- Squash bugs, squash vine borers, stink bugs, vinegar flies and whiteflies
Different bugs thrive in particular environments, and have specific “culinary” preferences. Keeping up with, and responsibly controlling, current bug threats means farmers like Gilberto Salazar Escoboza are constantly on their toes to find better ways of dealing with agricultural pests, which can have a significant impact on profits.
Biological Pest Control
For insects and bugs, life is pretty brutal as many bugs prey on their weaker fellows. Rather than pity the state of agricultural pests’ existence, farmers and even hobby gardeners should embrace nature. Make the lives of certain bugs more brutish—and shorter—by siccing their natural enemies on them.
Doing so is the basis of biological pest control. Sometimes predatory insects appear without any interference, but some biological control techniques involve introducing higher numbers of good bugs to take care of a pest problem. This method requires a thorough understanding of timing, such as releasing a predatory insect that feeds on larvae when the pest is in the larval stage.
The Good Guys
Plenty of bugs are on “our” side. Predatory bugs attack and then feed on other bugs. Parasitic insects lay eggs on or inside other insects, and, when the eggs hatch, they kill the host insect. So, (drum roll, please) welcome our top five groups of predatory and parasitic friends in agriculture:
- Parasitic wasps play a huge role in controlling pest populations.
- Eretmocerus eremicus is a tiny wasp, about 1 mm long, with a lemon yellow color and green eyes. It lays its eggs in the nymphs of the whitefly.
- Various other types of parasitic wasps attack the eggs of squash vine borers.
- Parasitic Flies
- One parasitic tachinid fly, the Celatoria diabroticae, attacks cucumber beetles.
- Trichopoda pennipes, which looks like a housefly with a bright orange abdomen, is a parasite of squash bugs and certain stinkbugs.
- Predatory Flies
- Adult and larval lacewings prey upon a number of insects, such as mealy bugs, thrips, mites, whiteflies, aphids, small caterpillars, and leafhoppers.
- Lady beetles (also called lady bugs) prey upon aphids, scale insects, whiteflies, and other insect eggs.
- Adult soldier beetles feed on aphids, but in their larvae stage, they feed on the eggs and larvae of other insects.
- The aptly named assassin bug preys on a wide variety of other insects such as caterpillars, aphids, and leafhoppers.
- Spiders, graceful predators that they are, eat a wide variety of bugs.
Nematodes, small round parasitic worms that kill insects but are harmless to other organisms, prey upon many soil-borne insect pests.
Making Bugs Work for Better Agriculture
Before ordering or collecting a load of “beneficial bugs,” remember that sometimes biological pest management goes awry. One example, the Asian lady beetle, demonstrates the care required in introducing any new organism to an environment, be it an island, a country, or a field. Imported to handle a plague of aphids on pecan trees, the Asian lady beetle accomplished their intended purpose—and then took over, often crowding out (or attacking and eating) native ladybug species.
IPM Responsibility in Agriculture
Using biological pest control comes with responsibility. Deploying bugs to do your dirty work often benefits the entire ecosystem, but requires not only the ability to properly identify the pest, but also knowledge of the life cycle of both the predator and the prey in addition to the possible problems involved in introducing more insects.