We all worry about the decline in the bee population, but what about the thousands of other insect species that are also disappearing? From ants to butterflies to wasps and weevils, insect numbers are steadily declining, and that’s bad news for any person, animal, or beetle that loves to eat. For every species of insect that is a pest, there are 1,700 species that benefit agriculture or society in some way. Jonathan Lundgren, an agroecologist from Brookings, South Dakota, says that “biodiversity is being lost on a large scale and it is no exaggeration to call it the insect apocalypse.” This decline was brought into focus in 2019 by an international team of scientists Collect data from 166 long-term surveys conducted in 1,676 locations worldwide. Data spanning more than 90 years from 1925 showed an average decrease of 0.92% per year. Doesn’t seem like much, but it adds up to a 24% loss over 24 years and a 50% loss over 75 years. That’s a lot of dead bugs! The decreases have been greatest in Europe and here in the West and Midwest, where we use the most insecticide.
One way that scientists determined this loss was through a splatometer test. They actually counted how many mistakes were sprayed on the license plates of 700 cars that drove the same route at the same speed annually from 1997 to 2017. This showed a decrease of 80%.
The Ecdysis Foundation, a nonprofit science laboratory founded by Mr. Lundgren after he left the USDA in 2016, works with our own General Mills to advance regenerative agriculture to 1 million acres by 2030. She counts insects on 130 farms in the US and Canada. Because different insects live in different environments, some fly over the crop, some live in the canopy, some on the surface of the ground, and some below, they must use different methods to catch and count their prey. Tools include bee shells, dust nets, Blue Vane traps, and soil samples. The aim of all of these tests is to determine which cultivation methods are least harmful to the insects we have left.
The General Mills project is testing a new high-tech method that can not only be used to count flying insects, but also to identify them. This is a sensor developed by the Danish company Fauna Photonics. It lets infrared light through and measures what is reflected from the leaflets. The data is sent to a cloud-based machine learning and artificial intelligence system that uses color, wing beat frequency, and wing-to-body ratio to accurately identify the species and label them as either pests or useful. If they could just make a device that would do that for phone calls, wouldn’t that be great?
The information in this article was provided by Libby Reichenberger, printed in The Furrow’s February 2021 issue.
Bev Johnson is a Master Gardener at the University of Minnesota Extension. Your column appears in the weekend edition.