Warm weather with sunshine this time of year prompts a tiny insect looking for final
food before winter to cause a painful bite on humans. I’ve received several questions about “what is that tiny black bug with white marks on back that bites?” The insect, known as the minute pirate bug (and insidious flower bug), is actually a beneficial predator of thrips, mites, aphids, tiny caterpillars, and insect eggs. People will even purchase these insects for biological control, particularly in greenhouse settings. They’re found throughout crop, garden, landscapes, and wooded areas in the summer preying on other insects. However, this time of year they start biting humans they land on. One doesn’t need to worry about them injecting a venom, feeding on blood or transmitting disease. People’s reactions to the bites range from no reaction to swelling like a mosquito bite. Unfortunately there’s also no method of controlling them. Insect repellents don’t work as they aren’t attracted to carbon dioxide like mosquitoes are. They are attracted to light colored clothing, so wearing darker colors and long sleeves can help when being outdoors during warm, sunny days. Otherwise, work outdoors on cool, cloudy days.
Bagworms: This year was a heavy year for bagworms and I’m still receiving calls about treating for them as people find damage. We would recommend it’s too late to treat now as eggs have been laid in most bags at this point and insecticides, including systemic ones, won’t move inside the bags to kill any adults or eggs within the bags. Wherever feasible, you can reduce next season’s load by picking off bags and either squishing them or drowning them in soapy water. Simply throwing them on the ground doesn’t help. I was even finding bags that had dislodged from windbreaks in adjacent crop fields this year with larvae traveling back towards the windbreak! Between 500-1000 eggs can be found in one bag. Aim for insecticide applications next year when larvae hatch and feed, usually at some point in June.
Harvest Thoughts: Several times the topic of palmer amaranth came up this week while in the fields with palmer in patches or especially on field edges. I believe the first step of palmer management begins at harvest by choosing to not run the combine through those patches. Research from the southern U.S. showed 99% of palmer seed survives the combine and we also know the combine is very effective at seed dispersal. Several farmers have shared they could see the worst palmer spreading in their fields the following year where the first combine pass occurred. Research supports this. The highest number of new palmer plants counted in a field were found the successive year where the first combine pass occurred after combining a patch of palmer. So some suggestions to consider: 1-Consider disking or shredding patches of palmer. 2-Plant a small grain like rye or bin-run wheat into endrows and/or patches where palmer was present. Research has shown that burying palmer seed 3-4” and leaving it buried for 3 years can reduce germination 80-100%. I realize disking doesn’t necessarily go that deep and that it’s difficult for no-till guys to want to do any tillage. Shredding won’t kill seed, but it will keep the seed from going through the combine. The small grain will help reduce light interception to the soil surface next spring. That’s the #1 trigger for palmer germination-light penetration on bare soil.
Also, I realize it’s difficult to achieve, yet a reminder to check your beans and harvest as close to 13% as possible. A number of fields last week even with green stems and some leaves remaining on lower plants were actually at 13% when harvested. Delivering soybeans below 13% reduces profits while there’s a dock for delivering wet beans. While not a dock, less than 13% moisture results in fewer bushels to sell (load weight divided by 60 lbs/bu assuming 13% moisture). Selling soybeans at 8% moisture, you’re losing about 5.43% yield; at 9% moisture, it’s 4.4%; at 10% moisture, 3.3%; at 11% moisture, 2.25%; and at 12% moisture, it’s 1.14% yield loss. That doesn’t take into account additional risk for shatter losses during harvest. So another consideration as we consider economics and profitability this year.