Chemical pesticides and herbicides used and crops, lawns, and gardens to control insect pests and weeds have often proved problematic in the long-run causing unforeseen environmental and human health problems. (See DDT, Lesson D-21) Biological controls are an attractive alternative. However, it requires a great deal of research to find the “bug” that will eat the pest and nothing else. Here is an example: https://www.sciencemag.org/news/2020/01/aphid-munching-beetle-could-help-save-hemlock-forests?utm_campaign=news_daily_2020-01-15&et_rid=49261787&et_cid=3165622
Have your kids consider entering this line of research.