I have read conflicting info on Neem and Pyrethrins. Cornell Cooperative Ext fact sheet on pyrethrins states, "These compounds are toxic to bees also". Yet label on bottle only states toxic to fish; nothing about bees. Meanwhile, National Pesticide Information Center, Oregon State University Extension Services writes on Neem Oil, "practically non-toxic to birds, mammals, bees and plants... bees and other pollinators are not likely to be harmed". Yet the bottle's instructions clearly says "Bee Hazard" "This product is toxic to bees exposed to direct treatment." Confusing. So which is recommended for harlequin bugs??
Frederick County Maryland
Your questions about apparent conflicts in labeling and cautionary information are well taken. We do not know why those decisions were made. We recommend that you email or otherwise contact the National Pesticide Information Center with specific questions such as those.
Addressing harlequin bugs and pesticides: you can start with the insecticidal soap, as mentioned in our harlequin bug page in the website. After that, avoid spraying neem or pyrethrum directly on flowers or plants in flowering phase of growth. Many of the plants which harlequin bug infests will not be flowering when harlequin bugs are present so you have more latitude.