Black Weevil Damage?

Question: I have some laurel shrubs planted against my house. In late spring I noticed what appeared to be insect damage to the leaves. I checked with my local garden store and they thought it was black weevil. They recommended I apply a product that has imidacloprid as the active ingredient. This we did in the third week of June using the soil soak method. It has produced new growth, but it appears something is still munching on the leaves. I have never actually seen an insect, but there is surely evidence of their presence. What do you suggest? Is it too late to spray the foliage? Thank you!

responder: Carolyn H. If you would like to learn more, please check out these resources.  Replied July 12, 2024, 6:57 PM EDT
response: Looking at the photos, my first thought was, "leaf cutter bees" or  megachile bee. See the attached image: Friend or foe? Leafcutter bee or black vine weevil:  Source:  Okanagan Master Gardeners https://www.facebook.com/groups/<personal data hidden>8334/posts/<personal data hidden>69060 Here's more information on leafcutter bees: https://marylandgrows.umd.edu/2022/05/09/bees-to-look-out-for-leaf-cutter-bees/  It is important to determine what is causing this current damage before "spraying with something." If it is the bee, pardon the expression, but the recommendation is to let it bee. You can remove the damaged leaves individually if it is too unsightly.   Also, imidicloprid is a powerful systemic pesticide that will remain effective in the soil/plant for a long time. Here is additional information on dealing with black vine weevil. https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/insects/beetles/black-vine-weevil#:~:text=Nematodes%20can%20be%20applied%20as,Steinernema%20carpocapsae%20and%20Heterorhabditis%20heliothidis.

responder: The Question Asker Replied July 15, 2024, 11:07 AM EDT
response: Thanks for this information, Carolyn.  Very helpful. Most of the leaves with damage look rounded like the leaf cutter bee and not the marginal notches which is the sign of the black weevil. (There are a few that could be that, but hard to say).  What is puzzling is that I have not seen any insect on the shrubs, either bee or black weevil. I realize that the weevils feed at night, so I may go out with a flashlight. But I am surprised I haven’t seen bees buzzing around. In either case, it would seem that for now there is nothing more to be done. Since we applied the imidicloprid in June, hopefully it will prevent further damage to the roots by the larvae. And we don’t want to interfere with bees activity if they are good for pollination.  Does that sounds right to you?  Thanks,Jane  On Jul 12, 2024, at 6:57 PM, Extension Foundation <<personal data hidden>> wrote:   ﻿

responder: Carolyn H. If you would like to learn more, please check out these resources.  Replied July 15, 2024, 6:44 PM EDT
response: You may want to review the information on integrated pest management:   "Integrated Pest Management We now use the term "integrated pest management" because we know from experience that there is no magic bullet to rid the garden of unwanted pests. We can merely attempt to keep pests at tolerable levels and minimize their damage—this is management. When using integrated pest management, remember these four important principles: The mere presence of a pest does not warrant control; determine a threshold for damage. Monitoring is essential, as is proper identification of the insect. Reliance on a single control technique will eventually fail. Use cultural, mechanical and biological control methods first; if those prove ineffective, choose the least toxic chemical control available. Go back to see if your methods were successful; if not, make appropriate adjustments.  Insects will always be present in a landscape; the key is to understand which insects are a threat, and which are merely pollinating or preying on other insects. Complete reliance on pesticides, whether organic or not, can be harmful to beneficial insects and can actually make a problem worse by killing off the natural enemies. In order to manage pests and their damage, integrate your approach and use cultural (and mechanical) control (i.e., resistant plants, traps, crushing and sanitation) and biological control (i.e., predators, parasites and diseases) in conjunction with chemical control." From: https://ohioline.osu.edu/factsheet/ENT-65   Whenever using chemical controls, always follow the instructions on the label.