It was about this time last year when my orange trees were nearly defoliated by weevils. The damage seemed to happen overnight and I was particularly mortified when the nasty critters began chewing new blooms from my dendrobiums that were growing nearby.
At the time there was no fruit on the tree as a result of multiple frosts from the previous winter so with no fear of being poisoned I decided to pull out the big guns. Initially I tried spraying the bugs directly with a strong contact bug killer and it didn't phase them. A thorough neem oil treatment didn't work either so I sprayed the entire orange tree with systemic insecticide spray and contact bug killer.
Weevils go through different stages of development. Their eggs are laid on the ground and when they hatch the grubs feed on the roots of the host plant. So with this in mind I treated the entire back yard with a Spectracide product that's guaranteed to kill about everything that crawls. When Spring rolled around and the weather warmed the yard was given a follow-up treatment.
You can imagine my dismay when I spotted a weevil roaming around on my Rhyncostylis Gigantea yesterday afternoon. He hadn't yet begun to chew...probably because the leaves are so thick...but his very presense caused my heart to drop.
The Rhynco was suspended from the same orange tree that was infested last year so I began searching the tree for signs of weevils and notched leaf damage. Sure enough they had returned, so I began blasting them with the remaining dredges of bug killer from a can I'd fetched from the back porch...and just like last year, it had no effect on them. Frustrated, I went to the garage to see if I could find a more effective bug killer. O.K. I'm desperate now so don't laugh at what I came up with. Sitting on the shelf of the garage was a can of Elmer's Craft Spray Adhesive. The thought occured to me that a light spritz of adhesive might freeze those bugs in their tracks and guess what?...It worked!
What I did was spot treat each bug I discovered with a light mist of spray. I don't think treating this way will cause any more devastation to the tree than defoliation caused by weevils. So far I've managed to kill about 5 or 6 dozen from the orange tree and another dozen or so from my passiflora vine.
Hopefully the adhesive will interrupt the weevil's 50 day cycle of growth by destroying the adults before they're able to lay more eggs. The adhesive has not yet caused any apparent damage to the leaves of the tree. Keep in mind that I'm using a minimum of spray in short bursts...just enough to coat a portion of the weevil. That seems to be all it takes to stop them in their tracks. The photo is of a dead adhesive treated Myllocerus undulatus.
Enjoy!
http://www.floridagardener.com/critt...Myllocerus.htm