Thanks so much for your question and I'm sorry to hear you're inundated with spotted lanternfly nymphs. They are certainly a nuisance, and it sounds like you have some prime plants for them to enjoy.

To protect your grapes, we recommend covering the plants with an exclusive netting with fine mesh, tightly securing the sides and bottom of the netting, preventing the spotted lantern fly nymphs from accessing your vines. Spotted lanternfly may feed on any plant stems in direct contact with the netting, so use poles or supports to keep the netting off of the vine itself, if possible. It is also important to note that netting could increase disease pressure under certain environmental conditions. Be prepared to use a fungicide of your choice if necessary. 

Before setting up any netting you'll first have to squish or kill the existing ones on the vines, of course. For that we recommend the following options: 

• Knock spotted lanternflies off of plants with strong water sprays, or by hand, into a container of soapy water.
• Destroy spotted lanternfly adults and nymphs by crushing them with gloved hands, stomping on them by shoed feet, smashing them with fly swatters or rackets, or placing them in a container of soapy water or rubbing alcohol (isopropyl alcohol).
  

• Purchase a trap or build a circle trap using instructions from Penn State Extension. Watch a video demonstration of how to install the trap.
• Adhesive (sticky) traps can be placed on trees but should be used in combination with a screen cover to prevent by-catch of birds, squirrels, beneficial insects, and other animals.
• Use a shop vacuum to suck up SLF, then destroy and discard them.

Note: insecticidal soap and horticultural oils, neem oil included, are effective only if they are applied directly to spotted lanternflies and the surfaces on which they are feeding and walking. They both have a short period of residual activity and need to be re-applied at regular intervals to be effective, which are recommended on the product label. Check your neem oil bottle and see how often you need to reapply (usually every 7-14 days and always after a heavy rain). If you have not been doing this then that could be why your neem oil is not working against them. If spraying the grape vines, both upper and underside of leaves and all sides of the stems need to be treated to be effective. 

You should be aware that spotted lanternfly is going to remain present in the landscape despite most management efforts. Even if you manage to eliminate the current population from your property, when the nymphs mature into adults in neighboring areas, they can fly in and lay more eggs on your property. So egg hunting should be in your future. Females prefer to lay their egg masses on a host tree, but they may also deposit eggs on a variety of flat surfaces including buildings, trailers, fence posts and vehicles. The eggs are laid in groups of approximately 30-50 and then coated with gray wax. When the wax has dried it can look similarly to a splash of mud making it difficult to notice them. Scrape egg masses off woody plant bark and hard surfaces such as lawn furniture, decks, and concrete surfaces using a plastic card or flat tool such as a putty knife. The eggs must then be crushed in order to kill them. Eggs can be crushed with gloved hands or dropped into a container of rubbing alcohol or hand sanitizer. Be sure that you confirm the identity of the egg mass before destroying it as there are many beneficial insects that lay egg masses on bark and other hard surfaces as well. 

Spotted lanternfly eggs typically hatch in the spring, usually in the first week of May. So, even if you haven't spotted any eggs on your property next year, make sure your netting is up and over your grape vines by the first week of May or earlier. 

I'm sorry to say there is nothing you can do for the willow, as it is on their list of favorite plants. But they will not kill the tree, and many beneficial predators are now feeding on spotted lantern fly nymphs, so look for them in your landscape and know they'll help you in your battle.

I know that's a lot of information but I hope some of it was helpful to you. Please let us know if there's anything more we can do, and don't for get to report your SLF sighting if you haven't already.