About every other day I notice a grasshopper or two on my hops. I'm pretty sure they are eating them since there are little bites taken out of the leaves. Any suggestions on how to keep them away, aside from manually killing them?
At all costs, avoid using Pesticides! Besides affecting your beer, some pesticides could remain in the soil for quite some time.
There are however some natural ways to keep them off your hops:
1 Grow a variety of flowering, fragrant plants in your garden to attract beneficial insects and birds. Birds, frogs, rodents, praying mantises, spiders and many other insects like to eat grasshoppers.
2 Plant herbs and flowers that grasshoppers hate near and around plants that you want to protect. Cilantro, calendula, sweet clover, peas and horehound effectively repel grasshoppers.
3 Make a garlic oil spray by combining 1 ounce of mineral oil with 3 ounces of chopped garlic. Allow the mixture to soak for 24 hours and then strain. Combine 16 ounces of water, 1 teaspoon of fish emulsion and 1 tablespoon of Castile soap. Combine the fish emulsion and garlic mixtures. To ward off grasshoppers, mix 2 tablespoons of the garlic oil with 1 pint of water and pour into a spay bottle. Spray the garlic oil on the foliage of plants and directly on grasshoppers.
4 Protect plants with a lightweight cloth or a floating row cover. Use stakes to keep the fabric above the plants and discourage grasshoppers from chewing through it.
5 Bury glass jars in the soil around your plants. Make a mixture of one part molasses and 10 parts water. Fill each jar halfway with the molasses mixture. The sweet fragrance attracts grasshoppers, and they fall into the jars and drown.
6 Cultivate your garden's soil in the fall to expose buried grasshopper egg pods. Cultivation exposes the egg pods to predators and the weather.
7 Apply Nosema locustae, a grasshopper-killing parasite, to your plants. This parasite also kills praying mantises, crickets and other bugs closely related to grasshoppers.
8 Allow a patch of grass to grow uncut in an isolated corner of the garden. Long grass serves as a habitat for grasshoppers, where they gather to breed and hide from predators. This makes it easier to control and eliminate a large number of grasshoppers at once. - How to Keep Grasshoppers Off Leaves Naturally.
If it is a question of only a few grasshoppers, you could catch them for any friends you might have that like to go fishing. Grasshoppers make excellent bait.
Attract natural preditors
I would try bird feeder with minimal food to get birds attracted to the area, but keep them hungry. Birds will usually go for juicy insect over seed if given the chance.
Avoid insecticides. Many of the toxins used in them have very high boiling points and could carry through into beer. While most toxins wash from produce, washing hops will wash away lupins and you won't be happy.
There is a real simple remedy that is non toxic and a natural remedy, get 3 tablespoons of Epson salts and sprinkle on the ground around the affected hops. This will eliminate any bugs, spiders or grasshoppers from sticking around. I'm amazed at some of the lengths people go to for such a simple solution.