The 70% Neem Oil will kill grasshoppers. Per the product label: 70% NEEM OIL is most effective when applied every 7 to 14 days. For heavy insect populations, spray on a 7 day schedule.
When using Monterey 70% Neem Oil, it is safe for you to consume the fruit after spraying with the oil. Some products require you to wait so many days before harvesting after using their product, however when using Monterey Neem Oil it is safe for you to consume the product right away, with no waiting period.