Insects are active in North Florida watermelon fields. According to his weekly email, Bob Hochmuth, UF/IFAS Regional Specialized Extension agent in Live Oak, Florida, said rindworms remain a problem. Growers need to maintain a good preventative program up until the last week of harvest.
There have also been various reports of whitefly populations. This is especially concerning because they vector different viruses. Growers are encouraged to report any high whitefly populations their fields are experiencing.
Wireworm is also a concern. Its feeding on the bellies of watermelons is like rindworm, except the feeding leads to smaller surface tunnels than rindworm. The damage from wireworms is nearly all on the belly.
Spider mites have been spotted in the last couple of weeks. The crop has been damaged significantly where there’s been heavy infestation. Spider mites prefer prolonged periods of hot and dry conditions, which had been the case until recently.
The most effective miticides that have three or less days of preharvest interval include Portal or Acramite. It is important to achieve good coverage of the undersurface of the leaves. Also, avoid mid-day spraying.