Agriculture: Pistachio Pest Management Guidelines

Budbreak Through Bloom

This year-round IPM program covers the major pests of pistachios in California.

About Budbreak Through Bloom

What should you be doing at this time?

Continue weed management. Mow ground cover before bloom for frost protection and to reduce small plant bug and false chinch bug populations. Do not mow during bloom.

If not done after the last harvest, at budbreak identify trees infested with mealybugs by looking for them on green bud tips. Note infested trees for more intense monitoring from mid-May to early June.

If the orchard has a history of Botryosphaeria panicle and shoot blight, treat when panicles (flower clusters) appear in the spring. If wet and cool weather occurs during bloom, consider treating for Botrytis blossom and shoot blight.

Hang navel orangeworm egg or pheromone traps on April 1. Check traps once or twice per week to monitor the first flight (typically in April to mid June with a peak in May) in pheromone traps and to observe the egg-laying peak (typically in May) using egg traps.

In late March through April, adult leaffooted plant bugs and stink bugs may migrate into the orchard edges from overwintering sites. Monitor weekly for:

  • Leaffooted plant bugs, small plant bugs, and stink bugs using a beating tray.
  • Plant bugs and stink bugs using a sweep net in surrounding cover crops and vegetation.

Leaffooted plant bugs and stinkbugs may require a pesticide application. Small plant bugs, with the exception of California buckeye bug, are less damaging. Areas heavily infested with green stink bug and leaffooted plant bug will require close monitoring after fruit set.

Look for obliquebanded leafroller strikes and leaf tying (rolled or folded leaves). Record observations for future pheromone trapping and treatment decisions.

Look for vertebrates and their damage and manage if needed:

  • Ground squirrels
  • Jackrabbits
  • Meadow voles
  • Pocket gophers

Sporadic or minor pests and disorders you may see:

Invertebrates

  • Darkling beetles
  • Thrips (onion, western flower)
  • Western tussock moth

Disease and abiotic disorders

  • Armillaria root rot (oak root fungus) mushrooms
  • Delayed leafing
  • Frost damage
  • Wood decay fungi mushrooms (e.g. Schizophyllum spp., Ganoderma spp.)
Text Updated: 10/14