Agriculture: Citrus Pest Management Guidelines

Fruit Development

This year-round IPM program covers major pests of citrus grown in California's Central Valley.

About Fruit Development (June through September)

  • Special issues of concern related to water quality: Insecticide application, fungicide application, drift, runoff due to irrigation.

What should you be doing during this time?

Look for Asian citrus psyllids on new flush if available and by using sweep sampling. Manage according to the Pest Management Guidelines.

Monitor California red scale males using pheromone-baited sticky traps, plus additional methods (e.g. calculate degree days, monitor crawler tapes, check scale infestations on fruit in the field, and examine harvested fruit).

Monitor fruit for immature citrus thrips (late April through June).

Manage if needed according to the Pest Management Guidelines.

Monitor leaves for citricola scale nymphs (late July–September).

Manage if needed according to the Pest Management Guidelines.

Monitoring for cottony cushion scale. If significant live immature stages are still present in June, manage according to the Pest Management Guidelines.

If fruit are likely to be exported to Korea, then Fuller rose beetle is of concern:

  • Estimate last season's levels of Fuller rose beetle in the block based on levels of egg masses found on harvested fruit or by looking inside the tree for the level of past leaf feeding (distinguish the jagged feeding of Fuller rose beetle from the rounder feeding of brown garden snails).
  • Trees must be skirt-pruned and maintained sufficiently to prevent tree skirts from contacting the ground from June until harvest.
  • Weed control must be practiced sufficiently to prevent a bridge forming from the ground to the skirt from June until harvest.
  • Determine current protocols for managing Fuller rose beetle in accordance with the Pest Management Guidelines.
  • Maintain records of the above in case they are needed by the packinghouse or APHIS.

Look for citrus peelminer and examine fruit for its damage.

  • Use degree-day units to predict the timing of infestations for susceptible varieties of citrus and manage according to the Pest Management Guidelines.

Monitor young citrus orchards (less than 5 years) for live citrus leafminer larvae in leaves. Manage according to the Pest Management Guidelines.

Look for other pests and their damage to fruit or damage to leaves and twigs, especially:

Manage if needed according to the Pest Management Guidelines.

Look for diseases that cause symptoms on fruit, leaves and twigs, and on limbs, trunks, and roots, especially:

Record the date and location of problem trees or sites. Manage if needed according to the Pest Management Guidelines.

Survey summer weeds. Identify common summer broadleaves and grasses and sedges.

Manage vegetation if needed according to the Pest Management Guidelines.

Look for vertebrates, especially ground squirrels, pocket gophers, rabbits, and roof rats. Manage if needed according to the Pest Management Guidelines.

Provide proper cultural care and good growing conditions to improve tree health and fruit yield, including:

  • Sample leaf nutrient levels at least once mid-August through October. Fertilize if needed.
  • Irrigate and adjust scheduling to meet trees' varying water needs.
  • Prune if needed and skirt-prune lower branches to reduce brown rot.

Determine whether application of plant growth regulator is warranted. Consider

Text Updated: 01/19