1. UC IPM
  2. Agriculture
  3. Citrus
  4. When to Monitor Pests and Natural Enemies
Agriculture: Citrus Pest Management Guidelines

When to Monitor Pests and Natural Enemies

Approximate monitoring times are for citrus growing in California's Central Valley. Actual times vary according to location, weather, history of pest problems, and crop cultivar and development stage.

TIME OF YEAR JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
CROP DEVELOPMENT PERIOD
Prebloom                        
Bloom                          
Petal fall                          
Fruit development                        
Fall                        
DISEASES Central Valley South Coast JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Anthracnose + +                          
Armillaria root rot mushrooms1 + +                        
Brown rot, Septoria spot + +                        
Dry root rot + +                        
Huanglongbing2 - +                        
Hyphoderma + +                        
Phytophthora gummosis + +                        
Phytophthora root rot + +                        
Stubborn disease + +                        
Tristeza + +                        
INVERTEBRATES Central Valley South Coast JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
Ants3 + +                          
Asian citrus psyllid + +                        
Bean thrips4 + +                        
Black scale - +                          
Broad mite2 - +                        
Brown garden snail + +                        
Brown soft scale - +                        
Caterpillars + +                        
California red scale + +                        
Citricola scale + -                          
Citrus peelminer + +                          
Citrus leafminer + +                        
Citrus red mite + -                        
Citrus thrips + +                          
Cottony cushion scale + +                        
Earwigs + +                        
Fuller rose beetle + -                          
Glassy-winged sharpshooter + +                        
Grasshoppers + -                        
Greenhouse thrips - +                          
Kanzawa spider mite - +                          
Katydids + +                        
Mealybugs - +                            
Potato leafhopper + +                        
Texas citrus mite + -                        
Twospotted mite + -                        
Whiteflies - +                          
Yuma spider mite + -                        
  Central Valley South Coast JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC
NEMATODES + +                            
VERTEBRATES + +                        
WEEDS + +                        
NATURAL ENEMIES
Aphytis melinus, Comperiella bifasciata red scale parasitism                        
Euseius tularensis and other predatory mites3>                        
Decollate snail                        
>Metaphycus                        
Sixspotted thrips                        
Stethorus spider mite destroyer beetle                            
Vedalia beetle                        
KEY:
+ Monitor routinely, commonly a pest
— Routine monitoring probably warranted only in special circumstances, such as in orchards that have a history of this problem.
1 Look for Armillaria root rot disease throughout the year; short-lived Armillaria mushrooms are apparent only after fall and winter rains.
2 See Asian citrus psyllid (the vector of huanglongbing) for monitoring information.
3 When using sweet liquid ant baits, begin monitoring early (about February along the coast, somewhat later in the Central Valley) before any Homopteran honeydew becomes abundant. Competition from abundant honeydew reduces ants' attraction to sweet baits.
4 Monitor bean thrips only on navels that may be exported to Australia.
5 In South Coast and Southern California growing areas, periodic monitoring for predatory thrips may be warranted through October.
Text Updated: 01/19
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