Citrus Insects

1. Citrus Insects

2. About Citrus Thrips • Adults are about 1 mm long, orange-yellow in color • Wings are fringed with long hairs • 1st instar larva is very small; the 2nd instar is about the same size as the adult Adult citrus thrips 2nd and 1st instar larvae • Overwinter as eggs • In spring and summer, adults lay eggs in new leaf tissue, young fruit or green twigs

3. About Citrus Thrips Citrus thrips- Adults- Abdomen rounded, active • Larva has spines or hairs not visible with a hand lens

4. Citrus Thrips Damage • Mostly caused by 2nd instar larvae feeding under the sepals of young fruit, leaving scabs on the rind • Fruit are susceptible to scarring until they are about 3.7 cm diameter • Navel oranges are more susceptible to damage than are Valencia oranges, which often do not require treatment

5. Citrus Thrips Solutions • Pesticide treatments post-bloom • Organophosphate and carbamate pesticides stimulate thrips reproduction • Thrips rapidly develop resistance to chemicals used repeatedly and frequently for its control • Treatments to prevent foliar damage are not recommended • When monitoring citrus thrips, distinguish them from flower thrips, which feed on flower parts but do not damage fruit

6. About Citrus Red Mite • Female mites are oval shaped with white hairs • Eggs are laid on both sides of leaves • Populations increase in spring, late summer, and early fall in response to new growth • Active stages prefer to feed on fully expanded young leaves but will also infest fruit

7. Citrus Red Mite Damage • Feeding results in pale stippling visible primarily on the upper leaf surface • May cause leaf drop and twigs dieback • Stippling or silvering also occurs on green fruit, but damage usually disappears when fruit change color • High populations can cause fruit sunburn in hot weather

8. Citrus Red Mite Solutions • Mites increase their reproduction on water-stressed trees. Good irrigation reduces red mite outbreaks. Water roads to limit dust buildup, which also promotes mites. • The most important natural enemies are predaceous mites, however, predaceous insects, and a virus are also important in regulating citrus red mite populations • Hot temperatures and low humidity also reduce citrus red mite populations • Monitor orchards and use narrow range selective miticides whenever possible

9. About Armored Scales • Female scales remain under a cover throughout their life, and do not move • Females lay many eggs; 1st instar 'crawlers' move around to find suitable places to settle • Mature males are winged and do not cause damage Red Scale Purple Scale Scale Crawlers

10. Armored Scales Damage • Feeding on leaves causes yellowing; on young fruit the feeding sites remain green • High populations may cause defoliation and twig dieback

11. Armored Scales Solutions • High levels of resistance to organophosphates and carbamates Adult Male Red Scale • Scales are often controlled by resident and augmented natural enemies • Minimize use of broad-spectrum pesticides Aphytis parasitoid

12. About Soft Scales Cottony Cushion Scale Brown Scale • Soft scales reproduce without mating and lay many eggs • May settle on leaves, twigs, branches, and trunk, and less often on fruit Black Scale Citricola Scale

13. Soft Scales Damage • Extract plant sap from leaves, twigs, and branches, reducing tree vigor • Soft scales secrete honeydew, promoting the growth of sooty mold; downgrades fruit quality • Heavy infestations may cause leaf and fruit drop, and twig dieback

14. Soft Scales Solutions • Predatory beetles • Parasitic wasps, Metaphycus spp. • Control ants, that interfere with biological control • If treatment is necessary, apply summer oil treatment as soon as possible when crawlers are present Metaphycus exit hole