Citrus Insects

About Citrus ThripsAbout 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

•Overwinter as eggs

•In spring and summer, adults lay eggs in new leaf tissue, young fruit or green twigs

Adult citrus thripsAdult citrus thrips

22ndnd and 1 and 1stst instar larvae instar larvae

Adults- Abdomen rounded, active

• Larva has spines or hairs not visible with a hand lens

Citrus thrips-

About Citrus ThripsAbout Citrus Thrips

•Navel oranges are more susceptible to damage than are Valencia oranges, which often do not require treatment

•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

Damage

Citrus ThripsCitrus Thrips

•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

Solutions

•When monitoring citrus thrips, distinguish them from flower thrips, which feed on flower parts but do not damage fruit

• Pesticide treatments post-bloom

Citrus ThripsCitrus Thrips

•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

About Citrus About Citrus Red MiteRed Mite

•Female mites are oval shaped with white hairs

•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

•Feeding results in pale stippling visible primarily on the upper leaf surface

Damage Citrus Red MiteCitrus Red Mite

•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

•Mites increase their reproduction on water-stressed trees. Good irrigation reduces red mite outbreaks. Water roads to limit dust buildup, which also promotes mites.

Solutions Citrus Red MiteCitrus Red Mite

About Armored ScalesAbout 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

Purple ScalePurple Scale

Scale CrawlersScale Crawlers

Red ScaleRed Scale

Armored ScalesArmored ScalesDamage

•Feeding on leaves causes yellowing; on young fruit the feeding sites remain green

•High populations may cause defoliation and twig dieback

Armored ScalesArmored ScalesSolutions

•High levels of resistance to organophosphates and carbamates

•Scales are often controlled by resident and augmented natural enemies

•Minimize use of broad-spectrum pesticides

Adult Male Red ScaleAdult Male Red Scale

AphytisAphytis parasitoid parasitoid

About Soft About Soft ScalesScales

•Soft scales reproduce without mating and lay many eggs

•May settle on leaves, twigs, branches, and trunk, and less often on fruit

Cottony Cushion ScaleCottony Cushion ScaleBrown ScaleBrown Scale

Black ScaleBlack Scale

Citricola ScaleCitricola Scale

Soft ScalesSoft ScalesDamage

•Soft scales secrete honeydew, promoting the growth of sooty mold; downgrades fruit quality

•Heavy infestations may cause leaf and fruit drop, and twig dieback

•Extract plant sap from leaves, twigs, and branches, reducing tree vigor

Soft ScalesSoft ScalesSolutions

•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 Metaphycus exit holeexit hole