What is it? Pest of cycads Cycad Aulacaspis Scale Aulacaspis yasumatsui Family Diaspididae (armored...

What is it?

Pest of cycads

Cycad Aulacaspis Scale

Aulacaspis yasumatsuiFamily Diaspididae (armored scale)

• Originally described from Thailand

• Found in Miami, Florida in 1996• Spreading northward in Florida

into Georgia• Very similar to a common scale in

Florida – Magnolia white scale (Pseudaulacaspis cockerelli)

Where is it from?


What Does it Look Like?


Female

Male

Female



Explosive population growth

• Life cycle – 28 days

• Females lay more than 100 eggs

• Egg hatch 8-12 days

• Most females live approximately 1 month (as long as 75 days)

• Infests the plant roots

• Males do not feed

Biology


Damage?


• Initially appears as chlorotic spots

• Fronds eventually become brown and desiccated

• Cycads become completely coated with a “white crust”

• Potential for disease development

• Ultimately plant death

Damage?


What are the Host Plants?


• Cycads

• Preferred host is Cycas species (king and queen sago)

• Observed on Dioon, Encephalartos, Microcycas and Stangeria

How Do I Control It?

• Control is difficult

• Long-term, continuous effort

• Continuous re-infestation from crawlers from the roots

• Inconsistent results

• Introduction of natural enemies


How Do I Control It? Biological Control

Two natural enemies were imported from Thailand and released in 1997 and 1998

• Coccobius fulvus – wasp parasitoid

• Cybocephalus binotatus – beetle predator


Biological Control - Parasitoid


Female Wasp

Biological Control - ParasitoidCycad Aulacaspis Scale

Wasp parasitizes the female scale



Development of the wasp inside the scale

Wasp larva

Wasp pupa



Autoparasitism

One female wasp larva Two wasp larvae

One male wasp larva


Biological Control - Parasitoid• Well established in southern Florida• Contributed to the control of this pest• Still have live cycads in southern

Florida• Need additional control measures• When possible, use low-risk

pesticides• On going efforts to release more

parasites (regulatory agencies)

Biological Control - Predator


FemaleMale


• Well established in southern Florida

• Probably not as good as the wasp parasitoid

• Need additional control measures

• When possible, use low-risk pesticides


How Do I Control It? Cultural Control

• Vigorous blast of water

• Removal of fronds

• Plant health

• Removal of plant


How Do I Control It? Oils and Pesticides

• Spray coverage is essential

• Repeat application

• Foliar and soil application


• Horticultural oil

• Organocide (fish oil)

• Insecticides (Dimethoate, Orthene, Distance)

How Do I Control It? Oils and Pesticides


Aulacaspis Cycad Scale Test

• Host plant: cycad (King Sago); 1 gal container• At the onset of the test, cycad infestation

among plants varied from low to high but in general was moderate. Plants were distributed so that varying infestation levels were in all treatments.

• Each treatment was replicated 5 times • All foliar treatments were applied at 3 week

intervals (0, 3, 6, 9 weeks)• All drench treatments were applied on day one

(no repeat application) • Female scales and eggs were evaluated under a

microscope; each plant was evaluated on a 1-5 scale (1 = low infestation; 5 = heavy infestation)

Mortality of Female Aulacaspis Scale

0

20

40

60

80

100

2 4 6 8 10 12

Weeks After Treatment

Mea

n P

erce

nt

Mor

tali

ty

Organocide(F) Merit(F) Merit(D)Merit(D) / Organo(F) Distance(F) Distance (D)Dimethoate(F) Dimethoate(D) Control

Female Aulacaspis Scale With Dead Eggs

0

20

40

60

80

100

2 4 6 8 10 12


Mea

n P

erce

nt F

emal

e w

ith

Dea

d E

ggs


Infestation Level of Cycad Aulacaspis Scale

0

1

2

3

4

5

2 4 6 8 10 12


Infe

stat

ion

Rat

ing

(1-5

)


How Do I Control It?

1. Monitor

2. Water wash

3. Oil spray

4. Soil and or foliar insecticide

5. Removal of fronds

6. Removal of plant


Catharine MannionResearch and Extension Specialist

Ornamental Entomology

University of Florida, IFASTropical Research and Education Center

18905 SW 280th StreetHomestead, FL 33031

[email protected]

What is it? Pest of cycads Cycad Aulacaspis Scale Aulacaspis yasumatsui Family Diaspididae (armored...

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