Insecticide classifications and toxicity.pdf

insecticides

1. Introduction to
Insecticides

Kinds, Modes of Action

2. What are some advantages of pesticides from
the standpoint of citrus production?

oe
a.
4 au
> \ A
6 A pes
d wh

3. Advantages of Insecticides

« Fast (compared to biocontrol)
+ Generally reliable

+ Flexible

+ increase yield (PROFIT $$)

4. Potential Disadvantages of
Insecticides

+ Direct hazards to humans

+ Perceived hazards, societal fears, litigation
+ Pest resistance

« Adverse side effects on non-target
organisms

« Pest resurgences; secondary pest outbreaks

5. Pest resurgence:

Insecticide eliminates pest’s natural enemies;
originaltargeted pest rebounds to even higher
densities than before

Secondary Pest Outbreak:

Insecticide eliminates natural enemies, allowing
a different pest(other than the original
targeted pest) to reach outbreak densities

6. Pest resurgence

7. Secondary Pest Outbreak

Use of broad spectrum insecticides, such
as Lorsban and Sevin, can lead to increase
in spider mite populations by negatively
affecting natural enemies.

8. Insecticide Toxicity

(Direct Hazards to Humans)

9. LDs0= Amount of pesticide
required to kill 50% of the test
animals under standard conditions

* Expressed as mg pesticide per kg of
body weight

+ Useful for comparing toxicity of
different pesticides

11. Remember: The lowerthe
LD50, the more toxicthe
pesticide!

12. Insecticide Toxicity
- Oral
- Dermal

- Inhalation

13. Signal Words on Pesticide Labels

DANGER

Moderately Toxic

POISON

Highly Toxic

Slightly Toxic or Relatively
Non-toxic

14. Human LD 50

DANGER Oral: 50 mg/kg or less:

lethal dose of a few drops
8 6 to teaspoon

A

POISON Dermal: 200 mg/kg or less

Highly Toxic

15. Moderately Toxic

Human LD 50
Oral: 50-500 mg/kg;
lethal dose of a teaspoon

to a tablespoon

Dermal: 200-2 ,000 mg/kg

16. Human LD 50

Slightly toxic
Oral: 500-5,000 mg/kg; lethal
dose of an ounce to a pint

Dermal: 2,000-20,000 mg/kg
Slightly Toxic or
Relatively Non-toxic

Low toxicity.

Oral: > 5,000 mg/kg
Dermal: > 20,000 mg/kg

(all compounds will have at least a caution)

17. Toxicityversus Hazard

(Putting things into perspective)

18. “What is it that is not poison? All
things are poison and nothing is
without poison. It is the dose only
that makes a thing not a poison."

— Paracelsus, 1567

19. LD50 for 150

Substance a ae pound Human
(ounces)

Sucrose (table sugar) 29,700 15.12
saccahrin 14,200 7.23
Benlate (fungicide) 9,500 4.84
Vinegar 3,310 1.69
Sodium chloride (table salt) 3,000 1.53
Resmethrin (insecticide) 2,500 1.27
Malathion (insecticide) 1,375 0.70
Aspirin 1,000 0.51
Sevin (insecticide) 500 0.25
Diazinon (insecticide) 300 0.15
Caffeine 192 0.10
Gasoline 150 0.08

Nicotine 53 0.03

20. Approximate lethal doses for naturally
occurring toxins

- The amount of caffeinein 100 cups of strong
coffee

«The amount of solaninein 100 - 400 pounds
of potatoes

The amount of oxalic acidin 10 - 12 pounds
of spinach or rhubarb

«The amount of aspirinin 100 aspirin tablets

«The amount of hydrogen cyanidein 4
pounds of lima beans

21. Properties of Pesticides

‘Different routes of entry
‘Different modes of action

>Varying effects on different
arthropod species

>Pest life stages affected

22. Routes of Entry

1. Stomach poisons

- Systemicinsecticides, B.t., etc...

2. Contact pesticides (most common)

3. Fumigants

23. Modes of action
(generalizedpesticide groups)
Chlorinated hydrocarbons
Organophosphates
Carbamates a an
* Multiple MOA's exist in
Pyrethroids these and other groups
Neonicotinoids
Insect Growth Regulators (IGR's)
Microbial insecticides
Horticultural Mineral Oils
Inorganics (sulfur)

24. Understanding the different pesticide
classes and how they work is important

Proper application

Determining if an application was
successful

Choosing products that are most likely
to control a pest without disrupting
natural enemies

25. Chlorinated Hydrocarbons

Examples: DDT, Chlordane, Dieldrin

26. DDT revolutionized pest control in
the 1940's

Saved millions from insect-borne
diseases such as malaria, typhus,
during WWII

AZ ET A
© Post-WWII “Green Revolution” |

27. Chlorinated Hydrocarbons

e Less acutely toxic than compounds used
before 1940s (e.g. lead arsenate)

e Cheap

e Broad spectrum; i.e. effective vs. a wide
range of different pests, BUT....

e Highly persistent, residues detectable in
soil for >10 years

28. Drawbacks of Chlorinated
Hydrocarbons
e Stored in fatty tissues of vertebrates,
excreted in milk (DDT)

e Biomagnification; adverse environmental
effects

e Carcinogenic
e Pest resistance

29. Organophosphates

e Developed in Germany during WWII;
spin-off of military nerve gas research

e Act as synaptic poisons, disrupting
normal transmission of nervous
impulses across synapses

e Contact poisons

30. A Sumple Nerve Pathway
Seta

a

Muscle

— ——
— ——

Motor Neuron

Sensory
Neuron

Synapse

—

|

31. Seta

Muscle

Direction
of impulse

Acetylcholineis released Fal Na

to transmit impulse across
the synapse

32. Seta

Muscle

©
Direction
of impulse \

4
Impulse crosses over. Then, an enzyme

called Cholinesteraseclears the
acetylcholine from the synapse

33. How Organophophates Kill

e The insecticide binds to the enzyme
cholinesterase, deactivating it

e Without cholinesterase, the
acetylcholine (transmitter substance)
cannot be cleared from nerve synapses,
so that the nerves keep “firing”

e Insect loses control of nervous system,
with tremors, paralysis, death

34. a,

vo
aN.
4 >
=>
o
«3
23
ea

35. Neurotransmitter
Neurotransmitter attached to receptor
released into synapse

Axon

Neurotransmitter Enzyme that destroys
stored in vesicles neurotransmitter

36. Carbamates

Same mode of action as organophosphates (i.e.,
synaptic poisons)

Toxicity to vertebrates varies

Highly toxic to all hymenoptera (parasitic wasps,
bees, etc..)

Contact poisons

37. Traditional Insecticides
(Organophosphates & Carbamates)

Broadly toxic

Affect systems common to both insects
and vertebrates; e.g. nervous system

Risk to non-target organisms
Secondary pest outbreaks
Pest resurgences and resistance

38. Organophosphate and Carbamate
insecticides used in Citrus

Organophosphates

Phosmet - Imidan

Dimethoate — Dimethoate
Chlorpyrifos — Lorsban
Malathion — Fyfanon
Acephate - Orthene
Methidathion - Supracide

Carbamates
Aldicarb - Temik
Carbaryl - Sevin
Oxamyl - Vydate

39. {IT MUST BE SPRING, L
THE ROBINS ARE

40. Food Quality Protection Act
(EPA, 1996)

41. EPA: Reduced-Risk Pesticides
+ Reduced risk to human health

+ Reduced risk to non-target organisms
including fish, birds and natural enemies

+ Reduce ground and surface water
pollution

+ Low use rate, low pesticide resistance
potential

42. Pyrethroid insecticides

e Fenpropathrin — Danitol

o Bifenthrin - Capture / Brigade

43. Pyrethroids

e High toxicity to insects, but low toxicity
to mammals

e fast-acting

+ moderately rapid degradation in the
environment

e used at very low rates

44. Pyrethroids

+ Target-selectivefor insect nerves (= low
vertebrate toxicity)

e Cause rapid paralysis of insect nervous
system by changing solubility of nerve cell
membrane (disrupting closure of the
“sodium gates”)

e Axon poisons

45. Pyrethroids prevent ion
channel closure; continued
electrical impulse (rapid
muscular paralysis)

Na+ ions

Axon nerve cell

K+ ions

46. Despite their low mammalian toxicity,
many pyrethroid insecticides are
classified as “Restricted Use” because
of their high toxicity to fish

47. Neonicotinoids
(Chloronicotinyls)

Examples:Assail (acetamiprid), Admire
and Provado (imidacloprid)

48. Neonicotinoids
(Chloronicotinyls)

“Agonist*”’ which binds directly with the
nicotinergic receptors in insects (like naturally
occurring acetylcholine), causing a nerve
impulse to be sent

Not degraded rapidly by acetylcholinesterase,
so the nerve system keeps “firing”

— *def: “One that is engaged in a struggle”

49. Chloronicotinyls block post-synaptic
receptor sites for acetylcholine

Imidacloprid blocking acetyl
Acetyl choline released choline receptor

into synapse @ y

50. IMIDACLOPRID

IS NOT A CHOLINESTERASE
INHIBITOR

Blocks post-synaptic receptor sites for
acetylcholine

51. Mode of Action of Imidacloprid and
other Important Insecticides
on the Cholinergic Synapse

Sodium |
—-| Channel

__ 4
Pyrethroids |

[OP's
| Carbamates
_L =
)—| Acetylcholine |
DO #fLesterase

a
Acetylcholine | à:
receptor i

A

Imidacloprid

52. Imidacloprid Toxicity & Mode of
Action

Imidacloprid was “designed” to take advantage of
the differences in the binding properties of the
nerve synapses of mammals and insects

Although mammals have the same general group
of receptors (nAChR), there has shown to be a
1000x lower binding affinity for vertebrates than
for insect receptors

53. Mode of Action of imidacloprid

Excellent systemic performance
Soil treatment can be the most
consistent method of delivery
Moves with the transpiration
stream

Moves across the leaf
(translaminar)

Both contact and ingestion routes,
ingestion is best

54. Insect Growth Regulators
(IGR'S)

«Very target specific in mode of action
"Exploit an insect's developmental biology
>Chitin synthesis inhibitors

> Juvenile hormone mimics

*“Reduced risk" insecticides

55. Insect Growth Regulators
(IGR'S)

Chitin synthesis inhibitors

Buprofezin — Applaud

Diflubenzuron — Micromite

56. Chitin synthesis inhibitors

Affect the ability of insects
to produce new exoskeletons
when molting

___— Epicuticle

| || } =
dt MEET Exocuticle
HD EE RE Endecuricle

IBERRISERBINMUUGUEMANHANATN.
CO MA
COTE EtG WUT

Sisie îJ Epidermis

57. Insect Growth Regulators
(IGR'S)

Juvenile Hormone Mimics

Pyriproxyfen - Knack
Fenoxycarb — Award fire ant bait

Methoprene - Extinguish ant bait

58. Insect Growth Regulators

MIDA
ei) 9008,

EE, A

SZ

at

y

po

AN

~

59. Insect Growth Regulators
(IGR'S)
High levels of JH at the wrong time produce an additional

larval stage (much larger) than then dies because it can't
molt to the adult stage

ecdysone JH Development E

immature characters
maintained during

larval stages

ur. Additional
larval stage

60. Microbial Insecticides

- Commercial products containing
pathogens or microbially-derived toxins
that kill insects

- mainly bacteria, nematodes, fungi, some
viruses

61. Bacillus thuringiensis(Bt)

e Used since 1950's to control leaf-eating
caterpillars (Bt kurstak£train)

e Produced commercially by fermentation
e Verylow vertebrate toxicity
e Short-residual

e Works better against small larvae than
vs. larger ones

e Must be ingested to kill

62. A B Dis: of als and C Toxins bind to receptors
Crystal solving Acts an in qu epiheh

= TT ana
em mE

Pi on
eae Activated toxin REA
=

Fig. 1. Mechanism of toxicity of Bt

63. Bt products registered for use in Citrus

Agree - B.t. aizawai strain GC-91

Biobit HP — B.t. kurstaki strain ABTS-351
Condor - B.t. kurstaki strain EG2348
Crymax - B.t. kurstaki strain EG7841
Deliver - B.t. kurstaki

Dipel DF - B.t. kurstaki strain HO-1
Javelin WG - B.t. kurstaki

Lepinox WDG - B.t. kurstaki strain EG7826
Xentari DF - B.t. aizawai strain ABTS-1857

(all uses are for lepidopteran pests)

64. New strains of Bt are being developed
that are active against insects other
than Lepidoptera (e.g., mosquitoes,
fungus gnats, Diaprepes root weevils)

$ for parís mosquito Bt for fungus gnat control
arvae In ponds in greenhouses

65. Other microbially based insecticides

These are not traditionally what we think of as
microbial pesticides, but they are toxins derived

from microbes.

Avermectin — Agri-mek
Spinosad - Spintor, Entrust, GF- 120 fruit fly bait

66. Avermectin — Agri-mek

Antibiotic derived from Streptomyces
avermitilis

Inhibits nerve transmission in to the
insect muscle

Requires several days to kill

Used in citrus for mites and leafminers

67. Spinosads

Derived from the bacterium
Saccharopolyspora spinosa

Kills by primarily by ingestion,
excitation of the insect nervous
system

Labeled for lepidopteran larvae,
thrips and fruit fly baits

68. Horticultural Spray Oils

- Highly refined petroleum-based oils
- Clog pest’s spiracles and suffocate

- Useful vs. small or sedentary pests,
e.g., aphids, scale insects, mites

69. Horticultural Oils
Advantages:
- non-toxic to vertebrates
- no resistance potential
Disadvantages:
- must contact insect with spray

- potential for phytotoxicity

70. Table 3 Spray rogaterod ha une raid bavi

nf by 14 Nagy ui

Mot vay aro rogpnlererl ba ung DEN COUN MU ETS GC
Drmgteram ant he rana seas net

220 menge ak nave ne Doon AMADA We thew emants

es sears oie Dean, Inet ange ae an nn

‘company Tease Name ‘Mes Port EJ EN
sii Greasy Citrus Rust
spot Mae
EP] SF TSOE CETTE] © o
Rea Sven 10 CET » ©
wa see Y ek seco . +
Rea Sonn WSF $8706 . .
win seve a 59208 4 © v
Dore 1s 968 SF agria o o
ren nee » 0
EI Nobex vy we . .
Canna! ost . ,
EI se . .
Theta Chun Died agus ve #51 Hans © o
Pe Cet sun se ym » .
Ho Clann + Oa mr m " .
eh Ci DOTE me on " »
Dunn mr 08205 © .
Po Canada Brant SF 727 . .
Pole) Canoa TO 80928 0 24:04 , .
Pom» Carta Dane SS 69826 7 24204 . .
Pot Carola Coal ss rosa © o
Sk Crane Fr Spray 99 sa © o
SK Cea En Srem N CR © o

pad quelo ios, velo amoo, rte. e os

armen,

71. Pesticide Resistance Management

1 |
“I wamed you, putting down poison for the ants only makes them stronger!*

73. Miticide Mode of Action

Agri-Mek (abamectin) Chloride channel activators

Comite (propargite) Inhibition of magnesium-stimulated ATPase
Kelthane (dicofol) Site Il electron transport inhibitors
Micromite (diflubenZuron) Inhibitors of chitin biosynthesis, type 0
Nexter (pyridaben) Site | electron transport inhibitors

Temik (aldicarb) Acetylcholine esterase inhibitors
Vendex (fenbutatin oxide) Inhibitors of oxidative phosphorylation

Sulfur

. No resistance potential
Petroleum oil

74. [National Agricultural “ (RS: LD icone Snares. ene trat tormcian Save

National Agricultura!
Statues Savion

75. Agricultural Chemical Usage 2003

Oranges — FL (587,600 acres / 237,800 hectares)

Active ingredient % Area applied O
Abamectin 15 0.9
Aldicarb 7 118.9
Dicofol <0.5 6.8
Diflubenzuron 2} 2.0
mice 2 25.6— Use cancelled
Fenbutatin-oxide 3 31.2
Petroleum oils 89 38,909.5
Sita 4 9.1
Sulfur 16 975.3

Processed: 95% Fresh: 5%

Agricultural Statistics Board NASS, USDA

76. Agricultural Chemical Usage 2003

Grapefruit — FL (95,500 acres / 38,650 hectares)

Active ingredient % Area applied ae
Abamectin 46 05
Aldicarb 14 38.3
Dicofol 3 75
Diflubenzuron 12 14
en 15 62.9— Use
Fenbutatin-oxide 17 20.1 cancelled
Petroleum oils 5 4,538.1
Pyridaben 32 06
Sulfur 51 846.5

Processed: 60% Fresh: 40% Agricultural Statistics Board NASS, USDA

77. Agricultural Chemical Usage 2003

Tangerines —FL (21,700 acres / 8,780 hectares)

Active ingredient % Area applied ( shes
Abamectin 60 02
Dicofol 2 1.5
Diflubenzuron 6 0.3
ES i 42 Use
Fenbutatin-oxide 35 a ee
Petroleum oils 92 1,479.1
See 56 4.8
Sulfur 41 110.1

Processed: 29% Fresh: 71% Agricultural Statistics Board NASS, USDA

78. Agricultural Chemical Usage 2003

Tangelos —FL (9,100 acres / 3,682 hectares)

Active ingredient % Area applied ane
Abamectin 34 0.05
Diflubenzuron 5 0.1
Ethion 1} 34 Use
Fenbutatin-oxide 9 15 cancelled
Petroleum oils 81 541.4
RE 21 0.6
Sulfur 14 27.5

Processed: 75% Fresh: 25% Agricultural Statistics Board NASS, USDA

79. Agricultural Chemical Usage 2003

Temples — FL (4,200 acres / 1,700 hectares)

FL total
Sr B é 2
Active ingredient % Area applied (1,000 Ibs)
Abamectin 16 0.05
Ethion 4 0.3 Use
cancelled

Fenbutatin-oxide 3 0.1

Petroleum oils 95 282.1

Pyridaben 8 0.1

Sulfur 13 13.0

Processed: 76 Fresh: 24% Agricultural Statistics Board NASS, USDA

80. Miticide Mode of Action

Agri-Mek (abamectin) Chloride channel activators

Comite (propargite) Inhibition of magnesium-stimulated ATPase
Kelthane (dicofol) Site Il electron transport inhibitors
Micromite (diflubenZuron) Inhibitors of chitin biosynthesis, type 0
Nexter (pyridaben) Site | electron transport inhibitors

Temik (aldicarb) Acetylcholine esterase inhibitors
Vendex (fenbutatin oxide) Inhibitors of oxidative phosphorylation

Sulfur

. No resistance potential
Petroleum oil

81. Miticide Concerns

Agri-Mek (abamectin) Tolerance in some mite populations (1999);
widely used for other citrus pests

Comite (propargite)
Kelthane (dicofol) Resistant mite populations documented (1989,1994)
Micromite (diflubenzuron)

Nexter (pyridaben) Problems reported 2004 ???

Temik (aldi carb) ne ground water contamination

Vendex (fenbutatin oxide)
Sulfur

. No resistance potential
Petroleum oil

82. 2007 Florida Citrus Pest Management
Guide: Pesticide Resistance and
Resistance Management

http://edis.ifas.ufl.edu/C6026

83. IRAG

Insecticide Resistance
Action Committee

on
resistance and

management

RAC Insocii ce Resistance Varegemer

Country Groups

Crop Proseston, Protecte ez

84. Pesticide Resistance
Management

«Use pesticides at labelled rates and no more
than one application per season

«Rotate between pesticides with different modes
of action

«Calibrate equipment for accurate application:
use recommended spray volumes and pressures

«Use products less likely to harm natural enemy
populations

85. See Handouts on
Pesticide Resistance and
Modes of Action

86. Arthropod Pests Affecting
Florida Citrus Production

(2

hos
pe

\
LEN

87. Citrus Production System

_ Generally a stable ecosystem
(in the absence of pesticides)

» Perennial crop
+ Retention of beneficial species

+ More successful cases of biological
control than any other cropping system

88. Vedalia lady beetle( Rodo/ía cardinalis)

«Introduced into California in 1888

«First outstanding success in the
field of classical biological control

«Successfully repeated in Florida in
1899

9
‘+

Cottony cushion scale (Icerya
“= purchasi)

90. Arthropod Effects on
Citrus

* Fruit Pests
* Foliage Pests

+ Vectors of Disease

91. DAMAGE DUE TO ARTHROPODS

+ DIRECT DAMAGE
+ PEEL AND OTHER COSMETIC INJURY
- PLANT HEALTH

> INDIRECT INJURY - HONEYDEW and SOOTY
MOLD

92. Table *. Groups of Canopy-Inhabiting Insects and Mites, their generation times, and primary (1*)
and secondary (2°) substrata.

Group Generation Time Flower Fruit Leaves TwigsBranches Trunk

Rust, Bud Mites 10 r r

Spider Mites 10 E 1

Scale, Mealybugs 30 E Ly 2 z
Whiteflies 45

Fruit Flies 25 r

Aphids 10 r

Foliage Feeders 30 r

Thrips r r

Woodborers months r 7
Leafminers 13 ” E

1 - Primary host tissue

O ie

93. Fruit Pests

Direct damage to fruit

‘feeding reduces fruit quality, shape, or

‘Zor :
‘Reduction in yield or cause fruit to drop

«Concern for fruit grown for both fresh and
processed markets

Damage to peel

«Cosmetic in nature

"Fruit grown for fresh market

94. Rust mites

Predominant arthropod pest of fresh
and processed citrus in Florida

Pink citrus rust mite Citrus rust mite
(Phyllocoptruta oleivora)

*

95. Rust mite damage to citrus

«Feeding injury
„Russeting of fruit and leaves
«Mild to severe distortion of new leaf growth

«Brown lesions on lower surfaces and along
midribs of immature leaves

«May produce mesophyll collapse, chlorosis
and leaf drop

96. Citrus rust mite
Phyllocoptruta oleivorx Ashmead)

98. Rust mite development

«Females lay 2 eggs / day (~30
lifetime)

+Egg to adult in 6 days

+ Adult male longevity ~ 6 days

»Adult female longevity ~ 14 days

99. Ist NYMPHAL STAGE

LIFE CYCLE OF
Phyllocoptruta oleivora (Ash)

2nd MOLT eer

100. Citrus rust mite
seasonality

pla 1 1 1 1 1 1 1 ñ 1 f ı
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

101. Pink citrus rust mite
Aculops pelekassi Keifer)

103. Pink citrus rust mite
seasonality

0 L L 1 1 4 L 1 1 1 1 1 L
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

104. Early in the season, pink
citrus rust mitesalso appear
to be more prone to damage
leaves than the citrus rust
mite

105. Natural Enemy Complex - Key Factor(s) ?

Stigmaeidae
Phytoseiidae—» ——— Cheyletidae

| |— disease

Tydeidae ——>

other predacious arthropods

106. Hirsutella
thompsonii

107. MEAN DAILY TEMPERATURE (°F)

75

70

POPULATION DENSITY —

TEMPERATURE -—

ro ones .
ES

——— CITRUS RUST MITE

MEAN DAILY RAINFALL (IN)

108. Action threshold for control
of rust mites

Processed fruit: 10 rust mites / 2 cm 2

(1-3 oil or miticide applications / season)

Fresh fruit: 2 rust mites / 2 cm ?
(3-5 miticide applications / season)

109. Citrus Mealybug (Planococcus citri)

110. Citrus Mealybug (Planococcus citri)

«Most common in spring and early summer
‘Prefer sheltered locations within citrus trees
«females lay 300-600 eggs

‘feeding causes cosmetic damage to fresh
fruit

«most significant problem is large amounts of
honeydew produced

‘cultivars most affected include grapefruit,
navals, and valencia

«heavy fruit drop can occur on grapefruit

111. Citrus Mealybug

Sooty-mold

112. Natural enemies of the citrus
mealybug

«In most cases, mealybugs occur at low levels
and are under good biological control by three
natural enemies

Ladybird beetle- Cryptolaemus montrouzieri
- the “mealybug destroyer"
- abundant May - July

Fungus- Entomophthora fumosa
- prevalent after summer rainy season begins

Hymenopteran parasitoid- Leptomastidae abnormis

113. Coccinellid spp. contribute
mortality to several species
Of Homoptera in Florida

Cryptolaemus montrouzieri

“The mealybug
destroyer”

nymphal stage o
montouzierí ~~

114. Control of Mealybugs

Effective products for mealybugs have
negative effects on beneficial insect
populations

Pesticides should only be applied to
severe infestations

Applications are most effective when
applied before mealybugs have settled
between fruit clusters

115. Scale Insect Pests of Fruit

Armored scales (examples: Red scale, purple scale, etc...)

«scale insects in Florida citrus are under
biological control by a large number of
natural enemies

«No longer key pests in the development of
pest management programs

116. Biological control of scale insects

Factors for success

Sessile (slow-moving or no movement of
pest)

«High number of offspring

Populations are concentrated (easy for
natural enemies to find)

(aggregation of red
scale on green fruit)

117. Florida Red Scale (Chrysomphalus aonidum)
Homoptera: Diaspididae

*Feeding occurs only on leaves and fruit

*Feeding on fruit results in
discoloration at feeding

Be).
ns

we