Unit D: Controlling Pests and Diseases in the Orchard
Lesson 3: Identify and Control Insects of Fruits and Nuts
Student Learning Objectives: Instruction in this lesson should result in students
achieving the following objectives:
1. Understand terminology related to insects and their life cycle.
2. Identify and describe common orchard insects.
Recommended Teaching Time:
4 hours
Recommended Resources: The following resources may be useful in teaching
this lesson:





A PowerPoint has been developed for use with this lesson plan
The Internet contains a large amount of information about orchard insect control. Below
are a few excellent sources.
http://extension.usu.edu/files/publications/insects%2013%20apple%20aphids..pdf
http://entnemdept.ufl.edu/creatures/veg/aphid/green_peach_aphid.htm
http://en.wikipedia.org/wiki/Codling_moth
http://agspsrv34.agric.wa.gov.au/Ento/Surveillance/Oriental%20red%20mite.html
List of Equipment, Tools, Supplies, and Facilities
Writing surface
PowerPoint Projector
PowerPoint Slides
Copies of student lab sheets
Common insects of Afghanistan (live or preserved)
Magnifying glass or microscope (optional) to view bugs
Terms: The following terms are presented in this lesson (shown in bold italics and on
PowerPoint Slide #2):
Eggs
Nymph
Adult
Instar
Imago
Larvae
Pupa
1
Interest Approach: Use an interest approach that will prepare the students for the
lesson. Teachers often develop approaches for their unique class and student situations. A
possible approach is included here.
If the students collected insects from the previous lesson have them set their samples
on the desk. If they do not have any insects provide them with samples or take them
outside again to search for insects. Once all students have at least one or more
insects, have them write down as many characteristics describing the insect as they
can. The students can then pass their insect around the room so that each student has
a chance to see the different insects. This activity will introduce the students to
describing insects and will also allow them to interact with the insects they will learn
about in the lesson.
Summary of Content and Teaching Strategies
Objective 1: Understand terminology related to insects and their
life cycle.
(PowerPoint Slide #3)
I.
Understanding the vocabulary used when describing insects will help when controlling
insects in the orchard. Some common terms include:
A. Most insects develop from eggs which contain the developing nymph
B. Nymph is the name given to the young stages of those insects which undergo a
partial metamorphosis. The nymph is usually quite similar to the adult except that
its wings are not fully developed. It normally feeds on the same kind of food as
the adult.
(PowerPoint Slide #4)
C. The adult is the mature form of the insect which has the ability to reproduce.
D. Instar is the stage in an insect's life history between any two moults. A newlyhatched insect which has not yet moulted is said to be a first-instar nymph or
larva. The adult (imago) is the final instar.
E. Larvae is the name given to a young insect which is markedly different from the
adult: caterpillars and fly maggots are good examples.
F. The 3rd stage in the life history of butterflies and other insects undergoing a
complete metamorphosis during which the larval body is rebuilt into that of the
adult insect is called a pupa. It is a non-feeding and usually inactive stage
Obtain an example of each of these insect stages. If all stages cannot be obtained show
some examples by using pictures. Alternatively, have the students go outside and try
to find each of these stages. Note: success in this activity will depend upon the season.
2
Objective 2: Identify and describe common orchard insects.
(PowerPoint Slide #5)
II. There are a number of insects which can cause damage in a fruit and nut orchard. The
most common insects and their control methods are covered below. This is not an allinclusive list and other insects may occur in your area.
(PowerPoint Slide #6)
A. Leopard Moth (Zeuzera pyrina)
1. Life cycle and description
a. oval and salmon to orange-yellow color about 1.5 mm long.
Females will lay 400-600 eggs under the bark of trees.
b. Adults Leopard Moths have a furry white thorax with six black
spots.
i.
The wings are heavily spotted and are about 35–60 mm
long.
ii.
Females are larger,
iii.
The moth flies from June to September depending on the
location.
c. Larvae will hatch in about 10 days after eggs are laid.
d. Soon after they will burrow into the nearest bud, twig or branch
crotch.
(PowerPoint Slide #7)
e. They will enter the pith and grow to about 25 mm by the end of the
first season.
f. In fall, larvae bore tunnels that slant upward, 50 mm or more below
the bark surface, where they remain dormant over winter.
g. Larvae resume feeding the following summer, pass a second
winter in dormancy, and begin pupation the second spring after the
eggs hatch.
h. Pupation takes about 4 weeks.
i. The pupal cases remain in the exit holes and is one method of
determining their existence in the orchard.
(PowerPoint Slide #8) This slide shows pictures of the life stages of the Leopard Moth
(PowerPoint Slide #9)
2. Damage
a. The caterpillar feeds on the fruit and nut trees.
b. It can burrow inside the branches and feed for up to two years
where it will emerge and pupate under the bark.
c. The earliest signs of damage will be girdled or broken twigs.
(PowerPoint Slide #10) This is a picture of a Leopard Moth caterpillar feeding inside a
branch.
3
(PowerPoint Slide #11)
3. Control
a. It is difficult to control this pest once it has burrowed into the stems
and branches.
b. Controlling the adults before they lay eggs or the caterpillars before
they burrow into the stems and branches will ensure control in the
next year.
c. The best control is birds, also remove any infected branches and
destroy them by burning.
d. Insecticides can be used in the tunnels.
e. Since females do not move far from where they pupated to lay their
eggs, space trees far enough so that the moths will not move to
other trees.
(PowerPoint Slide #12)
B. Apple Aphid (Aphis pomi)
1. Life cycle and description
a. Eggs are shiny black and oval shaped.
b. They are generally found on smooth twigs and water sprouts.
c. The green-colored young, called nymphs, begin to hatch from
overwintered eggs as soon as shoot leaves are rapidly expanding.
i.
The nymph is about 1.5 mm long, yellow-green to dark green
and oval shaped, generally found on smooth branches or
leaf undersides.
(PowerPoint Slide #13)
d. The adult can be winged or wingless about 3 mm long and bright
green.
i.
The adult will commonly be found on the underside of
leaves.
e. The first aphids produced in the spring are generally female who
produce live young asexually.
f. Towards the end of the season both male and females are born so
that eggs can be produced for overwintering.
(PowerPoint Slide #14)
g. During the spring and summer, females produce live young without
mating.
h. In addition, they can complete a life cycle in as short as one week
during the warm summer months.
i. The short generation time and ability of these aphids to reproduce
asexually allows them to rapidly increase their populations and
feeding injury to apple trees.
(PowerPoint Slide #15) This shows a picture of the life stages of the Apple Aphid.
(PowerPoint Slide #16) This slide shows Apple Aphids clustering on an apple branch.
4
(PowerPoint Slide #17)
2. Damage
a. Aphids feed by sticking their mouthparts into the leaf and sucking
out the sap.
b. Leaves affected by aphids will often appear dried and shriveled.
Aphids produce a secretion called honeydew.
c. If large populations of aphids are present this honeydew can drip
down onto fruit or other parts of the tree and cause sooty mold.
d. This will reduce marketability of fruit and weaken the tree.
e. Established trees are rarely damaged as any minor leaf loss will not
have a major impact on fruit production.
f. Young trees can be greatly damaged or even killed if aphid
infestations are too high.
(PowerPoint Slide #18) This shows a picture of sooty mold caused by honeydew from
aphids.
(PowerPoint Slide #19)
3. Control
a. Natural enemies include lady beetles, lacewings, parasitic wasps
and certain fungi.
b. Organic insecticidal sprays are effective and often include liquid
dishwashing soap.
c. Because of their size, aphids are often easily controlled by a strong
blast of water to displace them from the leaves of the affected plant.
d. Dry weather also greatly reduces the population.
(PowerPoint Slide #20)
C. Wooly Apple Aphid (Eriosoma lanigerum)
1. Life cycle and description
a. Wooly Apple Aphid produces live young.
b. The nymphs are about 1.25 millimeters long and are reddish purple
in color covered in a white cottony wax.
c. Wooly Apple Aphids (WAA) overwinters as nymphs.
d. The adults are about 1.5 millimeters long and similar in color to the
nymph.
e. Females are generally observed on the apple tree, males are rare.
f. Females produce live young without mating.
(PowerPoint Slide #21) This slide shows the different forms of the WAA.
(PowerPoint Slide #22)
2. Damage
a. WAA can attack the roots and cause galls.
b. Over several seasons the galls will increase in size and cause
major root damage.
c. Similar to the Apple Aphid, the WAA produces honeydew causing
sooty mold on the fruit and tree.
5
(PowerPoint Slide #23) This shows a picture of sooty mold caused by honeydew from
aphids.
(PowerPoint Slide #24)
3. Control
a. The most important natural enemies are green lacewing larvae,
lady beetle adults and larvae, and syrphid fly larvae.
b. Flowering plants in or on the borders of orchards provide nectar
and pollen, which helps maintain and attract natural enemies.
c. If replanting or starting a new orchard, plant resistant rootstock.
d. The Malling Merton (MM) rootstock series, MM.106 and MM.111,
have been bred to be resistant to WAA.
(PowerPoint Slide #25)
e. WAA are easily controlled with broad-spectrum insecticides.
f. In order to significantly increase insecticide efficacy, it is
recommended a horticultural oil be added to the tank mix.
g. Without horticultural oil the insecticide has difficulty penetrating the
waxy covering of the colony.
(PowerPoint Slide #26)
D. Green Peach Aphid (Myzus persicae)
1. Life cycle and description
a. Eggs are deposited on Prunus spp. trees.
b. The eggs measure about 0.6 mm long and 0.3 mm wide, and are
elliptical in shape.
c. Eggs initially are yellow or green, but soon turn black.
(PowerPoint Slide #27)
d. Mortality in the egg stage sometimes is quite high.
e. Nymphs begin greenish but turn yellowish.
f. Adults can be winged or wingless.
g. They have a black head and thorax and a yellowish green
abdomen.
h. They measure 1.8 to 2.1 mm in length.
(PowerPoint Slide #28) This shows various pictures of the aphids up close.
(PowerPoint Slide #29)
2. Damage
a. Green Peach Aphids will travel to any plant available and will
deposit a few young and then move on to another place.
b. Aphids will then begin to colonize on peach trees when the leaves
begin to turn color and fall off.
c. The Green Peach Aphid damages trees much like the other aphidsby sucking out the sap from leaves and tender stems.
(PowerPoint Slide #30)
d. The major damage caused by the Green Peach Aphid is through
the transmission of plant viruses.
6
e. Both nymphs and adults can spread the virus, but adults can
spread it more because of their mobility.
f. Over 100 viruses have been identified to be carried by the aphids.
(PowerPoint Slide #31) This is a picture of what a large population of aphids can do to a
plant.
(PowerPoint Slide #32)
3. Control
a. Natural enemies of the Green Peach Aphid are the same as the
other aphids- lady beetles, lacewings and parasitic wasps and
fungi.
b. Using horticultural oils and insecticides are a very effective way to
control large outbreaks.
(PowerPoint Slide #33)
E. San Jose Scale (Aspidiotus perniciosus)
1. Life cycle and description
a. Partially mature nymphs overwinter on branches and in spring
developed into winged males or females which do not move.
b. When the weather is warm and trees have budded out, females will
lay eggs which hatch immediately.
c. The young are called crawlers.
(PowerPoint Slide #34)
d. They look for new shoots and settle to feed until adults where they
will overwinter to complete the cycle again.
e. Multiple generations per year are possible.
f. Scale is a very tiny insect covered in a scab-like structure.
g. If the scale is removed a yellow body can be seen.
(PowerPoint Slide #35) This is a picture of the scale insect after the scale is pulled off.
(PowerPoint Slide #36)
2. Damage
a. San Jose scale can infest branches, shoots, leaves, and fruit.
Adults and nymphs suck plant juices and cause considerable
damage. They have been known to seriously weaken branches and
main scaffold limbs, thus causing permanent injury to mature trees.
Crawlers settling on fruit may cause fruit spotting.
(PowerPoint Slide #37) This picture shows damage on a pear caused by scale.
(PowerPoint Slide #38)
3. Control
a. Oil sprays can be effective in controlling low to moderate
populations of San Jose Scale.
b. Native predators are also very effective.
7
c. Predators include the twicestabbed lady beetle, Chilocorus orbus,
and another small beetle Cybocephalus californicus.
(PowerPoint Slide #39) This is a picture of a predatory insect attacking scale.
(PowerPoint Slide #40)
F. Olive Scale (Aspidiotus hederae)
1. Life cycle and description
a. The adult female scale is about 0.10 (2.5 mm) inch long, with a
grayish, oval, waxy covering.
b. The male scale is more elongate with a black spot at one end.
c. If the coverings are removed, the scale bodies of both sexes are
reddish purple.
(PowerPoint Slide #41) A picture of Olive Scale.
(PowerPoint Slide #42)
2. Damage
a. Olive scale feeds on twigs, leaves, and fruits.
b. The first brood will emerge early in the growing season and eat the
young rapidly growing fruit.
c. A second brood in mid-season causes purple spotting on the green
fruit.
d. Heavy infestations greatly reduce the productivity of the tree.
(PowerPoint Slide #43)
3. Control
a. Olive scale is effectively controlled by natural enemies such as
Aphytis maculicornis and Coccophagoides utilis.
b. Chemical treatment is rarely needed unless the biological control is
disrupted.
(PowerPoint Slide #44)
G. Citrus Whitefly (Dialeurodes citri)
1. Life cycle and description
a. Adults are white and have a distinctive Y-shape on their back.
b. Whiteflies develop rapidly in warm weather, and populations can
build up quickly in situations where natural enemies are destroyed
and weather is favorable.
c. They grow in stages.
i.
the first nymph is a very small crawler, later nymph stages
settle and remain immobile and are flattened and oval.
ii.
Older nymphs do not move.
iii.
Finally a winged adult emerges.
iv.
All stages feed by sucking juices from leaves.
(PowerPoint Slide #45) This slide shows the various life cycle stages of the Citrus
Whitefly.
8
(PowerPoint Slide #46)
2. Damage
a. Whiteflies suck sap out of the phloem.
b. Large populations can cause massive leaf death.
c. Whiteflies produce honeydew like aphids so black sooty mold can
occur.
d. Low levels of whiteflies are not generally damaging but some adults
can carry plant pathogens.
3. Control
a. Large populations of whiteflies are hard to control and can be
adequately controlled by beneficial insects.
(PowerPoint Slide #47) This is a picture of damage caused by Citrus Whitefly.
(PowerPoint Slide #48)
H. Citrus Leafminer (Phyllocnistis citrella)
1. Life cycle and description
a. Adults are very small, about 4 mm wingspan, with white and silvery
iridescent scales on the forewings.
b. There is a noticeable black spot on each wing tip.
c. The hind wings and body are white, with long fringe scales
extending from the hindwing margins.
(PowerPoint Slide #49)
d. Larvae are very small (3mm) and translucent yellow-green.
e. They can be found on the underside of leaves creating meandering
paths inside the leaf.
f. Usually only one leaf mine is present per leaf but heavy infestations
may have two or three mines per leaf.
g. larvae are protected within the leaf during their feeding cycle.
h. Larvae have four instars and development takes from five to 20
days.
(PowerPoint Slide #50)
i. Pupation is within the mine in a special pupal cell at the leaf margin,
under a slight curl of the leaf.
j. Pupal development takes six to 22 days.
k. Adults emerge about dawn and are active in the morning; other
activity is at dusk or night.
(PowerPoint Slide #51) This shows the life cycle of a Citrus Leafminer
(PowerPoint Slide #52)
2. Damage
a. Larvae mine into the leaves of citrus trees.
b. They eat through the leaf destroying tissue and disrupting nutrient
transfer.
9
3.
Control
a. Biological control and application of oil are suitable methods to help
reduce populations.
b. Because of their position inside the leaf, larvae may be hard to
eliminate.
(PowerPoint Slide #53) This slide shows the meandering path created by the larvae of
the Leafminer.
(PowerPoint Slide #54)
I. Codling Moth (Cydia pomonella)
1. Life cycle and description
a. The Codling Moth is the main pest of apple.
b. The adult moth is greyish with light grey and copper stripes on its
wings, with a wingspan of 17 mm.
c. The females lay eggs on fruit or leaves and the black-headed
yellow larvae attack the fruit immediately upon hatching.
d. Each larva burrows into the fruit, eats for around three weeks, then
leaves the fruit to overwinter and pupate elsewhere.
e. They mainly feed on the seeds of the apple.
(PowerPoint Slide #55) This slide shows pictures of the life stages of a Codling Moth.
(PowerPoint Slide #56)
2. Damage
a. Larvae bore into the interior of the apple consuming the seeds and
apple.
b. The infected fruits will often abort and fall off the tree.
c. Once the caterpillar has entered the apple it is of no use as a
marketable fruit.
(PowerPoint Slide #57) This is a picture of a Codling Moth caterpillar inside of an apple.
(PowerPoint Slide #58)
3. Control
a. Insecticides are generally the best method of control for Codling
Moths.
b. Because of their location inside the apple, they are protected from
any natural enemies, leaving biological control out of the control
methods.
c. Another method for control and sampling, 'trunk banding', consists
of wrapping a corrugated cardboard strip around the tree trunk.
d. Larvae making their way back to the tree to pupate after the
infested fruits are aborted will use bands as pupation sites.
e. Bands may then be removed and burned.
10
(PowerPoint Slide #59)
J. Red Spider Mite (Tetranychus telarius)
1. Life cycle and description
a. The adult female is approximately 0.65 mm long, rotund oval in
shape, and pale yellow or greenish with two characteristic lateral
dark green or black spots on the body.
b. The adult male is slightly smaller than the female and has a
narrower, more pointed abdomen.
c. Eggs are spherical and very small (about 0.1 mm in diameter).
(PowerPoint Slide #60)
d. Nymphs vary in coloration, depending on their host plant, but are
normally pale yellow, pale green, or beige, with two green spots.
e. Frequently the end of the abdomen is a dark green.
f. The first stage is six-legged while the second stage is eight legged.
g. The adult females overwinter to begin the life cycle the next
season.
(PowerPoint Slide #61) This shows pictures of various stages of the Red Spider Mite.
(PowerPoint Slide #62)
2. Damage
a. The Red Spider Mite will attack grapes, raspberries and tree fruits.
b. They damage the plant by piercing the plant cells and sucking out
the contents.
c. This results in a noticeable pale colored spotting on the topside of
the leaf.
(PowerPoint Slide #63) This is a picture of damage caused by mites.
(PowerPoint Slide #64)
3. Control
a. There are a number of miticides available for mite control in the
orchard.
b. However, mites rarely reach a level that can cause major economic
damage to an orchard.
c. In general, if fruit trees are healthy and well established a mite
population will not have a major impact on production.
(PowerPoint Slide #65)
K. Oriental Mite (Eutetranychus orientalis)
1. Life cycle and description
a. Adult females are larger than the males.
b. They are oval and flattened and are often pale brown through
brownish-green to dark green.
c. The citrus brown mite can only be identified by the adult male and
is easily mistaken for the Texas citrus mite (E. banksi).
11
(PowerPoint Slide #66)
d. Females begin to lay eggs when only a few days old.
e. The eggs are laid along the main veins of the host plant leaves and
hatch after a week or less.
f. The length of the entire life cycle is around 10-12 days.
g. Adult longevity lies between 1 and 3 weeks.
h. Under optimal conditions, there can be 10-30 generations per year,
depending on the geographical location.
(PowerPoint Slide #67) This is a picture showing the difference between male and
female Oriental Mites.
(PowerPoint Slide #68)
2. Damage
a. The presence of E. orientalis can be detected by discoloration of
the host leaves and pale-yellow streaks along the midribs and
veins.
3. Control
a. Oriental mites are primarily found on citrus.
b. There are a number of miticides available for mite control in the
orchard.
c. However, mites rarely reach a level that can cause major economic
damage to an orchard.
d. In general, if fruit trees are healthy and well established a mite
population will not have a major impact on production.
(PowerPoint Slide #69) This picture portrays what damage done by Oriental Mites looks
like.
After this objective, have the students determine if any of these insects are the ones
they collected. Also, have the students decide if any insects should be added to this
list and have them create the description, damage, and control for the insects.
Review/Summary: Use the student learning objectives to summarize the lesson. Have
the students explain the response to the anticipated problem of each objective. Student
responses can be used to determine which objectives need to be reviewed. Questions on
PowerPoint Slide #70 can be used as review.
Application: Have the students complete LS: D3-1 Insect Information.
LS: D3-1 Grading
Rubric can be used to help the students focus on what to include about the insect they will
study and how they will be evaluated on the project.
Evaluation: Evaluation should focus on student achievement of this lesson’s objectives. A
sample written test is attached.
12
Answers to Sample Test:
Matching
1. D
2. A
3. E
4. B
5. F
6. G
7. C
Short Answer
1. There are various answers possible but they could include: Organic control is healthier for
the applicator as the chemicals used are not harmful to the human body. Organic spray can
cost more than conventional chemical sprays. Conventional chemical sprays are also
sometimes more effective.
2. Because mites rarely ever reach a level of economic impact, no spraying would be
necessary. If there were a large outbreak, a miticide could be used.
13
Sample Test
Name_____________________________________
Test
Unit D Lesson 3: Identify and Control Insects of Fruits
and Nuts
Part One: Matching
Instructions. Match the term with the correct response. Write the letter of the term by the
definition.
a. Eggs
b. Nymph
c. Adult
d. Instar
e. Imago
f. Larvae
g. Pupa
_______ 1. The stage in an insect's life history between any two moults.
_______ 2. This contains the developing nymph.
_______ 3. This is another term for the adult, also the final instar.
_______ 4. The name given to the young stages of those insects which undergo a partial
metamorphosis.
_______ 5. The name given to a young insect which is markedly different from the adult.
_______ 6. Complete metamorphosis during which the larval body is rebuilt into that of the
adult insect.
_______ 7. The mature form of the insect which has the ability to reproduce.
Part Two: Short Answer
Instructions. Provide information to answer the following questions.
1. Describe the benefits of organic methods of insect control over conventional chemical
control.
2. You have found an outbreak of mites in your orchard. What can you do to control them?
14
LS: D3-1
Insect Information
Now that you have learned about some common orchard insects, you are going to create an
informative document that can be passed out to members of the class as well as local orchard
owners. The informative document should include the following items:
-Insect name: both common and Latin
-Description: describe what each life cycle looks like (egg, nymph, adult, etc. depending upon
insect)
-How does it damage the tree?
-Which tree species does it commonly attack?
-What are some methods of control? (try to include organic as well as chemical/biological)
-Does it have any native natural enemies?
-Other interesting facts (include at least 3)
The format of the document could be a pamphlet, a flyer, or a small booklet. The format does
not matter as long as the required information is included, however you will be graded on the
functionality and design of the document. The rubric that will be used to grade your
informative document is provided.
15
LS: D3-1 Grading Rubric
Insect Information Rubric
Item
Name
Plant species
attacked
3 points
Both common and
Latin name
provided and
spelled correctly
Description covers
all appropriate
stages of the
insect’s life cycle
Adequate detail of
damage caused is
provided
All possible
options are
covered including
organic and
chemical/biological
Lists major plant
species attacked
Natural
enemies
Lists all important
natural enemies
Interesting
facts
Overall design
of document
3 facts listed
Description
Damage
Control
Document is very
attractive and
purposeful
2 points
Has common
and Latin name
but is misspelled
1 point
Missing either
common or Latin
Name and is
misspelled
Description is
missing 2 or
more stages
0 points
No common or
Latin name
provided
No damage
detail provided.
Missing some
major plant
species attacked
Lists natural
enemies but is
missing some
2 facts listed
Very little
damage detail
provided
Needs more
options
available/more
options exists
that are not listed
Missing a lot of
major plant
species attacked
Missing a lot of
major natural
enemies
1 fact listed
Document is
designed well
but could
improve
Document has
major flaws and
needs
improvement
Document is
unsatisfactory
Description is
missing at least
one stage of the
insect’s life cycle
Damage detail is
provided but
could use more
Possible options
are included but
could use more
Points Earned
No description
provided
No control
options provided
No plant species
attacked
No enemies
listed
0 facts listed
Total Points
16