Bài thuyết trình Citrus insect pest and their natural enemies
CITRUS INSECT PEST AND THEIR
NATURAL ENEMIES
Hoà Vaên Chieán, Leâ Quoác Cöôøng, Laâm Thị Mỹ Nương
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Southern Regional Plant Protection
Compiling based on Citrus pests and their natural enemies - Integrated pest
management in Australia edited by Dan Smith, GAC Beattie & Roger Broadley
Leafminer
(Phyllocnistis citrella Stainton)
1) symptom
Leafminer
(Phyllocnistis citrella Stainton)
Leafminer
•Adult
Leafminer
Egg and larva
Leafminer
Pupa
Life Cycle
Eggs
First instar
Adult
Second instar
Pupa in pupal chamber
Pupa
Third instar
Pre-pupa
Leafminer
(Phyllocnistis citrella Stainton)
Leafminer usually occur in the early rain season
and young shoot stage.
2). Life cycle
The complete life cycle takes 14-17 days or
times longer.
Most adults live for less than a week, female
moths start laying eggs about 24 hours after
mating.
Leafminer
(Phyllocnistis citrella Stainton)
Life cycle
Eggs are laid at night, a female can laid more than
50 eggs their life (as many as 20 eggs per night).
The flat, slightly oval eggs are about 0.3 mm long
and look like tiny water droplets on the leaves. Eggs
are deposited singly, on the undersides of leaves
near the midrib, usually at the base of the leaf.
Young leaves 10-20 mm in length are preferred sites
for egg laying.
Leafminer
(Phyllocnistis citrella Stainton)
Hatching can occur within a day, and the young larva
immediately burrows under the leaf surface.
Each pale-green larva tunnels a characteristic, sinuous,
silvery mine in the leaf, with a raised parchment-like skin
lined centrally with dark excreta. Larva never leave their
mines to form other mines or move between lower and
upper sides of leaves. Damage is caused by the larvae as
they mine immature foliage. Twisted and curled leaves are
generally the first symptom noticed.
Larva stage is about 5-6 days. The pre-pupa and pupa are
about 6 days and then adults emerge.
The leaves growth stages and their symptom
Aphids
(Toxoptera sp.)
1) Symptom
Aphids
(Toxoptera aurantii Boyer de Fonscolombe)
Aphids are dark brown or black and about 2 mm long.
They live on the young leaves and shoots with high
density They feed on plant sap, using their sucking
mouthparts. They produce a sugary liquid (honeydew), on
which sooty mould grows, and can transmit plant viruses.
Aphids may be winged or wingless, depending on the
state of their food supply and their density
Damage: deformation, flower drop, sooty mould, reduced
fruit set, distortion of young leaves and shoots.
Aphids
2). Life cycle
There are probably
25-30 generations
per years.
The most important
known of vectors
tristeza virus to
citrus plant. It is
very dangerous for
citrus grower
wingless
Adult
winged
Adult
nymph
Whitefly
(Aleurodicus dispersus)
1). Symptom
Whitefly (Aleurodicus dispersus)
Citrus whitefly usually occur on undersides of
young leaves , they are 2.5 mm long, with white
powdery wings. Adult look like small moths,
they are related to scale insect.
Adult will fly out in swarms if foliage is
disturbed.
The eggs are yellow and oval-shaped with
white powdery wax, underside the young
leaves or fruits, and circular egg laying pattern .
Whitefly (Aleurodicus dispersus)
2). Life cycle
The larvae settle in group on the underside of
leaves . At first they are flat and resemble scale
crawlers feeding and developing beneath a
protective waxy covering. Both adults and nymphs
produce sticky honeydew on which sooty mould
grows, and transmitting virus diseases.
Three growth stages are followed by a pupa and
then winged adult. The pupae are often found on
leaf midribs and look like young soft brown scale.
There are at least 5 to 6 generations per year.
Whitefly
Citrus Hopper
(Colgar peracutum Walker)
Citrus Hopper
(Colgar peracutum Walker)
1). Shape and habits
Citrus Hopper is about 10 mm long. When at rest their
wings are tent-like shape. Citrus Hopper can occur on
mango also;
They are pale green to white, with small red spot in the
middle of each forewing, and usually a red border on the
forewings. Citrus Hopper are usually green, and covered with
small yellow spots. Both adult and larvae are mobile,
skipping short distances when disturbed. Adult are weak
fliers
Citrus Hopper
(Colgar peracutum Walker)
2). Life cycle
The eggs of species are laid in oval shaped
masses about 50 eggs. The eggs masses are
about 5 mm in diameter. At first eggs are
white, but they darken near hatching.
Four growth stages are followed by adult.
The complete life cycle takes 1 to 2 months
There are about 3 to 6 generations per year.
Citrus Hopper
2). Life cycle
Spined citrus bug
(Rhynochocoris poseidon Kirkaldy)
1). Shape and damage symptoms
The spined citrus bug 15-20 mm long with a
prominent spine on each shoulder of the
thorax. Both nymphs and adults of plant-
feeding species cause plant and fruit damage
with their sucking mouthparts. The bug pierce
the rind of fruit at any stage causing drying
and brown staining of segments, gumming and
fruit drop. In ripe fruit, damage is often not
evident until the fruit is cut open. Young fruit
fall readily after attack. They can cause total
crop loss
Spined citrus bug
(Rhynochocoris
poseidon Kirkaldy)
Damage symptoms
Spined citrus bug
(Rhynochocoris poseidon Kirkaldy)
2). Life cycle
Citrus butterflies
(Papilio demoleus L.)
1). Shape
There are many species butterflies on citrus; the fully
grown larva of the big citrus butterflies is 70 cm long(and
50 cm for small one), they are brown to olive green in
color, with a reddish band near the front.
Larvae of both species have rows of small fleshy spines
on the body.
The big citrus butterfly has the wing span of about 130
mm (75 cm for small one). Wings of the male are black
with white markings, while the hind wings of the female
are brightly marked with white, orange and blue.
Citrus butterflies
(Papilio demoleus L.)
Adults
eggs
Citrus butterflies
(Papilio demoleus L.)
Larvae
Adult and pupa
Citrus butterflies
(Papilio demoleus L.)
2). Life cycle
Butterfly lay eggs singly on the tip of the
young leaves. The eggs of species are
yellow, spherical and 2-2.5 mm in diameter.
The larvae pass through 5 instars, settle and
feeding on young leaves before pupating in
an upright position attached to a citrus twig
by silken pad at the tail end, and a fine silken
girdle at the waist.
The complete life cycle takes 2-3 months.
There are at least 3 generations per year.
Citrus butterflies
(Papilio demoleus L.)
2). Life cycle
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11/03/2024
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