Papaya mealy bug, an important insect pest which has a vast potential to harm the crop has been briefly discussed here. And further the control measures suitable for it are also mentioned
2. Papaya Mealybug (Paracoccus marginatus)
• Adult female is yellowish segmented, flattened oval, about two millimetres long
covered with mealy wax.
• a number of short waxy filaments projecting around the margin.
• The ovisac is well developed and visible underneath the posterior part.
• Sometimes the wax looks like cotton wool and oozes drops of fluid.
• The adult male is pinkish and about one millimetre long, with well-developed
wings each marked with a small basal vein.
• can easily be distinguished from Maconellicoccus marginatus (Green), the pink
hibiscus mealybug, because papaya mealybug females have eight antennal
segments, in contrast to nine in the latter.
5. Host plants
o Papaya
o Avocado
o Citrus
o Mango
o Cherry
o Pomegranate
o Hibiscus
o Cotton
o Tomato
o Eggplant
o Peppers
o Beans
o Peas
o sweet potato.
• The papaya mealybug is polyphagous and feeds on over 55
plants in more than 25 genera.
• Economically important host plants include
6. Symptoms
Papaya mealybug: sucking insect that injects a toxic substance into the leaves while feeding.
They are generally observed as clusters of cotton-like masses on leaves, stems or fruit and
symptoms caused by infestation are as follows:
• Leaf chlorosis, deformation or crinkling due to toxins
• Premature aging of leaves, flowers and fruit causing these plant parts to drop under severe
infestation
• Fruits may fail to develop normally and may be unusually small. Affected fruit may shrivel
and drop.
• Flowers may be distorted or fail to open. Petals may be malformed or blemished.
• Sooty mould formation due to honeydew excretions by mealybugs
• Thick, waxy coating on leaves, stems and fruit under heavy infestation
8. Biology
• Adult female deposits up to 600
eggs into her ovisac over a period
of one to two weeks.
• The eggs hatch ten days later and
the crawlers disperse.
• There are 4 instars in the females
and 5 in the males.
• The fifth instar male is a pupa in
which the nymph
undergoes metamorphosis into a
winged adult
9.
10. Economic impact
• causes serious damage to papaya, other tropical fruit and ornamentals such
as Annona and Hibiscus spp.
• Mealybugs suck sap and infestations can cause crinkled and twisted leaves,
reduced fruit development or reduced quality of fruit.
• Heavy infestations excrete honey dew, resulting in development of sooty
mould which can also reduce yield and plant growth.
• Due to the potential damage on papaya and wide host range the economic
impact is considered to be High.
11. Management
• none are currently registered specifically for control of papaya mealybug.
• Active ingredients acephate, carbaryl, chlorpyrifos, diazinon, dimethoate,
malathion, and white mineral oils.
• Typically, twice the normal dose is applied when treating for mealybugs because
mealybugs are protected by thick waxy, cottony sacs, and often are concealed
inside damaged leaves and buds.
• only partially effective and require multiple applications.
• Furthermore, problems with insecticide resistance and non-target effects on
natural enemies make chemical control a less desirable control option
Chemical control
12. Physical control
• Destruction of all heavily infested plant parts on the spot
• Avoiding transportation of infested plant material
• Avoiding pruned, infested plant parts being left unattended
• Spraying plants near houses and in home gardens with a soap + kerosene oil
+ water mixture
• Use of botanical pesticides to treat agricultural crops in home gardens
• Wrapping polythene/spongy tapes impregnated with insecticides around
tree trunks to exclude ants from the canopy
13. Biological control
• Four genera of encyrtid endoparasitoid wasps specific to mealybugs were collected as
potential biological control agents:
• Acerophagus papayae
• Anagyrus loecki
• Anagyrus californicus
• Pseudaphycus sp
• All four wasps were observed parasitising second and third instars of the papaya mealybug,
and Acerophagus papayae was the dominant species.
• All four have since been mass-reared and released
• A fifth collected species was later reared and identified as Pseudleptomastix mexicana
14. Other natural enemies of the papaya mealybug include
• Cryptolaemus montrouzieri
• other lady beetles,
• Lacewings (Chrysoperla rufilabris)
• Hoverflies (Pisyrphus balteatus).
17. • Papaya Mealybug in India
• Papaya mealybug found in August 2008
• Parasitoids introduced in August 2010
• Controlled by February 2011
18. THANK YOU
Reference:
• http://entnemdept.ufl.edu/
• Miller DR and Miller GL 2002 Redescription of Paracoccus marginatus Williams and Granara de
• http://creatures.ifas.ufl.edu/ fruit / mealy bugs / papaya_mealybug.htm
• http://www.bugwood.org/