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‫أنواع البق الدقيقى املنتشرة على العوائل النباتية املختلفة في مصر‬
Types of mealybugs deployed on different plant hosts in Egypt
Presented by,
Mohamed Abd El Wanis
Outline of presentation
Introduction
)1(Classification
(2)What do mealybugs look like?
(3)Mode of transport
The economic importance of mealybugs
Life cycle
 Case study
Families of mealybugs
LET’S GO TO CLASSIFICAION
PHYLUM
Arthropoda
CLASS
Insect
ORDER
Hemiptera - True Bugs, Cicadas, Hoppers, Aphids and Allies
SUBORDER
Sternorrhyncha
(12500 species)
SUPERFAMILY
Coccoidea - Scales and Mealybugs
)approx. 8000 species(
FAMILY(1)
Pseudococcidae
Pseudococcus citri (Risso)
Pseudococcus sacchari (Ckli)
Phenococcus hirsutus (Green)
Planococcus longispinus (Targioni)
Ferrisia vergata )Cockerell)
FAMILY(2)
Monophlebidae
Icerya purchasi (Mask)
Icerya aegyptiaca (Douglas)
Icerya seychellarum (Westwood)
FAMILY(3)
Ortheziidae
Orthezia insignis ( Browne )
Orthezia urticae (Linnaeus)
Phylogeny and higher classification of the
scale insects
(Hemiptera: Sternorrhyncha: Coccoidea)*
P.J. GULLAN AND L.G. COOK
1
2
Department of Entomology, University of California, One Shields Avenue, Davis, CA
95616, U.S.A. E-mail: [email protected]
2School of Integrative Biology, The University of Queensland, Brisbane, Queensland 4072,
Australia. Email: [email protected]
1
*In: Zhang, Z.-Q. & Shear, W.A. (Eds) (2007) Linnaeus Tercentenary: Progress
in Invertebrate Taxonomy. Zootaxa,
The Coccoidea is one of the four superfamilies of suborder Sternorrhyncha within the
Hemiptera (Schaefer, 1996; Bourgoin & Campbell, 2002; Gullan & Martin, 2003).
66 Accepted by C. Hodgson: 11 Jan. 2010; published: 16 Mar. 2010
ISSN 1175-5326 (print edition)
Copyright © 2010 · Magnolia Press ISSN 1175-5334 (online edition)
Zootaxa 2400: 66–68 (2010)
www.mapress.com/zootaxa/
Family-group names proposed in the family
Pseudococcidae
(Hemiptera: Sternorrhyncha: Coccoidea)
D.J. WILLIAMS & P.J. GULLAN
1
2,3
Department of Entomology, The Natural History Museum, Cromwell Road, London SW7 5BD, U.K
1
Subfamily Pseudococcinae
Antonina Signoret, 1875
Dysmicoccus Ferris, 1950
Humococcus Ferris, 1953
Mirococcopsis Borchsenius, 1948
Paraputo
Laing, 1929
Planococcus Ferris, 1950
Pseudococcus Westwood, 1840
Subfamily Phenacoccinae
Geococcus Green, 1902
Heterococcus Ferris,1923
Phenacoccus Cockerell, 1893
Rhizoecus Künckel d’Herculais, 1878
Ripersiella Tinsley, 1899
Ritsemia Lichtenstein, 1879
Xenococcus Silvestri, 1924
(Chun et all.2000)
These small insects are 1- 4 millimeters long. The females are covered with a
white, cottony or mealy wax secretion and look like tiny cotton balls on
plants, taking away a plant’s aesthetic value. They’ve got an oval body
outline, and functional legs allow them to be mobile in their immature
stage. Some mealybugs are more ornate than others, having filaments
around the edge of their bodies or even “tails.” Immature males and
females look similar, but they’re very different as adults: The adult male
looks like a gnat with one pair of wings. (Only the adult males fly.) Female
crawlers go though four developmental stages until they reach maturity.
The male goes through five
The mealybug is found on stems, leaves, buds, fruit and roots of many
plants
Crawlers crawl from an infected to healthy plant.
Small crawlers are readily transported by wind, rain, birds, clothing on new plants
The waxy coating facilitates passive transport of the insect by their
sticking/clinging to equipments, animals or people moving during field operations.
Long-distance movement is through transport of infested cotton sticks or seed
cotton.
Crawlers are also carried through irrigated water, when the mealy bug infested
plants are thrown in water channel.
Ants, attracted by the honeydew, carry crawlers of mealy bugs from plant to plant.
The economic importance of mealybugs
(Williams.2000)
Mealybugs rarely attack annuals but are important pests on perennials. They
attack roots, stems and leaves. Woody trees, shrubs and , grasses are the most
important plants infested.
Mealybugs prefer plants with a high nitrogen content.Trees grown in the
shade and those that received nitrogenous fertiliser have been observed to have
significantly heavier populations of mealybugs.
Nutritional differences may explain why some plants are infected with
mealybugs while other plants remain free from attack. Even differences in the
chemical composition between parts of any one plant could affect the choice of
feeding site.
The economic importance of mealybugs
(Kosztarab.1990) found that the damage caused by scale insects is
not primarily due to plant-sap ingestion itself but more often to the toxic
substances in the saliva which are injected into the plant tissue during the
feeding process. Enzymatic activity then causes a reaction by the host plant
that is manifested in different ways
(a) On leaves chlorosis (normally appears as a general or spottily yellowing)
(b) On fruits reddish discoloration encircles the insects while underneath the scale the
surface remains green
(c) Shoot and leaf petiol deformation
(d) Twig and branches deformations
usually as depressions on the barks
(e) Shallow often inconspicuous
open-top pit galls or blister-like galls are
produced
(f) Rarely pouch-like galls are
produced on host twigs and leaves
(g) A witches-broom type of
deformation caused
(h) Necrosis of cambial tissues and
stopping of the sap transportation in the
phloem is caused in cases of heavy
infestation
(i) Abortion of fruits due to
feeding on the fruit pedicel is
often observed
(j)Yellowish-brown
discoloration as well as
depression and cracking of the
fruit skin has been noted on
orange fruits
(k) Distortion of young fruits like vine is often indicated
(L) produce honeydew and infested plants may also exhibit sooty
mold fungi
ON ROOT
On leaves
ON BRANCHES
On fruits
Life cycle
Adult male
Life cycle
Adult female
Eggs hatch in 3 to 9 days into
nymphs called (crawlers)
ovisac
1-Scale insects are notorious pests on perennial plants as well as fruit and nut
trees. These pests belong to super family Coccoidae that contained twelve
families; three of them belong to genus Icerya: I. aegyptiaca (Douglas), I.
Purchasi Maskell and I. seychellarum (Westwood).
(Ezzat et all,1986)
2- the family Margarodidae is represented by six species of the mealybug
(Mohammad ,1998)
3- the family Diaspididae (the armored scales) represents the largest family
of the super family belonging to which includes major pests in Egypt. 72
species were listed of this family in Egypt. The second largest family is
Pseudococcidae that have 47 species of the mealybug belong to 28 genera
)Ghabbour et all,1996)
4-studied the distribution of the margarodid I.seychellarum on apple trees
where 61.9% of the margarodid where concentrated old branches,4.2% on
old leaves and 2.2% on new Leaves
(Mangoud,2000)
5- Scale insects were present in different parts of the world and they fall
within 23 families. Out of them 12 families are found in Egypt and the
most important families were: the armored scale insects (Diaspididae), the
mealybugs (Morgarodidae and Pseudococcidae) and the soft scales
(Coccidae). All important families contain dangerous species that attack
different important economic crops in Egypt
(Abd-Rabou, 2003
(John.1990)
Mealy bug provide ants with their sugary secretion (honeydew) as
food and in retur ants help in spreading of mealy bug
Ants provide protection to mealy bug from predatory ladybird
beetles, parasites and other natural enemies .
Ants keep mealy bug colony clean from detritus that accumulate in
the secreted honeydew, which may be harmful to the colony
PR
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A Review of the Association of Ants with
Mealybug Wilt Disease of Pineapple
Gary C. Jahn , John W. Beardsley , and Hector González-Hernández
1
2
Department of Entomology, University of Hawaii, Honolulu, Hawaii 96822 USA.
1Current address: International Rice Research Institute (IRRI), DAPO 7777, Metro
Manila,
Philippines. 2Passed away on February 5, 2001. 3Current address: Instituto de
Fitosanidad, Colegio
de Postgraduados, Montecillo, Texcoco, Edo. De México 56230 Mexico
1, 2, 3
3
Ants Associated with Mealybug Wilt Disease of Pineapple
In the 1920s, pineapple growers in Hawaii noticed that ants were common in the wilted areas of pineapple fields. They assumed that ants were
causing wilt disease and took mea- sures to destroy and prevent ant infestations. Based on observations, rather than experimen- tation,
Illingworth (1926a,b) concluded that ants did not cause wilt disease. He recognized the importance of mealybugs as pineapple pests and that ants
appeared to benefit mealy- bugs by deterring natural enemies, but thought that, overall, the predatory nature of ants made them beneficial to
pineapple growers. Therefore, he did not recommend ant control. A series of experiments led him to change his mind. Illingworth (1931)
demonstrated that ants themselves did not cause wilt disease, but that mealybugs did. He noted that without ants, the natural enemies already
present in the field might keep mealybugs under control. In light of this, he suggested that poisoning ants might be an effective means of
preventing mealybug wilt disease of pineapple. Since then, mealybug wilt disease has been controlled primarily through ant control. Experiments
confirm that ant control reduces mealybug popu- lations and prevents mealybug wilt disease (Beardsley et al. 1982; Carter 1933a, 1960; GonzálezHernández et al. 1999a,b; Jahn 1990).
While a number of ant species have been found in Hawaiian pineapple fields, the most pestiferous species in pineapple are Pheidole megacephala
(Fabricius), Solenopsis geminata (Fabricius), and Linepithema humile (Mayr). P. megacephala, the big-headed ant, is the dominant ant species
below 600 m elevation, where most Hawaiian pineapple fields are located (Fluker & Beardsley 1970, Reimer et al. 1990a). P. megacephala was
already com- mon on the Hawaiian island of Oahu in 1879 (Blackburn and Kirby 1880). The ants most commonly associated with pineapple
mealybugs throughout the world are species of Pheidole and Solenopsis (Table 1).
The Role of Ants in Mealybug Wilt Disease of Pineapple
Phillips (1934) hypothesized that mealybugs were associated with ants in pineapple fields
because: 1) ants protected mealybugs from natural enemies; 2) ants protected mealybugs from adverse weather by building earthen shelters
around them and moving them to pro- tected places; 3) ants transported mealybugs from plant to plant between and within fields, thus facilitating
mealybug dispersal; 4) ants stimulated increased feeding by mealybugs; and 5) ants removed honeydew from mealybugs, thereby preventing fungi
from attacking mealybugs. Rohrbach et al. (1988) hypothesized that honeydew feeding by ants could ben- efit mealybugs by preventing the
accumulation of honeydew on the mealybugs themselves. Presumably, immature mealybugs get stuck in honeydew and die if ants do not remove
it. Protection from natural enemies. Saying that ants “protect” mealybugs from natural enemies does not necessarily mean that ants are attacking
the natural enemies to save hon- eydew as a food resource. Possibly, ants are consuming the natural enemies as food and mealybugs benefit by
happenstance (Jahn and Beardsley 1994). There are numerous ex- amples of ants deterring the predators and parasites of scales, mealybugs, and
aphids (e.g., Van der Goot 1916; Way 1954, 1963; Wimp and Whitham 2001). For instance, in the ab- sence of Argentine ants, L. humile, parasites
suppress populations of lecaniine scale insects (Bartlett 1961). Ants also reduce parasitism of the cassava mealybug, Phenacoccus manihoti MatileFerrero (Cudjoe et al. 1993). Larval coccinellids eliminate green scales (Coccus viridis (Green)) from coffee trees in Hawaii unless P. megacephala
is present (Reimer et al.
1993). Green scales in Sri Lanka also cannot survive without ants (Oecophylla smaragdina Fabricius), but the ants apparently do not reduce
parasite and predator attacks on the scales (Bess 1958).
A wide variety of natural enemies prey on pineapple mealybugs (Table 2). Ants protect mealybugs from their natural enemies (GonzálezHernández et al. 1999a,b). In laboratory experiments with coccinellids, D. neobrevipes did not thrive on pineapples, unless ants were present
(Illingworth 1931). In the absence of natural enemies, laboratory populations of D. neobrevipes were not significantly different on pineapples with
and without ants (Jahn and Beardsley 1996). In the field, P. megacephala had a positive association with D. neobrevipes and a negative association
with the predators of mealybugs (Jahn and Beardsley
Conclusions
The available evidence suggests that mealybug wilt
disease of pineapple is a viral disease, though it is
possible that wilt is a toxemia induced by a virus that
affects the mealybug itself. The disease is managed
primarily by controlling ants. In the absence of ants,
natural enemies suppress mealybug populations on
pineapple. Chemical control of ants allows bio- logical
control of mealybugs to occur.
Table 1. Ants associated with pineapple mealybugs in various parts of the world.
References
Ants
Region
Carter 1939
Pheidole sp.
Australia
Brachymyrmex admotus Mayr, Camponotus cingulatus Mayr,
Crematogaster quadriformis Roger, Odontomachus haematoda (L.), Paratrechina fulva Mayr, Prenolepis
sp., Solenopsis saevissima (F. Smith)1, Wasmannia auropunctata (Rogers)
Brazil
de Bartoli 1982, Carter 1949
Nickel 1979
Tapinoma melanocephalum (Fabricius)
Cambodia
Carter 1935
Solenopsis sp.
Central America
Cuba Ministerio de
Agricultura 1989
Camponotus sp., Pheidole sp., Solenopsis sp.
Cuba
Carter 1939, 1942
Pheidole megacephala (Fabricius)
Fiji
Duodo and Thompson 1992
Araucomyrmex sp., Solenopsis sp.1
Guyana
Beardsley et al. 1982;
Carter 1932, 1967;
Fluker and Beardsley 1970;
Phillips 1934; Jahn 1992a
Linepithema humile (Mayr), Ochetellus glaber (Mayr), Pheidole megacephala1,
Hawaii, U.S.A.
Plagiolepis alluaudi Forel, Paratrechina bourbonica Forel, Paratrechina longicornis (Latreille), Solenopsis
geminata Jordon, Tapinoma melanocephalum, Tetramorium bicarinatum (Nylander), Tetramorium
simillimum (Smith)
Carter 1935
Solenopsis sp.
Jamaica
Carter 1939
Pheidole sp.
Kenya
Carter 1939
Solenopsis geminata (Fabricius)
Malaysia
Zarate 1987, Garcia 1987
Brachymyrmex sp., Monomorium sp., Pheidole sp., Solenopsis sp.
Mexico
Serrano 1934
Pheidole megacephala; Solenopsis geminata
Philippines
Table 1. Ants associated with mealybugs in various parts of the world
References
Ants
Region
Brachymyrmex heeri var. obscurior Forel, Cardiocondyla emeryi Forel,
Puerto Rico
Crematogaster steiheili Forel, Monomorium floricola (Jerdon),
Monomorium carbonarium ,ebenimum Forel, Paratrechina sp.,
Paratrechina fulva (Mayr),
Paratrechina longicornis, Pheidole megacephala, Solenopsis sp.,
Solenopsis geminata,
Plank and Smith 1940
Petty 1985, 1990
Tapinoma melanocephalum, Tetramorium sp.,
Wasmannia auropunctata
South Africa
Pheidole megacephala, Technomyrmex albipes (Fr. Smith)
Réal 1959
Camponotus sp., Crematogaster sp., and Pheidole sp.
North Africa
Families of mealybugs (Moursi et all.2009)
mealybugs belong to more than family most prominent in Egypt,
three families
Fam / Pseudococcidae ‫عائلة البق الدقيقى‬
SPECIES
Pseudococcus citri
Pseudococcus sacchari
Phenococcus hirsutus
Planococcus longispinus
Ferrisia vergata
Pseudococcus citri (Risso)
‫بق الموالح الدقيق‬
Saccharicoccus sacchari (Ckli( ‫بق القصب الدقيقى‬
Phenococcus hirsutus (Green) ‫بق الهبسكس الدقيقى‬
Planococcus longispinus (Targioni) ‫البق ذو الذيل الطويل‬
Ferrisia virgata )Cockerell) ‫البق الدقيقى األبيض‬
Fam / Monophlebidae
SPECIES
Icerya purchasi (Mask)
Icerya aegyptiaca (Douglas)
Icerya seychellarum (Westwood)
‫البق الدقيقى اإلسترالى )‪Icerya purchasi (Mask‬‬
Icerya aegyptiaca (Douglas) ‫البق الدقيقى المصرى‬
)‫عائلة اإلعالم القشرية (الصوب الزجاجية‬
Ortheziidae
SPECIES Orthezia insignis ( Browne )
Orthezia urticae (Linnaeus)
QUESTIONS??