In Alexandria and north coast the most dominant species of pine trees was Pinus
halepensis (Aleppo pine) and P. brutia (Turkish pine). They were
closely related species of Genus Pinus, Family Pinaceae. The study was done
in two different areas. The first area was about two and half acres of mixed
pine trees in Nubaria district south Alexandria. This cultivated area was the
farm of Plant Protection Research Institute (PPRI). The second area was cultivated
with about 125 trees of Aleppo pine species in Marina resort (94-114 km) west
of Alexandria. They were public garden mixed with other ornamental trees.
The area belongs to Agency of tourist villages of the New Urban Communities
Agency. They were cultivated during the period 2000-2004 (documentation paper
in the Ministry of Housing and Construction). The rest of investigated pine
trees were found in private gardens with mixed flora of other plants. The species
Pinus radiata D. Don dose not included in this survey, for it is recently
under investigation for cultivation experiments in Horticulture Research Centre
Pine trees are medium sized tree, 3-5 m tall, their resin commercially used
around the world as timber wood. Pine trees were mostly infested by many insects
mainly scale insects; they are piercing and sucking insects which cause damage
to their hosts directly by feeding on the sap. Weakening of the trees by scale
insects causes the infestation of trees by many pests. The needles become yellow,
then red with translucent and glassy aspects, which causes the weakening of
the trees and are susceptible for secondary pests. Species feed on needles and
bark tissues, suck the sap, cause wilt symptoms and early fall of the needles
and may be deadly to the young trees. Mature trees may cope with coccid pests
but become vulnerable to bark beetles and other pests and diseases.
Due to the importance of woody trees, recently Horticulture Research Centre
started co-operation with Environmental Affairs Agency for cultivating pine
trees in economic scale irrigated with recycling water. The aim of the present
work is to identify harmful different insect species infesting pine plants and
their associated natural enemies in Alexandria and its vicinity for the first
time. This study will help minimize the damage of the trees for economic purpose.
The information given in this study is based upon the collecting species by
the author herself and through a conducted literature search.
MATERIALS AND METHODS
Survey study was performed in Alexandria and north coast at the period from
2009-2011, samples were collected from Nubaria, Antoniadis garden, the international
garden and private gardens in El-Amriya district and from Marina resort in the
north coast, every two weeks. The examined trees are identified in El-Orman
Garden Herbarium Unit at Giza by Mrs. Treza Labib. Different methods were used
to collect insects according to their habit, size and stage (Ibrahim
et al., 2001).
Yellow sticky traps: Yellow board sticky traps were used to monitor
the population of the flying insects (Gerling and Horowitz,
1984; Awad et al., 1998). One trap was placed
in the center of the tree at a height of 40 cm from the center of the tree crown.
These traps were then examined in the laboratory using a stereoscopic binocular
for identifying and counting both insects and natural enemies.
Picking method: During the experiment, 10 leaves from upper, middle
and lower portions of 10 randomized branches from each tree were picked up half
monthly. The samples examined in the laboratory to survey the insects using
a stereoscopic binocular microscope.
Sweeping-net method: Samples were also collected and poured onto white
tray for counting and surveying the insects. The scale insects were prepared
for microscopically studies using (Mckenzie, 1956) and
were identified using the keys of Mckenzie (1956) and
Ben-Dov (2005). Their existent in Egypt were confirmed
according to the list of Shalaby (1958).
In the laboratory, each sample was placed in a closed cartoon jar with a clear
emergence tube to which any emerging parasitoid would fly. For the following
two weeks, all emerging hymenopterous parasitoid were removed and placed in
pure lactic acid for 24 h, rinsed in distilled water and then mounted on a labeled
glass slide in Hoyers solution.
Then, they wormed in oven 35-40°C for a week. After which they identified
in the Plant Protection Institute Research (Taxonomy Department), Doki, Giza.
Scanning electron microscope (SEM): Samples were prepared for electron
microscope and examined with GSM 5300, Scanning Electron Microscope in the Faculty
of Science, Alexandria University.
RESULTS AND DISCUSSION
The present study surveyed most of the insect and non insects orders revealed
that a total of 39 species belonging to 19 families under 10 orders. The insect
fauna comprises 8 orders with 37 species. The non insect fauna represented by
the orders Acarina and Araneae, the first by one species and the last one represented
by the true spiders.
The different insects orders could be arranged in a descending orders as follow:
Hemiptera were represented by the highest numbers of species (13 spp.), followed
by Mantodea (6 spp.) (Salem et al., 2001), followed
by Diptera (5 spp.), Coleoptera was represented by (4 spp.) species also Hymenoptera
(4 spp.), both orders Lepidoptera and Orthoptera each represented by (2 spp.)
and Thysanoptera was represented by only (1) species. Meanwhile these insects
depending on their economic value they were divided into harmful pests, visitors,
predators and parasites (Table 1).
||A taxonomic list of collected insects, natural enemies, mites
and true spiders from the pine needle trees during the two years 2009-2011
and with reference to their economic value and their time of occurrence
through the surveyed period
Harmful pests: This group contained 17 species including in three orders
of insects. They were Hemiptera, Orthoptera and Thysanoptera. One species only
in the non insects in order Aranida, Order Hemiptera has the largest numbers
of pests with 13 species, they belonging to 4 families they were Asterolecaniidae,
Coccidae, Diaspididae and Margarodidae.
Family Diaspididae represents the largest family which includes major pests
in Egypt (Mohammed and Ghabbour, 2008), the present
survey revealed the presence of nine armored scales on pine trees in Alexandria,
from these species Chrysomphalus aonidum (Lin.), Chry. dictyospermi
(Morgan), Fiorinia fioriniae (TargioniTozzetti), Lepidosaphues
beckii (Newman) and Parlatoria proteus (Curtis) were collected in
few numbers, while the last species was collected in rare numbers. The most
dominant of which was Leucaspis pusilla Low one of the most native pest
to the pine trees around the world. It is reviewed in Egypt by Hall
(1922) and Ezzat (1958) and in the Palearctic region
by Kosztarab (1988), Dov et al.,
2003 and Ben-Dov (2005). This pest was collected
with high frequency and high density, always associated with the phyto phagous
mite Cenopalpus fewstrii Zaher and Yousef Aspidiotus nerii
(Bouche), Coccus hespridium and Chrysomphalus aonidum (Linn.)
was recorded for the first time on pine specie in Alexandria although the last
species recorded on citrus, date palm and jasmine in Alexandria (Ghabour
and Mohammad, 1996), the other two species were recorded on a variety of
plants. Whereas Aspidiotus nerii (Bouche), Leucaspis pini (Hartig)
and L. pusilla Low, were registered for the first time as a host on pine
treesa in Alexandria and north coast. Whereas Leucaspis pusilla Low was
collected on Pinus canariensis (King) at Cairo and Giza (Gezira) locality,
also L. pini collected on Pinus sp. at Cairo and Qualubiya locality
(Ghabour and Mohammad, 1996).
Both families Asterolecaniidae and Margarodidae were represented by one species
each, Russellaspis pustulans (Cockerell) and Icyria purhasi Maskell,
respectively. The first was the rarest one.
Family Coccidae represented here by 2 species, Coccus hesperidum Linn.
and Parthenolecanium persicae (Fab.). The most numerous one of them was
Coccus hesperidum Linn., which recorded on Pinus sp. as a new
host in Alexandria for the first time in Egypt.
Lindingaspis rossi Mask., only surveyed from the literature (Swailem
et al., 1976). He mention the presence of the pest on Pinus radiate
in ornamental gardens of the Faculties of Agriculture at Giza and Zagazig.
Also Watson et al. (2002) reported the presence
of the insect after the same author in her catalogue.
Order Orthopetra were represented by the two speciesthe grass hopper Acrotylus
insubricus (Scop.) and the rice hopper Aiolopus strepens (Latr.),
they were collected by the sweeping-net strokes and the yellow sticky traps
(Ibrahim et al., 2001).
Order Thysanoptera represented by only the species Thrips tabaci.
||(a) Illustratingthe condensed infestation of scale insects
Leucaspsis pusilla on the needle leaf of pine tree and (b) Illustrating
the mite Cenopapulpus fewstrii under the armored Scale Leucaspis
pusilla, the arrow monitor the mite under the insect body
For the non-insects species, the most dominant pest of the trees, associated
with the scale insects was the mite Cenopalpus fewstrii Zaher and Yousef
which lay eggs and lives under the test of the armored scale Leucaspis pusilla
Low (Fig. 1b). The mite Cenopalpus fewstrii Zaherand
Youssef, consider as a main pest came in the second class after Leucas pispusilla
Low the most common species in all of the sampling sites (Fig.
1a). Especially for the Aleppo pine Pinus halipensis in Amriya and
Predators: Thirteen insects predator belonging 5 families affiliated
to 4 orders in addition to true spiders were collected in the present investigation.
They are well known to feed on eggs larvae and adults of insects. These predators
are classified as follows:
|| Chilocorus bipustulatus L., Cydoni avicina Muls.,
Pharoscymnus varius Kirsch and Paederus alfierii (Koch), three
coccinellid beetles and one staphylinid beetle, relatively existed in abundance
(Badr et al., 2001)
||Six species of order Mantodea all from family Mantidae were collected
in relatively moderate abundance. They were Calidomantis savignyi
Saus. (El-Shazly, 2006). Embusa hedenberchii
St. Eremiaphila khamsin Lef., Hypsicorypha gracilis Bur.
Iris oratoria L. and Sphedromantis bioculata B. The two Sphedromantis
bioculata B. and Iris oratoria L. species were the most abundant
than the others
||Cataglyphus bicolor Fab. and Monomorium pharaonis L. species
were captured in moderate numbers according to the relation between ants
and coccid insects for the honey dew. The syrphid dipterous spp. were collected
in negligible numbers
||The non insects predator represented here by the true spiders were collected
in negligible numbers (Ibrahim et al., 2001).
These above mentioned predators play very important role in controlling
pests especially for scale insects (Abd-Rabou, 2003)
Parasites: All the collected parasites were collected by the yellow
sticky traps. The most abundant parasites associated with the diaspidid scales
of the Present work were the Aphytis spp. and the Encarsia spp.
Parasites complete the role of predators as natural enemies in controlling the
Visitors: The insect visitors were not specific. They were captured
in few numbers, except for species of family Muscidae. Visitors species were
collected by two collecting methods, the yellow sticky traps and the sweeping
net. They were 5 species. Among themVenessa cardui and Pieris rapae
were the two species represented order Lepidoptera with non observed numbers
all over the inspection period.
Their were 5 species which consider here as a visitor not a pest,Venessa
cardui L. and Pieris rapae L. were the two species represented order
Lepidoptera with non observed numbers allover the inspection period.
Studying insect and non-insect fauna associated with pine trees in Alexandria
and north coast in the period from (2009-2011). It was concluded that scale
insect were the most dominant among them. The two insects Leucaspis pini
(Hartig) and L. pusilla Low were recorded for the first time in Alexandria,
while the two insects Aspidiotus nerii Bouche and Chrysomphalus aonidum
(Linn.) were recorded as a new host on pine trees. The insect Leucaspis pusilla
Low and the non-insect mite Cenopalpus fewstrii Zaher and Yousef were
the most abundant through all the period of study, this mite lays the eggs under
the test of the armored scale Leucaspis pusilla. Low especially on Pinus
halipensis in Al-Amria District.
The author wants to express her great thanks to all scientists helped in identified
specimens. First of all Dr. Hedaya (Alexandria University College of Agriculture),
Dr. Zeinat K. Mohamed, Dr. Mona W. Ghabbour. Also to all the authorities in
the Taxonomy Department of PPRI (Plant Protection Research Institute, Cairo).
Deep thanks to Dr. Dug Miller, Systematic Entomology Laboratory, Agricultural
Research Service, U.S. Department of Agriculture, Beltsville, Maryland, USA.
For confirming the identification of Leucaspis pusilla, I also thank
the agriculture engineer in the Agency of Tourist Villages, Mr. Asem Osman for
helping in providing materials and data.