Leaf Miners on Urban Greenery Trees of Municipalıty Ilıdza-Azra Ćosović

Ilidža is a municipality of Sarajevo Canton in central Bosnia and Herzegovina. It has a metro population of 157,654 and is a chief suburb of Sarajevo and de facto its neighborhood . It is famous for the natural beauty of its surroundings and historical tradition dating back to neolithic times. Sarajevo International Airport is located nearby, as is the famous Vrelo Bosne spring.

 

About the AuthorThis article was written by Azra Ćosović from Bosnia and Herzegovina. azra vesikalıkAzra Cosovic was born on 22nd of May 1987 in Sarajevo, Bosnia and Herzegovina. She graduated from Faculty of Forestry  http://sfsa.web.ba/v2/ and became engineer of Forestry with a degree of Master of forestry science.She is employee of Cantonal Public Company ‘Sarajevo fotests’  http://www.sarajevo-sume.ba/index.php/en/

Recognizing the need to perform the sustainable menagement of forest resources according to the national development policy,priorities and agreed principles of sustainable menagement, Cantonal public company ‘Sarajevo-sume’ has comitted itself to improve forest menagement in order to meet social, economic, ecological, cultural and spuritual human needs of present and future generations.

‘Sarajevo-sume’ accepts the principles and criteria of ISO as a basis for forest certification. ‘Sarajevo-sume’ deals with these activities: Silviculture, Forest protection, forest exploitation, construction and maintenance of forest transport infrastructure, Bioengeneering, Ecological projects, Hunt department, Nursery and Projects and partnership. Number of employees is 425 including 35 engineer of forestry

Ms. Azra Cosovic  works as coordinator of GIS. Beside this, she actively participated in a few international projects and the most important one is the project ‘Sarajevo Kent Ormani’.

 

 

Summary

The air we breathe today is getting more polluted, climatic conditions are worse from day to day, stressful life requires rest and recreation, natural beauty are desirable tourist attractions, historical significance of individual parks, etc. All of these are enumerated reasons for very important, invaluable existence of urban greenery.

However, the health status of a specific urban greenery and it is not just the high level.
This paper presents a study of the existence of leafminers on trees of urban greenery of Ilidža, specifically in the area of Big avenue and Nature Stojčevac. The main objective of this study was to determine whether the listed pests are present, what are the types of pests, what kinds of trees they attack, and their impact on the state of urban greenery.
The results tell us that the existence of the species Cameraria ohridella – Chestnut miner moth, and it is present mainly on the type of tree Aesculus hippocastanum, on any given tree. Then type Phyllonorycter platani – Platanov miner, on the type of tree Platanus acerifolia. In addition to these species, there is a kind of Ticheria decidua, invading species of the genus Quercus, in this case Quercus robur.
Keywords: leaf miner, mines, urban greenery

 

1. INTRODUCTION
Leaf miners are one of the many specialized herbivorous insects. These herbivores related to woody species, are very important from the point of view of forestry science, especially when it comes to forestry entomology and forest protection. Knowing these insects contributes to faster and more efficient methods of protection in the case of their breeding.
Leaf miners are insects that lives in and eats the leaf tissue of plants. As a result of their feeding, the plant organs are being disturbed, especially leaves. Often we notice the tunnels of various shapes and sizes on leaves and sometimes even larvae itself is visible inside those tunnels. Marks they leave behind are called mines. Larva also lives and feeds itself in the mine, leaving the epidermis intact. Knowing the form of mines and the plant host, the type of the leaf miner can be determined in a large number of leaf miners.
According to previous researches, about 10 000 species of leaf miners are described till today and they are divided into 50 families of four lines: Coleoptera, Diptera, Hymenoptera and Lepidoptera (Matošević, 2007.according to Hering 1957.).
The possibility of introducing the pests into new areas increases with more frequent exchange of goods and using many transport vehicles.
Natural enemies play an important role in population dynamics of plant-eating insects. Predators, parasites and pathogens are considered as natural enemies (Matošević, 2007. According to Speight et al, 1999.) Beside the natural enemies of these insects, it is important to analyze and know similar indigenous species of pests and their natural enemies that regulate their number, since it will be much more easier and faster to realize issues of the newly introduced types of pests.
City greenery, as an integral part of modern urban planning, beside the decorative role, has many other important functions such as: sanitation, purification of air pollution, improvement of the city microclimate in the way that it moderates the extremes of excessive heat in summer and cold in winter; recreation of people, especially for rest, refresh and entertainment of children, the sick and aged people, it is attractive for tourists and so on. Along with this, those areas of the city have a scientific function because they promote knowledge of plant life, history of the city and others.
There are no areas in which such harmony of nature is being achieved as it is in Ilidza area. Beside that Ilidza is being known for its forests, numerous springs of hot and cold water, rich flora and fauna, it seems that the municipality of Ilidza is more known for its greenery – parks and alleys. Due to its multiple gifts of nature that are found in this area, we still can meet successful horticultural solutions, the combination of water, stone and greenery. Ilidža’s alley of plane trees in combination with chestnuts is unique landscaping creation, environment of a pleasant recreation.
It is this natural phenomenon and gift that have excellent opportunities for the development of modern tourism of various forms of recreation and educational tourism. For these reasons, it deserves more attention and respect. If it is managed in the right way, with a focus primarily on improving the health condition of greenery, which plays a very important role, this area can be a real nature park in the heart of a metropolis of Sarajevo.
2. OBJECTS AND METHODS
2.1. Objects of researches
Two working surfaces in the area of Ilidza are selected as objects of research, where the presence of leaf miners on woody species is monitored. Work surface I represents The Big alley where 112 trees of horse chestnut and plane trees were monitored. The importance of the Big alley dating back to 1982 when the great value was represented as a road that connects the local railway station and Sanatorium Ilidza with village Vrutci and Vrelo Bosne.

The road is designed as four kilometers long promenade, with a roadway and walking side. The promenade is along its entire length planted by plane trees and chestnuts and represented a very important horticultural and environmental value of Ilidža. Work surface II is a Nature Park “Stojčevac”, where different types of trees were observed. Horticultural and environmental value of this worksurface is nothing less significant than in the case of work surface I.

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Picture 1. The cartographic representation of the Big Alley Ilidza and Nature Park „Stojčevac“
The Nature Park “Stojčevac” is one of the most popular resorts in the municipality. These working surfaces are chosen precisely because they play an important, generally beneficial, function.
2.2 Research methods
In order to achieve the objectives, field research and data collection were conducted and were followed by their editing and processing.
Researches were performed during May and July in 2012.
For the purpose of collecting samples of leafminers the two working surfaces, located in the Municipality of Ilidža, were separated :
 Work surface 1 – The Big alley;
 work surface 2 – Nature Park “Stojčevac”
These are two spatially separated working surfaces, which are characterized by different terrain conditions. Certain tree species have been observed in more than one working surface. These working surfaces have beneficial functions.
2.2.1. Collection of samples
Collection of samples was performed on two of the above mentioned working surfaces. Collection of samples included taking leaves from infested trees which contain traces of leafminer. The leaves, or samples, were taken in the way to provide access to each tree that was visually examined. If the presence of leaf miners was noticed on the leaves, these leaves were taken as samples.

The taken samples are stored in hard cover notebooks to avoid their damage during transportation to the place of analysis. Each sample is marked with the number of trees from which the sample was taken, with the exposure at which the sample was taken, the date when it was taken, and a work surface on which it was taken.

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A) Leaf miners A.hippocastanum L.-standing tree

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B) Mines on the leaf of A.hippocastanum L. (photo original)

The next step after collecting the samples was:
1. Classification of leaves in accordance with the plant hosts
2. Determination of the type of leaf miner
3. Photographing collected samples with characteristic leafminer trace
4. Pressing of samples

The trees on work surface 1 that were observed during this research were selected in a way that each 10th tree on both sides of the avenue was taken. The exceptions were the trees from which it was not possible to take a sample. Finally, the number of trees that will be seen on the work surface 1 is 56, as on one side of the avenue and same on the other. That means 112 trees in total, including 41 European plane trees, 71 horse chestnut trees.
The trees on the work surface 2 are chosen selectively in order to take as many different species of trees as possible. Around 20 trees, mostly different species, are taken into consideration. The total number of trees that will be observed in this research is 132.
Species are determined on the basis of the following diagnostic characteristics: shape and color of mine, traces of excrement and plant host. The collected leaves are photographed with a digital camera Sony. Taken photos are used in this paper.

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A) Caterpillar on the leaf of A.hippocastanum

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B) Mines on the underside of leaf of plane tree (original photo)

3. RESULTS AND DISCUSSION

Results of this study are based on determining the presence of certain species of leaf miners on work surfaces I and II, showing the number of taken samples and the influence of certain factors, particularly the exposure of the treetop and position of trees in the alley, to the occurrence of leaf miner.
On the work surface 1 the samples were taken from the left and right sides of the Big alley. Although this is the same work surface, appearance of leafminers is not uniform. The trees on both sides of the alley were analyzed. Left side of the alley (direction Ilidža – Vrelo Bosne) is more sunny during the day, which represents ideal conditions for the occurrence of pests. Exceptions are the trees that are at the very beginning of the alley, which is slightly less exposed to sunlight and therefore the intensity of the attack of these pests was weaker. At the beginning of this research, the presence of leaf miners was observed at sides getting more sunlight, i.e., warmer sides, which confirms one of the characteristics of insects, and that is that the attack intensity depends on the light or heat.
The right side of the alley is in shade for most of the day because the trees on the left side block the light. The trees on this side of the alley get most of the light in the afternoon, and for that reason, at the beginning of the research more intensive attack is observed on the north and west exposure of treetop, while after some time, the intensity of attacks expanded mainly on all the treetops. And when it comes to this side of the avenue, exceptions are the trees that are at the beginning, but also at the end of the avenue at the foot of Mount Igman, where temperatures are slightly lower.
On the work surface II-Stojčevac, the presence of leaf miners is noticed slightly later than on the work surface I – The Big alley. Leaf miners are noticed on the type of Quercus and A.hippocastanum. The number of mines ranged from one to five when it comes to the type of Q.robur. However, the number of mines on types A.hippocastanum is much higher. Overall, the intensity of the attack was not significant as is the case on the work surface I-The Big alley.
Since the greatest attention in this paper is dedicated to species A.hippocastanum L. and P.acerifolia Njilld., therefore the greatest attention was given to the species of leaf miners that harm these host plants. In fact, these leaf miners are Cameraria ohridella Deschka & Dimic and Phyllonorycter platani Standiger.

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Cameraria ohridella Deschka & Dimic

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Phyllonorycter platani Standiger.

No

 Date of collecting samples

Location/Work surface

Number of samples

1 25.05.2012.  Work surface 1

44

2 10.6.2002.  Work surface 1

48

3 25.06.2012.  Work surface 1

50

4 05.07.2012.  Work surface 1

55

5 15.07.2012.  Work surface 1

65

6 25.07.2012.  Work surface 1

67

7 30.07.2012.  Work surface 1

71

400

Table 1. Review of results taken for Cameraria ohridella Deschka&Dimić

The number of mines, when it comes to the type of Aesculus hippocastanum, ranged from one to a maximum of 25. First appearance of mines in the observed trees was in late May.

Graph 1. Review of samples taken for Cameraria ohridella Deschka&Dimić (Please see the PDF Version)

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Figure : Mines on the leaves of horse chestnut /Increasing intensity of leafminers attack ( orginial photo)
In the case of the observed type of Platanus acerifolia, the intensity of the attack of leaf miners was significantly weaker than on the A.hippocastanum. Also, parts of the treetop that get more light and heat suffer more from attacks of these pests.

No

Date of collection

Location

Number of taken samples

1 25.05.2012. Work surface  1

27

2 10.6.2002. Work surface  1

30

3 25.06.2012. Work surface  1

31

4 05.07.2012. Work surface  1

33

5 15.07.2012. Work surface  1

36

6 25.07.2012. Work surface  1

31

7 30.07.2012. Work surface  1

27

215

Table 2. Review of samples taken for za Phyllonorycter platani Standige

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Figure: Mines on the leaf of plane trees (original photo)

Graph 2. Review of samples taken for Phyllonorycter platani Standiger (Please see the PDF Version)

 

The fact that the most important appearance of leaf miners on the work surface I is noticed on the left side of the avenue (line Ilidža – Bosnia Spring) indicates the acceptability of the resulting data that the largest number of samples is taken from the southern exposure of treetops. At the end of the study, the presence of leaf miners is noticed on all exposures of the treetop with most of the observed trees, especially when it comes to the type of A.hippocastanum.

 

Exposure of treetop

East

West

North

South

Number of taken samples

20

69

93

218

Table 3. Number of taken samples due to the exposure

Graph 3. Number of taken samples due to the exposure

 

4. CONCLUSIONS
Not even the greatest experts of today are not able to establish how many species live on our planet. It is very difficult to determine the number of species that have been described until now. Insects that feed within plants are a great part of the so far described species (700,000).
These herbivorous insects are incredibly different in terms of their size, shape, form, diet and so on. They use special methods and “smart” tricks to more efficiently utilize plant tissue. But the plants are the ones that strive to make it as difficult as possible for these insects.
Based on the fossil remains it is found that the first mines existed in the late Jurassic, about 150 million years ago. In the last few decades, leaf miners have become a very interesting group of insects for research.

The evolutionary development of leaf miners is proven by their huge number and the fact that they can be found in several rows or lines. Based on previous findings, there are around 10,000 found types of leaf miners, that belong to approximately 50 families from four lines: Coleoptera, Hymenoptera, Diptera and Lepidoptera. The richest line is Lepidoptera type, followed by Diptera, while lines of Coleoptera and Hymenoptera contain fewer species.
Listed 10000 leafminer species is assumed to be only a fraction of their actual number, and of the number that will arise in the future.
There are still plenty of spaces on the planet which have not been studied, as for example tropical parts, which seem to have perhaps the highest density of population. (G.Csoka, 2003)

Based on these analyzes, we have come to the following conclusions:

  1. The effect of these harmful species causes almost complete reduction of both primary and secondary functions that chestnut should have, considering that this is a species that is readily used for growing alleys and, in general, the kind that is gladly seen in urban areas. Some of these features are aesthetic, ecological, sanitary – medical etc.
  2. These pests cause premature defoliation of leaves, which entails a number of other consequences for the chestnuts, for example stopping the growth, maturation of the tissue, drying, etc. Furthermore, they cause relatively early leaf fall. All this affects the reduction of the assimilation surface, and thus negatively affects the process of photosynthesis (Dautbašić M., 2005).
  3. Damages that leaf miners cause are primarily environmental and aesthetic, and then economic, which is very important when it comes to decorative types of urban greenery. We can take a horse chestnut as an example, which is often used in the establishment of the avenue, and is gladly seen species on green areas. However, its aesthetic and ecological value is being greatly reduced by pest such as Cameraria ohridella Deschka & Dimic
  4. Strong attack intensity of leaf miners is present on trees that are on the work surface I – The Big alley. Especially concerning is the situation on the trees Aesculus hippocastanum that suffer from strong intensity attacks of Cameraria ohridella Deschka & Dimic, given that each observed tree was attacked and infected.
  5. On the work surface II – Stojčevac, the presence of leaf miners is seen on the trees of Quercus robur L., and leaf miner Ticheria decidua. The intensity of attacks was not so strong to ruin the aesthetic appearance of the tree, or significantly have an impact on the reduction of the assimilation surface, and therefore there has been no negative impact on the process of photosynthesis. Mines were visible only at certain parts of the lower leaves of the tree. The number of mines ranged from one to three. The study focused on three oak trees, which were located in the immediate vicinity. Those were trees with the same symptoms when it comes to the appearance of leaf miners. Oak trees are exposed to sun for the lesser part of the day, which reduces the possibility of a stronger attack of leaf miners.
  6. Besides oak, leaf miners apperance was observed on the horse chestnut Aesculus hippocastanum L., whose intensity was just as strong as the intensity of trees in the alley. Aesthetic appearance of the trees is dignificantly destroyed , the area of the assimilation apparatus is reduced, which ultimately has a negative impact on the further development of the tree.
  7. Also, the presence of a leaf miner is observed on the tree of Acer pseudoplatanus, but its presence is almost insignificant, given that mines are noticed only on two leafs per tree. Tree species Acer pseudoplatanus was not exposed to direct sunlight. However, it may be a warning for all of us to take care of these species and these types in the future and a possibility of its disapperance that comes as a result of leafminer attack.

Please note that the full size of this article can be reached at this following link as PDF Format
Leaf Miners on Urban Greenery Trees of Municipalıty Ilıdza-Azra Ćosović

 

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