Electronic Journal of Polish Agricultural Universities (EJPAU) founded by all Polish Agriculture Universities presents original papers and review articles relevant to all aspects of agricultural sciences. It is target for persons working both in science and industry,regulatory agencies or teaching in agricultural sector. Covered by IFIS Publishing (Food Science and Technology Abstracts), ELSEVIER Science - Food Science and Technology Program, CAS USA (Chemical Abstracts), CABI Publishing UK and ALPSP (Association of Learned and Professional Society Publisher - full membership). Presented in the Master List of Thomson ISI.
2004
Volume 7
Issue 2
Topic:
Horticulture
ELECTRONIC
JOURNAL OF
POLISH
AGRICULTURAL
UNIVERSITIES
Ja¶kiewicz B. 2004. APHIDS (Homoptera, Aphidodea) INHABITING THE SHRUBS OF Cotoneaster divaricatus Rehder et E. H. Wilson IN THE URBAN GREEN AREA OF LUBLIN. PART II. DOMINATION AND FREQUENCY OF APHIDS, THEIR NATURAL ENEMIES AND THE INJURIES CAUSED BY APH, EJPAU 7(2), #02.
Available Online: http://www.ejpau.media.pl/volume7/issue2/horticulture/art-02.html

APHIDS (HOMOPTERA, APHIDODEA) INHABITING THE SHRUBS OF COTONEASTER DIVARICATUS REHDER ET E. H. WILSON IN THE URBAN GREEN AREA OF LUBLIN. PART II. DOMINATION AND FREQUENCY OF APHIDS, THEIR NATURAL ENEMIES AND THE INJURIES CAUSED BY APH

Bożenna Ja¶kiewicz

 

ABSTRACT

Three aphids species: Aphis pomi De Geer, Aphis fabae Scop. and Rhopalosiphum insertum (Walk.) were observed on the shrubs of Cotoneaster divaricatus Rehder et E.H. Wilson in the urban habitat of Lublin. A. pomi was dominated species in all years of study in both sites and it clearly decreased decorative values of cotoneaster shrubs, caused deformations of young shoots and leaves. Predators and parasitoids of I and II grades were observed in aphids colonies but they had no significant effect on limiting the aphid population.

Key words: aphids, domination, frequency, natural enemies, injuries caused by aphids..

INTRODUCTION

Cotoneaster divaricatus Rehder et E. H. Wilson is one of the most beautiful decorative shrubs, with abundant fruit and decorative colouring of the leaves in autumn [1]. These shrubs looked the most effective when planted in small groups or individually [2]. They often appear in parks, squares and city lawns; they have small soil requirements and show exceptional resistance to the air pollution. C. divaricatus is a host for certain phytophagous species, among which it is only aphids that cause considerable injuries to the plants.

Results of the studies presented here are a continuation of observations contained in part I, concerning the population dynamics of aphids on the shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson. The purpose of the studies presented in part II was to establish the domination and frequency of particular aphid species, their effect on the decorative value of plants and the occurrence of natural enemies in aphid population.

MATERIALS AND METHODS

The studied area and the methods of observation concerning the occurrence of aphids on the shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson in urban conditions are discussed in detail in part I [9]. Besides, in order to determine the qualitative and quantitative relations between particular aphid species occurring on the studied shrubs, two ecological indexes were used, namely domination and frequency (persistence of occurrence) [5, 11, 12].

The index of domination (D) termed also as relative abundance (Ar) determines the percentage of specimens of a given species in the total number of aphids on the studied plant. The index of domination (D) was calculated according to the following formula:

where:
na – number of individuals belonging to a given species in all samples,
n – number of individuals of a studied systematic group in all samples.

The following classes of domination were distinguished:

Superdominants
Eudominants
Dominants
Subdominants
Recedents
Subrecedents
>60%
31-60%
21-30%
10-20%
1-9%
<1%

The index of frequency (F) shows the relation between the number of all samples where a given species occurred and the number of all samples taken from the studied plant. The constancy of occurrence (C), in other words the index of frequency (F) was calculated according to the following formula:

where:
q – number of trials when a given species was noted,
Q – number of all samples.

Four classes of constancy (frequency) were distinguished:

Class I (euconstants)
Class II (constants)
Class III (accessory species)
Class IV (accidents)
0.76-1 (76-100%)
0.51-0.75 (51-75%)
0.26-0.50 (26-50%)
≤0.25 (≤25%).

RESULTS

Figure 1 presents the percentage proportion of particular aphid species inhabiting the shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson in site A (street) and B (park) in the years 1999-2001. Table 1 contains the numbers, domination and frequency of particular aphid species; table 2 presents the number of predators found in aphid colonies, while table 3 shows the populations of parasitoids and hyperparasitoids.

Table 1. The number, domination and frequency of aphid species inhabiting Cotoneaster divaricatus Rehder et
E. H. Wilson in the years 1999-2001

Species of aphids

Year

Site A (street site)

Site B (park site)

N

D

C

N

D

C

Aphis pomi De Geer

1999

758

96.80 (SD)

0.476 (III)

5359

96.52 (SD)

0.809 (I)

2000

7365

100 (SD)

0.917 (I)

13354

99.9 (SD)

0.417 (III)

2001

6483

99.89 (SD)

0.958 (I)

9334

98.79 (SD)

0.875 (I)

Total

14606

99.78 (SD)

0.797 (I)

28047

99.01 (SD)

0.696 (II)

Aphis fabae Scop.

1999

25

3.19 (R)

0.19 (IV)

193

3.47 (R)

0.143 (IV)

2000

0

0

0

13

0.09 (SuR)

0.083 (IV)

2001

7

0.1 (SuR)

0.042 (IV)

74

0.78 (SuR)

0.167 (IV)

Total

32

0.21 (SuR)

0.072 (IV)

280

0.98 (SuR)

0.13 (IV)

Rhopalosiphum insertum (Walk.)

1999

0

0

0

0

0

0

2000

0

0

0

0

0

0

2001

0

0

0

40

0.42 (SuR)

0.083 (IV)

Total

0

0

0

40

0.14 (SuR)

0.029 (IV)

N – Number (in specimens)
C – Constancy of aphid appearance:
(I) – class I (euconstant)
(II) – class II (constant)
(III) – class III (accessory species)
(IV) – class IV (accident)

D – Domination (in %):
SD – superdominant
E – eudominant
D – dominant
SuD – subdominant
R – recedent
SuR – subrecedent

The structure of domination and frequency of aphids. The percentage proportion of Aphis pomi De Geer among all aphids inhabiting the shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson ranged from 96.52% to 100%, depending on the year of studies and the site (fig. 1). This species was a superdominant in both sites and in all the studied years (tab. 1). Considering the frequency (constancy of occurrence), it was included within class I (euconstant) or class III (accessory species) of frequency, depending on the season.

Fig. 1. Percentage contribution of particular species of aphids inhabiting the shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson in the years 1999-2001

Aphis fabae Scop. was a species occurring on the observed shrubs for rather a short period and in small numbers. The percentage proportion of these aphids ranged from 0% to 3.48%, depending on the year and the site (fig. 1). Considering the domination, it was either a subrecedent or a recedent, belonging to class IV of frequency – accident (tab. 1).

Aphids Rhopalosiphum insertum Walk. on the shrubs of C. divaricatus were observed only in site B in 2001, and their population was 0.42% (fig. 1). It was included in the group of subrecedents and class IV of frequency (accident) – table 1.

Signs of injuries. Among the three species of aphids occurring on the shrubs of C. divaricatus, it was only A. pomi which clearly decreased the decorative properties of those plants. They preyed especially on the young shoots of cotoneaster, causing their deformation. Numerous signs of discoloration occurred on the leaves, and the flower buds and the fruit were deformed. The other two species of aphids (A. fabae and R. insertum), which occurred on the examined plants in very small number and for a short period of time, did not cause any visible injuries.

Predators of aphids. On the observed shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson, the studies found out the following predators in the aphid colonies: young and adult specimens of Araneida; larvae and adults of Anthocoridae and Dermaptera; eggs, larvae and adults of Coccinellidae (photo 1); eggs and adults of Chrysopidae; larvae of Cecidomyiidae; eggs and larvae of Syrphidae (tab. 2). During the three years of studies they occurred in small number in both sites. The most predators were observed in 2000 and those were mainly eggs, larvae and adults of Coccinellidae; eggs of Syrphidae and Chrysopidae, while in 1999 and 2001 only scarce predatory arthropods were observed. Among these, Chrysopidae and Syrphidae, whose eggs were frequently observed near the aphid colonies, could have been of any greater importance.

Photo 1. Larvae of Coccinellidae preying in the colony of Aphis pomi De Geer

Table 2. The number of aphid predators from different systematic groups on Cotoneaster divaricatus Rehder et E. H. Wilson in sites A and B in the years 1999-2001

Predators and their life stages

Site A (street site)

Site B (park site)

Number/shrub

Number/shrub

1999

2000

2001

Total

1999

2000

2001

Total

Araneida

young and adult

2.0

2.0

-

4.0

0.8

-

-

0.8

Coccinellidae

eggs

-

0.4

-

0.4

-

0.8

-

0.8

larvae

-

-

-

-

-

0.8

-

0.8

adult

0.4

1.2

-

1.6

0.4

1.6

0.4

2.4

Dermaptera

larvae and adult

-

-

-

-

-

0.4

-

0.4

Syrphidae

eggs

-

2.4

2.0

4.4

-

2.4

0.4

2.8

larvae

1.8

-

-

1.8

0.2

0.4

0.4

1.0

Cecidomyiidae

larvae

-

-

-

-

-

2.4

-

2.4

Chrysopidae

eggs

-

14

-

14

-

7.6

-

7.6

adult

-

0.8

-

0.8

-

-

-

-

Anthocoridae

young and adult

-

-

-

-

-

0.8

-

0.8

Table 3. The number of aphid parasitoids and hyperparasitoids on Cotoneaster divaricatus Rehder et E. H. Wilson shrubs in site A and B in the years
1999-2001

Parasitoids and hyperparasitoids
(family, species)

Species of host aphid

Number of parasitoids (in specimens)

Total

1999

2000

2001

A

B

A

B

A

B

Parasitoids

Ichneumonoidae

Aphidiidae

Aphidiinae:

Trioxys angelicae Haliday

Aphis pomi De Geer

   

1

 

1

4

7

3

13

8

3

13

53

Ephedrinae:

Ephedrus plagiator Nees

Aphis pomi De Geer

               

2

5

2

4

13

Prainae:

Praon sp.

Aphis pomi De Geer

       

1

             

1

Hyperparasitoids

Cynipoidae

Cynipidae

Charpinae:

Charpis victrix Westwood

Aphis pomi De Geer

 

1

         

6

 

3

 

3

13

Chalcidoidea

Pteromalidae

Pteromalinae:

Pachyneuron aphidis Bouché

Aphis pomi De Geer

           

8

9

       

17

Encyrtidae

Encyrtinae:

Aphidencyrtus ephidivorus Mayr

Aphis pomi De Geer

           

3

3

       

6

Megaspilidae

Megaspilinae:

Dendrocerus carpenteri Curtis

Aphis pomi De Geer

 

1

       

1

1

       

3

Aphid parasitoids. A culture of aphid mummies collected on the shrubs of C. divaricatus gave 67 specimens of parasitic hymenoptera of grade I from the family of Aphidiidae (tab. 3). The most numerous was Trioxys angelicae Haliday, whose proportion among all parasitoids of grade I was 79.1%. Parasitoids were obtained only from aphids A. pomi. Hyperparasitoids, limiting the population of Aphidiidae were included into four families (Cynipidae, Pteromalidae, Encyrtidae, Megaspilidae) and they constituted 36.8% of all the obtained parasitoids of I and II grades. Pachyneuron aphidis Bouché from the family Pteromalidae was the most numerous species among the hyperparasitoids.

DISCUSSION

Three aphid species were found out on the shrubs of Cotoneaster divaricatus Rehder et E. H. Wilson in the urban green area of Lublin, namely Aphis pomi De Geer, Aphis fabae Scop. and Rhopalosiphum insertum Walk. Observations carried out by Ja¶kiewicz [6] show that in the area of Lublin they can also inhabit other shrubs: A. pomi on Crataegus monogyna Jacq. and Cotoneaster horizontalis Dec., A. fabae on Viburnum opulus L., Philadelphus coronarius L. and Evonymus europea L., whereas R. insertum can inhabit Crataegus monogyna Jacq.

A. pomi appeared in both sites in the biggest number, that is why it was included into superdominants. Aphids of that species were more numerous in the park site as compared to the street one. On the other hand, Ja¶kiewicz [7] found out that those aphids occurring on the shrubs of Cotoneaster horizontalis Dec. were more numerous in the street site.

Aphids A. fabae occurred on the studied shrubs in a small population and for a short period of time, that is why, considering domination, they were most often included into subrecedents belonging to class IV of frequency (accident).

Aphids R. insertum on the shrubs C. divaricatus were observed only in one year of the studies (2001) and only on the park site (B), that is why they were included in the group of subrecedents and class IV of frequency – accident.

All aphid species were found to be more numerous in the park site as compared to the street one. On the other hand, Cichocka and Goszczyński [4] and Wilkaniec [14] stated that these insects were more numerous on various plants in the street sites, where they find favourable conditions for their development because of the stinging-sucking mouth apparatus.

Only aphids A. pomi decreased the decorative value of the shrubs of cotoneaster. They preyed on the top parts of shoots, causing their deformation, discoloration of the leaves and deformation of the flower buds and fruit. Similar signs of injuries caused by this species of aphids were observed by Ja¶kiewicz [8] on the shrubs of Chaenomeles japonica Lindl. The other two aphid species (A. fabae and R. insertum) occurring on the studied shrubs of cotoneaster were scarce and they preyed for only a short period of time. Probably, that was the reason why they did not cause any visible injuries. Łabanowski et al. [10] stated that aphids R. insertum on cotoneaster preyed on the buds and leaf petioles, the result of which was the twisting of the leaves. Besides, honey-dew secreted by aphids limits the assimilation area of the leaves.

The presence of predators was observed in aphid colonies but their number was small. The most frequent were the eggs, larvae and adults of Coccinellidae, the eggs of Syrphidae and Chrysopidae. Cichocka [3] stated that Coccinella septempunctata L. was reluctant to prey on aphids A. pomi. Ladybirds of this species feeding on this aphid die very soon.

Among the parasitic hymenoptera of grade I (Hymenoptera, Parasitica), Trioxys angelicae Haliday was the most numerous. All specimens of this species were obtained from aphids A. pomi. Werstak and Wi±ckowski [13] found out that parasitoid to limit not only the number of aphids A. pomi on the shrubs of C. divaricatus, but also the number of aphids A. fabae on marigold, dahlia, garden syringa and others.

CONCLUSIONS

  1. Aphis pomi De Geer was the dominating species in both sites in each year of studies.

  2. Among three aphid species inhabiting Cotoneaster divaricatus Rehder et E.H. Wilson, it was only Aphis pomi De Geer which clearly decreased the decorative value of those shrubs, causing deformation of young shoots.

  3. Predators occurring in the aphid colonies were scarce and probably had no effect on limiting the aphid population.

  4. The species with the most numerous population among parasitic hymenoptera of grade I was Trioxys angelicae Haliday from the family Aphidiidae, while among hyperparasitoids – Pachyneuron aphidis Bouché from the family Pteromalidae.

REFERENCES

  1. Bugała W., 2000. Drzewa i krzewy dla terenów zieleni [Trees and shrubs for green areas]. PWRiL, Warszawa [in Polish].

  2. Chojnowska E., 2000. Ozdobne krzewy i pn±cza [Ornamental shrubs and creepers]. Krajowa Rada Polskiego Zwi±zku Działkowców, Warszawa, 396-398 [in Polish].

  3. Cichocka E., 1980. Mszyce ro¶lin sadowniczych Polski [Aphids of fruit plants in Poland]. PWN, Warszawa [in Polish].

  4. Cichocka E., Goszczyński W., 1991. Mszyce zasiedlaj±ce drzewa przyuliczne w Warszawie. [W:] Mszyce ich bionomia, szkodliwo¶ć i wrogowie naturalni [Aphids inhabiting street trees in Warsaw. [In:] Aphids and their bionomy, harmfulness and natural enemies]. (red. Cichocka E., Goszczyński W.), PAN, Warszawa, 9-18 [in Polish].

  5. Górny M., Grüm L., 1981. Metody stosowane w zoologii gleby [Methods used in soil zoology]. PWN, Warszawa [in Polish].

  6. Ja¶kiewicz B., 1996. Quantity and species composition of aphids occurring on ornamental shrubs in Lublin. Aphids and other homopterous insects, PAS, Skierniewice, 65-73.

  7. Ja¶kiewicz B., 2000a. Aphids occuring on selected ornamental shrubs in Lublin. Proc. of the XVth Czech and Slovak Plant Procetion Conference in Brno, September 12-14, 356-357.

  8. Ja¶kiewicz B., 2000b. The number and growth dynamics of aphids on the bushes of Chaenomeles japonica Lindl. in Lublin. Annales UMCS, Vol. VIII, Sec EEE, 129-141.

  9. Ja¶kiewicz B., 2004. Aphids (Homoptera, Aphidodea) Inhabiting the Shrubs of Cotoneaster divaricatus Rehder et E.H. Wilson in the Urban Green Area of Lublin. Part I. The Population Dynamics. Electronic Journal of Polish Agricultural Universities, Series Horticulture, www.ejpau.media.pl, w druku.

  10. Łabanowski G., Orlikowski L., Soika G., Wojdyła A., 2000. Ochrona ozdobnych krzewów li¶ciastych [Protection of leafy ornamental shrubs]. PLANTPRESS, Kraków [in Polish].

  11. Szujecki A., 1980. Ekologia owadów le¶nych [Ecology of forest insects]. PWN, Warszawa [in Polish].

  12. Trojan P., 1977. Ekologia ogólna [General ecology]. PWN, Warszawa [in Polish].

  13. Werstak K., Wi±ckowski S., 1998. Mszycarzowate (Hymenoptera, Aphidiidae) w aglomeracjach miejskich województwa kieleckiego [Hymenoptera, Aphidiidae in urban agglomerations of the Kielce district]. [W:] Fauna miast – [In:] Urban fauna, (eds. Barczak T., Indykiewicz P.), Wyd. ATR, Bydgoszcz, 73-82 [in Polish].

  14. Wilkaniec B., 1994. Afidofauna of selected tree species in the urban area of Poznań. Aphids and Other Homopterous Insects, 4, PAS, Skierniewice, 71-79.


Bożenna Ja¶kiewicz
Department of Entomology
University of Agriculture in Lublin, Poland
7 Leszczyńskiego, 20-950 Lublin, Poland
tel. (+48 81) 5323047
e-mail: bozenna@consus.ar.lublin.pl

Responses to this article, comments are invited and should be submitted within three months of the publication of the article. If accepted for publication, they will be published in the chapter headed ‘Discussions’ in each series and hyperlinked to the article.


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