Population Fluctuations of Thrips tabaci Lind. (Thysanoptera: Thripidae) on Strawberry Plants in Relation to Certain Ecological Factors at Qalyoubia Governorate, Egypt

Document Type : Original Article

Authors

Plant Protection Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt.

Abstract

Population fluctuations ofThrips tabaci was studied during the two successive seasons, 2017/2018 and 2018/2019 on two varieties of strawberry plants; Festival and Fortuna, at Shebin El-Qanater, Qalyoubia Governorate, Egypt. Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a serious insect pests affecting strawberries in all stages of growth. The seasonal abundance of this species was higher during the second season than the first one (the total numbers of 5631 and 6086 individuals respectively). The population of Thrips tabaci showed two peaks, the higher one was recorded in the 1st week of December during the two seasons of study, while the lower one was recorded in the 3th week of march during the two seasons of study. Statistical analysis indicated that there was a highly significant relation between the insect numbers and the age of the plant, while this relation was insignificant for each of temperature, relative humidity and wind velocity. The combined effects of temperature, relative humidity, wind velocity and plant ages on thrips activity were (81.2 %) and (92.7 %) during the first and second seasons, respectively.

Keywords

Main Subjects


Population Fluctuations of Thrips tabaci Lind. (Thysanoptera: Thripidae) on Strawberry Plants in Relation to Certain Ecological Factors at Qalyoubia Governorate, Egypt

H. M. Faleh*, G. F. Abo Laban, M. M. Megahed, and I. L. Ibrahim.

Plant Protection Department, Faculty of Agriculture, Al-Azhar University, Cairo, Egypt

*Corresponding author E-mail: hamadafaleh@azhar.edu.eg  (H. Faleh)

ABSTRACT

Population fluctuations ofThrips tabaci was studied during the two successive seasons, 2017/2018 and 2018/2019 on two varieties of strawberry plants; Festival and Fortuna, at Shebin El-Qanater, Qalyoubia Governorate, Egypt. Thrips tabaci Lindeman (Thysanoptera: Thripidae) is a serious insect pests affecting strawberries in all stages of growth. The seasonal abundance of this species was higher during the second season than the first one (the total numbers of 5631 and 6086 individuals respectively). The population of Thrips tabaci showed two peaks, the higher one was recorded in the 1st week of December during the two seasons of study, while the lower one was recorded in the 3th week of march during the two seasons of study. Statistical analysis indicated that there was a highly significant relation between the insect numbers and the age of the plant, while this relation was insignificant for each of temperature, relative humidity and wind velocity. The combined effects of temperature, relative humidity, wind velocity and plant ages on thrips activity were (81.2 %) and (92.7 %) during the first and second seasons, respectively.

Key words: Strawberry plants, Thrips tabaci, population fluctuation, temperature, plant age.

 

Introduction

Strawberry (Fragaria x ananassa Duch.) is one of the most important members of the family Rosaceae. It has become one of the most economic vegetable crops in Egypt and considered the main cash crop for strawberry growers in Qalyubia, Ismailia, Sharkia and Beheira governorates. It is one of the most favorite and delicious fruits of where its demand has been increased in Egypt for local consumption and for exportation. The fruits are rich in vitamin C and are commonly eaten fresh as a dessert fruit, it also used as a pastry or pie filling. Cultivation of strawberries is an important economic activity for small- and medium sized farms in different producing regions (Ferla et al. 2007 and Gamila et al. 2019).

Egypt ranked as the fifth country in the world in strawberry production after China, USA, Mexico, and Turkey (FAO, 2019).

Under Egyptian conditions, strawberry is liable to be attacked by several pests which are responsible for considerable quantitative and qualitative losses in the fruit yield. It is appropriate that attention be given to the more important insect and other pests which attack strawberry plants. These pests can cause serious economic loss by markedly reducing crop yields and quality (Rings and Neiswander, 1966).

Thrips tabaci Lindeman (Thysanoptera: Thripidae) is one of the mainly significant insect pests affecting strawberries in all stages of growth (Shakya et al., 2010). It generated significant yield loss globally (Lewis, 1997).

This work aimed to study the population fluctuations of Thrips, T. tabaci on strawberry plants and also to evaluate the combined effects of certain ecological factors on the population of tested pest. The obtained data can help producers to implement an integrated pest management (IPM) program for the pest and define the best time to employ control measures (Miller and Foottit) (2009); Henz (2010).

MATERIALS AND METHODS

Experimental design:

The population fluctuations of Thrips on strawberry plants were studied at Shebin El-Qanater, Qalyoubia Governorate, Egypt from the 3rd week of October, 2017 to the 4th week of April, 2019. An experimental area of about 1/8 feddan was divided into four replicates (each replicate about 130m2). This experimental area was planted by fresh strawberry seedlings of two cultivars; festival and Fortuna. Sowing dates were in Sept. 20th in early planting and for the late planting Oct.10th, during 2017 and 2018. The weekly sampling started after four weeks of cultivation date and continued until the end of the season (the fourth week of April) in both seasons of the study. These samples were taken weekly. Yellow sticky cards measuring 20×10 Cmsteady fixed on stalks were distributed at a rate of 4 traps / (1/8) feddan and were put in the center of the cultivated area. Traps were located just or slightly above the top of the plants. Then the traps (yellow cards) replaced weekly and transferred to the laboratory for insects' identification.

Study of the influence of ecological factors on the population fluctuations of T. tabaci:

This part of the study aimed to obtain information about the effect of certain ecological factors such as temperature (˚C), R.H. (%), wind velocity and plant age on the activity of the pest. Records of these meteorological factors were obtained from weather underground program and its location on the internet https://www.wunderground.com.

Statistical analysis:

In order to determine the effect of each of the previous ecological factors separately on the variability within the insect populations, the partial regression term ʺCʺ multipliers was the best statistical method for evaluating the previous relation exactly using Proc. Reg. and Anova in SAS (SAS Institute, 1988), (EL.Saadany 1969 and Fisher, 1950).

RESULTS AND DISCUSSION

Population fluctuations of insect Thrips tabaci on strawberry plants:

The First Season 2017/2018:

Data presented in Table (1) and illustrated in Fig. (1) show that the first appearance of T. tabaci on both Festival and Fortuna varieties was at the 1stweek of November in early planting. The weekly numbers of insects were 33 and 46, respectively. The insect population increased gradually to give the highest peak in 1st week of December with weekly numbers of 420 and 430 individuals on Festival and Fortuna respectively. The insect population decreased gradually, but a moderate peak was noticed in the 4th week of December on Festival v. (54 insects), and in the 4th week of December also on Fortuna (48 insects). The insect population decreased gradually week by week until the end of the season on both varieties.

While in case of late planting, the first infestation with T. tabaciwas noticed during the 3rd week of November by 132 and 141 individuals on Festival and Fortuna respectively. The insect population raised gradually to reach the highest weekly number by the beginning of December on both varieties, the insect numbers were 310 and 520 individuals respectively. A moderate peak was observed (32 individuals) on Festival in the 4th week of December and (46 individuals) on Fortuna during the 4th week of December, also. From the beginning of January, the pest population tended to decline until the end of the season.

The Second Season 2018/2019:

Data presented in Table (1) and illustrated in Fig. (1) show that the first appearance of T. tabaci on both Festival and Fortuna varieties was at the  4th  week of October in early planting. The weekly numbers of insects were 32 and 30, respectively. The insect population increased gradually to give the highest peak in 1fr week of December with weekly numbers of 330 and 372 individuals on Festival and Fortuna respectively. The insect population decreased gradually, but a moderate peak was noticed in the 4th week of December on Festival v. (62 insects), and in the 4th week of December also on Fortuna (82 insects). From the beginning of January, the pest population tended to decline and increase; ups and down until the end of season.

While in case of late planting, the first infestation with T. tabaciwas noticed during the 1st week of November by 121 and 132 individuals on Festival and Fortuna respectively. The insect population raised gradually to reach the highest weekly number in 3rd of November on both varieties, the insect numbers were 322 and 354 individuals respectively. A moderate peak was observed (43 individuals) on Festival during the 3rd week of December and (55 individuals) on Fortuna during the 3rd week of December, also. From the beginning of January, the pest population tended to decline and increase; ups and down until the end of season.

These results greatly correspond with the findings of Shivanna et al. (2011), who revealed that Thrips population was found throughout the year except in July and August months. In contrary, Seham (2016) stated that the highest numbers of Thrips species was recorded in August plantations for T.tabaci. While Abd El-Salam et al. (2019) stated that this pest is a serious insect pest affecting strawberries in all stages of growth. It is clear that the insect pest which has a wide range of host plants so, may be found during the most of the year.

 

 

The effect of ecological factors on the population fluctuation of Thrips tabaci:

Statistical analysis of results obtained in the 1st season  indicated thatsimple correlation between the mean numbers of T. tabaciand each of  plant age1, plant age2 and plant age3 were negative and nonsignificant (r= -0.416 & -0.375 & -0.317 respectively). While the correlations between the insect numbers and each of daily mean maximum temperature, daily mean minimum temperature, and the daily mean relative humidity were positive correlation but they were nonsignificant. On the other hand, the daily mean wind gave a negative correlation and nonsignificant with the insect numbers in 2017/2018 season (Table 2).

In the 2nd season (2018/2019), data in Table (2), show that simple correlation between mean numbers of T. tabaci and plant age1, plant age2 ,plant age3 were negative and significant (r= -0.494 & -0.559 & -0.583 respectively ). Daily mean maximum temperature, daily mean minimum temperature recorded significant negative correlation. While, the daily mean relative humidity recorded negative correlation but it was nonsignificant (r= 0.309). On the other hand, the daily mean wind velocity, gave insignificant positive correlation in 2018/2019 season.

The partial regression analysis gave negative and significant effect for Plant age1 & Plant age3 on mean numbers of T. tabaci (b= -1513.49 and -2.134) during 2017/2018 season. But it was positive and significant for plant age2. Moreover, daily mean minimum temperature and the R.H. % had negative and nonsignificant regression. The daily mean maximum temperatures, and wind speed had positive and nonsignificant regression during this season. The partial regression analysis of 2018/2019 season gave positive and significant effect between Plant age1 & Plant age3 and mean numbers of T. tabaci (b= 177.87 and 0.268). But it was negative and significant correlation for plant age2. Daily mean minimum temperature and the R.H. % were negative and nonsignificant correlation. The daily mean maximum temperatures, and wind speed had a positive and nonsignificant regression during this season. 

As shown in Table (2) the combined effect of studied ecological factors was highly significant on mean numbers of T. tabaci during the first season (2017/2018). The explained variance (E.V. %) was 81.2 % during 2017/2018 season could be attributed to the combined effect of such considered factors on T. tabaci population. The remaining percentage is due to other factors not included in this study.

The same trend was observed during the second season (2018/2019), Table (2). The combined effect of the three weather factors and all plant ages was highly significant on mean numbers of T. tabaci during the tested season (2018/2019). The explained variance (E.V.%) was 92.7% could be attributed to the combined effect of studied different factors on mean numbers of T. tabaci, the remainder precent is due to other factors not included in this study, besides of course to the experimental error.

Obtained data proved that plant age and temperature significantly affected the population of T.tabaci, particularly in the second season. Whereas, Palomo et al. (2015) stated that the main suppressive effect of weather on thrips populations was caused by rainfall. In another study, El-Sappagh (2018) showed that the weather factors as maximum temperatures and maximum & minimum relative humidity did not give significant correlation. On the contrary, minimum temperature give significant correlation in the 1st season. On the other hand, the author stated that all weather factors were positively correlated with insignificant except the minimum R.H. during the 2nd season. In addition, plant age resulted in strong and significant correlation and regression which correspond with our results. 

CONCLUSION

The population of T.tabaci on strawberry plants showed two peaks during growing season. The highest one was recorded in the first week of December during the two seasons of study. There was a highly significant relation between the insect numbers and the plant age, this relation was insignificant in respect to each of temperature, relative humidity and wind velocity.

REFERENCES

Abd El-Salam, A.M.E., Maklad, A.M.H., El Saiedy, E.M.A. 2019: Efficacy of the predatory mites and entomopathogenic fungi against Thrips tabaci (Thysanoptera: Thripidae) infesting strawberry in Egypt. Egypt. J. Plant Prot. Res. Inst. (2019), 2 (2): 417 – 427.

EL– Saadany, G.B. 1969: Further ecological studies on certain corn pests. Ph.D dissertation, Fuclty of Agric.Ain

shamis.Univ.EL-Sappagh, I.A. 2018: Effect Of Certain Weather Factors On Population Density Of Thrips Tabaci Lind. Attacking Onion Crop. Egypt. J. Agric. Res., 96 (1), 2018.

Ferla, N.J., Marchetti, M.M., Gonçalves, D. 2007: Ácarospredadores (Acari) associados à cultura do morango (Fragaria sp., Rosaceae) e plantaspróximas no Estado do Rio Grande do Sul. Biota Neotrop, 7:1–8

Fisher, A.R. 1950: Statistical methods for research workers. II. Rev. Ed. Oliver and Boyd. London.

FAOSTAT 2019: Food and Agriculture Organization of the United Nations Statistics. http://faost at.org/. Accessed 10 Oct 2019.

Gamila Sh. Selem, Ghada M.A. Morsi, Saneya R.M. Farag 2018: Seasonal Fluctuation of main Pests Inhabiting Strawberry Plants In Relation To Certain Weather Factors at Sharkia Governorate, Egypt. Middle East J. Agric. Res., 7(2): 481-491, 2018.

Henz, G.P. 2010: Desa fiosen frenta dospor agricultores familiaresna produção de morango no Distrito Federal. Hortic Bras 28:260–265.

Lewis, T. 1997: T.tabaci as crop pests. CAB International, New York, NY.

Miller, G.L., Foottit, R.G. (2009): The taxonomy of crop pests: the aphids. Insect biodiversity Science and Society, p 463–473.

Palomo, L.A.T., Martinez, N.B., Johansen, R.N., Napoles, J.R., Leon, O.S., Arroyo, H.S., Graziano, J.V. 2015: Population fluctuations of thrip (Thysanoptera) and their relationship to the phenology of vegetable crops in the central region of Mexico. 2015 - Florida Entomologist — Volume 98, No. 2.

Rings, R.W., Neiswander, R.B. 1966: Insect and Mite Pests of Strawberries in Ohio. Research Bulletin, 987. 

SAS instituite, 1988. SAS/Stat User's Guide. 6.03 ed. SAS institute Cary, Nc.

Seham, S.M. 2016: Studies on Thrips (Order: Thysanoptera: Family: Thripidae) and their relation in tospovidae transmission to some curbitaceous crops in Giza, Egypt. Department of Economic Entomology and pesticides, Faculty of Agriculture, Cairo University.

Shivanna, B.K., Gangadhara, N.B., Basavaraja, M.K., Nagaraj, R., Kelleswara Swamy, C.M., Karegowda, C. 2011: Impact of abiotic factors on population dynamics of sucking pests in transgenic cotton ecosystem. Int. J. of sci and nature, 2 (1) : 72-74. 

Shakya, S., Coll, M., Weintraub, P.G. 2010: Incorporation of intraguild predation into a pest management decision-making tool: The case of thrips and two pollen-feeding predators in strawberry. J. Econ. Entomol. ,103:1086–1093.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


Table 1: Weekly numbers of Thrips tabaci on strawberry plants at Shebin El-Qanater, Qalyoubia, Governorate during 2018 ̸ 2019 and 2018/2019 seasons.

2017 - 2018

2018 - 2019

" Date of

inspection"

 

Early  20/9/2017

Late  10/10/2017

" Date of

inspection"

 

Early  20/9/2018

Late  10/10/2018

Festival

Fortuna

Festival

Fortuna

Festival

Fortuna

Festival

Fortuna

29-Oct

0

0

0

0

28-Oct

32

30

0

0

05-Nov

33

46

0

0

04-Nov

50

53

121

132

12-Nov

45

85

0

0

11-Nov

57

76

172

193

19-Nov

75

140

132

141

18-Nov

116

135

322

354

26-Nov

330

360

250

270

25-Nov

211

237

216

257

03-Dec

420

430

310

520

02-Dec

330

972

118

133

10-Dec

135

148

78

65

09-Dec

182

211

98

111

17-Dec

76

85

34

38

16-Dec

97

162

43

55

24-Dec

54

48

32

46

23-Dec

62

82

22

18

31-Dec

14

12

9

7

30-Dec

22

27

15

11

07-Jan

15

12

13

14

06-Jan

14

13

19

21

14-Jan

28

16

14

18

13-Jan

11

15

13

12

21-Jan

9

14

8

11

20-Jan

7

8

7

6

28-Jan

18

7

16

21

27-Jan

8

11

9

11

04-Feb

10

11

9

13

03-Feb

13

9

13

15

11-Feb

25

13

20

12

10-Feb

17

14

11

8

18-Feb

12

10

13

6

17-Feb

16

21

18

21

25-Feb

27

18

22

15

24-Feb

23

28

22

28

04-Mar

33

26

31

22

03-Mar

42

35

26

32

11-Mar

38

32

41

48

10-Mar

54

61

30

32

18-Mar

54

48

62

57

17-Mar

51

57

54

59

25-Mar

33

31

42

48

24-Mar

35

22

32

37

01-Apr

0

0

25

22

31-Mar

0

0

13

17

08-Apr

0

0

0

0

07-Apr

0

0

0

0

Total

1484

1592

1161

1394

Total

1450

1679

1394

1563

mean

61.83a

66.33a

48.37a

58.08a

mean

60.41a

69.95a

58.08a

65.12a

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table 2: Simple correlation coefficient and partial regression values of different factors with their significant levels and percentages of explained variance on the population of Thrips tabaci during seasons 2017-2018 and 2018-2019 on strawberry at Shebin El-Qanater, Qalyoubia Governorate.

Years

Factors

Simple correlation

Partial Regression

F. value

P.

E.V.%

r.

P.

b.

P.

2017-2018

 

Plant age1

-0.4164

0.0539

-1513.49

0.0097

5.56

0.0103

81.2

Plant age2

-0.3751

0.0854

100.52

0.0189

Plant age3

-0.3178

0.1495

-2.134

0.0309

Temp. Max.

0.013

0.9542

22.74

0.6587

Temp. Min.

0.1467

0.5146

-27.07

0.5814

R.h.%

0.2168

0.3324

-3.057

0.8479

Wind v.

-0.3713

0.0888

25.79

0.6408

2018-2019

Plant age1

-0.4941

0.0268

177.871

0.0019

18.18

0.0001

92.7

Plant age2

-0.5592

0.0104

-12.599

0.0012

Plant age3

-0.583

0.007

0.268

0.0011

Temp. Max.

-0.7291

0.0003

3.24

0.6387

Temp. Min.

-0.7251

0.0003

-7.15

0.1923

R.h.%

-0.3095

0.1842

-1.009

0.3838

Wind v.

0.3645

0.114

8.137

0.1209

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 1. Population density of T. tabaci Lind. on onion plantations during the two seasons.

 

التذبذبات العددية لحشرة (Thrips tabaci Lind. (Thysanoptera: Thripidae على نباتات الفراولة وعلاقتها ببعض العوامل البيئية في محافظة القليوبية ، مصر.

حماده محمود فالح *، جمعة فتح الله أبو لبن، محمد محمد محمد مجاهد، إبراهيم لبيب إبراهيم

قسم وقاية النبات , کلية الزراعة بالقاهرة , جامعة الأزهر

* البريد الإليکتروني للباحث الرئيسي:  hamadafaleh @azhar.edu.eg 

الملخص العربى

أجريت هذه الدراسة بغرض دراسة التذبذبات العددية لحشرة Thrips tabaci Lind.  علي نباتات الفراولة علي مدي موسمين (2017/2018 – 2018/2019) في منطقة شبين القناطر بمحافظة القليوبية. کما استهدفت الدراسة بيان تأثير بعض العوامل البيئية علي نشاط هذة الحشرة (الحرارة والرطوبة وسرعة الرياح وعمر النبات). أوضحت النتائج المتحصل عليها أن الوفرة الموسمية للحشرة في الموسم الثاني (6086 حشرة) أعلى منها في الموسم الأول (5631 حشرة) وکان للحشرة فترتان واضحتان للنشاط في الموسم الأول (2017/2018)، فترة النشاط الأولي والتي تحتوي علي أکبر عدد للحشرة کانت في أول ديسمبر في کلا ميعادي الزراعة (المبکرة والمتأخرة)، بينما کانت فترة النشاط الثانية في منتصف شهر مارس من العام التالي. کما أشارت بيانات الموسم الثاني (2018/2019) أن للحشرة فترتين للنشاط أيضا،  فترة النشاط الأولي والتي تحتوي علي أکبر عدد للحشرة کانت في أول ديسمبر بالنسبة لميعاد الزراعة المبکر، بينما کانت في أواخر شهر نوفمبر بالنسبة لميعاد الزراعة المتأخر، بينما کانت فترة النشاط الثانية للحشرة في منتصف شهر مارس من العام التالي في کلا ميعادي الزراعة. وأوضح التحليل الإحصائي وجود إرتباط قوي بين أعداد الحشرة وعمر النبات وضعف هذا الإرتباط مع الحرارة والرطوبة وسرعة الرياح. بلغ التأثير المجمع لدرجات الحرارة والرطوبة النسبية وسرعة الرياح وأعمار النبات على نشاط التربس (81.2٪) و (92.7٪) خلال الموسم الأول والثاني على التوالي.

الکلمات الاسترشادية: نباتات الفراولة, التربس, التذبذبات العددية, درجة الحرارة, عمر النبات.