Egypt. J. Plant Prot. Res. Inst. (2020), 3 (4): 1121-1128

Egyptian Journal of Plant Protection Research Institute www.ejppri.eg.net

Seasonal abundance of the brassicae ( : ) infesting canola plants in relation with associated natural enemies and weather factors in Sohag Governorate Waleed, A. Mahmoud Plant Protection Research Institute, Agricultural Research Center, Dokki, Giza, Egypt. ARTICLE INFO Abstract: Article History Received: 19 / 10 /2020 Canola ( napus L.) is grown in more than 120 Accepted: 22 / 12 /2020 countries around the world, including Egypt, hold the third position oil crop after palm and soybean oils . the cabbage aphid Keywords (L.) (Hemiptera : Aphididae) is distributed in many parts of the world and is present in Egypt, especially in Brevicoryne brassicae, Upper Egypt. Its damage occurs on the plant leaves and transmit population, canola, plant viruses. The present studies were carried at The Experimental , predators, Farm of Shandweel Agricultural Research Station, Sohag temperature and Governorate, Egypt during the winter seasons of 2017/2018 and humidity. 2018/2019 to investigate the population density of the cabbage aphid B. brassicae infesting canola in relation to some biotic and abiotic factors in Sohag Governorate. Data revealed that aphid started to take place in canola fields during the first week of December in both seasons (36 days after planting), then increased to reach its peak in at 20th and 13th February in the two seasons (Between 106 to 113 days after planting), respectively. The rate by (MacIntosh) (Hymenoptera: Braconidae) simultaneously increased as aphid populations increased in both seasons, also, the highest parasitism percentages were synchronization of the aphid numbers reduction in both seasons. Coccinella undecimpunctata L. (Coleoptera : ) , Chrysoperla carnea (Stephens) (: Chrysopidae) and Syrphus corollae Fabricius (Syrphidae: Diptera) were the main predators inhabiting canola plants, started to take place in canola fields after 2-3 weeks from aphid infestation. Predators showed their highest abundance during February and simultaneously increased as aphid populations increased in both seasons. Using simple correlation and simple regression values, the effects of parasitoid and predators showed positive, highly significant and significant effects, respectively, on B. brassicae during the two seasons. However, none of abiotic factors (Maximum and minimum temperature and mean relative humidity) showed significant effects in the two seasons.

1121

Mahmoud, 2020

Introduction al., 2019). The present work was Canola (Brassica napus L.: oriented to obtain better knowledge Cruciferae) became one of the most about B. brassicae population infesting important oil crops all over the world. canola in relation to some biotic and In Egypt, it is cultivated in winter and abiotic factors at Sohag Governorate. can grow in the new reclaimed lands. Materials and methods Therefore, canola is one of the 1. Experimental design: promising oil crops which could help in The present studies were carried reducing the gap between the local at The Experimental Farm of production and the consumption in Shandweel Agricultural Research Egypt (Abdrabou et al., 2017). Canola Station, Sohag Governorate, Egypt crop was attacked by several during the winter seasons of 2017/2018 pests, but one of the most important and 2018/2019. An area of about half is the cabbage aphid feddan (2100 m2) was cultivated with Brevicoryne brassicae (L.) (Hemiptera: canola plants ( pactol) in Aphididae) was the most serious one completely randomized block design. (Mazeed, 2006; Amer et al., 2009 and Normal agricultural practices were Syaid et al., 2020). The population performed, and no insecticidal trend of the pest is the central corner to treatments were used during the whole select the best time insecticide study period. applications against cabbage aphid in 2. Population trend of aphid: canola fields. So, several authors In to study the population studied the population density of this density of B. brassicae, ten canola pest (Khan and Begum, 2005 and plants were randomly selected, and the Temerak et al., 2014). The parasitoid number of was counted in each Diaeretiella rapae (MacIntosh) replicate. Data were collected at weekly (Hymenoptera: Braconidae) is intervals from emergence to the described as the main primary harvesting time. parasitoid of cabbage aphid and 3. Population trends of natural considered as one of the most effective enemies: factors decreased cabbage aphid In order to study the population population in canola fields (Sayed and trends of insect predators associated Teilep, 2013 and Abdel-Galil and with cabbage aphid infesting canola Mahmoud, 2019). The insect predators, plants, the numbers of C. Coccinella undecimpunctata L. undecimpunctata, C. carnea and S. (Coleoptera: Coccinellidae), corollae larvae were counted on 10 Chrysoperla carnea (Stephens) randomly plants selected from each (Neuroptera: Chrysopidae) and Syrphus replicate. Data were collected at weekly corollae Fabricius (Syrphidae: Diptera) intervals from emergence to the was reported as the most prevalent harvesting time. predator species found associated with For the main associated the aphid in canola fields and their role parasitoid, D. rapae, the number of in suppressing aphid populations in mummified aphids was counted from canola fields was studied by many the first inspection date and continued authors (Saljoqi et al., 2012 and Abbas to the end of the two seasons. The et al, 2017). Weather, especially, percentage of parasitism caused by temperature and relative humidity play aphid parasitoid was calculated in each a major role in the development of sampling date according to following aphid populations (Abbas et al, 2014; formula: Nematollahi et al., 2016 and Akbar et

1122

Egypt. J. Plant Prot. Res. Inst. (2020), 3 (4): 1121-1128

Number of to take place in canola fields during the parasitoid first week of December in both seasons Parasitism aphids X (36 days after planting). A gradual percentage = The total 100 increase in aphid numbers were number of recorded until the appearance of its aphids peak at 20th and 13th February in 2017/2018 and 2018/2019 seasons 4. The effect of some biotic and (Between 106 to 113 days after abiotic factors on population trend of planting), respectively, with 591.33 and cabbage aphid: 904.33 aphids/ plant. Then the numbers The effects of plant age, of aphid decreased until the end of the maximum temperature, minimum two seasons. The highest aphid temperature, average relative humidity, population was observed during total predator number and parasitoid February, followed by January in both number were tested for population seasons. fluctuation of aphid infesting canola In agreement with the above using simple correlation according to results, Khan and Begum (2005) who Gomez and Gomez (1984). found that the population of aphid on Results and discussion canola peaked in 3rd week of February, 1. Population trend of Brevicoryne and Amer et al. (2009) who found that brassicae on canola plant: the highest population was recorded The seasonal abundance of during the last week of February to the cabbage aphid inhabiting canola plants second week of March. Also, Temerak during 2017/2018 and 2018/2019 et al. (2014) showed that the highest growing seasons at Sohag Governorate population density of cabbage aphid was presented in Figure (1). Data was recorded during the plant age of revealed that the cabbage aphid started 108-125 days old.

1000 2017/2018 season 2018/2019 season 800 600 400 200 Mean plant No./ Mean 0 14 21 28 5 12 19 26 2 9 16 23 30 6 13 20 27 6 13 20 27 Nov. Dec. Jan. Feb. March Samplin date

Figure (1): Population trend of Brevicoryne brassicae infesting canola plants during 2017/2018 and 2018/2019 seasons at Sohag Governorate.

1123 Mahmoud , 2020

2. Population trends of natural recorded in 9th January (15.58%) and enemies associated with Brevicoryne 27th February (43.01%). The brassicae on canola plant: appear delay by about three weeks after 2.1. Diaeretiella rapae parasitoid: canola infestation by aphids. However, The mean percentage of the parasitism rate simultaneously cabbage aphid parasitized by D. rapae increased as aphid populations during 2017/2018 and 2018/2019 increased in the both seasons, also, the growing seasons at Sohag Governorate highest parasitism percentages were was estimated as shown in Figure (2). synchronization of the aphid numbers The first mummified aphids appear was reduction in both seasons. observed during the last week of Relations between B. brassicae December in both seasons, the seasonal and its parasitoids were clarified by mean of parasitism percentage Temerak et al. (2014). The previous maximized two times in both seasons. results support the findings of Abdel- The peaks were observed in 16th Galil and Mahmoud (2019) who January (12.03%) and 13th March reported that the aphid number decrease (39.99%) in 2017/2018 season. While, was in simultaneous with the increase in 2018/2019 season, the peaks of its parasitoid.

50 2017/2018 season 2018/2019 season 40 30 20 10

Parasitisim% 0 14 21 28 5 12 19 26 2 9 16 23 30 6 13 20 27 6 13 20 27 Nov. Dec. Jan. Feb. March Samplin date

Figure (2): Mean percentage of Diaeretiella rapae parasitism on Brevicoryne brassicae infesting canola plants during 2017/2018 and 2018/2019 growing seasons at Sohag Governorate. January (3.33 larvae/ plant) and at 13th 2.2. Predators: February (4.00 larvae/ plant). However, The seasonal abundance of C. in the second season, the peaks undecimpunctata associated with recorded in 2nd January (2.33 larvae/ cabbage aphid inhabiting canola plants plant) and at 20th February (3.67 during 2017/2018 and 2018/2019 larvae/plant). After that, the numbers growing seasons at Sohag Governorate decreased to the end of the two seasons. was presented in Figure (3). Data It is clear that the highest abundance of revealed that the coccinellid predator this predator was detected during started to take place in canola fields the February followed by January and last half of December (After 2 weeks of simultaneously increased as aphid aphid infestation) and recorded two populations increased in both seasons. peaks in both seasons. During first season, the peaks observed in 2nd

1124 Egypt. J. Plant Prot. Res. Inst. (2020), 3 (4): 1121-1128

6 2017/2018 season 2018/2019 season

4

2 Mean plant No./ Mean 0 14 21 28 5 12 19 26 2 9 16 23 30 6 13 20 27 6 13 20 27 Nov. Dec. Jan. Feb. March Samplin date

Figure (3): Population trend of Coccinella undecimpunctata inhabiting canola plants during 2017/2018 and 2018/2019 growing seasons at Sohag Governorate. The seasonal abundance of C. presented in Figure (5). Data revealed carnea associated with cabbage aphid that the syrphid predator started to take inhabiting canola plants during place in canola fields the last week of 2017/2018 and 2018/2019 growing December (After 3 weeks of aphid seasons at Sohag Governorate was infestation) and recorded one and two presented in Figure (4). Data revealed peaks in the two seasons, respectively. that the chrysopid predator started to During the first season, the predator take place in canola fields the last half maximized at 6th March (3.33 larvae/ of December (After 2 weeks of aphid plant). However, in the second season, infestation) and recorded three peaks in the predator maximized at 9th January both seasons. During the first season, (1.67 larvae/ plant) and at 27th February the peaks were obtained in 26th (2.33 larvae/plant). After that, the December (2.33 larvae/ plant), 23rd numbers decreased to the end of the two January (3.33 larvae/ plant) and in 27th seasons. The highest abundance of this February (2.33 larvae/ plant). However, predator was detected during February in the second season, the peaks were followed by March and January in the recorded in 26th December (3.33 larvae/ two seasons, respectively, and plant), 6th February (3.67 larvae/ plant) simultaneously increased as aphid and in 20th February (2.00 larvae/plant). populations increased in both seasons. After that, the numbers decreased to the In harmony with the previous end of the two seasons. The highest results, Saljoqi et al. (2012) found that abundance of this predator was detected at the time when the aphid population during February followed by January started to increase the population peaks and simultaneously increased as aphid of C. septempunctata and C. carnea populations increased in both seasons. was recorded. Also, Abbas et al. (2017) The seasonal abundance of S. reported that among the various natural corollae associated with cabbage aphid enemies, the dominions were inhabiting canola plants during coccinellid followed by green 2017/2018 and 2018/2019 growing lacewings and syrphid flies. seasons at Sohag Governorate was

1125 Mahmoud , 2020

4 2017/2018 season 2018/2019 season

3

2

1 Mean plant No./ Mean 0 14 21 28 5 12 19 26 2 9 16 23 30 6 13 20 27 6 13 20 27 Nov. Dec. Jan. Feb. March Samplin date

Figure (4): Population trend of Chrysoperla carnea inhabiting canola plants during 2017/2018 and 2018/2019 Growing seasons at Sohag Governorate. 4 2017/2018 season 2018/2019 season

3

2

1 Mean plant No./ Mean 0 14 21 28 5 12 19 26 2 9 16 23 30 6 13 20 27 6 13 20 27 Nov. Dec. Jan. Feb. March Samplin date

Figure (5): Population trend of Syrphus corollae inhabiting canola plants during 2017/2018 and 2018/2019 growing seasons at Sohag governorate.

3. Effect of biotic and abiotic factors the data of simple correlation and on population of Brevicoryne simple regression analysis (Table 1). brassicae infesting canola plants: The parasitoid gave highly The effect of biotic factors positive and significant effects of (Plant age, parasitoid and total simple correlation and simple predators) and abiotic factors regression values on the population of (Maximum and minimum temperatures B. brassicae during the two seasons. and mean relative humidity) on the Also, total predators gave positive and population of B. brassicae infesting significant effects of simple correlation canola plants was worked by processing and simple regression values on the population of B. brassicae during the

1126 Egypt. J. Plant Prot. Res. Inst. (2020), 3 (4): 1121-1128 two seasons, no effects were observed aphid. In agreement with these results, for plant age in both seasons. in contrast Abbas et al. (2014) found that none of with these results, Sayed and Teilep abiotic factors were significantly (2013) found that the effects of correlated with B. brassicae population predators and percent parasitism except minimum temperature in the showed insignificant effects of simple second season. Akbar et al. (2019) correlation values on the population of found that the aphid abundance showed canola aphid. While, Abdel-Rahman et non-significant association with mean al. (2020) suggested that the differences temperature, humidity and sunshine. in levels of infesting between the From the values of R-Squared seasons might be attributed to the (R2) in the simple regression analysis, differences in weather factors and / or the most effective factor in the the effect of natural enemies in each population of B. brassicae during the season. two seasons was the parasitism However, it is evident from the followed by the total predator number. results that the effects of abiotic factors The high R-Squared (R2) value has been (Maximum and minimum temperatures considered as evidence of the and mean relative humidity) showed responsibility of parasitoids and insignificant effects of simple predators to serve as a good biological correlation and simple regression control agent against B. brassicae values on the population of cabbage populations.

Table (1): Simple correlation (r), simple regression (b) and R-Squared (R2) between Brevicoryne brassicae and certain abiotic and biotic factors on canola at Sohag Governorate during 2017/2018 and 2018/2019 seasons. 2017/2018 season 2018/2019 season Tested factors Simple Simple regression Simple Simple regression correlation correlation b R2 b R2 (r) (r) Plant age 0.294 1.434 0.086 0.174 1.258 0.030 Parasitoid 0.962** 4.735** 0.925 0.976** 3.415** 0.953 Total predators 0.689** 42.458** 0.474 0.572* 55.877* 0.327 Maximum temperature -0.027 -1.030 0.001 0.001 0.069 0.000 Minimum temperature 0.062 3.214 0.004 -0.194 -28.794 0.038 Mean relative humidity -0.105 -1.656 0.011 -0.149 -5.068 0.022

*: Significant (p < 0.05%) **: Highly significant (p < 0.01%) References Abbas, Q.; Hussain, M.; Hasnain, Abbas, Q.; Ahmad, L.; Shahid, M.A.; M.; Shahid, M.; Akram, M.; Akhtar, M.F.; Hussain, M.; Raza, A.; Shahid M.R. and Akram, M. and Raza, A. Ahmad, K.J. (2017): (2014): Role of climatic factors Population distribution and on population fluctuation of species richness of canola aphids (Brevicoryne brassicae, aphids and their natural enemies Mayzus persicae and Lipaphis in different areas of Punjab, erysimi) on canola (Brassica Pakistan. Journal of nupus) in Punjab, Pakistan. Pak. Entomology and Zoology J. Nutr., 13(12): 705-709. Studies, 5(3): 1302-1308.

1127 Mahmoud , 2020

Abdel-Galil, F.A. and Mahmoud, M. Mazeed, R.A. (2006): Studies on A. (2019): Biotic factors insects associated with canola responsible for management the plant Brassica napus L. population trend of cabbage (Rapeseed) in Sohag aphid Brevicoryne brassicae L., Governorate. M.Sc. Thesis, Fac. inhabiting canola plants. Egypt. Agric., Minia Univ., Egypt., Acad. J. Biolog. Sci., 12(5):89- pp.115. 98. Nematollahi, M.R.; Fathipour, Y.; Abdel-Rahman, M.A.A.; Salman, Talebi, A.A.; Karimzadeh, J. A.M.A. and Syaid, A. S. and Zalucki, M.P. (2016): (2020): Population dynamics of Comparison of degree-day the cabbage aphid Brevicornae distribution models for brassicae (Hemiptera: predicting emergence of the Aphididae) infesting canola in cabbage aphid on canola. Crop El-Minia Governorate. Egypt. J. Protection, 80 : 138-143 Plant Prot. Res. Inst., 3 (1): 248 Saljoqi, A.R.; Zada, R.; Munir, I.; – 256. Rehman, S. and Khan, H.J.A. Abdrabou, R.T.; Fergany, M.A.H. ; (2012): Population trend of Azzam, C. R. and Nahid, A.A. canola aphid, Morsi (2017): Development of (Kalt.) (Homoptera: Aphididae) some canola genotypes to and its associated natural salinity tolerance using tissue enemies in different Brassica culture technique. Egypt. J. Lines along with the effect of Agron., 39(3): 431–448. gamma radiation on their Akbar, W.; Asif, M.U.; Muhammad, population. Pakistan J. Zool., R.; Khan, A.H. and Bux, M. 44(4): 1051-1057. (2019): Abundance of aphids on Sayed,A.M.M. and Teilep, W.M.A. various canola genotypes and (2013): Role of natural enemies, role of abiotic factors in its climatic factors and population fluctuation. Sci. performance genotypes on Lett., 7(2):52-58. regulating pests and Amer, M.; Aslam, M.; Razaq, M. and establishment of canola in Afzal, Muhammad (2009): Egypt. The Journal of Basic and Lack of plant resistance against Applied Zoology, 66: 18–26. aphids, as indicated by their Syaid, A. S.; Salman, A. M.A. and seasonal abundance in canola, Abdel-Rahman, M.A.A. (Brassica napus l.) in southern (2020): Insect pests and the Punjab, Pakistan. Pak. J. Bot. associated natural enemies in 41(3): 1043-1051. the cultivation of canola in El- Gomez, K.A. and Gomez, A.A. Minia Governorate. Egypt. J. (1984); Statistical Procedures Plant Prot. Res. Inst. 3(1): 257- for Agricultural Research, 267. Second ed. Jhon Willey and Temerak, S.A.H.; Abo-ELmaged, Sons, 680. T.M. and Amro, S. M. (2014): Khan, S.M. and Begum, H.A. (2005): Population trends of certain Population dynamics of canola canola with notes of aphid and varietal performance its resistance to some sap of canola varieties against it in feeding insect pests. Entomol. D.I.Khan, Pakistan. Pak. Appl. Sci. Lett., 1 (3):5-12. Entomol., 27(2): 37-41.

1128