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Subject: Entomology × Author: Ambarish, K. × End date: 2024 × Start date: 2020 × Type: Thesis ×
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    ThesisItemOpen Access
    Studies on predatory potential and pollination efficiency of Syrphid flies
    (G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-08) Ambarish, K.; Srivastava, Poonam
    The family Syrphidae is considered the most species-rich family in the order Diptera, which has about 6000 known species that belong to 180 genera from three subfamilies. The present study on the predatory potential and pollination effectiveness of syrphid flies were discusses the significance of syrphids as a biological control agent and pollination agent since both the larval and adult stages of the syrphid fly have an economic relevance. The present investigation on the diversity of syrphids on mustard, mango and litchi crops, revealed that the maximum number of 7 species of syrphids were observed in the litchi, while mustard and mango with 6 species each that belongs to two subfamily Eristalinae and Syrphinae. The Eristalinus arvorum (Fabricius) was the major syrphid pollinators in mustard with maximum abundance ranged from 2.45 to 3.3 syrphids /m2 /5min with pollination index (24490.2 to 40114.8), followed by 1.95 to 2.6 syrphids /m2 /5min of maximum abundance with pollination index of 17050.8 to 27820 in Eristalis cerealis (Fab.) at different flowering stages in mustard. While in mango, Episyrphus balteatus (Deg) has a maximum mean abundance of 7.4 to 8.3 syrphids /inflorescence /5min with pollination index (64054.4 to 70574.4), followed by in Eupeodes confrater Wied (3.9 to 6.45 syrphids /inflorescence /5min) and (38088.8 to 66177), respectively at different flowering stages. Whereas in litchi E. balteatus (Deg) had higher pollination index that ranging from 57405.5 to 83446.2, compared to Ischiodon scutellaris (Fab.) (17631 to 41072) and both had a maximum abundance ranging from 7.25 to 8.2 syrphids/ inflorescence /5min in E. balteatus and 2.3 to 3.35 syrphids/ inflorescence /5min in I. scutellaris at different flowering stages of litchi. Among all the syrphid species, E. arvorum that comprising of 28 per cent, E. cerealis (21.8 per cent) in mustard, while in mango E. balteatus and E. confrater that comprising (39.4 and 25.4 per cent, respectively) and in litchi E. balteatus (39 per cent) and I. scutellaris (19.6 per cent) are major syrphid pollinators. Irrespective of day hours and syrphid species, the maximum abundance was observed during the 100 per cent flowering stage with a mean population of 2.77 (in mustard), 7.12 (in mango) and 5.08 syrphids/ inflorescence /5min in litchi. While the maximum foraging rate were observed with 6.47 in mustard (at 75 per cent), 7.35 in mango (at 25 per cent) and 7.6 flowers /min in litchi at 100 per cent flowering stage and the maximum foraging speed were recorded at 100 per cent flowering in mustard and litchi (4.19 and 4.6 sec. /flower, respectively) while in litchi (4.47 sec. /flower) it was observed at 25 per cent flowering stage. However the correlation co-efficient between the syrphid foraging behaviour with abiotic factors revealed non-significant, though it showed a negative correlation in mustard in the month of Nov-Dec and a positive correlation in mango and litchi for maximum temperature and other parameters in the month of March. The mean total aphid consumption by Eupeodes confrator (Wied) in its entire larval stage was more in the case of Lipaphis erysimi (Kalt) with 286.8 aphids /larvae, as compared to the Rhaphalosiphum maidis (Fitch) with 241.3 aphids /larvae while the maximum and minimum predation were observed at 9th day (52.7 aphids /larvae) and 1st day (7.1 aphids /larvae) in L. erysimi and 10th (44.4 aphids /larvae) and 1st day (6.0 aphids /larvae ) in case of R. maidis.