Some ecological aspect of mustard aphid Lipaphis erysimi, infestation on broccoli (Brassica oleracea) and efficacy of bio-insecticides for management of mustard aphid in Bangladesh

Insect pests act as main barrier in enhancing yield potential of Brassica crops. Lipaphis erysimi is considered as one of the most destructive insect species in mustard production due to its voracious type feeding and multiplication. Therefore application of insecticide is inevitable for cultivation of cruciferous crops, although systemic insecticides has been found to be suitable for management of aphid, despite of high cost, residual effect and ecological ramification have necessitated the application of bio and botanical insecticides as novel approach and are recorded significant in research. Aphids having exclusively viviparous parthenogenesis type reproduction from January to March month with the completion of eight generations are helpful in quick mass multiplication. Natural enemies Coccinella spp., Syrphid larvae and bio-pesticide found effective in suppress aphid numbers. Manipulation in sowing dates of mustard crop provides good yield and less incidence of aphid which is proved through research. Lack of environmental resistant varieties has dispensed toward non feasibility of conventional breeding approaches for developing aphid-resistant Brassica. Although application of genetic engineering plan has resulted in moderate success in development of aphid resistance, so far commercialization of such genetically modified crops has not conceivable, intimate the necessity of further insights in to host plant and aphid communication to form effective approach against aphid resistance. Therefore in this chapter the components involved in Brassica aphid communication are highlighted and present statuses and problem in aphid management are discussed.

Management of Mustard aphid Lipaphis erysimi (Kaltbach) using Botanicals in field condition was carried out during Rabi 2023-24 at central Research field SHUATS Prayagraj, UP., India. The management of Mustard aphid was done using 8 different treatments and benefit cost ratios of all the treatments were calculated. Total one sprays were applied to protect the crop from Lipaphis erysimi using randomized block design with three replications. The observations of Lipaphis erysimi 24 hours before (Pre-treatment) and 3th, 7th and 14th day after spraying (post-treatment) were recorded for computing the percent of pest reduction. The data were subjected to statistical analysis after appropriate transformation for interpretation. The treatment with recommended (T4) Imidacloprid 17.8SL +NSKE5%Was of the most effective treatment followed By (T7) Imidacloprid 17.8 SI and (T3) Azadiractin the next best treatment were found to be (T1) Neem oil 5% and (T2) NSKE5%, (T5) Castor oil and (T6) cow urine were found to be least effective against Lipaphis erysimi (Kaltbach). The highest cost Benifit ratio was recorded with (T4) Imidacloprid17.8SL+NSKE5% (1:5.4) followed by the (T7) Imidacloprid 17.8SL (1:4.96), (T3) Azadiractin ts, Neem oil 5% (1:3.97), (T2) NSKE 5% (1:3.64), (T5) Castor oil (1:3.52), (T6) cow urine (1:2.3) as compared to untreated (T8) control (1:1.75).

Management of Mustard aphid Lipaphis erysimi (kaltbach) using Bio-pesticides in field condition was carried out during Rabi 2022-23 at central Research field SHUATS Prayagraj,UP, India. The management of Mustard aphid was done using 8 different treatments and benefit cost ratios were calculated. One spray is applied to protect the crop from mustard aphid (Lipaphis erysimi) using randomized block design with three replications. The observations of mustard aphid (Lipaphis erysimi) 24 hours before (Pre-treatment) and 3rd, 7th and 14th day after spraying (post-treatment) were recorded for computing the per cent of pest reduction. The treatment Spinosad 45%SC (T6) (86.75%) shows highest per cent reduction and the most effective treatment followed by Imidacloprid 17.8%SL (T7) (76.97%), Nisco sixer plus 45 SC (T1) (61.83 %), Verticillium lecanii (2×108 Spore/ml) (T2) (51.04%), Beauveria bassiana (2CFU×108 ml) (T4) (47.60%), Metarhizium anisopliae (2×108 CFU/gm) (T3) (42.01%), Least percentage reduction was obtained with Neem oil 5% EC (T5) (33.42%). While Spinosad 45%SC (T6) shows higher cost benefit ratio with (1:7.96), followed by Imidacloprid 17.8%SL (T7) (1:7.83), Nisco sixer plus (1:6.57), Metarhizium anisopliae (2×108 CFU/gm) (T3) (1:5.79), Beauveria bassiana (2CFU×108 ml) (T4) (1:5.64), Verticillium lecanii (2×108 Spore/ml) (T2) (1:5.63) and Neem oil 5% EC (T5) (1:5.03).

Aphids are major pests of mustard and wheat crops, causing significant yield losses worldwide, necessitating effective management strategies. Spinosad, a bio pesticide with a unique mode of action, offers an environmentally friendly alternative for pest control. A study was conducted in the Insect Biotechnology and Biopesticide Laboratory, Department of Entomology, Bangladesh Agricultural University, from February 2019 to February 2020, to assess the efficacy of Spinosad (Tracer 45SC) against mustard aphids (Lipaphis erysimi) and wheat aphids (Diuraphis noxia) using a leaf-dip bioassay. Different concentrations of Spinosad were tested, and mortality was recorded at intervals of 24, 48, 72, 96, and 120 hours after treatment (HAT). Results indicated that Spinosad exhibited significant insecticidal activity against both aphids, with the highest concentration (500 ppm) causing maximal mortality. For mustard aphids, mortality increased from 3.33–16.67% at 24 HAT to 36.67–66.67% at 120 HAT, with a maximal mortality of 66.67% at 500 ppm. The LC50 values decreased from 2883.88 ppm at 24 HAT to 232.31 ppm at 120 HAT, indicating increased toxicity over time. Similarly, for wheat aphids, mortality ranged from 10–30% at 48 HAT to 46.67–73.33% at 120 HAT, with a maximal mortality of 73.33% at 500 ppm. The LC50 values fell from 3049.90 ppm at 24 HAT to 140.31 ppm at 120 HAT. LC90 values for both aphids also decreased over time, demonstrating heightened efficacy with protracted exposure. These findings emphasize Spinosad’s potential as an effective insecticide against mustard and wheat aphids, with its lethality increasing substantially over time. The concentration of 500 ppm consistently delivered the highest mortality for both aphids.

Background: Due to ozone depletion, the potential threat of rising solar UV radiation levels at the Earth’s surface has led to demand for worldwide measurement of solar UV radiation. UV is electromagnetic radiation with a wavelength ranging from 200 nm - 400 nm and constitutes about 10% of the light output of sun. It is the most photochemically reactive wavelength of solar radiation and important critical abiotic stressor for organisms, particularly in their early stages of life. UV radiation directly regulates insect life processes and indirectly changes in insect biochemistry and morphogenesis. Methods: In this study, measurement of solar UV-B was performed in the Haridwar and Tehri Garhwal, Uttarakhand with the help of radiometer having UV-B sensor. Artificial UV-B provided with UV-B lamp. Mortality rate, Protein content and GSH level were observed in mustard and pea crop aphids species after exposure to solar and artificial UV-B irradiation separately and with alpha-terthienyl photosensitizer. Result: The data of measurement of UV-B showed that the maximum intensity of UV-B was found in during month of June and minimum in the month of January. Mortality rate of aphids that artificial UV-B radiation with alpha-terthienyl shows a highly toxic effect on aphids population diversity and dispersal. Protein and GSH level decreased in all groups compared to control. Maximum reduction in protein and GSH level was found in after treatment of artificial UV-B with alpha-terthienyl. Exposure of artificial UV-B radiation with alpha-terthienyl shows stunted growth, morphological changes, low reproduction and high mortality in aphids. Artificial UV-B was found to be more toxic than solar UV-B. Mustard aphid (Lipaphis erysimi) was found to be more sensitive than pea aphid (Acyrthosiphon pisum). Climate change and increase in UV-B levels affect aphid development and population growth.

The aphid incidence and its correlation with environmental factors were studied. Mustard variety "Sampad" was used as test crop. Aphid incidence varied significantly at various parts of mustard plant and time of the day. The highest number of aphid was observed in the vegetative parts of the mustard plant in the morning. High cloudiness, relative humidity and dew point favoured the aphid population and slight rain fall quickly declined the aphid population. Among the different environmental factors maximum temperature, dew point and sun shine hours were positively correlated with aphid population and minimum temperature, relative humidity and wind speed were negatively correlated with aphid population. Keywords: Mustard aphid; Incidence; Environmental factors DOI: 10.3329/jbau.v7i1.4791 J. Bangladesh Agril. Univ. 7(1): 15-18, 2009

The present study on seasonal incidence of mustard aphid Lipaphis erysimi (Kalt) with their natural enemies, was taken at the field of AICRP on Rapseed and Mustard, College of Agriculture Nagpur, during Rabi 2023-24. The experiment was laid out in 10m2 separate plot. Based on regular monitoring it was observed that only three insect pests, mustard aphid (Lipaphis erysimi), mustard sawfly (Athalia lugens proxima) and leaf webber (Crocidolomia binotalis) were found to cause damage in mustard crops in this area. The population of natural enemies Coccinellids and Aphid parasitoid (Diaretiella rapae) were also documented as major natural enemies of mustard aphid. The incidence of mustard aphid was recorded from 50th Standard Meteorological Week (SMW) 2023, which continued up to 9th Standard Meteorological Week (SMW) of 2024. Mustard sawfly was reaches peak population in 49th SMW. Mustard sawfly population reached its peak in 1st SMW. Thereafter, the population was declined and it was not appeared in 4th SMW (last week of January). The appearance of leaf webber population was initiated from 49th SMW to 5th SMW. The population of Natural enemies viz., coccinellid (Coccinella septempunctata) (3.60 number/plant) and mustard aphid parasitoid (Diaeretiella rapae) (50.35%) also seen from 52nd SMW to 9th SMW.

Resource allocation and post-reproductive degeneration in the freshwater cnidarian Hydra oligactis (Pallas, 1766)

Four different IPM modules were designed and tested for the management of mustard aphid in mustard crop including farmer practices. It was observed that all four IPM modules significantly reduced mustard aphid incidence on mustard crop and enhanced the yield over farmers’ practices (FP). The Module 4 [Taramira (Trap crop) + Installation of yellow sticky trap @ 25/ha + Two spray with Acetamiprid 25 SP @ 25 g a.i./ha] was found most effective treatment with minimum number of aphids and it was significantly superior over rest of the treatments. It is followed with the Module 3 [Taramira (Trap crop) + First spray of Beuauveria bassiana @ 1 kg/ha + Second spray Nimbicidine 0.03 EC @ 2.5 liter/ha], Module 1 Installation of yellow sticky traps @ 25/ha + First spray of NSKE 5% + Second spray of Lantana leaf extract 1.5%) and Module 2 (Manual removal of infested twigs + First spray of Verticillium lecanii @ 2.5 kg/ha + Second spray Kunap Jal) were effectively found to reduce aphid population. The highest yield (15.53 q/ha) recorded in Module 4. All the IPM modules were significantly superior over the farmer practices.

Mustard aphid, Lipaphis erysimi (Aphididae: Hemiptera) is one of the major constraints for mustard production in Pakistan. Sustainable management of mustard aphids is a serious issue due to their unusual life cycle and widespread habitats. Synthetic chemicals are a great threat to the environment and human health. In the present study, as an alternative different sowing dates and plant extract being ecofriendly approaches to manage insect pests. In this study two different experiments were performed to test the effect of sowing dates on the population trend of canola aphids (Lipaphis erysimi (Kalt) on four selected canola cultivars (Tara seed, Dalay, Abaseen and KS-75). The trials comprised three different sowing dates at a time interval of 10 days; (S1) 26th October 2021, (S2) 6th November 2020, (S3) 16th November 2020. In second experiment, the efficacy of insecticide (Fipronil) and botanical extract (Neem seed extract) against canola aphids on two tested canola cultivars (Abaseen and KS-75) regarding different parameters were studied. Data regarding the population trend of aphids on four tested cultivars at three various sowing dates show that significantly minimum aphids plant-1 (S1 (7.60), S2 (6.79), S3 (8.79) was obtained from canola cultivar KS-75, while, statistically maximum aphids plant-1 (S1 (77.91), S2 (53.28), S3 (62.40) was obtained from Abaseen variety on all three sowing dates. During second experiment, significantly maximum mean per cent population reduction (67.183), Sub-branches plant-1 (29.360), Pods plant-1 (377.58), and Yield (105.62) was obtained from Fipronil treated plots while statistically minimum mean per cent population reduction (2.467), Sub-branches plant-1 (16.625), Pods plant-1 (210.99), and Yield (48.39) was recorded from control. Our findings show that KS-75 is the most resistant canola variety among all tested cultivars and conventional pesticide Fipronil proved highly effective against L.erysimi.

Research experiment was carried out under the field conditions during the rabi season of 2023-2024 at Central research field SHUATS Prayagraj, UP, India. The management of mustard aphid, Lipaphis erysimi (Kalt) was done using different treatments and benefit cost ratio of all the treatments were calculated. One spray was applied to protect the crop from Lipaphis erysimi using randomized block design with three replications. The observation of mustard aphid, Lipaphis erysimi 24 hours before (Pre-treatment) and 3rd, 7th, and 14th day after spraying (Post-treatment) were recorded for computing the per cent population reduction of pest. The different chemicals and biopesticides treatments revealed that Imidacloprid 17.8% SL (87.21%) shows the highest per sent reduction and was the most effective treatment followed by Cypermethrin 10% EC (84.31%), Nisco sixer plus (78.06%), Bacillus thuringiensis (73.02%), Beauveria bassiana (2×108 CFU/ml) (70.02%), Verticillium lecanii 1.15% WP (68.78%) the least per cent reduction was observed in Neem oil 5% EC (64.85%). The highest crop production, at 38.33 q/ha on average was recorded in Imidacloprid 17.8 SL with cost benefit ratio of (1:9.71) followed by Cypermethrin 10% EC 34.00 q/ha with (1:8.54) C:B ratio, Nisco sixer plus 31.66 q/ha with (1:7.22) C:B ratio, Bacillus thuringiensis 28.33 q/ha with (1:6.53) C:B ratio, Verticillium lecanii 1.15% WP 26.00 q/ha with (1:6.07) C:B ratio, Beauveria bassiana (2×108CFU/ml) 26.66 q/ha (1:6.04) C:B ratio, Neem oil 5% EC 21.66 q/ha with (1:4.64) C:B ratio and control 15.00 q/ha with (1:3.93) C:B ratio.

Among the two methods of growing white cabbage, the seedling technology is more widely used in North-Western Russia. Watering seedlings in cassettes with a systemic formulation of neonicotinoid insecticide Actara, WDG (250 g/kg thiamethoxam) prior to planting has been developed to protect white cabbage from early spring pests: flea beetles of the genus of Phyllotreta and the cabbage root fly. This approach is widely used by commercial growers and its efficacy requires monitoring under current conditions because of a possibility of resistance development. Testing Actara, WDG in 2019 and 2021 at the experimental field of All-Russian Institute of Plant Protection didn’t show any significant decrease of biological effectiveness of seedling treatment. Testing biological effectiveness of systemic insecticides belonging to the chemical class of carbamates Lannate, WSP (250 g/kg metomil) and the new class isoxazolines isocycloseram was carried out in parallel. Biological effectiveness of the latter insecticide was higher compared to Actara against the flea beetles and the cabbage root fly during a 21-day period. In addition, plant infestation with diamondback moth decreased. Efficacy indices of Lannate were significantly lower. Isocycloseram shows a good potential for inclusion into the Index of Registered Formulations of the Russian Federation to protect cabbage against a complex of insect pests. Having an additional active ingredient available to farmers will be begenicial for developing rotation schemes to combat pest resistance.

Field experiments were conducted during 2021-2022 and 2022-2023 to determine the population dynamics of mustard aphid Lipaphis erysimi (Kalt) and its coccinellid predators on two mustard varieties viz. Rohini (highly susceptible) and RH0749 (least susceptible) in relation with different abiotic factors. The infestation was observed in last week of December to the first week of March, the overall mean indicates the incidence was at its peak in the second week of February. Maximum incidence of 160-120/ five plants was recorded on Rohini while 160-100/five plants on RH0749. The predatory activities of coccinellids viz., Cheilomenes sexmaculata (L), Coccinella septempunctata (F) and Coccinella transversalis (F) revealed significant positive correlation with aphid incidence.

Field experiments were carried out at the National Maize Research Program in Rampur, Chitwan, with the objective of comparing the effectiveness of insecticides in the field for controlling maize leaf aphid (Rhopalosiphum maidis Fitch) during the winter season of 2019 and 2020. The design of the experiment was randomized complete block with four replications. The plot size was 6 rows of 5 m long with the spacing of 60cm × 25cm. Maize hybrid Rampur Hybrid-14 (RML-86/RML-96) was used as experimental variety. The efficacies of five insecticides viz., thiomethoxam 25% w/w 0.2g/L (T1), acetamiprid 20%WP 2g/L (T2), flonicamid 50% WG 0.5g/L (T3), neemix 3ml/L(T4), imidacloprid 0.5ml/L(T5) and untreated control (T6) were used as experimental treatments. The recommended dose of fertilizer was 180: 60: 40 N: P2O5: K2O kg/ ha with farm yard manure 10 t/ha and seed rate was 20kg/ha. Data on aphid incidence, severity, yield and yield components were recorded. All the tested insecticides significantly (P≤0.05) reduced the plant infestation caused by maize aphid, and thereafter increased the grain yield of maize compared to control. However, newer insecticide flonicamid 50% WG 0.5g/L was found as the most effective insecticide with lower aphid colony per plant (2.85), aphid score (2.63), aphid infested plant (7.33%) and higher crop yield (7904.79kg/ha). The application of insecticides prior to their severe infestations is necessary for the efficient control of the maize leaf aphid. The research findings will assist maize farmers in choosing and applying the best insecticide to ensure efficient management of maize leaf aphid with high yield.

A field experiment was conducted during Rabi 2019-2020 at Research Farm of Agricultural Research Sub Station Nagaur (Agriculture University, Jodhpur) to know the pest incidence in mustard variety ’BIO 902’. The incidence of aphid 3.65 aphids per plant started in the first week of January (1st SMW) continued thereafter for a long period and reached to maximum 128.80 aphids per plant in the third week of February (7th SMW). The incidence of ladybird beetles appeared in the second week of January and reached its peak 9.95 coccinellids/plant in the third week of February (7th SMW). The correlation coefficient of L. erysimi with ladybird beetle population had a positive significant correlation (r= 0.979).