Mean Aphid Research Articles

Efficacy of Plant Extracts for the Control of Pepper Insect Pest (Green Peach Aphid (Myzus persicae L.)

Aphids pose significant threats to crop productivity, necessitating effective and sustainable pest management strategies. This study investigated the repellent properties of neem and papaya leaf extracts on green peach aphids and the impact of the extracts on plant growth in pepper (Capsicum spp.). The experiment involved 7 treatments and 3 treatment replications with varying concentrations of neem and papaya extracts (6.5 v:v, 7.5 v:v, and 8.5 v:v) compared to a control group (Distilled water). The Randomized Complete Block Design (RCBD) was used as an experimental design. The study site was Cuttington University’s College of Agriculture Research site. The distances between plots and blocks were 0.6 m and 1 m, correspondingly. In the laboratory bioassay, results uncovered distinct trends, with the control treatment exhibiting the highest mean aphid count (41.0), while neem 8.5 v:v (6.0) and papaya 8.5 v:v (8.1) treatments established substantial effectiveness in reducing aphid populations. The highest mean aphid counts following biopesticidal application were 48.0 and 76.7 after 1 and 2 weeks, respectively and were recorded in the untreated control plots, while the lowest mean aphid counts were 21.3 and 6.0 after 1 and 2 weeks, respectively. Furthermore, neem 8.5 v:v treatment consistently showed the highest mean values across plant height (16.2 cm), leaf length (8.2 cm), leaf width (5.2 cm), and repellency index (3.0), indicating potential positive impacts on plant growth and repellency. Untreated control measured the lowest values for plant height (13.8 cm), leaf length (6.0 cm) and repellency index (1.0). The study demonstrated the potential of both extracts to suppress aphid populations and enhance plant growth. Applying these natural extracts as part of an integrated pest management (IPM) strategy can be beneficial for controlling aphid infestations in pepper crops. Their use as repellents can reduce aphid populations, minimizing potential crop damage and yield losses.

Comprehensive Assessment of Aphid (Lipaphis erysimi (Kalt.) Resistance in Mustard Cultivars

The study focuses on mustard (Brassica spp.) crops, crucial rabi oilseed crops in India. This study aimed to assess the susceptibility of 45 mustard crop cultivars to Lipaphis erysimi Kaltenbach, commonly known as the mustard aphid, a significant biotic stressor affecting Indian mustard (Brassica juncea). The necessity of this study lies in the importance of identifying aphid-resistant cultivars to enhance pest management strategies and improve mustard crop yields. Field experiments were conducted at Jawaharlal Nehru Krishi Vishwavidyalaya in Jabalpur, Madhya Pradesh, India during the rabi season, using a Randomized Block Design. The study utilized a mean aphid index-based scoring scheme to categorize the cultivars into different susceptibility levels, ranging from highly resistant to highly susceptible. The classification was determined based on normal distribution values, including highly resistant (HR), resistant (R), moderately resistant (MR), moderately susceptible (MS), susceptible (S), and highly susceptible (HS). The results revealed that none of the cultivars fell into the highly resistant category, but five cultivars demonstrated resistance, with mean aphid index values below 0.34. Thirty cultivars were classified as moderately resistant, displaying mean aphid index values between 0.34 and 0.66. Six cultivars exhibited moderate susceptibility (mean aphid index between 0.66 and 0.82), while four cultivars were categorized as susceptible (mean aphid index between 0.82 and 0.98). Notably, none of the cultivars were highly susceptible. The study underscores the importance of identifying aphid-resistant cultivars to enhance pest management strategies and improve mustard crop yields. The results provide valuable insights into the susceptibility levels of different cultivars, guiding farmers in selecting appropriate varieties for cultivation. The research also emphasizes the significance of environmentally friendly pest management options, considering the potential risks associated with pesticide use. Overall, this study contributes to the development of sustainable Integrated Pest Management (IPM) techniques for Indian mustard cultivation.

The potential of the hoverfly Allograpta exotica as a biological control agent of the strawberry aphid Chaetosiphon fragaefolii

AbstractSyrphid larvae are effective biological control agents in numerous crops due to their voracity, and they are used in both augmentative and conservation‐based strategies within horticultural systems. This study conducted laboratory trials to ascertain the predation rate of Allograpta exotica (Wiedemann) (Diptera: Syrphidae) on Chaetosiphon fragaefolii (Cockerell) (Hemiptera: Aphididae) and to compare it with the predation rate on Aphis gossypii Glover (Hemiptera: Aphididae), another significant aphid species affecting strawberries. Additionally, field trials were conducted to assess the reduction in the field population of C. fragaefolii achieved by A. exotica within strawberry crops. We observed a significant increase in the number of aphids consumed by a larva as it progressed from first‐instar larvae (L1) to third‐instar larvae (L3). Specifically, the mean aphid consumption by second‐instar larvae (L2) was nearly 11 times higher for C. fragaefolii and 10 times higher for A. gossypii compared to L1. Furthermore, the consumption rate of L3 larvae was approximately 2 times higher for both aphid species compared to L2. In laboratory conditions, A. exotica larvae significantly reduced the number of both aphid species, but the control on A. gossypii was higher than on C. fragaefolii. The results of the field experiment demonstrated that the predatory hoverfly A. exotica significantly reduced the numbers of C. fragaefolii compared to the control treatment, highlighting its potential as a promising biological control agent in strawberry crops.

Genetic diversity and population structure analyses in barley (Hordeum vulgare) against corn-leaf aphid, Rhopalosiphum maidis (Fitch).

Corn-leaf aphid (CLA), Rhopalosiphum maidis (Fitch) (Hemiptera: Aphididae) is a serious economic pest of barley worldwide. Breeding for aphid resistance in plants is considered a cost-effective and environmentally safe approach for aphid control, compared to the use of chemical pesticides. One of the challenges in breeding for aphid resistance is the identification of resistant plant genotypes, which can be achieved through the use of molecular markers. In the present study, a set of aphid specific 10 simple-sequence repeats (SSR) markers were used to investigate genetic diversity and population structure analyses in 109 barley genotypes against R. maidis. Three statistical methods viz., multivariate hierarchical clustering based on Jaccard's similarity coefficient, principal coordinate analysis (PCoA) and the Bayesian approach were utilized to classify the 109 barley genotypes. The analyses revealed four subpopulations i.e., SubPop1, SubPop2, SubPop3 and SubPop4 with 19, 46, 20 and 24 genotypes including admixtures, respectively and represented 17.43%, 42.2%, 18.34% and 22.01% genotypes of the total population size, respectively. The studied SSR markers produced 67 polymorphic bands, with an average of 6.7 and ranging from 3 to 12 bands. Heterozygosity (H) was found to be highest in SSR28 (0.64) and lowest in SSR27 (0.89). The observed genetic diversity index varied from 0.10 to 0.34 (with an average of 0.19). Major allele frequency varied from 74.08% to 94.80%. On an average, 87.52% of the 109 barley genotypes shared a common major allele at any locus. Based on the Aphid Infestation Index (AII), only 2 genotypes were found to be resistant against CLA. SubPop2 also had lowest mean aphid population (28.83), widest genetic similarity index (0.60-1.00) and highest genetic similarity coefficient (0.82), which highlighted its potential for inclusion in future CLA resistance breeding programs.

Screening of Mustard Varieties for Resistance against Mustard Aphid, (Kaltenbach)

The present investigation was conducted at Agronomy Farm and Laboratory, Department of Biochemistry, S.K.N. College of Agriculture, Jobner (Rajasthan) during Rabi, 2019-20 and Rabi, 2020-21 to screen out the varieties of mustard for their resistance to mustard aphid, Lipaphis erysimi. The overall pooled mean aphid population ranged from 42.99 to 80.55 per 10 cm terminal shoots of five plants on different varieties. The minimum aphid infestation (42.99 aphids/ 10 cm terminal shoot) was recorded on Varuna followed by Bio-902 (44.63 aphids/ 10 cm terminal shoot) and both were found statistically same in reaction to aphid incidence. The maximum infestation/ 10 cm terminal shoot was recorded on Kranti (80.55 aphids) followed by GM-2 (79.99 aphids), and RH-30 (79.46 aphids) which remained at par to harbour the aphid population. The variability of resistance in mustard varieties in the decreasing order was Varuna, Bio-902, NRCDR-2, Pusa Bold, Laxmi, NRCHB-101, Rohini, Durgamani, Vardan, RH-9304, GM-1, Maya, RH-30, GM-2 and Kranti. The statistical characterization of results revealed that out of fifteen mustard varieties, two varieties Varuna and Bio-902 were found less susceptible to the mustard aphid, L. erysimi. Nine varieties viz., NRCDR-2, Laxmi, Pusa Bold, NRCHB-101, Rohini, Vardan, RH-9304, Durgamani and GM-1 were categorized as moderately susceptible, whereas, four varieties viz., Maya, RH-30, GM-2 and Kranti were categorized as highly susceptible in both years of the study.

Adoption and Assessment of Integrated Strategies for Managing Major Insect Pests in Kharif Green gram [Vigna radiata (L.) Wilczek

For assessing the integrated strategies towards managing insect pest of green gram the concerned experiment was executed for consecutive three years using two treatments, viz., IPM nodule and Farmer’s practice. In case of IPM module management tactics included seed treatment with fungicide (Tebuconazole 50% + Trifloxystrobin 25%) and insecticide like thiamethoxam, seed dressing with rhizobium, installation of yellow sticky traps, pheromone traps, growing border crops, applying neem based insecticides and need based application of chlorantraniliprole. In case of Farmer’s practice only two round spray of chlorpyriphos + cypermethrin were given. In all the years aphid and spotted pod borer population were significantly less compared to the farmer’s practice (mean aphid population of 2.53 per 10 cm apical twig in IPM plots against 29.37 in Farmer’s practice while pod borer population of 0.77 larva plant-1 in IPM and 4.8 in Farmer’s practice). Natural enemy population was considerably higher in IPM module (5.23 plant-1) compared to the farmer’s practice (1.36 plant-1). Higher incremental benefit cost ratio was also obtained from IPM modules.

Adoption and Assessment of Integrated Strategies for Managing Major Insect Pests in Kharif Green gram [Vigna radiata (L.) Wilczek

For assessing the integrated strategies towards managing insect pest of green gram the concerned experiment was executed for consecutive three years using two treatments, viz., IPM nodule and Farmer’s practice. In case of IPM module management tactics included seed treatment with fungicide (Tebuconazole 50% + Trifloxystrobin 25%) and insecticide like thiamethoxam, seed dressing with rhizobium, installation of yellow sticky traps, pheromone traps, growing border crops, applying neem based insecticides and need based application of chlorantraniliprole. In case of Farmer’s practice only two round spray of chlorpyriphos + cypermethrin were given. In all the years aphid and spotted pod borer population were significantly less compared to the farmer’s practice (mean aphid population of 2.53 per 10 cm apical twig in IPM plots against 29.37 in Farmer’s practice while pod borer population of 0.77 larva plant-1 in IPM and 4.8 in Farmer’s practice). Natural enemy population was considerably higher in IPM module (5.23 plant-1) compared to the farmer’s practice (1.36 plant-1). Higher incremental benefit cost ratio was also obtained from IPM modules.

Studies on Morphophysiological and Biochemical Parameters for Sucking Pest Tolerance in Organic Cotton

The demand for organic cotton is primarily driven by manufacturers and brands with a corporate focus on environmental and social responsibility. These entities strive to be responsible stewards by seeking organic cotton, which not only offers environmental benefits but also provides softer, more durable, and longer-lasting clothing. Unlike conventional cotton, organic cotton is processed without the use of harsh chemicals, making it more comfortable for individuals with sensitive skin. A study was conducted at the Center of Organic Agriculture Research and Training Center, Department of Agronomy, Dr. PDKV, Akola, Maharashtra, India to evaluate 22 cotton genotypes, including control samples, using a randomized block design with three replications during the kharif (June–October) season in the years 2019–2020 and 2020–2021, under complete organic conditions. During the initial year of the study (2019–2020), visual observations were made to assess the incidence of sucking pests on the cotton genotypes’ leaves, including the top, middle, and bottom portions. The observations indicated promising results, leading to a more detailed study in the subsequent year (2020–2021). This extended study identified several tolerant genotypes to sucking pests, such as AV-G11, PA-255, GA-8004, AV-C14, and AV-G13 from the arboreum species, as well as AKH-09-5, a hirsutum cultivar. Among the recorded data, it was found that the lowest mean aphid population occurred at 90 days after sowing (DAS), with only 1.53 aphids per leaf. Similarly, the lowest mean populations of Cicadellidae, thrips, and whitefly were recorded at 0.75, 0.97, and 0.63 per leaf, respectively, all at 30 DAS. Microscopic analysis of trichome density and gossypol glands revealed a negative and significant correlation with Aphis gossypi (aphids), Cicadellidae sp. (Cicadellidae), and Thrips tabaci (thrips). However, a positive and significant correlation was found with Bemesia tabaci (whitefly). Furthermore, the estimation of total soluble sugar using the Anthrone method, total nitrogen, and crude protein showed positive and significant correlations with aphids, Cicadellidae, and thrips, but negative, significant correlations with whitefly. The findings indicate that higher trichome density provides greater resistance to sucking pest infestation. It was concluded that G. arboreum genotypes exhibit greater tolerance to sucking pests compared to G. hirsutum varieties. This implies that G. arboreum varieties may require less intensive pest management, aligning with organic farming principles. The discovery of these genotypes opens up possibilities for utilizing them as sustainable and pest-resistant options in cotton cultivation, promoting environmentally friendly and organic farming practices in cotton fiber production.

POTENTIAL IMPACT OF NITROGEN ON POPULATION FLUCTUATION OF APHID AND YIELD PARAMETERS IN BARLEY

The present study was carried out on the farmer field under the supervision of the Department of Plant Protection and Quality Control of Pesticides during 2020 and 2021. Barley cultivar ‘Haider-93’ was sown in a randomized complete block design (RCBD) with three replications to examine the effect of two levels ofnitrogen fertilizer, 50 and 100 kg/ha along with control (no fertilizer), on population fluctuation of aphid and on barley yield components like grain protein (%), 1000-grain weight and the barley grain yield. Aphid incidence was recorded throughout the cropping season. The results revealed that peak infestation of aphids per tiller were recorded in the 3rd week of February in successive year. The study indicated a significant relationship between nitrogen fertilizer and aphid population density per tiller. The mean aphid population per tiller was recorded a significantly higher (34.12 ± 0.81 and 28.65 ± 0.17 for the years 2020 and 2021, respectively) at 100 kg/ha of nitrogen level while lowest infestation (14.51 ± 0.20 and 12.30 ± 0.10 aphids per tiller for the year 2020 and 2021, respectively) was recorded at 0 kg/ha of nitrogen fertilizer. Nitrogen fertilizer level at 100 kg/ha gave significantly higher grain protein (12.80 ± 0.17 and 13.70 ± 0.26% for the years 2020 and 2021, respectively) and grain yield (2758.75 ± 60.82 and 2673.79 ± 61.88 kg/ha produce for the year 2020 and 2021, respectively) of the barley crop. However, treatment differences for 1000-grain weight (g) were recorded as non-significant. These findings suggest that the nitrogen fertilizer at 100 kg/ha level produced significantly higher grain protein (%) and grain yield at the same time, also supported the higher infestation of aphids per tiller. Still, this aphid density did not affect the accumulation of grain protein (%) and grain yield of the barley crop. The results of this study might be used for decision-making to apply nitrogen fertilizer for better grain yield of barley crop but at the same time considering the colonizing aphid population.

Endophytic Effect of the South African Beauveria bassiana Strain PPRI 7598 on the Population Growth and Development of the Russian Wheat Aphid, Diuraphis noxia

The Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is one of the main pests of small-grain cereal crops, including bread wheat, Triticum aestivum (Poaceae). In a series of glasshouse experiments, we evaluated the systemic effect of endophytic Beauveria bassiana strain PPRI 7598 on D. noxia biotype RWASA1 using three South African wheat cultivars, Gariep, Molopo, and Kariega. The objectives of the study were: (a) to determine the effect of endophytism on RWA reproduction and population growth, and (b) to assess the effect of the endophyte on aphid biomass and T. aestivum response to D. noxia herbivory using a damage rating index. Plant endophytic colonisation was confirmed before each trial using a B. bassiana-selective medium. Three independent trials were performed 10 days apart under glasshouse conditions. The effect of the endophyte-treated versus non-treated plants varied significantly in terms of net reproductive rate (R0) and the intrinsic rate of increase (rm) of the D. noxia population. Overall, the endophyte significantly reduced D. noxia R0 by approximately 14 nymphs/female and decreased the aphid mass by 13% in treated plants, whereas the mean aphid mass increased by 17% in control plants in all pooled cultivars. These findings demonstrated the endophytic potential of B. bassiana strain PPRI 7598 for suppression of D. noxia populations in RWASA1-susceptible cultivars. The integration of B. bassiana endophytism with host plant resistance may counteract biotype development and support a more sustainable approach towards RWA control in integrated pest management programmes.

Insecticidal Application Methods against Melanaphis sacchari (Hemiptera: Aphididae) on Sorghum in Northeastern Mexico

Invasion of the sugarcane aphid, Melanaphis sacchari (Zehntner), into all sorghum (Sorghum bicolor (L.) Moench)–producing areas in Mexico in 2013 prompted a series of studies on assessing and developing integrated pest management strategies for the pest. To avoid economic yield losses, studies were first focused on identifying effective insecticides against this new insect pest. Several trials identified the best insecticides, and their use was soon popular among sorghum growers (Rodríguez-del-Bosque and Terán 2015, Southwest. Entomol. 40: 433–434). However, there was a need to explore economic and effective application methods against this invasive aphid; thus, the objective of this investigation was to determine the effectiveness of four application methods and timing of those applications for controlling M. sacchari in northeastern Mexico.This study was conducted at the Instituto Nacional de Investigaciones Forestales, Agrícolas y Pecuarias Experiment Station near Río Bravo, in northern Tamaulipas, Mexico (N25°57′, W98°01′), during the fall growing season of 2014, spring and fall of 2015 and 2016, and spring of 2017. The sorghum hybrid DK-54 was planted in February and in July during the spring and fall seasons, respectively, using a randomized complete block design with four replications. Plots were 4 rows (0.8 m) wide × 10 m long. Imidacloprid (Velfidor 350 SC®, Velsimex, Cd. México, México) was applied with a 20-l manually operated backpack sprayer in the following treatments: (1) in-furrow application at planting at 210 g active ingredient (a.i.)/ha; (2) banded application of 210 g a.i./ha 7 cm to the side of the row and 7 cm deep when plants were in the boot stage; (3) application of 105 g a.i./ha at the base of the plants during the boot stage; (4) application of 105 g a.i./ha over the plants during the boot stage; and (5) no treatment (control). Insecticide was applied in Treatments 2–4 when M. sacchari density averaged 100 aphids/leaf at the boot stage of plant growth. For these treatments, aphid (adults + nymphs) density was determined on two leaves (bottom and middle) of 10 randomly selected plants in the two central rows of the plots 7 and 14 d after application. Percentage control obtained in each treatment was calculated as % control = ([No. aphids in control – No. aphids in treatmentn)/(No. aphids in control)] × 100. Percentage data were transformed by square root to normalize distribution. These transformed data were subjected to analysis of variance with treatment means compared using the LSD test (P < 0.05) (SAS Institute 2012, SAS release 9.3 ed., Cary, NC).At 7–14 d after application, mean aphid density in the control treatment varied from 2,170 aphids/leaf during fall 2014 to 180 aphids/leaf during spring 2017 (Table 1), showing a progressive decline of M. sacchari population after first detected in 2013. Based on these results, the two most efficacious treatments were application of 105 g a.i./ha at the base of the plants during the boot stage (Treatment 3) and application of 105 g a.i./ha over the plants during the boot stage (Treatment 4) with a mean % control > 93%. These two methods were intended to simulate ground and aerial applications. Both were consistently effective in reducing aphid density, with the exception of the spring 2017 application over the plants that yielded only 75% control. Any differences in effectiveness of application over the plants versus application to the base of the plants might be explained by a longer time for translocation of the imidacloprid to reach the basal leaves where aphids are highly concentrated on the sorghum plant (Simon-Delso et al. 2015, Environ. Sci. Pollut. Res. 22: 5–34).On the other hand, the prophylactic in-furrow application of imidacloprid at planting (Treatment 1) resulted in an observed 82% (range 41–96%) control, and the banded application at the boot stage (Treatment 2) resulted in 76% control (range 25–99%). Treatments 1 and 2 were inconsistent and costly (double insecticide dose) as compared with Treatments 2 and 3. In summary, the best application and timing methods for controlling M. sacchari in northeastern Mexico were either the application at the base or over the top during the boot stage.

Multiplication index of Lipaphis erysimi on mustard cultivars under in-vitro conditions

Mustard cultivars were screened under in-vitro conditions for their resistance to Lipaphis erysimi. Forty five cultivars of mustards were tested against Lipaphis erysimi (Kaltenbach). The results were categorized based on aphid multiplication index values. Lowest aphid multiplication index values were observed on two cultivars namely Aravali (3.23) and RP-9 (3.93) that were found under highly resistant category (mean aphid multiplication index values less than (4.04).

Effect of Different Sowing Dates for the Management of Chilli Pests

The field experiment was conducted at Spices Research Centre, Shibganj, Bogra, Bangladesh during Rabi season of 2015-16 to assess the effect of varying sowing dates against insect pest of chilli. The treatments were T1= 30 August (1st sowing); T2= 15 September (2nd sowing); T3= 30 September (3rd sowing); T4= 15 October (4th sowing), T5= 30 October (5th sowing) and T6= 15 November (6th sowing). Sowing was done at 15 days interval from August to November in the experimental field. The results showed that the maximum mean aphid (9.27/leaf), thrips (10.77/leaf), mite(11.51/leaf) and fruit borer population like H. armigera and S.litura larvae (8.25 and 6.74/plant, respectively) were found in 15 November sowing and minimum number of those insect pest were present in 30 August sowing. Red ripe chilli yields were also found to differ in descending order as follows: 30 August (13.05 t/ha)> 15 September (12.70 t/ha)> 30 September (10.30 t/ha)> 15 October (8.41 t/ha)> 30 October (5.20 t/ha)> 15 November (3.10 t/ha). It was inferred that early sowing (30 August or 15 September) resulted in lower incidence of aphids, thrips, mite and fruit borer. Such low level of insect pest caused less crop injury which resulted in enhancing the red ripe yield of chilli. So, it is suggested that for early sowing of winter chilli, the appropriate planting time may be 30 August to 15 September.

Screening of Coriander Genotypes for their Relative Susceptibility against Aphids under Field Conditions

The field experiments were conducted during Rabi 2013-14 and 2014-15 to screen out twelve varieties/entries of coriander (Coriandrum sativum L.) for their relative susceptibility against aphids. None of the varieties/entries escaped the infestation of aphids. The build-up of aphid infestation started from second half of December and reached to its maximum in the first to third week of February in both years and then gradually declined. On the basis of grade index of mean aphid population, coriander varieties RCr- 684 (25.45 aphids/plant), RCr-446 (26.45 aphids/plant), ACr-1 (26.60 aphids/plant), RCr- 436 (41.75 aphids/plant), Gujarat Coriander-2 (42.45 aphids/plant), Pant Haritma (43.50 aphids/plant) and Gujarat Coriander-1 (43.70 aphids/plant) were categorized as least susceptible, Rajendra Swati and RCr-41 were moderately susceptible, whereas, Swati (CS-6), Sadhna (CS-4) and Sindhu (CS-2), 73.88, 70.60 and 69.50 aphids/plant, respectively were categorized as highly susceptible varieties of coriander against aphids under field conditions. Coriander variety RCr-684 received maximum yield (16.82 and 16.63 q/ha) for both the years followed by ACr-1 and RCr-446.

Screening of Coriander Genotypes for their Relative Susceptibility against Aphids under Field Conditions

The field experiments were conducted during Rabi 2013-14 and 2014-15 to screen out twelve varieties/entries of coriander (Coriandrum sativum L.) for their relative susceptibility against aphids. None of the varieties/entries escaped the infestation of aphids. The build-up of aphid infestation started from second half of December and reached to its maximum in the first to third week of February in both years and then gradually declined. On the basis of grade index of mean aphid population, coriander varieties RCr- 684 (25.45 aphids/plant), RCr-446 (26.45 aphids/plant), ACr-1 (26.60 aphids/plant), RCr- 436 (41.75 aphids/plant), Gujarat Coriander-2 (42.45 aphids/plant), Pant Haritma (43.50 aphids/plant) and Gujarat Coriander-1 (43.70 aphids/plant) were categorized as least susceptible, Rajendra Swati and RCr-41 were moderately susceptible, whereas, Swati (CS-6), Sadhna (CS-4) and Sindhu (CS-2), 73.88, 70.60 and 69.50 aphids/plant, respectively were categorized as highly susceptible varieties of coriander against aphids under field conditions. Coriander variety RCr-684 received maximum yield (16.82 and 16.63 q/ha) for both the years followed by ACr-1 and RCr-446.

EVALUATION OF THE NEW MOLECULAR INSECTICIDES AND BIOPESTICIDES AGAINST MUSTARD APHID LIPAPHIS ERYSIMI (KALT.) ON YIELD PARAMETER IN MUSTARD

A field experiment on mustard var. Varuna was conducted during Rabi season of year 2013-14 and 2014-15 at CSAUA&T, Kanpur. Among the various insecticides evaluated against the mustard aphid, Lipaphis erysimi Kalt, imidacloprid 17.8 SL @ 0.2 g/litre showed highest reduction Significantly lower mean aphid intensity 14 days after second spray 6.89 and 19.66 aphids/ 10 cm apical shoot were recorded on the crop treated with imidacloprid 17.8 SL with 94.09 and 90.34 percent reduction over control which provided significantly highest seed yield 2287 and 2235 kg/ha with 40.73 and 37.79 percent increase in yield, respectively. Application of Thiamethoxam 25% WP was found second best treatment with 8.49 and 23.46aphids 10 cm apical shoot 14 days after second spraying with 89.91 and 87.54 percent reduction over control during both year with provided 2229 and 2216 kg/ha with 37.71 and 36.62 percent increase in yield. The ranking of insecticides on the basis percent reduction over control after second spraying after 14 days for the management of aphids most effective were imidacloprid 17.8SL and thiametoxam25 WP and least effective spinosad 45 SC. Among biopesticides M.anisopoliae 1.15 WP was more effective than B.bassiana 1.15WP.Among the chemical insecticides imidacloprid 17.8 SL found safe followed by thiamethoxam 25WP with less number of percent reducing over control. Keywords: Imidacloprid, Thiamethoxam, Microbial, Mustard aphid, Management

Population dynamics of wheat aphid on different landraces of wheat under field conditions

Wheat (Triticum aestivum L.) is the leading food grain and staple diet in Pakistan. Cereal aphids are a severe problem in wheat growing areas. Among environmentally safe and economical methods for the control of aphids, the use of resistant wheat cultivars is one of the promising approach in pest management programs which can overcome the economic damage caused by aphid infestation. In the present study, the population dynamics of wheat aphid was observed on 114 landraces of wheat. The results showed that during March, nine landraces showed the highest population of Rhopalosiphum padi while the lowest R. padi population was recorded on fourteen different landraces with aphid populations ranging from 3.25 to 4.08. In the month of April, the highest population of R. padi was recorded on 81 landraces while the lowest population was recorded on 33 landraces with mean aphid numbers ranging from 2.91 to 6.9. The peak population was recorded during the month of May on 78 landraces of wheat and proved to be the susceptible while the remaining thirty eight landraces of wheat proved to be resistant with low aphid densities. The mean aphid population varied from 4.25 to 6.95. The results obtained from the month of March were non-significant while those obtained during the months of April and May were significant

Feeding Preference of Larvae and Adults of Zigzag Beetle on Sucking Insect Pests of Brinjal Under Lab. Condition at Tando Jam

Study was carried out on Feeding Preference of Larvae and Adults of Zigzag Beetle on Sucking Insect Pests of Brinjal Under Laboratory Conditions in 2013 at Tando Jam. Observations on feeding preference of Zigzag beetle shows that the highest feeding consumption of first instar larvae of Zigzag beetle were consumed 9.28±1.47aphids/day. Similarly on whiteflies the feeding rate was 7.56±1.05, and on thrips 5.28±0.98. The mean highest consumption of 1st instar was recorded on aphids, and lowest on. Similarly in the second instar larva the mean highest consumption rate during 24 hours was recorded on aphids. 19.21±1.97 / day followed by whiteflies 13.39±2.82/day and thrips 10.36±1.89/day. In case of third instar larvae the maximum feeding rate was recorded on aphids 35.26±2.06/day followed by whiteflies. 23.15±2.45/day and thrips 16.36±3.82/day. The fourth instar larvae of Zigzag beetle was consumed 52.69±3.89aphids/day followed by whiteflies 39.64±3.02/day and thrips 26.85±5.56/day. While the feeding preference rate of both male and female adults of Zigzag beetle also observed. The male adults of Zigzag beetle was 61.17±4.67 aphids/ day. On whiteflies was 42.89±4.12. Similarly on thrips was 32.56±6.26 thrips/ day. The mean aphid consumption by female adults was more on aphids 72.34±5.33 / day followed by whiteflies 47.23±4.93/day and thrips 37.89±7.19/day. The overall data indicated that fourth instar larvae of Zigzag beetle was more voracious feeder of different sucking insect pests of brinjal as compare to 1st, 2nd and 3rd instar larvae and female adults of Zigzag beetle consumed more sucking pests of brinjal than male adults . However, there is no significant difference between both sexes. The data reveals that aphids was most preferred food and thrips was least preferred prey for Zigzag beetle.
 Int. J. Appl. Sci. Biotechnol. Vol 7(1): 27-30

The occurrence and intensity of mustard aphid Lipaphis erysimi (Kalt.) on dates of sowing in different varieties respect to yield parameter

Significantly lowest aphid intensity of 7.3 and 7.4 aphids/10 cm apical shoot on the seasonal total emergence to maturity (ST) was noticed on 15th October sown crop during rabi 2013–14 and 2014–15, respectively, which provided significantly highest seed yield of 1800.1 and 1945.0 kg/ha in the respective year. Sowing of variety Rohini on 15th October during both years proved to be best combination as received significantly lower mean aphid intensity, 58.6 and 60.4 aphids/10 cm apical shoot. This also gave significantly superior seed yield, 1670.7 and 1915.1 kg/ha seed yield during 1st and 2nd year.

Evaluation of Insect Pests on Edamame Varieties in Minnesota.

Edamame, Glycine max (L.) Merrill, consumption continues to rise in the United States. Improved understanding of production threats, including insect pests, could facilitate increasing production of edamame in the north-central United States. Two years of complimentary field and laboratory experiments were performed to assess insect pest populations on commercially available edamame varieties. Fourteen varieties of edamame and four grain-type soybean varieties were tested in the laboratory with soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), and subsets of these varieties were tested in the field with naturally occurring insect populations. In the laboratory, mean aphid densities on the edamame varieties Agate and Chiba Green did not differ from the aphid-resistant grain-type soybean. Among edamame, aphid densities on Agate, Chiba Green, and Kuroshinju were significantly lower than on Hokkaido Black. In both years of the field experiment, aphid densities were significantly lower on the aphid-resistant grain-type compared to all others varieties. In 2016, aphid populations on edamame varieties did not differ from the aphid-susceptible grain-types. However, in 2017 with greater aphid exposure, differences were seen among edamame varieties, and between edamame and aphid-susceptible grain-types. In both years, potato leafhopper, Empoasca fabae (Harris) (Hemiptera: Cicadellidae), densities tended to be higher on edamame varieties compared to grain-types, and varied significantly among edamame varieties. In a laboratory study, differences were seen among varieties in mean density of trichomes, with grain-types generally having more trichomes than edamame. Results of this research will provide a foundation for development of production recommendations for edamame in the north-central United States.