Melanagromyza Obtusa Research Articles

Morphological Basis of Resistance in Pigeonpea (Cajanus cajan (L.) Millsp.) against Pod Borer Complex

Field experiment was carried out to determine the morphological basis of resistance in pigeonpea against pod borer complex during kharif 2021-22, 2022-23 and 2023-24 at College of Agriculture, Navsari Agricultural University, Bharuch (Gujarat). Among the twelve pigeonpea genotypes/cultivars screened, BP-17-02 was found highly resistant and BP-16-182, BP-16-228, BP-16-261, ICPL-87119 and BP-16-166 were found resistant whereas, GNP-2 and Vaishali were found highly susceptible against pod borers. Genotypes/cultivars namely, BP-16-178, ICPL 87119, BP-16-182, BP-16-228 and BP-16-183 were found resistant to pod fly. Genotypes/cultivars having short pod length, narrow pod breadth, narrow seed breadth, more seeds/pod, more seed weight, more seed density, thick pod wall thickness and long trichome length recorded lower pod borers population. Pod length had a significant positive correlation with Maruca vitrata, Exelastis atomosa and Melanagromyza obtusa. Significant positive association was found between pod breadth and larval population of Helicoverpa armigera and Maruca vitrata. Significant negative correlation was found between Exelastis atomosa and pod wall thickness.

Influence of different sowing dates on seasonal incidence of pod fly, Melanagromyza obtusa in pigeonpea

Influence of different sowing dates on seasonal incidence of pod fly, Melanagromyza obtusa in pigeonpea

Bio efficacy of selected insecticides against pod fly, Melanagromyza obtusa (Malloch) in pigeonpea

In the present study, efficacy of selected insecticides was evaluated against pod fly, Melanagromyza obtuse (Malloch) over three consecutive years in pigeonpea cultivar, Rudreswara (WRG-65). The relative efficacy of nine insecticides was assessed in terms of pod fly population and pod damage. The insecticides were applied twice at 15 days interval, starting from pod formation stage. The results revealed that thiamethoxam 25WG at 0.4g/l + Jaggery @ 5g/l followed by flubendiamide 480 SC @ 0.3ml/l proved significantly superior by reducing pod fly population and pod damage by recording highest grain yield (1582 kg ha-1) and best Cost: Benefit ratio (1:2.39). The potential insecticides observed in this study may be used in rotation with other effective ones in order to avoid development of insecticide resistance in pod fly.

Damage of Melanagromyza obtusa (Malloch) and Management Potential of Newer Insecticides in Pigeon Pea

Background: The pod fly, Melanagromyza obtusa (Malloch) is one of the major biotic constraints in increasing production and productivity of pigeonpea crop throughout the country and it causes up to 100 per cent losses in field condition. Injudicious use of pesticides against this destructive pest, further ignites the problem of resistance, resurgence and environmental and ecological imbalances. Methods: Experiments were conducted at Banda University of Agricultural and Technology, Banda during kharif, 2020 and 2021. To estimate the bio-efficacy of insecticides for the management of M. obtusa in pigeonpea the experiment was laid out in randomized block design (RBD) with eight treatments and three replications. Pod and grain damage were assessed and C:B ratio was calculated. Result: First appearance of pod fly was noticed in third standard week. Throughout cropping period highest pod damage was recorded in eighth standard week and lowest pod damage was recorded in twelfth standard week. Emamectin benzoate 5 SG @ 11g a.i./ha + Dimethoate 30 EC @ 300 g a.i./ha was the best treatment as it exhibited minimum pod damage and highest yield.

Management of pod fly, Melanagromyza obtusa (Malloch) through newer insecticides

A field experiment was carried out at research farm of T.C.A., Dholi (Muzaffarpur) during Kharif season 2019-2020 to manage the pod fly Melanagromyza obtusa (Malloch) through newer insecticides. All eight novel insecticides were substantially potential over control in lowering the damage caused by pod fly and also recorded increased yields. Minimal pod and grain damage was recorded in chlorantraniliprole 18.5 SC (11.63 % and 8.42 % respectively) followed by flubendiamide 480 SC (14.66% and 15.37%). The highest yield (1945 kg/ha) was recorded in chlorantraniliprole 18.5 SC as against 682 kg/ha in untreated control with a Cost Benefit Ratio (CBR) of 1:41.8.

Insect pest spectrum of french bean Phaseolus vulgaris (pole type) grown under nethouse

Pole bean (Phaseolus vulgaris L.) is an annual herb grown vertically on a support. The present study asseses the insect pests infesting this bean along with their natural enemies under nethouse conditions. The study was done at the Hi-tech Horticulture Unit, UAS, Dharwad. The results revealed five species of insects and one mite species infesting pole bean at various phases of crop growth. These include- the serpentine leaf miner (Liriomyza trifolii), pod fly (Melanagromyza obtusa), seed fly (Anthomyia sp.), leafhopper (Ianagallia bifurcate), tobacco caterpillar (Spodoptera litura), and red spider mite (Tetranychus urticae). The natural enemies include- Brachymeria sp. (Chalcididae), Ichneumon sp. (Ichneumonidae) and Microplitis sp. (Braconidae).

Positioning New Pesticide Chemistries in the Management of Pod Fly, Melanagromyza obtusa Malloch (Diptera: Agromyzidae) in Pigeonpea

Background: Pigeonpea is an important pulse-cum-grain legume crop of India. Major constraint in its production is the insects damage. Pod fly, Melanagromyza obtusa is of regular occurrence in South and Central India causing yield loss to the tune of 60 to 80 per cent particularly in late maturing pigeonpea crop. Due to its feeding habit as an internal borer, cultural, biological and mechanical methods are ineffective in reducing the damage due to pod fly and insecticides play a paramount role in managing their population under field conditions. Hence, present study have been aimed to evaluate the efficacy of different new pesticide chemistries against pod fly in pigeon pea ecosystem. Method: Two field experiments were conducted during Kharif 2019 and 2020 in RCBD using pigeonpea cv. GRG 811 with 14 treatments replicated twice. Two sprays were imposed at 15 days interval initiating from pod initiation stage. At maturity, number of damaged pods were recorded and expressed as percentage. Grain yield was recorded and benefit cost ratio was also worked out. Results: Among the screened insecticides, fipronil 4+thiamethoxam 4 SC @ 40+40 g a.i./ha followed by thiamethoxam 25 WG @ 50 g a.i./ha and fipronil 40+imidacloprid 40 WG @ 160+160 g a.i./ha provided better control of pod fly in terms of reduction in pod damage (69.54, 62.13 and 62.57%) and seed damage (72.51, 71.35 and 70.39%) respectively over untreated check. The average grain yield of 1577 kg/ha was highest in fipronil 4+thiamethoxam 4 SC @ 40+40 g a.i./ha followed by fipronil 40+imidacloprid 40 WG @ 160+160 g a.i./ha (1555.5 kg/ha) and thiamethoxam 25 WG @ 50 g a.i./ha (1536.5 kg/ha). Whereas, B: C was higher in fipronil 4+thiamethoxam 4 SC @ 40+40 g a.i./ha (2.84) and thiamethoxam 25 WG @ 50 g a.i./ha (2.83). Therefore these insecticides can be used for effective management of pod fly.

Reaping the Potential of Wild Cajanus Species through Pre-Breeding for Improving Resistance to Pod Borer, Helicoverpa armigera, in Cultivated Pigeonpea (Cajanus cajan (L.) Millsp.).

Simple SummaryPigeonpea is an important legume crop that is severely affected by various insect pests, especially pod borer. Because there are low resistance levels to pod borers in the cultivated pigeonpea gene pool, it is necessary to introduce resistance-related traits from its wild relatives. In this study, we conducted a series of crosses to introduce traits related to pod borer resistance from two wild relatives of pigeonpea into two popular cultivated varieties. We generated populations from four different crosses and screened these populations for traits related to pod borer resistance: i.e., low levels of insect damage, high concentrations of insect-deterring compounds in the seeds, and the presence of trichomes on the leaves. The most promising lines were tested across seasons and locations. Ultimately, we identified 21 lines with excellent traits related to pod borer resistance. These lines will be useful for breeding new insect-resistant pigeonpea cultivars. The availability of such cultivars will reduce the use of pesticides to control pests on pigeonpea crop.Pod borer (Helicoverpa armigera) causes the highest yield losses in pigeonpea, followed by pod fly (Melanagromyza obtusa). High levels of resistance to pod borer are not available in the cultivated genepool. Several accessions of wild Cajanus species with strong resistance, and different resistance mechanisms (antixenosis and antibiosis) to pod borer have been identified. These accessions can be utilized to improve the pod borer resistance of cultivated pigeonpea. Using pod borer resistant Cajanus scarabaeoides and Cajanus acutifolius as pollen donors and popular pigeonpea varieties as recipients, pre-breeding populations were developed following simple- and complex-cross approaches. Preliminary evaluation of four backcross populations consisting of >2300 introgression lines (ILs) under un-sprayed field conditions resulted in identifying 156 ILs with low visual damage rating scores (5.0–6.0) and low pod borer damage (<50%). Precise re-screening of these ILs over different locations and years resulted in the identification of 21 ILs having improved resistance to pod borer. Because these ILs were derived from wild Cajanus species, they may contain different alleles for different resistance components to pod borer. Hence, these ILs are ready-to-use novel and diverse sources of pod borer resistance that can be utilized for improving the pod borer resistance of cultivated pigeonpea.

Abundance of pigeonpea pests in relation to crop phenology under organic and conventional farming systems

The abundance of pod borer (Helicoverpa armigera Hubner) and pod fly (Melanagromyza obtusa Malloch) was studied in organic and conventional farming systems of pigeon pea (cv. Vaishali) at Navsari Agricultural University (NAU), Gujarat. The highest larval population (14.68 ± 2.97 and 12.70 ± 3.11 larvae/ plant in organic and conventional farming systems) and highest pod damage (15.12 ± 5.42 and 13.23 ± 4.57/50 pods) due to pod borer were noticed at the pod formation stage. Correlation of pod borer population and its damage with crop stage was significant and positive (‘r’ = 0.461 & 0.411 and ‘r’ = 0.455 & 0.45The highest larval (maggot) population of pod flies was noticed at pod maturity stage (28.31 ± 5.70 and 25.44 ± 5.70 larvae/ 50 pods). Similarly, the highest seed damage due to pod fly was noticed at harvest (76.50 ± 2.83 and 71.67 ± 7.79 %). The correlation of pod fly population and seed damage with crop stage was significant and positive (‘r’ = 0.746 and 0.736 and ‘r’ = 0.931 and 0.929).

Population dynamics of stem fly and defoliator pests of soybean and their natural enemies in relation to weather parameters

The field experiment was carried out at Polasa Farm, Regional agricultural research station Jagtial during the Kharif, 2014-15 and 2015-16. Study about pre dominant lepidopteran insect –pests in soybean crop noticed that the tobacco cut worm, (Spodptera exigua Hubner), green semi looper(Crysodexis acuta Walker), and tobacco caterpillar (Spodoptera litura Fab) along with stemfly, (Melanagromyza obtusa Zehnter) as non lepidopteran pest were noticed at various growth stages of cropgrowth. The peak activity of stem fly (37.84%) was observed during 37th standard week per meter row) for the year 2014 and for the year 2015 to a maximum infestation of 35.70 per cent during 30th std.week. The peak activity of caterpillar pests i.e., S. litura (7.6 larvae per meter row) for the year 2014 was observed during 34th std.week and for the year 2015 (12.4 per meter row during 36th std.week and C. acuta (0.7 larvae per meter row) during 36th std. week for the year 2014 and for the year 2015 (2.20 larvae/mrl on 37th std week. S. exigua (1.6 larvae per meter row) for both the years 2014 and 2015 was observed during 32th std.week Among the natural enemies, one predators namely, spiders (Oxyopes sp. was observed to prey on the insect pests.The biocontrol agent’s one species, lynx spider, Oxyopes sp. population recorded on the crop during Kharif , 2014 ranged from 0.15 to 0.40 /mrl and 0.15 to 0.60/ mrl during Kharif, 2015.

Screening of pigeonpea [Cajanus cajan (L.) Millsp.] against Tur Pod fly, Melanagromyza obtusa (Malloch) (Diptera: Agromyzidae) in long duration pigeonpea genotypes

The pigeonpea was infested with the number of insect pests at various stage of crop growth. Out of which the incidence pattern of C. gibbosa was studied. The result of the investigation pertaining to the “Screening of pigeonpea [Cajanus cajan (L.) Millsp.] against Tur Pod fly, Melanagromyza obtusa (Malloch) (Diptera: Agromyzidae) in long duration Pigeonpea genotypes” was carried out in 2018-19 at the Agricultural Research Farm, Institute of Agricultural Sciences, Banaras Hindu University, Varanasi. This insect was studied during reproductive phase of the crop during 2018-19. The very first presence of pod fly, Some insect populations were observed during the crop's reproductive period. Pod Fly's First Incidence, M. obtusa was observed in all genotypes during the 4th standard week of 2018-19. The various peak of the pod fly population was reported in different genotypes from the 6th standard week to the 11th standard week. The peak population of maggots was observed in the 11th standard week in the genotype MAL- 13 (AVT1), AVT1-704, AVT1-706 and AVT1-709 with population of (2.61 maggots/plant), (2.42 maggots/plant) and (2.40 maggots/plant), respectively. Pod fly's M. obtusa the damage ranged from 27.33 per cent in the genotype AVT2-904 to 51.00 per cent in cultivar AVT1-703 among all genotypes screened by the genotype. The percentage of grain damage caused by pod fly damage ranged from 12.68% in genotype AVT2-904 to 30.52% in genotype AVT2-907 Highest grain damage was recorded in genotype. In AVT1-704 the cereal yield of different genotypes was from 617kg / ha to 1434kg / ha with AVT1-708 genotype.

Bioefficacy of Chlorantraniliprole 18.5 SC Against Pod Borer, Helicoverpa armigera (Hubner) and Pod Fly, Melanagromyza obtusa (Malloch) in Pigeonpea, Cajanus cajan (Linn.) Millsp.

Background: Pod borer, Helicoverpa armigera (Hubner) and pod fly, Melanagromyza obtusa (Malloch) are important pod boring insects infesting the pigeonpea, Cajanus cajan (Linn.) Millsp. throughout the world. A number of synthetic insecticides are known to be effective against these borers but most of them have been phased out as a result of high toxicity to the pollinators and other biotic agencies, therefore, a new molecule, chlorantraniliprole has been tested for bioefficacy against these insect pests.Methods: The experiment was conducted during Kharif, 2017 in a Randomized Block Design (RBD) with 7 treatments and 3 replications. Observations were made to record pod borer, H. armigera and pod fly, M. obtusa maggot present before treatment imposition and 3, 7 and 14 days after each spray from five randomly selected and tagged plants/ plot. From the data recorded per cent reduction in population over control was calculated. The per cent pod damage was calculated by counting damaged pods out of healthy pods. The numbers of coccinellids and spiders were recorded on 5 randomly selected plants before treatment and 7 and 14 days after spray (DAS) in each treatment.Result: The chlorantraniliprole 18.5 SC was found most effective @ 200 ml/ha which was found at par with chlorantraniliprole 18.5 SC @ 150 ml/ha and chlorantraniliprole 18.5 SC (Market sample) @ 150 ml/ha for suppression pod borer, H. armigera and pod fly, M. obtusa. The yield was maximum and at par in the chlorantraniliprole 18.5 SC @ 200 ml/ha (18.25 q ha-1), chlorantraniliprole 18.5 SC @ 150 ml/ha (17.82 q ha-1) and chlorantraniliprole 18.5 SC (Market sample) @ 150 ml/ha (17.42 q ha-1). Predatory population of coccinellids and spiders after imposing the treatments declined to some extent at seven days after treatment, however, increased after 14 days. Based on the results, the use of chlorantraniliprole 18.5 SC @ 150 ml/ha was most effective to control pod borer and pod fly in pigeonpea crop.

Role of abiotic factors on the incidence of major insect pests of pigeonpea, Cajanus cajan (L.) Millsp

During present studies incidence of pod fly; Melanagromyza obtusa Malloch (Diptera: Agromyzidae), thrips; Megalurothrips usitatus Bagnall (Thysanoptera: Thripidae), pod bug; Clavigralla gibbosa (Spinola) (Hemiptera: Coreidae), Kudzu bug; Megacopta cribraria Fabricius (Hemiptera: Plataspidae) and cow bug; Otinotus oneratus (Walker) (Hemiptera: Membracidae) was found negatively correlated with temperature (both maximum and minimum) and rainfall whereas positively correlated with morning relative humidity except thrips. It was also found that Leaf webber; Grapholita critica (Meyr.) (Lepidoptera: Tortricidae) incidence was positively correlated with temperature and morning relative humidity. Regression analysis showed that minimum temperature significantly contributed more than 49% variation to the high population buildup of the C. gibbosa, M. cribraria and O. oneratus insects. The present study also report first time the effects of different abiotic factors on the incidence of Kudzu bug; M. cribraria.

Field screening of pigeonpea for their resistance against Melanagromyza obtusa (Diptera: Agromyzidae)

Melanagromyza obtusa (Malloch) has been recorded for the first time on pigeonpea at Nagpur, India and named as 'tur pod fly'. It is a monophagous species and devours the developing seeds of pigeonpea crop. It was reported to infest 12 to 100% pods causing losses of 2.4-95.0% on seed or grain (=250000 tonnes by weight) and are estimated at US $ 256 million annually. Therefore, a field experiment was conducted at Research Farm, Agricultural Research Station, Badnapur (VNMKV), India during kharif 2015-16 to source some promising pigeonpea genotypes against M. obtusa. The present investigations revealed the population of M. obtusa on 20 genotypes ranged from 0.00-277.64 maggots per 100 pods; pod and grain damage were ranging from 0.00-89.75 and 0.00-82.02%. The highest M. obtusa population, pod and grain damage was recorded in BRG-2 (277.64 maggots and 101.26 pupae per 100 pods; and 89.75 and 82.02%). On the basis of pod damage a total of five, two, eight, four and one genotypes were categorized as highly tolerant, tolerant, moderately tolerant, susceptible and highly susceptible; for grain damage these were seven, seven, three, two and one, respectively. The maximum yield was recorded from BDN-2010-1 (22.33 q/ha), followed by V-127 (21.61 q/ha). However, Cajanus scarabaeoides showed no maggot and pupal population, pod and grain damage by M. obtusa indicating its virtue of genetic resistance and it can be used in breeding programmes to develop resistant cultivars for farmer’s welfare.

Identification of redgram resistant genotypes and morphological bases of resistance to pod fly, Melanagromyza obtusa (Malloch)

Screening of 49 redgram genotypes conducted to identify pod fly resistant genotypes and morphological basis of resistance to pod fly revealed consistently resistance reaction of ICP 8864 (mean PSI 3.0) and VRG–59-1(mean PSI 3.3) to redgram pod fly. Pod length of various redgram germplasm ranged between 3.55 and 4.84 cm. Pod width ranged from 0.64 to 1.28 cm. Pod wall thickness ranged from 0.21 to 0.43 mm. Trichome density ranged between 302 and 375 per 9 mm2. Redgram pod width was the important morphological factor that influenced the redgram pod fly seed damage to a tune of 34.2 per cent. Pod length and width were positively correlated with the redgram pod fly seed damage while pod wall thickness and trichome density were negatively correlated. However, relationship between pod width and seed damage only was found to be significantly positive and rest of the morphological factors were not significant.

Management of Pod fly, Melanagromyza obtusa on Pigeonpea (Cajanus cajan L.)

Background: Pod fly, Melanagromyza obtusa is one of the most obnoxious pest causing grain damage ranging from 10-80% with a monitory loss of US$ 256 million annually. Being an internal feeder, infested pods do not show any external symptoms of damage until the fully grown maggots chew the pod wall, leaving a thin papery membrane intact called as window, through which adults exit from the pod. Several field studies were conducted to determine the efficacy of insecticides for the control of pod fly. However, these findings did not find acceptability and led to partial success. Insecticides that should leave lesser residues and pose lesser environmental threat have become imperative. The present study aimed to evaluate the efficacy of certain new insecticide molecules against pod fly in pigeonpea ecosystem. Methods: Two field experiments were conducted at Regional Agricultural Research Station, Lam, Guntur during Kharif, 2012 and 2013 in a randomized block design (RBD) using pigeonpea cv. ICPL 85063 (Lakshmi) with 17 treatments including untreated control and 3 replications. Two sprays were given at 10 days interval starting from pod initiation stage. At maturity, number of pods showing pod fly damage were recorded and expressed as percentage. Grain yield was recorded and cost–benefit ratio was worked out. Result: Among different insecticides, thiacloprid 21.7 SC, followed by diafenthiuron 50 WP, flubendiamide 480 SC and dimethoate 30 EC were very effective against pod fly with more grain yield and registered highest incremental cost benefit ratio (ICBR). It was further suggested that effective insecticides may be alternated in order to avoid development of resistance to pod fly in pigeonpea.

Validation of integrated pest management module against major insect pests of pigeonpea, (Cajanus cajan (L.) Millsp.)

Integrated Pest Management (IPM) module was validated against major insect pests of pigeonpea in farmers’ fields during Kharif, 2011 in Warangal district, Andhra Pradesh (now in Telangana), India. IPM module included installation of pheromone traps @ 10/ha, erection of bird perches @ 50/ha, spraying of Helicoverpa armigera nucleopolyhedrosis virus (Ha NPV) @ 500 LE/ha, need based spraying of insecticides like acephate (@ 500 g/ha) + DDVP (@ 500 ml/ha); indoxacarb (@ 500 ml/ha), spinosad (@ 200 ml/ha). Farmers’ practice included only 2 sprays of quinalphos @ 1 lt/ha at flowering and at 20-25 days after 1st spraying. Per cent pod damage by different insect pests viz., gram pod borer (Helicoverpa armigera), pod fly (Melanagromyza obtusa), spotted pod borer (Maruca vitrata) decreased by 61.08, 37.65 and 48.66 per cent, respectively, in IPM over farmers’ practice fields. IPM fields recorded 61 per cent yield increase over farmers’ practice with mean Benefit Cost Ratio of 1.73.

Parasitisation of pigeon pea pod fly Melanagromyza obtusa and its population dynamics as influenced by genotypes

Three hymenopteran chalcidoid parasitoids viz., Euderus sp. (Eulophidae), Torymus sp. (Torymidae) and Systasis dasyneurae Mani (Pteromalidae) were observed as ectoparasitiods of maggots of pigeon pea pod fly Melanagromyza obtusa (Malloch). Parasitism increased with pest population irrespective of the parasitoid species. The peak activity of Euderus sp. was observed during 5th SMW (52.38%), whereas Torymus sp. attained its peak activity during 3rd SMW (61.54%) and S. dasyneurae during 4th SMW (4.76%) on the pigeon pea genotype ICP-8863. The maximum parasitism by Euderus sp. was observed on the genotype BSMR-736 (25.53%) and Torymus sp. on ICP-8863 (12.16%). Parasitisation showed negative correlation with maximum and minimum temperature and wind velocity, and it was more on the susceptible genotypes.

Efficacy of some insecticides against pod borers and blister beetle in pigeon pea

Pigeon pea is one of the important pulse crops in India. Among the different production constraints, infestation by insect pests is of major concern. In present study, six insecticides were evaluated in sequential schedules to manage pod borers and blister beetle which were major pests. Spray of chlorantraniliprole 18.5 SC@ 30g a.i./ha followed by indoxacarb 15.8 EC @ 73ga.i./haat 15 days interval was found to be effective in reducing spotted pod borer, Maruca vitrata larva and two sprays of dimethoate 30 EC@ 600g a.i./ha was found to be effective in reducing adult blister beetle population. Least pod damage (cumulative of M. vitrata and Melanagromyza obtusa) was observed with chlorantraniliprole 18.5 SC@ 30g a.i./ha followed by dimethoate 30 EC @ 600g a.i./ha at 15 days interval. Based on cost benefit ratio, two sprays of acephate 75 SP@ 750g a.i./ha at 15 days interval was found to be superior with C: B of 1: 9.38.

Evaluation of sequential application of insecticides against pigeonpea pod fly Melanagromyza obtusa (Mall)

Evaluation of sequential application of insecticides against pigeonpea pod fly Melanagromyza obtusa (Mall)