Maruca Vitrata Research Articles

Seasonal Incidence of Insect Pests and Predatory Fauna in Black Gram

The succession and seasonal incidence of insect pests and predatory fauna in black gram were studied in a field experiment at the Agronomy farm, Anand Agricultural University, Anand during kharif 2019 and 2020. The results revealed nine species of insects (7 pests and 2 predators) from seedling to pod maturity stage. Besides, the peak incidence of whitefly, jassid, flower thrips, tobacco caterpillar, Bihar hairy caterpillar, and spiders were observed during 37th standard meteorological week (SMW); with spotted pod borer and coccinellids, maximum incidence was observed during 38th SMW, and the green stink bug during 35th SMW. Correlation coefficients revealed that tobacco caterpillar had a significant positive correlation with minimum temperature, morning RH and evening vapour pressure; and the incidence of spotted pod borer showed a significant negative correlation with bright sunshine hours and rainfall.

Earliness and Crop Morphological Traits Modulate Field Pest Infestation in Green Gram.

Breeding has significantly improved drought tolerance in green gram but marked yield losses continue due to damage by insect pests. Important pests of green gram are pod borers, Maruca vitrata (F.), aphids, Aphis gossypii Glover and whiteflies, Trialeurodes vaporariorum (Westwood). Management of these pests has partly been constrained by the limited understanding of crop traits that modulate their infestation. Field experiments were conducted in southeastern Kenya to evaluate a collection of old and new green gram varieties for tolerance to field pests, and to identify traits that confer resistance. The old varieties were KS20 and N26, both released in 1990s whereas the modern counterparts were Biashara, Karembo, and Ndengu-Tosha. Results showed significant differences among the varieties in maturity, leaf area, leaf hair density, leaf moisture content, and pod wall thickness. Earliness significantly reduced pest infestation, whereby KS20 matured early while N26 was late, and the new varieties were intermediate. On average, across the three environments, leaf area (R2 ≥ 0.32) and leaf moisture content (R2 ≥ 0.18) positively correlated with pest infestation while leaf hair density (R2 ≥ 0.30), and pod wall thickness (R2 ≥ 0.54) showed a negative association with pod borer and aphid counts. However, results did not reveal any particular traits that associated with the varieties, which implied that breeding of green gram in Kenya has not selected for tolerance to field pests. Nonetheless, green gram field pest management practices could select for varieties with early maturity, open plant canopy, pubescent leaves, and thicker pod walls.

EVALUATION OF THE EFFICACY OF PLANT EXTRACTS (Cassia nigricans, Azadiracta indica and Carapa procera) AGAINST INSECTS (Aphis craccivora and Maruca vitrata) OF COWPEA IN A CROPPING SYSTEM IN MALI

Cowpea Vigna unguiculata L. Walpers (Fabaceae) is one of the main seed legumes produced and consumed in the world and particularly in West Africa precisely in Mali. In Mali, the cultivation of sorghum and cowpea in association occupies an important place in agriculture and contributes to achieving food and nutritional security in the country. Cowpea is an important source of vegetable protein. This crop is faced with many biotic (insects) and abiotic (drought) problems. The attack of pests (insects) can completely reduce the production of cowpea. Most farmers use chemicals to reduce these pests. While these chemicals (insecticides) have a negative impact on human health and that of the ecosystem. Aphids (Aphis craccivora) and Marucas (Maruca vitrata) can cause yield losses of up to 80%. Finding alternatives to synthetic pesticides is therefore a major challenge for the design of cropping systems. The study was carried out at the Sotuba agronomic research station for two years. Three varieties of cowpea (Sangaranka, djiguifa and Ghana Shoba) were planted in split plot in pure culture and in association with sorghum (Tiandougou coura). Three (3) products (Azadiracta indica and Cassia nigricans leaf, Carapa procera oil) and two controls (optimal K and without treatment) were used against Aphis craccivora and Maruca vitrata of cowpea. Observations focused on the number of Maruca vitrata and Aphis craccivora colonies before and after each treatment, the weight (pod, grain, haulm). The data was analyzed with GENSTAT Release 12.1 of the 12th edition of 2012. Zarama(Cassia nigricans) extract was the most effective among the others after the first treatment on Aphis and Maruca with a count average of 1.44 and 1.33 respectively of these two insects. The best grain yield was recorded in the same Sangaraka variety (1623 kg.ha-1) by treatment with Neem extract (Azadiracta indica), i.e. an increase of 8.1%.

Evaluation of different insecticidal treatments against spotted pod borer (Maruca vitrata) on cowpea

Evaluation of different insecticidal treatments against spotted pod borer (Maruca vitrata) on cowpea

Effect of bio-rational and botanical insecticides against Maruca vitrata in black gram

Effect of bio-rational and botanical insecticides against Maruca vitrata in black gram

Inheritance and expression analyses of cry1Ab gene in transgenic pigeonpea tolerant to Maruca pod borer

Inheritance and expression analyses of cry1Ab gene in transgenic pigeonpea tolerant to Maruca pod borer

Parasitoid complex of legume pod borer, Maruca vitrata Fabricius (Lepidoptera: Crambidae) on different pulses

The spotted pod borer, Maruca vitrata Fabricius is an important herbivore of major pulses and vegetable legumes in India and the chemical pesticides are major contributors for its management. In order to have an idea on other alternative management tools, the present studies were carried out on the availability of parasitoids and its genetic variation. Totally, four larval parasitoids viz., Bassus sp., Trathala flavoorbitalis Cameron, Phanerotoma hendecasisella Cameron and an undetermined Braconid wasp were recorded on M. vitrata larva. The occurrence of P. hendecasisella was reported for the first time from Tamil Nadu, India. The Bassus sp. was found to be dominant with the parasitism of 3.0 to 12.7% in different pulses and total parasitism of four parasitoids was maximum in pigeonpea (16.1 %). Total parasitism had a positive relationship with number of webbings on cowpea. The larval parasitoids Bassus sp. and braconid wasp (undetermined) yielded specific fragments (~800 bp) with mitochondrial COI primer. Presence of Wolbachia was confirmed in all four larval parasitoids with the amplicons size between 600 and 650 bp. Present study clearly indicated the close proximity of Bassus sp. on M. vitrata than other parasitoids studied. Hence, it gives way for further insights on suitability, mass culturing and development for sustainable management of this insect pest.

Influence of Plant Resistance in Certain Genotypes of Green Gram on Insecticide Tolerance on Spotted Pod Borer, Maruca vitrata (Geyer)

Ten genotypes of green gram viz., WGG-42, LGG-407, PM-115, MGG-360, PM-110, LGG-410, PM-112, TM-962, LGG-450 and LGG-460 were screened for their susceptibility to Spotted pod borer, Maruca vitrata (Geyer) infestation at wetland farm, S.V.Agricultural College, Tirupati in a randomized block design (RBD) during the late Kharif season of 2014. Two crops were raised one at during last week of August-2014 and second was raised durin second week of September-2014. Readings on the number of Maruca webbings per plant, total number of caterpillars per plant and per cent infestation were taken at weekly intervals. Field screening experiments which were conducted on green gram genotypes against M. vitrata infestation revealed that WGG-42, TM-962 and MGG-360 were observed resistant, moderately resistant and susceptible reaction based on number of webbings per plant and number of caterpillars per plant. Further investigation on feeding preference of Maruca by free-choice and no-choice techniques on selected genotypes of green gram in the laboratory to confirm the resistance ranking observed in the field screening have yielded similar resistance reaction to Maruca infestation. Larvae of the first instar were allowed to feed on the susceptible and resistant genotypes of green gram upto third instar. At the third instar stage, they were allowed for topical bioassay application with Chlorpyriphos insecticide after taking the larval weights. The larvae which fed on the WGG-42 (resistant) gave LC50 (Lethal Concentration) and LD50 (Lethal Dose) values of 1.39 µL/ml and 36.98 µg/g and the larvae which fed on the MGG-360 (susceptible) gave LC50 and LD50 values of 1.63 µL/ml and 36.85 µg/g.

Screening of Cowpea Genotypes for Field Resistance to the Spotted Pod Borer (Maruca vitrata)

Background: Cowpea [Vigna unguiculata (L.) Walp.] is an important legume crop known for its nutritional value. However, the cultivation of this crop is greatly hampered by a destructive pest, a spotted pod borer (Maruca vitrata Fab.). Keeping the caustic nature of the pest in view, the present study was undertaken. Methods: Field evaluation of thirty cowpea genotypes was carried out by raising cowpea plants in an open field. Observations on the M. vitrata incidence were recorded at three days’ intervals starting from the development of the first buds to the end of flowering. Based on the level of infestation of buds, flowers and pods, the cowpea genotypes were categorised into four groups viz., resistant, moderately resistant, susceptible and highly susceptible. Results: Results of the study revealed a significant variation between the genotypes in terms of total damage (0.21 to 48.46%). Genotype IC 2918 recorded remarkably low damaged (0.12%) and was on par with Palakkadan thandan payar, Hridya, EC 300039, EC 101216, EC 98668, IC 39945, IC 52110, IC 39922 and IC 39916. The genotype Bhagyalaxmi recorded the highest damage (48.46%) followed by the variety Lola (30.04%). Flower buds were more susceptible to M. vitrata and suffered severe damage as compared to flowers and pods. Conversely, genotypes EC 98668 and IC 39922 were free from bud damage. Genotypes EC 300039, EC 98668, IC 52110, IC 39945, IC 2918 and IC 39922 recorded no flower damage and Palakkadan thandan payar, IC 39945, IC 2918 and IC 39947 recorded no pod damage.

Development and validation of integrated pest management modules against spotted pod borer Maruca vitrata Fabricius on garden bean Lablab purpureus var. typicus (L.)

To reduce the detrimental effect of insecticides, an effective Integrated Pest Management (IPM) module is necessary for the eco-friendly management of Maruca vitrata in garden bean ecosystem. Two field trials were carried out to evaluate the efficacy of different insecticides and botanicals against M. vitrata on Lablab purpureus var. typicus. Two seasons field evaluation of insecticides revealed that chlorantraniliprole 18.5 SC was the most effective treatment to control the pest recorded 0.11 and 0.36 larva/plant in two seasons, respectively after two rounds of spray followed by flubendiamide 20 WG (0.46 and 0.92 larva/ plant) and emamectin benzoate 5 SG (0.50 and 0.95 larva/plant). Among botanicals tested, commercial neem formulation and 5% Ageratina adenophora recorded the least larval count of 1.64 & 1.05 larva/plant and 2.24 & 1.45 larva/plant in two seasons, respectively. IPM modules were developed with three effective insecticides (chlorantraniliprole 18.5 SC, flubendiamide 20 WG and emamectin benzoate 5 SG), two effective botanicals (commercial neem formulation 1500 ppm and 5% A. adenophora) along with the pheromone trap for validation. All the IPM modules were equally effective in managing M. vitrata population on L. purpureus and recorded a significantly (at 5 %) lower larval population than the farmer’s practice. The residues of chlorantraniliprole, flubendiamide and emamectin benzoate reached below the detectable level at the time of harvest. The population reduction of predatory coccinellids and spiders was also lower in IPM modules than in farmer’s practice. An increased benefit cost (1.95 to 1.99) ratio was observed in IPM modules.

Impact of climate change (elevated CO2 and temperature) on growth and development of cowpea pod borer, Maruca vitrata (Fabricius) (Lepidoptera: Crambidae)

Climate change has a widespread influence on agricultural productivity and relies upon the fact that responses vary between crops. Any changes in the nutritional quality of the host plant will have direct influences on associated insect pests and the damage that it causes. In this context, a study was conducted to measure the impact of elevated CO2 and temperature on the growth and development of cowpea (C3 plant) and its herbivore pod borer, Maruca vitrata (Fabricius) under open top chambers at the Center for Agro-climatic Studies, UAS, Raichur, Karnataka. Elevated CO2 had a positive impact on cowpea growth by encouraging crop boom along with vital changes in its phytochemistry. The increased supply of CO2 resulted in higher concentrations of ‘C’ and C-based metabolites and chlorophyll (39.81 µg/cm2) and nitrogen balance index (104.52). However, ‘N’ and N-based compounds were reduced. Larvae fed upon such nutrient-deficient food increased their development period (36.07 ±0.42days) and compensatory feeding inflicting more damage (7.72 webbings/plant). Although the larvae consumed more food, it decreased the body weight of the larvae and pupae, which in turn decreased the percent moth emergence, ultimately decreasing the fecundity (60.09 ± 0.20/female) and fitness of the pest in the long run.

Identifying Soybean Pod Borer (Leguminivora glycinivorella) Resistance QTLs and the Mechanism of Induced Defense Using Linkage Mapping and RNA-Seq Analysis.

The soybean pod borer (Leguminivora glycinivorella) (SPB) is a major cause of soybean (Glycine max L.) yield losses in northeast Asia, thus it is desirable to elucidate the resistance mechanisms involved in soybean response to the SPB. However, few studies have mapped SPB-resistant quantitative trait loci (QTLs) and deciphered the response mechanism in soybean. Here, we selected two soybean varieties, JY93 (SPB-resistant) and K6 (SPB-sensitive), to construct F2 and F2:3 populations for QTL mapping and collected pod shells before and after SPB larvae chewed on the two parents to perform RNA-Seq, which can identify stable QTLs and explore the response mechanism of soybean to the SPB. The results show that four QTLs underlying SPB damage to seeds were detected on chromosomes 4, 9, 13, and 15. Among them, qESP-9-1 was scanned in all environments, hence it can be considered a stable QTL. All QTLs explained 0.79 to 6.09% of the phenotypic variation. Meanwhile, 2298 and 3509 DEGs were identified for JY93 and K6, respectively, after the SPB attack, and most of these genes were upregulated. Gene Ontology enrichment results indicated that the SPB-induced and differently expressed genes in both parents are involved in biological processes such as wound response, signal transduction, immune response, and phytohormone pathways. Interestingly, secondary metabolic processes such as flavonoid synthesis were only significantly enriched in the upregulated genes of JY93 after SPB chewing compared with K6. Finally, we identified 18 candidate genes related to soybean pod borer resistance through the integration of QTL mapping and RNA-Seq analysis. Seven of these genes had similar expression patterns to the mapping parents in four additional soybean germplasm after feeding by the SPB. These results provide additional knowledge of the early response and induced defense mechanisms against the SPB in soybean, which could help in breeding SPB-resistant soybean accessions.

Efficacy of Selected Insecticides and Biopesticides against Spotted Pod Borer [Maruca vitrata (Geyer)] on Green Gram [Vigna radiata (L.) Wilczek

A field trial was conducted at Central Research Farm (CRF), SHUATS, Prayagraj, Uttar Pradesh during the Kharif season of 2021. The field was laid in a Randomized Block Design (RBD) replicated thrice with seven treatments. The larval population per plant was taken as the first spray and second spray on one day before spraying and 3rd,7th and 14th day after each spray all the treatments tested and found to significantly reduced the larval population compared to control. The results of the efficacy showed that the mean larval population recorded in the treatment Chlorantraniliprole 18.5 SC (3.45%), was most effective. The next effective treatments was Spinosad 45 SC (3.70%) followed by Emamectin benzoate (3.80%), Metarihizium anisopliae (4.00%), Neem oil (4.15%), Karanj oil (4.30%) as compared to Control (7.10%). The best and most economical treatment in terms of yield and B: C ratio was Chlorantraniliprole 18.5SC (20.98q/ha and 1:3.99). It was followed by Spinosad 45SC (20.62 q/ha and 1:3.92). Emamectin benzoate 5% SG (17.45 q/ha and 1:3.84), Metarhizium anisopliae (17.01 q/ha and 1:3.83), Neem oil 5% (16.6 q/ha and 1:3.61), Karanj oil 5% (15.13 q/ha and 1:3.46), as compared to control (9.5q/ha and1:2.28).

Seasonal activity of spotted pod borer, Maruca vitrata (Fabricius) in relation to weather factors infesting cowpea

A field experiment was conducted to study the seasonal incidence of spotted pod borer, Maruca vitrata in cowpea variety AVCP-1 at Entomology farm, B. A. College of Agriculture, AAU, Anand during Kharif, 2021. The incidence of M. vitrata in cowpea was commenced from 6th week after sowing i.e. 4th week of August (34th SMW) with 0.60 larva/plant and gradually increased to reached its first peak (3.51 larvae/plant) and the highest peak (6.97 larvae/plant) during the 1st week of September (36th SMW) and 2nd week of October (41st SMW) when crop age was 8th and 13th weeks old, respectively. Thereafter, the population gradually declined towards the crop maturity. Concerned to the damage of M. vitrata on pods of cowpea, it was recorded between 8.63 to 59.93% per plant. The maximum pod damage i.e. 59.93% per plant was observed in the second week of October (41st SMW) when M. vitrata incidence was at its highest peak. The population of M. vitrata had highly significant negative correlation with wind speed (-0.882**) whereas, bright sunshine hours (0.586*) and maximum temperature (0.625*) showed significant positive association on cowpea. Furthermore, it was worked out that the bright sunshine hours, maximum temperature and wind speed each contributed 11, 10.9 and 68.2% of the variation in the M. vitrata larval population, respectively.

Bionomics of Soybean Pod Borer, Cydia ptychora (Meyrick) (Lepidoptera: Tortricidae) under in vitro Condition

Background: The post-flowering pest pod borer, Cydia ptychora causing huge yield losses in soybean. It is said to be active in soybean ecosystem from September to December with 10.50-91.29 per cent incidence. The maximum incidence (95.55%) was observed to be in July sown crop. Methods: Culture of the insect was initiated by collecting larvae and pupae from infected soybean crop and was shifted to rearing cages. Ten pairs of newly emerged adult moths were released in plastic container containing soybean pods for oviposition. On hatching, larvae were reared on soybean pods till pupation. Moist sand was provided for pupation. Further, the life cycle was tracked thoroughly to understand bionomics. Result: Freshly laid eggs were pearly white, translucent, spherical having mean length of 0.49±0.016 mm and 0.31±0.009 mm width. Larval development completed within 20.86±4.59 days passing through five instars. The pupal period lasted for 9.13±2.45 days. Longevity of male and female was 1.90±0.80 and 4.93±1.60 days respectively. The total life cycle of the pod borer from egg to adult was 34.53±4.90 days.

Efficacy of insecticides against pod borers of Indian bean

Among the various insecticides evaluated for their field efficacy against pod borers of Indian bean, the treatment of emamectin benzoate 5SG at 0.002%, indoxacarb 14.5SC at 0.007% and lambdacyhalothrin 5SC at 0.005% were found to be most effective against Helicoverpa armigera (Hubner) and Maruca vitrata Geyer. While, thiacloprid 21.7SC at 0.012% and novaluron 10EC at 0.01% were moderately effective. The least pod damage was observed with emamectin benzoate 5SG at 0.002% (13.16%) which was at par with indoxacarb 14.5SC at 0.007% (14.16%) and lambdacyhalothrin 5SC at 0.005% (16.33%). Maximum pod yield (21.75 q/ ha), increase in yield over control (95.76%) and % of avoidable loss (48.91%) was observed with emamectin benzoate 5SG at 0.002%.

Population dynamics of major insect pests of Indian bean

The incidence of aphid Aphis craccivora Koch in Indian bean Lablab purpureus (L.) reached its peak during 2nd week of January (2nd SMW) with 25.27 aphids/ twig of 10 cm. Maximum incidence of jassid Empoasca kerri Pruthi (8.20/ leaf) and whitefly Bemisia tabaci (Gennadius) (7.12/ leaf) was observed during 4th week of December (52nd SMW). The thrips Megalurothrips distalis Karny started appearing from 4th week of November (48th SMW) reaching its peak (10.35/ flower) during 1st SMW. Maximum larval counts of Helicoverpa armigera (Hubner) (5.79/ plant) was observed during 2nd week of January (2nd SMW), while in case of Maruca vitrata Geyer (7.21/ plant) it was during 2nd week of January (2nd SMW). Maximum and minimum temperature showed significant negative influence on the incidence of all these pests; and morning relative humidity showed significant negative effect on all except M. distalis. While morning vapour pressure showed significant negative influence on the incidence of all pests except E. kerri and B. tabaci.

LIPOLYTIC ACTIVITY DURING METAMORPHOSIS OF Maruca vitrata (FABRICIUS)

Lipolytic activity during metamorphosis of Maruca vitrata (Fabricius) has been attempted. The maximum activity was observed in 5th day old pupa of M. vitrata.Lipolytic activity gradually increased from 1 to 5 day and decreased from 6 to 8-day pupae of M. vitrata. The main sources of energy and structural component during histogenesis are lipid. The physiological role of lipase during metamorphosis of M. vitrata is discussed.

SEASONAL INCIDENCE AND REACTION OF GREENGRAM GENOTYPES AGAINST SPOTTED POD BORER, Maruca vitrata (FABRICIUS)

Greengram cultivation is hampered by various insect pests, among which the spotted pod borer, Maruca vitrata (Fabricius) inflicts extensive damage. Insecticides are widely used to suppress this damage but are found to culminate in undesirable effects in the environment and humans. Exploring and exploiting host plant resistance in the gene pool of crop plants is an effective, ecofriendly alternative approach to manage such insect pests. Considering this, 333 greengram genotypes were gathered and screened under field condition to identify resistance sources against spotted pod borer during Rabi 2020 and Kharif 2021 at Sivapuri village, Chidambaram, Tamil Nadu, India. The larval population and their active webbing were accessed from flower bud initiation to end of crop growth period and per cent pod damage was worked out after harvest. The results of this study revealed that, the larval population and active webbing and per cent pod damage were the least on IC-39301-1 followed by IC-311451 and IC-39301-1 followed by IC-103207 during Rabi 2020 and Kharif 2021 respectively. In both seasons, the larval population, active webbing, and percent pod damage were higher in the genotype IC-39317, followed by IC-103981. Based on per cent pod damage 4 and 10 genotypes were found resistant, while 182 and 175 genotypes were moderately resistant, 70 and 78 genotypes were tolerant, 56 and 63 genotypes moderately susceptible and 21 and 7 genotypes were highly susceptible in Rabi 2020 and Kharif 2021 respectively. The genotypes which were grouped under resistant and tolerant category in both the seasons were selected for further evaluation to develop desirable varieties.

REACTION OF COWPEA GENOTYPES FOR RESISTANCE AGAINST LEGUME POD BORER, Maruca vitrata (Fabricius)

Among different pulses, cowpea is considered as most important source of nutrition to human and livestock. Several insect pests cause major constraint in cowpea production. Among the pests, the legume pod borer, Maruca vitrata (Fabricius) is a serious threat which ultimately reduces the quality and quantity of the economic produce. Management of M. vitrata using insecticides is commonly followed. But, indiscriminate use of insecticides leads to unwanted repercussions in the environment. It prompted to turn the focus on eco friendly methods to manage this pest. Among various management methods, use of tolerant and/or resistant genotypes is the first line of defence against insect pests. In the light of this consideration, 280 cowpea genotypes were screened against M. vitrata during Rabi, 2020 and Kharif, 2021 seasons at Vallampadugai Village, Cuddalore district, Tamil Nadu state, India. The per cent flower and pod infestation were noted at different days after sowing. The results revealed that, minimum flower infestation was noted on IC-202800(6.60% and 5.00%) in both rabi and kharif. Maximum infestation in rabi and kharif was noted on IC-249141(76.66%) and IC-9883 (66.66%) respectively. Minimum and maximum per cent pod infestation was noted on IC-39870 (15.00% in rabi and 10.00% in kharif) and EC-161916(100% in rabi and 93.33% in kharif) in both seasons. Based on per cent pod damage, 30 genotypes were found highly resistant, with 52 moderately resistant, 81 susceptible genotypes and 38 highly susceptible genotypes in rabi season. In kharif, 18 genotypes were highly resistant and 86 genotypes have recorded moderately resistant in contrast to 13 genotypes secured highly susceptible ratings.