Insect Pests Of Cowpea Research Articles

ETUDE DE LEFFICACITE DES BIOPESTICIDES A BASE DE GRAINESDE NEEM ET DELENTOMOPATHOGENEBEAUVERIABASSIANA(BALS.) VUILL.POUR LA GESTION DES PRINCIPAUX INSECTES RAVAGEURS DE LA CULTURE DU NIEBE DANS LA REGION DE MARADI AU SAHEL

The insect pests of cowpea, Vignaunguiculata L. Walper, is one of the constraints which affect the cultivation this crop in Africa. The pod sucking bug Clavigrallatomentosicollis(Stål), the flower thripsMegallurothripssjöstedti(Trybom) and the pod borer Marucavitrata(Fabricius) are the main insect pests whose damage causes considerable yield losses on cowpea crop. In this study, neem Azadirachtaindica based biopesticides and the entomopathogenBeauveriabassiana(Bals.) Vuill were tested todeterminetheir efficiency in the management of cowpea insect pests. The trials were established in a farming environment with producers in 15 villages of the Maradiregion during three consecutive cropping seasons 2020, 2021 and 2022. The experimental design is the Fisher block with 4 treatments (Neem grain, B. bassiana, Chemical pesticide and the control without treatment) and two repetitions per site. The results for this studybiopesticide treatments (Neem grains and entomopathicfungus B. bassiana) reduced the insect pest damageof 73.21% and a yields increase of 104.12% compared to the control treatment. . Neem was effective as the synthetic chemical pesticide in the management of insect pests as it reduced the populations of M. sjöstedti, M. vitrata and C. tomentosicollis by 67.29, 70.57 and 71.26%respectively. This Neem biopesticide resulted a yield increase of 140.33% on cowpea for the three years of the study. Thus, for low-income producers, neem is an available resource that can constitute an effective and ecological alternative for managing cowpea insect pests in the Sahel.

Bioefficacy and economics of newer insecticides against sucking insect pests of cowpea

Bioefficacy and economics of newer insecticides against sucking insect pests of cowpea

Population dynamics of major insect-pests of cowpea and their correlation to abiotic parameters

Population dynamics of major insect-pests of cowpea and their correlation to abiotic parameters

INSECT BIODIVERSITY AND ASSESSMENT OF POST-HARVEST GRAIN LOSSES IN STORED COWPEA (Vigna aunguiculata L.)

Insect pests cause huge economic losses to stored grain cereals and pulses in tropical and subtropical areas around the globe. The level of damage and losses caused by different insect pests varies depending upon the infesting species, type of food materials, duration of storage and structures. The information about the diversity of infesting species, their dispersal and abundance are key for devising effective pest management techniques against storage insect pests. The present study aimed to collect information on the distribution, relative abundance and biodiversity of major insect pests of stored cowpeas in Dera Ismail Khan (Khyber Pakhtunkhwa) and its adjoining Punjab province areas of Pakistan. The areas selected for biodiversity studies were Paniala, Mankera, Bhakkar, Paharpur, Kulachi, Ramak, Dera Ismail Khan, Darya Khan, Notak and Behal. A vast survey of godowns was conducted to find out the population dynamics of insect pests of stored cowpeas and to explore the % grains damage and weight losses in the mentioned areas. For the collection of samples, a spear sampler was used to collect 500-gram samples from the top, middle and bottom portions of the bags. Samples were preserved in plastic containers and after 30 days, were sieved out with the help of a 2mm mesh sieve to remove different types of dead and alive insects. A total of five species representing two distinct orders i.e., Coleoptera and Lepidoptera. Coleopterans are Callosobruchus maculatus, Tribolium castaneum, Oryzaephilus surinamensis, Trogoderma granarium belonged to four families including Chrysomelidae, Tenebrionidae, Silvanidae, Dermestidae and Lepidopteron are Sitotroga cerealella belonging to family Gelechidae. The most abundant species among all the recorded insect pests of cowpea was C. maculatus (53.60%) followed by T. castaneum (18.60%), S. cerealella (16.97%), O. surinamensis (6.49%) and T. granarium (04.34%). The maximum infestation (26.98%) and weight loss (28.91%) of cowpea was recorded in Darya Khan followed by Dera Ismail Khan (22.70% and 26.33%), whereas; minimum % infestation and weight losses were recorded in Bhakkar (16.91% and 17.14%) area showing significant differences between the surveyed areas. The C. maculatus is the most abundant specie of the stored cowpea grains in the surveyed areas and needs management tactics to minimize the post-harvest grains losses. The population of C. maculatus starts to build up during the month of March (23.30⁰C and 56.25% RH) and reaches at peak in May (35.32⁰C and 68.88% RH). Special measures should be taken during these months to minimize the infestation and losses caused by C. maculatus.

Preliminary Evaluation of Onion Bulb and Tobacco Leaf Extracts for Insect Control and Yield of Cowpea in the Southern Guinea Savanna of Nigeria

The study evaluated the effects of onion (Allium cepa) bulb and tobacco (Nicotiana tabacum) leaf extract on the insect pests and yield components of cowpea. The extracts were tested on number of the flower thrips, Megalurothrips sjostedti Trybom, the pod-sucking bug, Clavigralla tomentosicollis Stal, the pod borer, Maruca vitrata (F.) and cowpea aphid, Aphis craccivora Koch. Also evaluated were the dry seed weight, 100-seed weight, pod length, number of pods per plant, number of seeds per pod, pod load, pod damage and pod evaluation index. Field experiment was conducted in the Faculty of Agriculture, University of Ilorin, Ilorin, Nigeria. Plots were laid out in a randomized complete block design with three replications. Treatments included 10% (w/v) of each of onion bulb and tobacco leaf extracts, synthetic insecticide (Cypermethrin 1 L/ha) and untreated control. Results revealed that cowpea treated with the plant extracts had significantly (p<0.05) lower insect pest population than plants in untreated plots which suffered greater insect pest attack. However, plots treated with Cypermethrin produced significantly higher number of seeds per pod than other treatments. Nevertheless, tobacco leaf extract produced significantly (p<0.05) heavier 100-seed weight than other treatments including the control. It could be concluded that the plant extracts had potential to replace the synthetic insecticide for control of insect pests of cowpea, thus ensuring environmental safety.

Bioefficacy of Newer Insecticides against Major Sucking Insect Pests of Cowpea [Vigna unguiculata (Linn.) Walp.

Bioefficacy of Newer Insecticides against Major Sucking Insect Pests of Cowpea [Vigna unguiculata (Linn.) Walp.

Comparative Evaluation of Neem Seed Extract as Bio-insecticide for the Control of Three Field Insect Pests of Cowpea in Maiduguri, Borno State, Arid Zone of Nigeria

Cowpea Vigna unguiculata is an important source of nutritious food for man for healthy living and provides fodder to the animal for optimum production and grows in the ecological part of Nigeria. However, despite its importance to man and national development, its main cultivation challenge is insect pests which sometimes account for as high as 40 % loss in production. The continuous use of conventional insecticides to control pests is resulting in unbearable health hazards, hence the need for alternative control measures such as the use of botanicals. This study evaluated the efficacy of neem seed extract biopesticide compared to cypermethrin synthetic insecticide for the management of Thrips, Maruca vitrata and Clavigralla tomentosicollis on cowpea varieties in Maiduguri, Borno State of Nigeria. The neem seed extract was extracted following standard procedures and used as a treatment alongside cypermethrin against the three pests at weekly intervals on four cowpea varieties. Pest population buildup was monitored for five weeks on treated and untreated (control) crops beginning from 24 hours after each treatment on weekly bases. The result revealed a significant reduction (P>0.05) in the population buildup of the three pests on both neem seed oil and cypermethrin-treated crops compared to the control. No significant difference (P>0.05) in population reduction was observed between crops treated with neem seed extract and Cypermethrin. Consequently, there was a significant increase in the grain yield of cowpea on treated plots compared to untreated plots. The neem seed extract has demonstrated a high potential substitute for synthetic insecticide to control the three insect pests.

Synergism of Adjuvants Mixed With Spinetoram for the Management of Bean Flower Thrips, Megalurothrips usitatus (Thysanoptera: Thripidae) in Cowpeas.

The bean flower thrips, Megalurothrips usitatus (Bagnall) is an economically important insect pest of cowpea, Vigna unguiculata (L.) Walp in south China. Spinetoram is a newly available commercial active ingredient in the spinosyn mode of action group of insecticides that has been recommended for thrips management in China. In this study, the toxicity and efficacy of spinetoram for controlling M. usitatus were evaluated and compared to six other conventional insecticides. In addition, the synergistic effects of adjuvants (Silwet 806, Silwet 618, AgroSpred 910, and AgroSpred Prime) mixed with spinetoram for thrips control on cowpea were evaluated in both the laboratory and the field. Results of this study showed that spinetoram had higher toxicity and field efficacy of M. usitatus than other tested insecticides. A significant increase in efficacy was observed when spinetoram was applied at a recommended rate of 0.67 ml/L, mixed with Silwets (806 and 618) at the rate of 0.5 ml/L. Reductions of 50% and 40% in thrips infestation in the field over treatments without adjuvants were observed 3- and 7-days posttreatments, respectively. However, no significant reduction of M. usitatus was recorded when spinetoram was mixed with AgroSpreds (910 and Prime). Furthermore, no significant differences were found in thrips infestation between spinetoram sprayed alone at the rate of 0.67 ml/L and a reduced rate of spinetoram (0.45 ml/L) mixed with Silwets (806 and 618). The current research shows that Silwets mixed with spinetoram has a synergistic effect in the management of thrips.

Effect of Various Intercrops on the Incidence of Major Sucking Insect Pests of Cowpea [Vigna unguiculata (Linn.) Walp

Background: Ecological maneuvering of major sucking insect pests of cowpea, [Vigna unguiculata (Linn.) Walp.] at the micro level was aimed through various agronomic techniques. The tactics of appropriate intercropping is gaining thrust in the present scenario in overall strategy of insect pest management. Methods: The experiment was conducted during kharif, 2018 in a randomized block design (RBD) with 5 treatments and 4 replications. The populations of major sucking insect pests were recorded at weekly interval from their appearance till harvesting of the cropearly in the morning of 10 cm terminal shoot for aphid and from three leaves, viz., one each from top, middle and lower canopy of the plant for leafhopper and whitefly. Result: The experiment on cowpea [Vigna unguiculata (Linn.) Walp.] grown along with, pearlmillet [Penisetum glucum (Linn.) R.Br.emend stunntz] sesame, (Sesamum indicum) sorghum (Sorghum bicolor) and cluster bean (Cyamopsis tetragonloba) as intercrops showed reduced population of sucking insect pests (aphid, Aphis craccivora Koch, leafhopper, Empoasca fabae (Harris) and whitefly, Bemisia tabaci (Genn.) over the sole crop (cowpea), cowpea with pearlmillet and sorghum combinations proved significantly less conducive to aphid, leafhopper and whitefly infestation as compared to other intercrops.

Cowpea Vigna unguiculata (L.) walp and chilli pepper Capsicum frutescens (L.) intercropping as affected by planting pattern and insect pest management in the rain forest area of Nigeria

Field experiments were conducted at Yaba College of Technology Instructional and Research Farm during 2019/2020 wet and dry seasons to investigate the performance of cowpea and chilli pepper intercropping for the management of insect pests of cowpea. The experiment was arranged in alternate intercropping (chilli pepper and cowpea), strip cropping (chilli pepper and cowpea), border cropping (chilli pepper around cowpea) and sole cropping in a randomized complete block design (RCBD) replicated three times with twelve plots of sixty ridges. Data were collected on growth parameters of cowpea at 2, 4 and 6 weeks after planting, pest population, assessment of thrips (Megalurothrips sjostedti) and legume pod borer (Maruca vitrata), assessment of both nymphs and adult of legume pod borer and pod sucking bugs (Clavigralla tormentosicollis), pod damage, grain yield and yield loss. Alternate intercropping was significantly (p ≤ 0.05) superior to another cropping system concerning grain yield (0.12±0.01), reduction in pest infestation (3.56±0.11) and yield loss (322.12±5.43) when compared to sole cropping. Intercropping cowpea and chilli pepper can therefore be used to reduce the attack of insect pests on cowpea.

COMPARATIVE STUDY OF BOTANICALS AND SYNTHETIC INSECTICIDE ON THE CONTROL OF INSECT PESTS AND DISEASES OF COWPEA

The quest to minimize synthetic insecticide use due to their adverse environmental effects and the need to improve yield has led to eco-friendly botanical pesticides use. This study was carried out to demonstrate the efficacy of garlic and lemon liquid botanical extracts in mitigating cowpea insect pests, diseases and increasing yield at Faculty of Agriculture and Veterinary Medicine, University of Buea, Cameroon. The design was a randomized complete block with four treatments, replicated four times. The treatments comprised synthetic insecticide, garlic liquid extract, lemon liquid extract, and control. Data collected were subjected to ANOVA (P<0.05). Cowpea vegetative parameters differed significantly (P<0.05), with garlic liquid extract dominating synthetic insecticide in the number of leaves having 32 highest leaves, but there was no significance between botanical pesticides and synthetic insecticide. Botanical pesticides effectively mitigated pest, significantly different from the control (P<0.05) but similar to the synthetic insecticide. Garlic liquid extract had 11 thrips per 10 flowers, three less than synthetic insecticide, and one pod borer/10 flowers less than synthetic insecticide. Fusarium oxysporium, Curvularia lunata and Botryodiplodia theobromae (BT) were identified to infect cowpea. Least disease incidence was 11.6 % from plants treated with garlic liquid extract. Cowpea treated with garlic liquid extract was least infected with the pathogens (23). The highest weight of pods yield was recorded in garlic liquid extract 10 kg/treatment with the lowest in control 5 kg/treatment and differed significantly (P<0.05) across treatments. Thus garlic and lemon liquid extracts improved cowpea yield while minimizing environmental hazards.

Genetic variability and trait association under thrips (Megalurothrips sjostedti Trybom) infestation in cowpea (Vigna unguiculata [L.] Walp.)

Flower bud thrips is one of the most destructive insect pests of cowpea in sub-Saharan Africa. Information on genetic variability among cowpea germplasm and interrelationships among traits under thrips infestation would facilitate the development of resistant varieties. The objectives of the study were to assess genetic variability for thrips resistance, estimate heritability of yield and other traits and investigate inter-trait relationships under thrips infestation. One hundred and fifty-six cowpea lines, including one resistant and one susceptible check, were screened for resistance under natural infestation at two locations in Nigeria, in 2016. Test lines were scored for thrips damage weekly for three consecutive weeks, after removal of spreader plants, to obtain damage scores (DS) 1, 2 and 3 while data were collected on agronomic traits. The data were subjected to analysis of variance from which genetic components of the phenotypic variance were computed. Interrelationships among traits were determined using phenotypic and genotypic correlation, and sequential path analyses. Significant variability was observed among test lines. Lines TVu 6824 and TVNu 1307 were identified as possessing thrips resistance. DS3 had significant genetic and phenotypic correlations with DS1, DS2 and yield-related traits. Number of pods per peduncle, number of peduncles per plant and DS3 were identified as first-order traits. Heritability estimates ranged from 0.55 to 0.73. Genetic variability among the lines suggests the possibility of genetic control of thrips while number of pods per peduncle, number of peduncles per plant and DS3 would serve as useful selection criteria for thrips resistance.

Efficacy of commercial insecticides for cowpea pod borer (Maruca vitrata F.) management in Pokhara, Nepal

Cowpea (Vigna unguiculata Walp.) is a major grain legume used as vegetables and pulses. Among the several insect pest of cowpea, spotted pod borer is one of the most destructive pest. To evaluate the available chemical pesticides for pod borer management, a set of field experiments on cowpea variety Malepatan-1 were conducted at Horticulture Research Station, Malepatan, Pokhara in years 2019 and 2020. The experiments were laid out in Completely Randomized Block Design (RCBD) having seven treatments viz.Flubendiamide 39.35 % SC @ 0.3 mL/L, Chlorantraniliprole 18.5 % SC @ 0.2 mL/L, Emamectin benzoate 5 % SG @0.3 g/L, Spinosad 45 % SC @0.3 mL/L, Bacillus thuringiensis Kurstaki @2g/L, Azadirechtin 0.03%@ 5mL/L and Control with four replications. Flubendiamide 39.35 % SC @ 0.3 mL/L and Emamectin benzoate 5 % SG @0.3 g/L were found the most effective insecticides in lowering cowpea flower and pod damage with highest benefit cost ratio; however, considering environment, Chlorantraniliprole 18.5 % SC @ 0.2 mL/L and Spinosad 45 % SC @0.3 mL/L being next effective treatments could be viable option to manage spotted pod borer in cowpea production. 

Push-pull strategy combined with net houses for controlling cowpea insect pests and enhancing crop yields

Net houses can be used in tropical environments to protect crops such as cowpea against large insect pests, thereby avoiding pesticide treatments while sustainably mitigating the effects of climate change. We investigated a push-pull strategy to prevent small insect pest outbreaks in a net house. The push component consisted of two stimulus plants, i.e. Cymbopogon citratus and Tagetes minuta, and the pull stimuli consisted of visual cues from blue and yellow sticky traps. Field experiments were set up in central Kenya and conducted during a rainy and a dry season, involving an open field control treatment, and three management treatments consisting of (1) an open field push-pull treatment, (2) a net house treatment and (3) a combined net house + push-pull treatment. Trialeurodes vaporariorum infestations were lower in the net house and net house + push-pull treatments than in the two open field treatments during the dry period or in the control treatment during the rainy period. Aphis craccivora infestations were higher in the net house and net house + push-pull treatments than in the control and open field push-pull treatments during the dry period, while no differences were observed among treatments during the rainy period. Megalurothrips sjostedti infestations did not vary among treatments in both periods. Among the larger insect pests, Clavigralla tomentosicollis infestations were lower in the net house and net house + push-pull treatments than in the open field treatments during the dry period, while Maruca vitrata infestations were lower in the net house treatment than in the control. During the rainy period, C. tomentosicollis infestations were higher in the net house + push-pull treatment than in the net house treatment, whereas M. vitrata infestations did not vary among treatments. Compared to the control, Empoasca sp. infestations were lower in the net house and net house + push-pull treatments in both periods, and in the open field push-pull treatment in the rainy period. Cowpea pod and grain yield and quality were higher in the net house and net house + push-pull treatments than in the control irrespective of the period. Although the treatments 1 reduced some of the pests, the net house and net house + push-pull treatments were effective in protecting cowpeas against most of the pests while improving pod yields in both periods.

Efficacy of Kigelia africana Lam. (Benth.) leaf and stem bark ethanolic extracts on adult cowpea seed beetle, [Callosobruchus maculatus Fabricius (Coleoptera: Chrysomelidae)] affecting stored cowpea seeds (Vigna unguiculata)

Callosobruchus maculatus is the most damaging insect pest of stored cowpea (Vigna unguiculata) seeds in Nigeria. Thus, this present research work was put in place to assess the insecticidal activities of the extracts obtained from the leaf and stem bark of Kigelia africana (Lam.) Benth against the cowpea seed beetle, C. maculatus. The parameters that were assessed were adult mortality, oviposition and adult emergence of C. maculatus. The experiments were conducted under laboratory conditions of 28±2 °C temperature and 75 ± 5% relative humidity. The extracts were applied at dosages of 0.3, 0.6, 0.9 and 1.2 mL per 20 g of cowpea seeds. The two extracts of K. africana were found to be toxic to the survival of the C. maculatus. However, the extract obtained from the leaf was more potent to the beetle than the extract obtained from the stem bark of the same plant. The two extracts also reduced ovipositipon and completely suppressed adult emergence at the highest dose of 1.2 mL per 50 g of cowpea seeds. The results obtained in the present research work showed that the two extracts of K. africana were effective in suppressing the population of the infamous stored pest of cowpea seed beetle, C. maculatus and could therefore be recommended to replace the harmful synthetic chemical insecticides in protecting cowpea seeds in storage.

Introgression Breeding in Cowpea [Vigna unguiculata (L.) Walp.

The narrow base of genetic diversity characteristic of cowpea can be attributed to it being self-pollinating, evolving from narrow wild germplasm and exhibiting very limited gene flow between wild and cultivated types. Backcrossing to introduce simply inherited desirable traits and utilization of improved breeding lines and varieties as parents in crossing programs further narrowed the genetic base of cowpea varieties. In most cowpea breeding programs, genes for resistance and market traits were pyramided into lines characterized by high levels of acceptance to farmers and consumers. Besides predisposing widely distributed improved varieties to genetic vulnerability, a narrow base of genetic variation may be contributing to the plateauing in cowpea grain yield, which compromises genetic gains. Cross compatible wild relatives have not been used in variety development because breeders shy away from them due to their tiny seed size, unattractive seed coat color and texture, pod shattering, and susceptibility to viruses. A number of wild cowpea relatives, both within and outside section Catiang of Vigna species, have been evaluated for their reaction to cowpea insect pests and diseases. Vigna vexillata lines were resistant to the legume pod borer (Maruca vitrata), the cowpea weevil (Callosobruchus maculatus), and Striga gesnerioides but are cross incompatible with cultivated cowpea. Some lines among the cross compatible wild relative V. unguiculata ssp. dekindtiana were found to be resistant to aphid in the seedling stage, while others showed good levels of drought and heat tolerance. Molecular markers are being generated to identify quantitative trait loci (QTL) with effects on some desirable attributes in cowpea. Modern breeding tools, including transgenics, can be applied for the improvement of cowpea, bypassing the natural barriers of traditional breeding. Transgenic cowpea with Bt gene cry1Ab showing resistance to M. vitrata has been released in Nigeria. Genome editing, a powerful emerging tool, can also be used for developing improved cowpea varieties with durable resistance to pests and diseases.

Identification of sources of resistance in cowpea mini core accessions to Aphis craccivora Koch (Homoptera: Aphididae) and their biochemical characterization

Cowpea (Vigna unguiculata (L. Walp) is an important grain legume for human and livestock nutrition, especially in sub-Saharan Africa. Aphid, Aphis craccivora Koch (Homoptera: Aphididae), is one of the most widespread and destructive insect pests of cowpea and host-plant resistance is an effective approach to minimize the pest damage at seedling stage. This study was aimed at identifying resistant sources to A. craccivora within the cowpea mini core collection, a set of accessions from the largest world cowpea germplasm collection maintained at the International Institute of Tropical Agriculture (IITA). A total of 375 lines including 373 from IITA mini core collection, one resistant (TVu-801) and one susceptible (TVx-3236) checks were evaluated through artificial infestation in screening cages during the seedling stage. In cages, genotypes were planted in single rows containing four plants. They were arranged in an augmented design in which the two checks were sown in individual cages. Scoring for aphid population and damage levels were carried out on individual plants at 7, 14, and 21 days after planting. Advanced bioassays and biochemical analyses were conducted to investigate the mechanism of resistance to A. craccivora. Overall, three genotypes TVu-6464, TVu-1583, and TVu-15445 showed good levels of resistance comparable to the resistant check TVu-801. The HPLC analyses proved that both low sucrose levels in the plant, as well as high levels of kaempferol and quercetin, aglycones of phenolic compounds, were related with high resistance to aphids. The above genotypes with promising levels of resistance to A. craccivora will be used in cowpea breeding programs to develop improved resistant lines against this pest.

Population dynamics of major insect pests of cowpea (Vigna unguiculata L. Walp) and its correlation with different abiotic factors under south Gujarat conditions

Investigations were carried out to know the population dynamics of major insect pest of cowpea (Vigna unguiculata L. Walp) and its correlation with different abiotic factors under south Gujarat conditions at Navsari Agricultural University, Navsari during summer 2018. The results revealed that aphid, jassid and whitefly population started from 3rd week of March reached to a peak level of 3.0 aphid index, 4.66 jassids/leaf and 4.06 whiteflies/leaf respectively. The incidence of cowpea pod borer and spotted pod borer initiated from 4th WAS i.e. 3rd week of April (16th SMW) with the initiation of the flower and pod formation occurs pest population reached to a peak level 2.82 larvae/plant and 2.70 larvae per plant during 8th WAS (19th SMW).Then after the pest population declined throughout the cropping period. Almost all the insect pests were found abundant in 2nd week of May, i.e. 8th week after sowing. Among various weather parameters, rainfall showed a significantly negative influence on population of almost all pests and morning relative humidity showed a significantly negative influence on population of almost all pests except jassid and H. armigera.

INSECT PESTS PREFERENCE FOR COWPEA: THE DILEMMA OF FARMERS IN WEST AFRICA

<p><strong>Background: </strong>Cowpea is a cosmopolitan crop cultivated in most of West Africa where the livelihood of people revolves around farming. It is a vital form of livelihood all through the value chain from seed production to farming, grain processing, distribution, and culinary purposes. <strong>Main findings: </strong>The high demographic growth, rapid urbanization, and burgeoning markets of West African countries are the key drivers for the intensification of cowpea production in these regions. Cowpea as a linkage crop connects agriculture to the prevalent local environments of West Africa; farmers to productive resources; and consumers to local healthy foods. As a choice crop among the resource-poor farmers, it is largely grown in intercrop with other food crops such as maize, sorghum, millet, sugar cane, cotton, and cassava. This is due to the ecosystem services and carbon credits derived from its cultivation. These ecosystem services and carbon credits are displayed through its nitrogen-fixing capability, drought-tolerant nature, and ground covering potential against erosion. <strong>Implication: </strong>Although benefits accrue from cultivating this crop, a major constraint to its production is its susceptibility to attack by an array of insect pests. These pests include the pod borer ( <em>Maruca vitrata</em>)<em>, </em>Flower thrips (<em>Megalurothrips </em>sjostedti)<em>, </em>Spiny bugs (<em>Clavigralla spp.</em>)<em>, </em>Other pod sucking bugs (<em>Aspavia armigera, Anoploclemis curvipes, Riptortus dentipe</em>), Whitefly (<em>Bemisia tabaci</em>)<em>, </em>Aphids (<em>Aphis craccivora</em>)<em>, </em>Leafhoppers (<em>Empoasca spp</em>), Foliage beetle(<em>Ootheca mutabilis</em>), Flower beetle (<em>Mylabris spp.</em>)<em> and </em>mites (<em>Tetranychus spp</em>)<em>. </em>Their attack could be so severe that over 90% of harvestable yield may be lost and the farmer is left in a dilemma of fighting hunger and poverty. <strong>Conclusion: </strong>Despite the huge research collaborations in the management of insect pests of cowpea, this paper seeks to find out how much of these documented findings become transferred to resource-poor farmers in West Africa.</p>

Phylogeny, chitinase activity, and pathogenicity of Beauveria, Metarhizium and Lecanicillium species against cowpea aphid, Aphis craccivora Koch

Cowpea aphid, Aphis craccivora Koch is a serious insect pest of cowpea distributed in almost all states of India and its management is essential to increase the quality and quantity of cowpea yield. This study sought to characterize the indigenous isolates of fungal entomopathogens, Beauveria bassiana, Metarhizium pingshaense, M. guizhouense, and Lecanicillium muscarium, using molecular phylogeny and evaluate their pathogenicity against A. craccivora under greenhouse conditions and compare their extracellular chitinase activity. Thirty isolates of fungal entomopathogens were collected from semi-natural and agricultural habitats. Molecular phylogeny of these isolates using partial nuclear sequences, Bloc and MzIGS3, and mitochondrial sequence, nad1, resolved four species. Screening of the isolates against A. craccivora using a single concentration of 1 × 106 conidia/ml revealed that all isolates were pathogenic, with mortality of aphids ranging from 16.67 to 100%. Bioassays of the highly pathogenic isolates of B. bassiana, M. pingshaense, and L. muscarium against A. craccivora revealed low LC50 value of L. muscarium isolate GKVK 03_11 (1.4 × 105 conidia/ml) under greenhouse conditions. Comparison of the extracellular chitinase activity of these isolates detected high chitinase activity of GKVK 03_11 isolate (0.621 U/ml). Study results suggest the biocontrol potential of indigenous L. muscarium isolate for the management of A. craccivora and the possible role of chitinase enzyme in the virulence of fungal entomopathogens.