Insect Pests Of Vegetable Crops Research Articles

Emerging Insect Pests of Vegetable Crops under Changing Climate Scenario

Crop losses in vegetables vary greatly depending on plant variety, cropping season, geographical location, and pest damage potential. Vegetable crops are heavily impacted by insect pests and diseases due to their softness, fragility and short duration in comparison to other crops. An emerging insect pest is one that has been observed in a specific crop-infested area and has progressively increased in population over time. Emerging insect pests have the potential to cause economic harm. In other words, an emerging insect pest is a pest insect whose position has shifted from minor to major or secondary to primary pest. The number of existing minor pests is increasing, as is the arrival of new ones, such as mealybugs, fruit flies, stem borers, diamondback moths among phytophagous insects and red spider mites among acarine. Recent infestations, such as South American tomato pinworm and chili black flower thrips, have caused serious damage to tomato and chili harvests. This review envisages on the variables that contribute to the establishment of new invasive pests, the persistence of main pests, general pest management practices, and integrated pest management to achieve sustainable vegetable production.

Predation and reproduction of the generalist predator Nabis pseudoferus preying on Tuta absoluta

AbstractThe damsel bug, Nabis pseudoferus Remane (Hemiptera: Namidae), is a generalist predator of small arthropods, including key insect pests of vegetable crops. In this study, we characterized the predation and development of various N. pseudoferus life stages when preying on the eggs and first‐ and fourth‐instar nymphs of the invasive South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). These findings were compared to those of the bug’s common prey, cotton aphid, Aphis gossypii Glover (Hemiptera: Aphididae). Of the life stages tested, females showed the highest predation rate on all tested prey, due to their high longevity, large body, and great energy requirements for reproduction. The predator’s oviposition rate was clearly influenced by prey type, and was highest when feeding on fourth instars of T. absoluta. Considering the zoophytophagy of most of the life stages of other mirid species of tomato, and the lower propensity of N. pseudoferus to feed on plants, these results show that this species can be considered as a key indigenous natural enemy for sustainable pest control packages against T. absoluta in newly invaded areas.

Natural insecticides from native plants of the Mediterranean basin and their activity for the control of major insect pests in vegetable crops: shifting from the past to the future

The Mediterranean basin thrives in native plant species are able to produce numerous derivatives that can be used for insect pest control. This article provides an up-to-date overview of the most important native plant species commonly found in this region that have a certain insecticidal value in vegetable crops. Regarding the insecticidal activity of extracts from selected native species, results from both laboratory and field experiments will be also presented to highlight the potential of the latter as alternatives to synthetic insecticides. Considering the great diversity in ingredients among the various plant species, it is essential to record and describe the chemical composition of these species, in conjunction with their insecticidal activity against the main insect pests of vegetable crops. The review concludes in underlining the critical points for increasing the effectiveness and consequently the practical use of natural insecticides in crop protection. Moreover, emphasis is given in understanding the importance of the production of standardized and stable natural resource-based insecticides through the development of suitable formulations, such as capsule suspension that protects the active ingredients from environmental degradation and improves their residual activity.

Isolation, identification and biocontrol potential of entomopathogenic nematodes occurring in Purvanchal and Bundelkhand regions of Uttar Pradesh, India

Entomopathogenic nematodes (EPNs) are being used for the management of insect pests occurring in both agricultural and horticultural crops. But native EPNs are reasonably more efficacious in controlling insect pests than introduced EPNs species because they are adapted to local environmental conditions and insect pests. Therefore, in the present study, a survey was conducted to isolate EPNs at 4 districts of Purvanchal Region and 1 district of Bundelkhand Region of Uttar Pradesh, India, between 2016 and 2017 years. Out of 130 soil samples, EPNs were recovered from 3 soil samples (2.3%). Morphological characters examination and ITS-rDNA region revealed that the 3 EPNs such as Steinernema sp. (IIVR JNC01 strain) Steinernema sp. (IIVR JNC02 strain), and Steinernema sp. (IIVR EPN03 strain) are belonging to Steinernema siamkayai. Further pathogenicity of all these strains was tested on Galleria mellonella Linnaeus and the most effective strain was used to determine the biocontrol potential against lepidopteran and coleopteran pests of major vegetable crops in comparison to commercially available Heterorhabditis indica (NBAIIH38 strain). Results revealed that S. siamkayai (IIVR JNC01 strain) caused 100, 100, and 85%, mortality of 3rd instar larvae of Spodoptera litura Fabricius, Spilosoma obliqua Walker, and Spoladea recurvalis Fabricius, respectively. Similarly, S. siamkayai (IIVR JNC01 strain) caused 92.5% mortality of 2nd instar grubs of Myllocerus subfaciatus Gurein under laboratory conditions. The present study revealed that EPNs commonly present at Purvanchal and Bundelkhand regions of Uttar Pradesh and S. siamkayai (IIVR JNC01 strain) isolated from the Bundelkhand Region showed a good biocontrol potential against major insect pests of vegetable crops.

Validation of a QuEChERS-Based Method for the Estimation of Afidopyropen in Brinjal (Solanum Melongena L.) and Soil.

Afidopyropen is a recently introduced insecticide that provides effective control of insect pests in vegetable crops, including brinjal. Field applications of this insecticide can often result in accumulation of residues in brinjal fruits, leaves, and soil at harvest, which might be a concern for food and environmental safety. This demands an appropriate method for analysis of the residues of this insecticide in these matrices to facilitate residue monitoring and safety compliance checks. The study aims to validate a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based method for estimation of afidopyropen in/on brinjal leaf, fruit, and soil by ultrahigh-performance liquid chromatograph-tandem mass spectrometer (LC-MS/MS). The brinjal fruit, leaf, and soil samples were extracted by an optimized QuEChERS workflow-based sample preparation method and analyzed by LC-MS/MS. Linearity [with coefficient of determination (R2) >0.99] was obtained in calibration curves drawn from standards prepared in the matrix and neat solvent. Although negligible matrix effects were noted in fruit and soil, ion suppression was significant in the leaf matrix (71.6%). The recoveries were within the acceptable range of 70-120%, with relative SD ≤20%. In all cases, Horwitz ratio values were within the acceptable range of 0.3-1.3, indicating satisfactory repeatability. The LOQs were 0.004, 0.001, and 0.001 mg/kg for brinjal fruit, leaf, and soil, respectively. At the spiking concentrations of 0.01, 0.05, and 0.1 mg/kg, the estimated measurement uncertainty was <50% for all matrices. Because of its satisfactory precision and accuracy, the proposed method can be extended for estimation of afidopyropen in other vegetables for evaluating maximum residue limit compliance. The study reports an optimized method for high-throughput residue analysis of afidopyropen in/on brinjal leaf, fruit, and soil. The accuracy, precision, selectivity, and sensitivity of the method comply with the regulatory requirements.

Trichoderma asperellum reduces phoxim residue in roots by promoting plant detoxification potential in Solanum lycopersicum L.

Phoxim, a broad-spectrum organophosphate pesticide, is widely used in agriculture to control insect pests in vegetable crops as well as in farm mammals. However, the indiscriminate use of phoxim has increased its release into the environment, leading to the contamination of plant-based foods such as vegetables. In this study, we investigated the effect of Trichoderma asperellum (TM, an opportunistic fungus) on phoxim residue in tomato roots and explored the mechanisms of phoxim metabolism through analysis of detoxification enzymes and gene expression. Degradation kinetics of phoxim showed that TM inoculation rapidly and significantly reduced phoxim residues in tomato roots. Phoxim concentrations at 5d, 10d and 15d post treatment were 75.12, 65.71 and 77.45% lower in TM + phoxim than only phoxim treatment, respectively. The TM inoculation significantly increased the glutathione (GSH) content, the activity of glutathione S-transferase (GST) and the transcript levels of GSH, GST1, GST2 and GST3 in phoxim-treated roots. In addition, the activity of peroxidase and polyphenol peroxidase involved in the xenobiotic conversion also increased in TM + phoxim treatment. The expression of detoxification genes, such as CYP724B2, GR, ABC2 and GPX increased by 3.82, 3.08, 7.89 and 2.46 fold, respectively in TM + phoxim compared with only phoxim. Similarly, the content of ascorbate (AsA) and the ratio of AsA to dehydroascorbate increased by 45.16% and 57.34%, respectively in TM + phoxim-treated roots. Our results suggest that TM stimulates plant detoxification potential in all three phases (conversion, conjugation and sequestration) of xenobiotc metabolism, leading to a reduced phoxim residue in tomato roots.

Entomopathogenic nematodes: A tool in biocontrol of insect pests of vegetables-A review

Biological control agents have become increasingly important component in integrated pest management programme. Entomopathogenic nematodes are effective biological control agents for many important insect pests of vegetable crops. Therefore entomopathogenic nematodes are gaining attention in the field of biocontrol research worldwide. With the development and improvement of isolation and identification technique many novel species and strains have been utilized for management of several insect pests. This review aims to explore the potentiality of entomopathogenic nematode species against economically important insect pest of vegetables in India as well as in other countries.

Detection of insecticidal resistance against various insect pests in vegetable crops at Raipur

Bioassay methods such as leaf dip and larvae dip were used in the laboratory conditions for testing lethal dose of insect pests conducted at laboratory of department of entomology, IGKV, Raipur (C.G.) during 2009-2010. At least five dilutions for each of the selected insecticides were tested using different methods. In each method and insecticide at least 10 larvae of 2-3 rd instars were released on each dilution in 3 replications along with untreated control. The results shown that the Helicoverpa armigera population was maximum LD 50 value to Chlorpyriphos (O.633 μg/lit) followed by Spodoptera litura population LD 50 (0.576 μg/lit) and lower value for Leucinodes arbonalis LD 50 (0.503 μg/lit) and the Plutella xylostella population showed maximum LD 50 value to Cypermethrin (0.810μg/lit) and lower LD 50 value (0.246 μg/lit) for Trichoplusia ni. Therefore, H. armigera showed higher resistance to Chlorpyriphos and P. xylostella showed higher resistance towards Cypermethrin.

Natural Enemy (&lt;i&gt;Arthropoda-Insecta&lt;/i&gt;) Biodiversity in Vegetable Crops in Northeastern Tamil Nadu, India

Natural enemies of insect pests in vegetable crops (brinjal, okra and tomato) were recorded and their diversity was studied in Kancheepuram and Tiruvallur Districts, Tamil Nadu. Natural enemies were collected by pitfall traps, sweeping nets and by hand picking from January 2011 to December 2013 twice in a month. Totally 129 species of predatory and parasitic insects were recorded. All the natural enemies were grouped into 50 families under eight different orders. Order hymenoptera contained the highest number of families and species. Among the predators, Coccinellidae (ladybird beetles) was found to be the dominant group with high number of species. It was clear that Coccinellidae, Staphylinidae, Carabidae and Pentatomidae were the predominant natural enemies throughout the study period. In 2013, formicidae formed the major family of occurrence from July to December in the vegetable fields; in this period the total number of individuals collected from all families was the highest. The maximum Shannon-Wiener diversity index was 3.70 during the second season in 2013. Maximum richness (5.99) was recorded in the second season of 2012. The variations in the diversity, species richness and evenness between two cropping systems are discussed in this paper.

Natural Enemy (&lt;i&gt;Arthropoda-Insecta&lt;/i&gt;) Biodiversity in Vegetable Crops in Northeastern Tamil Nadu, India

Natural enemies of insect pests in vegetable crops (brinjal, okra and tomato) were recorded and their diversity was studied in Kancheepuram and Tiruvallur Districts, Tamil Nadu. Natural enemies were collected by pitfall traps, sweeping nets and by hand picking from January 2011 to December 2013 twice in a month. Totally 129 species of predatory and parasitic insects were recorded. All the natural enemies were grouped into 50 families under eight different orders. Order hymenoptera contained the highest number of families and species. Among the predators, Coccinellidae (ladybird beetles) was found to be the dominant group with high number of species. It was clear that Coccinellidae, Staphylinidae, Carabidae and Pentatomidae were the predominant natural enemies throughout the study period. In 2013, formicidae formed the major family of occurrence from July to December in the vegetable fields; in this period the total number of individuals collected from all families was the highest. The maximum Shannon-Wiener diversity index was 3.70 during the second season in 2013. Maximum richness (5.99) was recorded in the second season of 2012. The variations in the diversity, species richness and evenness between two cropping systems are discussed in this paper.

Floral attractants for the female soybean looper, Thysanoplusia orichalcea (Lepidoptera: Noctuidae)

The soybean looper, Thysanoplusia orichalcea (F.), is a polyphagous insect pest of vegetable crops. Indonesian in origin, it has spread to Europe, India, Africa, Australia and New Zealand. The identification of an attractant for female T. orichalcea could enable the development of alternative pest management strategies to those provided by insecticides or sex pheromones, which are often only attractive to males. Traps baited with synthetic lures derived from Canada thistle, Cirsium arvense (L.) Scop., floral volatiles attracted female T. orichalcea. Phenylacetaldehyde, a floral compound attractive to many Lepidoptera and present in C. arvense, was tested alone as an attractant for the soybean looper and caught significantly more female than male T. orichalcea. Trap catch was greatest when phenylacetaldehyde was combined with five prevalent volatiles present in C. arvense headspace collections: 2-phenylethyl alcohol, methyl salicylate, dimethyl salicylate, benzaldehyde and benzyl alcohol. Twice as many female moths as males were collected. Successful trapping of female T. orichalcea in either a lure-and-kill or a mass trapping system may offer an effective way to manage its population size.

Incidence and Control of Insect Pests of Vegetable Crops on Jos Plateau, Northern Nigeria

A study on the insects associated with green beans, okra, peas and cabbages was carried out at Vom and Riyom Agricultural Stations in Jos, Nigeria from October, 1980 to April; 1984. During the study period, a wide range of insects were found in association with green beans and okra plants. Sericothrips occipitalis, Empoasca spp., Aphis craccivora, Zonocerus variegatus and Bemisia tabaci were found on pea, green beans and okra plants while Myzus persicae and Brevicoryne brassicae were common on cabbage plants. Early infestation of okra and cabbage by Podagrica spp. and Brevicoryne brassicae respectively within the first three weeks after sowing, resulted in poor plant performance and low yield. Insecticide treatments reduced insect population on the treated plants and enhanced yield. In this study, insecticide treatments and the treatment of using ordinary water to hand wash aphids from cabbage plants bi-weekly, reduced aphid population on plants and increased crop yield. The number of insects on different experimental plants treated with Dichlorvos at 500, 750 and 1000g a.i/ha; pennethrin at 12.5g a.i/ha; deltamethrin at 7.5, 10.5, 12.5 and 17.5g a.i/ha, cypennethrin at 12.5g a.i/ha; carbofuran 3g at 100g a.i/ha was less than those on untreated plants.