Pest Of Corn Research Articles

Comparative Analysis of Mechanical In-Field Corn Residue Shredding Methods: Evaluating Particle Size Distribution and Rating of Structural Integrity of Corn Stalk Segments

The European corn borer is a major pest of corn that overwinters in corn stubble and stalks. Shredding these residues disrupts the larvae’s habitat or directly harms them. A corn header has been engineered with a new type of cutting tool on its horizontal choppers, featuring sharp edges and dulled flails, to shred corn stubble near the soil surface. This study investigated the effect of the dulled flails on the shredding intensity of corn stover. Field trials compared flail knives with standard knives for particle size distribution of corn stover and structural integrity of corn stalk segments. Additionally, a common two-step method, which involved a standard knives-equipped corn header followed by tractor-driven flail mowers, was tested. The flail knives reduced the mean particle size by 3.6 mm compared to the standard knives. Subsequent processing with tractor-driven flail mowers, following the corn header using standard knives, led to a reduction in mean particle size by 11.8 mm. It also further reduced the number of incompletely destroyed stalk segments. However, completely intact internodes were scarce in all methods. Given that flail knives enhance shredding intensity without a second processing step, this concept is concluded to be effective for corn stover shredding.

Soil microbes from conservation agriculture systems reduce growth of Bt-resistant western corn rootworm larvae

Sustainable agricultural management practices aimed at improving soil health can alter the soil microbiome, which can influence plant health and defenses against insects. The western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, is a major belowground pest of corn. Pest management relies heavily on the planting of transgenic crops expressing Bacillus thuringiensis (Bt) toxins. In this study, we ask how corn-WCR interactions via the soil microbiome are affected by a conservation management system (extended corn-soybean-wheat rotation with cover crops under no-till) compared with a conventional management system (corn-soybean rotation under mulch tillage and no cover crops) when combined with transgenic Bt corn. To do this, we applied soil microbes from the conservation and conventional management systems to two corn lines, one producing Bt and one non-Bt. We then reared Bt-resistant and Bt-susceptible WCR on inoculated seedlings to examine plant and insect changes in fitness. We found that Bt was effective against susceptible larvae in both soil treatments. Bt-resistant larvae were ~ 20% smaller when reared in the presence of soil microbes from the conservation management system. Thus, control of Bt-resistant WCR may be improved in a conservation system without sacrificing Bt effectiveness in susceptible insects. Comparing the microbial communities using 16S rRNA sequencing revealed that management practices influenced the microbiomes associated with the soil and the plant rhizosphere, but not WCR. Our findings suggest value for growers in utilizing conservation management practices, such as no-till and cover crops, in agricultural systems through bottom-up changes to plant–insect interactions via the soil microbiome.

Recognizing feeding injury to corn ears in the United States

Abstract Corn is one of the major commodities in the United States, and is grown for fuel, feed, and food around the world. Much of the production is centered in the Midwest, but corn is grown throughout the country and has a national production value of $91.7 billion. Because of the substantial national economic impact of corn production, as well as the profitability of individual farming operations, crop protection from pests is critical. Corn is most vulnerable during ear and kernel formation, and pest infestations during this time can have a substantial impact on grain quality and yield. Detecting pests is one of the most important components of integrated pest management, and regular scouting can allow farmers to make timely management decisions for pests in corn. However, farmers and crop consultants sometimes do not notice ear-feeding pests of corn until the fall, or near harvest, when pests are nearly done feeding or have vacated the ear. When this happens, it can be difficult to diagnose the problem, which can be important for assessing management tactics that were used in the field during the current growing season or making decisions for the following growing season based on pest activity in the field. This article provides profiles of common ear-feeding pests, with written descriptions and photographs of typical injury to corn ears for those pests.

Grower perceptions and adoption of IPM and non-Bt refuge in field corn: a survey in North and South Carolina

Abstract Production of field corn in the southeastern United States is often impacted by a number of insect pests. However, surveys to assess stakeholder perception of the relative importance of insect pests and adopted management decisions for these pests have not been extensively reported in the region. A survey was conducted in North and South Carolina to address deficiencies in our knowledge about how corn producers perceive insect pests, implement management and insect resistance strategies, and understand and implement integrated pest management (IPM). The survey indicated that stink bugs (Hemiptera: Pentatomidae) and corn earworm, Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), were the most commonly managed insect pests in field corn. For transgenic corn expressing insecticidal toxins from Bacillus thuringiensis (Bt) (Berliner), the rate of resistance management (i.e., planting of non-Bt corn refuge) implemented (59%) by growers was higher than previously reported. The majority of grower respondents identified ear development as the most critical corn growth stage for managing stink bugs (52%), with the most commonly reported management strategy being applications of insecticide at the economic threshold. Growers also reported understanding the concepts of IPM and implementing it in field corn. Assessing the adoption of preventative approaches, such as Bt corn and insecticide seed treatments, and strategies to manage insect resistance, in the case of Bt corn in particular, is critical for tailoring research and Extension efforts to protect the durability of these management tactics.

Evaluation of Peregrinus maidis transformer-2 as a target for CRISPR-based control.

The corn planthopper, Peregrinus maidis, is an economically important pest of corn and sorghum. Here we report the initial steps towards developing a CRISPR-based control method, precision guided sterile insect technique (pgSIT), for this hemipteran pest. Specifically, we evaluated the potential of transformer-2 (tra-2) as a target for sterilizing insects. First, we identified tra-2 transcripts within our P. maidis transcriptome database and performed RNA interference (RNAi) to confirm functional conservation. RNAi-mediated knockdown of Pmtra-2 in nymphs transformed females into pseudomales with deformed ovipositors resembling male claspers. While males showed no overt difference in appearance, they were indeed sterile. Importantly, the results were similar to those observed in another planthopper, Nilaparvata lugens. We also used CRISPR/Cas9 genome editing to assess the impact of tra-2 knockout in injectees. CRISPR-mediated knockout of Pmtra-2 had lethal effects on embryos, and hence not many injectees reached adulthood. However, mosaic knockout of Pmtra-2 did impact female and male fertility, which supports the use of tra-2 as a target for pgSIT in this hemipteran species.

Sublethal Effects of Emamectin Benzoate on Development and Reproduction and RNAi of the Vitellogenin Gene in Spodoptera frugiperda.

Spodoptera frugiperda, one of the most destructive corn pests in the world, invaded China in December 2018. In this study, sublethal concentrations (LC10 and LC30) of emamectin benzoate (EB) were used to treat pesticide-free treatment (PFT) and EB treatment (ET) of S. frugiperda. In PFT, compared with the control (CK), the pupal weight, hatching rate, and pupation rate of LC10 and LC30 groups were significantly reduced. The fecundity and the expression of vitellogenin gene (SfVg) were decreased after LC30 treatment, while the LC10 treatment groups showed no significant difference from the control group. In ET, compared to CK, the fecundity was increased by 11.14 and 18.8%. The expression of SfVg was upregulated by 2.6 times after LC30 treatment. Moreover, RNAi-mediated SfVg knockdown resulted in a nearly 70% reduction in oviposition. The result provided a theoretical basis for optimizing the application of EB and Vg-dsRNA in the control of S. frugiperda.

Precision Corn Pest Detection: Two-Step Transfer Learning for Beetles (Coleoptera) with MobileNet-SSD

Using neural networks on low-power mobile systems can aid in controlling pests while preserving beneficial species for crops. However, low-power devices require simplified neural networks, which may lead to reduced performance. This study was focused on developing an optimized deep-learning model for mobile devices for detecting corn pests. We propose a two-step transfer learning approach to enhance the accuracy of two versions of the MobileNet SSD network. Five beetle species (Coleoptera), including four harmful to corn crops (belonging to genera Anoxia, Diabrotica, Opatrum and Zabrus), and one beneficial (Coccinella sp.), were selected for preliminary testing. We employed two datasets. One for the first transfer learning procedure comprises 2605 images with general dataset classes ‘Beetle’ and ‘Ladybug’. It was used to recalibrate the networks’ trainable parameters for these two broader classes. Furthermore, the models were retrained on a second dataset of 2648 images of the five selected species. Performance was compared with a baseline model in terms of average accuracy per class and mean average precision (mAP). MobileNet-SSD-v2-Lite achieved an mAP of 0.8923, ranking second but close to the highest mAP (0.908) obtained by MobileNet-SSD-v1 and outperforming the baseline mAP by 6.06%. It demonstrated the highest accuracy for Opatrum (0.9514) and Diabrotica (0.8066). Anoxia it reached a third-place accuracy (0.9851), close to the top value of 0.9912. Zabrus achieved the second position (0.9053), while Coccinella was reliably distinguished from all other species, with an accuracy of 0.8939 and zero false positives; moreover, no pest species were mistakenly identified as Coccinella. Analyzing the errors in the MobileNet-SSD-v2-Lite model revealed good overall accuracy despite the reduced size of the training set, with one misclassification, 33 non-identifications, 7 double identifications and 1 false positive across the 266 images from the test set, yielding an overall relative error rate of 0.1579. The preliminary findings validated the two-step transfer learning procedure and placed the MobileNet-SSD-v2-Lite in the first place, showing high potential for using neural networks on real-time pest control while protecting beneficial species.

Fall armyworm, Spodoptera frugiperda (J.E. Smith) damage on rice in the Philippines

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a global invasive pest of corn, and is also common on sorghum, rice and millets, and is reported to be a larval host of 353 cultivated and uncultivated plants . FAW, a native to the tropical and subtropical regions of north, Central, and South America, continues to rapidly spread to Africa and Asia since 2016, threatening food security worldwide . In the Philippines, its first damage on corn was reported in June 2019 in Piat, Cagayan , while that on rice was in May 2021 in Gonzaga, Cagayan, and subsequently to other municipalities in Region 2 . Unlike corn, however, little is known about FAW damage and host preference for rice in the Philippines. Rice, a key food security crop for the Philippines and in Asia, is amongst the key host of the FAW elsewhere (e.g., USA) . The injury that the FAW will inflict in the rice plant should be known and assessed to quantify the potential yield losses, and predict when an intervention is necessary to avoid incurring potential yield losses. With this background, we conducted FAW monitoring and damage assessment in the areas reported to have FAW occurrence starting May 2021. During 2021 and 2022 assessment periods, monitoring was conducted during the months of May, June, and July. However, starting January 2023, the monitoring and damage assessments were conducted monthly with the exception for May and June wherein it was done weekly since these months coincided with the seedling stage of the rice in a majority of rice-growing areas in the Philippines and where FAW attack was reported during the previous years. FAW larval population and damage were assessed in rice seedbeds. The number of FAW larvae were counted and visual damage was estimated in a 1 m2 quadrat with three replicates.

The effects of water‐stress, temperature, and plant traits on the outbreak potential of a specialist and generalist spider mite species (Acari: Tetranychidae)

AbstractThe host‐generalist two‐spotted spider mite [Tetranychus urticae (Acari: Tetranychidae); TSM] and host‐specialist Banks grass mite [Oligonychus pratensis (Acari: Tetranychidae); BGM] are common pests of corn (Zea mays L.) in the arid western United States. Climate warming and decreased precipitation may promote conditions favoured by these spider mites. However, rapid evolution of spider mite resistance to commercially available acaricides is driving the need for alternative solutions for managing outbreaks. Planting of drought‐tolerant corn hybrids has been proposed to be a dual‐purpose strategy for mitigating water deficits for irrigation and reducing leaf conditions favourable for BGM outbreaks. However, understanding of the mechanisms responsible for reducing the BGM in the field is lacking and determining whether outbreaks of the TSM can also be averted using drought‐tolerant corn is a pressing concern. We conducted a 2‐year field study testing a drought‐tolerant corn hybrid and an analogous drought‐susceptible hybrid under water‐stress, with artificially infested spider mite populations. Drought‐tolerant corn had larger stem diameter, more massive cobs, and greater leaf water mass compared to the drought‐susceptible corn under water stress. We also found that the BGM populations were reduced on drought‐tolerant plants under water‐stress, as expected, but we found an opposite trend in the TSM. Lastly, water‐stressed leaves were warmer, transpired less, and had higher carbon concentration, which contributed to larger investment in eggs and growth in the BGM. We anticipate that further evaluation of irrigation and crop drought‐tolerance in management of agriculture systems for multiple pest species will be increasingly impactful in arid regions.

Substrate and Moisture Affect the Pupation Depth of the Corn Silk Flies Chaetopsis massyla and Euxesta eluta (Diptera: Ulidiidae).

Corn silk flies, or picture-winged flies (Diptera: Ulidiidae), are important pests of fresh market sweet corn in commercial production areas in southern Florida. Issues with pest management related to insecticide resistance, problems in insecticide application, and alternate crop population sources constitute a significant challenge for the protection of developing corn ears. Developed larvae leave cobs and pupate in the soil; however, relatively little is known about these behaviors. In this study, two soil types collected from fields were compared with sand under six different moisture levels in the laboratory to determine the pupation depths of the larvae. Comparisons were carried out concerning the pupation depth of Chaetopsis massyla and Euxesta eluta, which are major pest species in Florida. Both soil type (muck, loamy sand, and sand) and moisture levels (0, 10, 25, 50, 75, 100% field holding capacity) significantly affected pupation depth, with shallow pupation observed under dry or saturated wet conditions. The addition of structures such as pipe cleaners simulating corn roots resulted in deeper pupation under most conditions.

Host search behaviors of specialist and generalist root feeding herbivores (Diabrotica spp.) on host and non-host plants

Western, northern, Mexican, and southern corn rootworms (WCR, NCR, MCR, and SCR) are serious corn pests. We evaluated host search behavior of these pests on six plant species using a video tracking system. After a 5-min exposure to plant roots, behavioral parameters were automatically recorded and used to quantify the search behavior. The search behavior was not observed for sorghum since no neonates survived after contacting sorghum roots. After exposures to corn roots, all neonates exhibited the localized search behaviors (i.e., shortening total distance traveled, lowering movement speed, increasing turn angle, moving farther from origin) which are used to stay in and search within root systems. When larvae contacted roots of wheat, barley, oats, soybean, or controls, they expanded the search area by extending the travel path, increasing velocity, and reducing turn angles and total distance moved. The intensity of the search expansion is highly associated with the host preferences known for the four rootworm species and subspecies. Neonates of each corn rootworm exhibited distinct search behaviors. In fact, NCR larvae had the highest speed, the greatest travel path, and the lowest turn angle, whereas MCR larvae had the highest turn angle and moved faster than WCR and SCR larvae.

Baseline Susceptibility of the Field Populations of Ostrinia furnacalis in Indonesia to the Proteins Cry1A.105 and Cry2Ab2 of Bacillus thuringiensis.

Genetically modified MON 89034 corn (Zea mays L.) expressing Bacillus thuringiensis (Bt) insecticidal proteins, viz. Cry1A.105 and Cry2Ab2, is a biotechnological option being considered for the management of the major corn pest in Indonesia, the Asian corn borer (Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae)). As a part of a proactive resistance-management program for MON 89034 corn in Indonesia, we assessed the baseline susceptibility of field-collected populations of O. furnacalis to Cry1A.105 and Cry2Ab2 proteins. Dose-response bioassays using the diet-dipping method indicated that the lethal concentration (LC50) values of Cry1A.105 and Cry2Ab2 in 24 different field populations of O. furnacalis ranged from 0.006 to 0.401 µg/mL and from 0.044 to 4.490 µg/mL, respectively, while the LC95 values ranged from 0.069 to 15.233 µg/mL for Cry1A.105 and from 3.320 to 277.584 µg/mL for Cry2Ab2. The relative resistance ratios comparing the most tolerant field populations and an unselected laboratory population were 6.0 for Cry1A.105 and 2.0 for Cry2Ab2 based on their LC50 values. Some field populations were more susceptible to both proteins than the unselected laboratory population. The LC99 and its 95% fiducial limits across the field populations were calculated and proposed as candidate diagnostic concentrations. These data provide a basis for resistance monitoring in Bt Corn and further support building resistance-management strategies in Indonesia.

The role of combination insectary plants and botanical pesticides in increasing arthropod populations of natural enemies and suppressing populations of s. frugiperda in corn

Spodoptera frugiperda is the main pest of corn with a high level of attack intensity. Utilization of natural enemies both predators and parasitoids can be lured using zinnia flowers could be an effective control technique in suppressing armyworm pest populations. Pests hate the smells and taste of botanical insecticides a mixed of maja fruit and giant milkweed leaves which contain secondary metabolites such as volatile, pectin, saponins and tannins. This study aims to determine the effect of zinnia flowers and the application of botanical insecticides in suppressing armyworm populations. This research was carried out in Padakkalawa, Mattirobulu District, Pinrang Regency and Universitas Hasanuddin’s Laboratory of Insect and Plant Disease Relations. The research observed pest intensity, larval population and natural enemies. The results showed that the highest attack intensity was observed in the control treatment with an average of 12.59%/plant. The highest observed larval population was in the control with an average of 2.13 individuals/plant. In observing natural enemy arthropods in all observation techniques, the highest population of natural enemy arthropods was in the combination treatment of zinnia flowers and botanical insecticides with the most species being Lasius niger or ants which was significantly different from the control treatment. The results showed that the combination of insect plants and the application of botanical pesticides had an effect on the population and attack intensity of S. frugiperda larvae and populations of natural enemy arthropods.

Shared genetic basis of resistance to Cry1F protein in three independent Brazilian strains of fall armyworm

Field strains of the fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), a global pest of corn, have evolved practical resistance to transgenic corn-producing the Bt protein Cry1F in Brazil, Argentina, and the United States. Considering the rapid invasion of FAW and the worldwide adoption of Bt crops for its control, it is important to understand the genetic basis of resistance to Cry1F in resistant strains of FAW from different regions of the world. This information is essential for developing new transgenic Bt crops and designing appropriate strategies for resistance management for FAW in Bt crops. Thus, the objective of this work was to determine whether Brazilian strains of FAW from different geographic origins share the same locus of resistance to Cry1F. We conducted interstrain complementation tests for allelism among three resistant strains. The survival of F1 progenies from crosses among FAW-resistant strains in purified Cry1F protein or Cry1F-corn was similar to that observed for the parental strains. Our results suggest that mutations conferring resistance to Cry1F Bt protein in three strains of FAW are present in a single locus. Results from this study provide information for developing effective strategies for Bt resistance management, which is the main limitation for sustainable use of Bt technology against this pest.

Susceptibility to cold suggests low risk of establishment of a tropical parasitoid attacking the corn pest Sesamia nonagrioides

Low temperatures limit the distribution and performance of many crop pests and their natural enemies in non-native areas. Here we evaluated the lower thermal thresholds for survival, development and reproduction of the tropical species Cotesia typhae Fernandez-Triana (Hymenoptera: Braconidae), a gregarious larval parasitoid of Sesamia nonagrioides Lefèbvre (Lepidoptera: Noctuidae), an important corn pest in southern Europe. C. typhae is highly host specific and a very efficient biocontrol agent of S. nonagrioides in greenhouse, with minimal impact on non-target species. Immature and adult stages of the parasitoid were exposed to five constant temperatures ranging from 5 to 27 °C. High mortality was observed in all immature stages below 15 °C and thresholds for egg, larval, and external pupal development were between 10 and 15 °C. Adult locomotor activity decreased dramatically within this temperature range, and males were more susceptible to cold than females. Given these thermal limitations and based on winter temperatures recorded over the past 20 years, we estimated that C. typhae had a low probability to survive in French winters. This finding supports the safe use of C. typhae as an augmentative biological control agent against S. nonagrioides.

Control of the Maize Pest Beetle, Anomala denuda (Coleoptera: Scarabaeidae), Using Insecticidal Plants Ricinus communis and Azadirachta indica in a Laboratory Setting

The aim of this study was to identify a natural alternative to synthetic insecticides for controlling the Anomala denuda beetle, a destructive corn pest. The investigation took place at Félix Houphouët-Boigny University's Natural Environments and Biodiversity Conservation Laboratory at a temperature of 17°C. Aqueous extracts of Azadirachta indica leaves and Ricinus communis seed capsules were tested for their effectiveness against the beetle. The reference pesticides, Cypercal 50EC and Viper 42EC, were used as positive control. The tests included three types of toxicity (inhalation, ingestion, and repulsion) with four repetitions each and a four-day exposure period. The ingestion test was the most effective. At 110 g/l, A. indica and R. communis extracts had corrected mortality rates of 87.41 ± 3.21 and 90.28 ± 1.71%, respectively. In the inhalation test, A. indica and R. communis extracts resulted in 80.92 ± 5.88% and 83.14 ± 7.57% mortality rates, respectively, at the same concentration. At the same concentration, R. communis extract repelled 60% of beetles, which was higher than A. indica's 53.3%. The insecticidal effects of the extracts were similar to those of Cypercal in all tests. These results suggest that R. communis and A. indica extracts could be used to control A. denuda pests without relying on synthetic chemical pesticides.

Burrowing depth mediates the extent of metabolic suppression in a soil‐overwintering insect

Abstract Conserving energy through winter is important for the fitness of temperate insects. While insects can use buffered microhabitats, metabolic suppression or decreases in the thermal sensitivity of metabolic rate to override seasonal‐scale thermal trends, the relative importance of these strategies for limiting energy use by insects overwintering in soil remains underexplored. We used a combined laboratory, field and simulation approach to investigate the overwintering energetics of the western bean cutworm (Striacosta albicosta), a univoltine lepidopteran pest of dry beans and corn that overwinters underground as a dormant prepupa. We hypothesised that (1) the selection of thermally buffered microhabitats (i.e. deeper soil sites) reduces energy use in early autumn and late spring, and that (2) changes in the metabolic rate–temperature relationship reduce the impact of elevated temperatures on overwintering energy use. We provide evidence that during the warmest parts of winter, dormant S. albicosta prepupae that had burrowed deep benefited from a cool, stable microclimate, whereas those near the soil surface appeared to rely on deeper metabolic suppression to maintain their energy stores. Although elevated temperatures in the laboratory depleted their energy reserves, these strategies appear sufficient to limit energy drain under natural conditions in the field. We suggest that small‐scale variation in the depth of soil refuges may mediate the interaction between the risk of energy drain and changes in the metabolic rate–temperature relationship in soil‐overwintering insects. Read the free Plain Language Summary for this article on the Journal blog.

European Corn Borer (Ostrinia nubilalis Hbn.) Bioecology in Eastern Romania.

Between 2020 and 2021, we conducted research in eastern Romania to monitor the bioecology of the European corn borer (Ostrinia nubilalis Hbn.), an important pest of corn. The bioecology research established the pest stage duration (egg, larva, pupa, and moth), the flight curve, and the flight peak. The bioecological study occurred in the experimental corn field and a field cage. According to our findings, the insect has one generation per year. The European corn borer hibernates as a mature larva in corn residues and continues developing in the spring, when the weather warms. It pupates from May to July over 37 days. Analyzing the data recorded during the winters of 2020 and 2021, we observed that the warming trend favored the high survival of hibernating larvae (60.7%). Due to the large number of mature larvae that had favorable conditions during the winter, there is an intense flight, starting in June and ending in September. When the first moth was caught in the light trap, the ∑(tn-10) °C (sum of degree days) was 245.6 °C. In 2020, the flight was recorded for 94 days. In 2021, the European corn borer flight lasted 104 days. The initial egg masses were detected when the total of ∑(tn-10) °C reached 351.5 °C. Moths laid the eggs for 25 days, mostly during peak flight in late June and early July. The first larvae hatched when ∑(tn-10) °C totaled 438.4 °C, and stages III-V were recorded in the harvested crop. Understanding the bioecology of the European corn borer can offer valuable insights into managing population levels and identifying optimal timing for addressing infestations in corn crops.

Enhancing Corn Pest and Disease Recognition through Deep Learning: A Comprehensive Analysis

Pests and diseases significantly impact the quality and yield of maize. As a result, it is crucial to conduct disease diagnosis and identification for timely intervention and treatment of maize pests and diseases, ultimately enhancing the quality and economic efficiency of maize production. In this study, we present an enhanced maize pest identification model based on ResNet50. The objective was to achieve efficient and accurate identification of maize pests and diseases. By utilizing convolution and pooling operations for extracting shallow-edge features and compressing data, we introduced additional effective channels (environment–cognition–action) into the residual network module. This step addressed the issue of network degradation, establishes connections between channels, and facilitated the extraction of crucial deep features. Finally, experimental validation was performed to achieve 96.02% recognition accuracy using the ResNet50 model. This study successfully achieved the recognition of various maize pests and diseases, including maize leaf blight, Helminthosporium maydis, gray leaf spot, rust disease, stem borer, and corn armyworm. These results offer valuable insights for the intelligent control and management of maize pests and diseases.

Studies on the degradation effect of corn straw by Asian corn borer larva (Ostrinia furnacalis) digestive enzymes combined with white rot fungus (Phanerochaetc chrysosporium).

The lignin, cellulose and hemicellulose contained in corn straw need to be degraded before reuse. Therefore, it is urgent to explore a new strategy that can enhance the degradation effect of lignin, cellulose and hemicellulose. Ostrinia furnacalis is one of the corn pests feeding on corn straw, which can degrade and consume corn straw by digestive enzyme secreted in the midgut. Herein, the degradation efficiency of lignin, cellulose and hemicellulose was tested by a stain of white rot fungus combined with digestive enzyme of O. furnacalis extracted from its midgut. It was proved that the selected strain of white rot fungus could degrade lignin, cellulose and hemicellulose effectively. The contents of lignin, cellulose and hemicellulose decreased with the extension of degradation time, with the lowest level reached at 35 d with 9ml digestive enzyme solution of O. furnacalis added. Compared with the control group, digestive enzyme of O. furnacalis could improve the degradation effect of the selected white rot fungi on lignin, cellulose and hemicellulose. The effect of degradation was enhanced with the extension of degradation time and the increase in the amount of digestive enzyme added. The results provide a new strategy and a basis for strengthening the degradation effect of white rot fungi on corn straw.