Sugarcane Aphid Research Articles

Genetic, breeding and environmental parameters for yellow sugarcane aphid (Sipha flava) damage in advanced South African sugarcane breeding populations

Yellow sugarcane aphid (YSA), a native pest of temperate and subtropical regions in North America, has spread to many regions of the world including KwaZulu-Natal and Mpumalanga sugarcane growing regions of South Africa. Cultivar differences to YSA damage have been observed in Mpumalanga where high infestation levels occur. The objectives of this study were to determine genetic, breeding, and environmental parameters for YSA damage and implications on breeding for resistance. Data for YSA damage were collected from 12 genotype populations planted in Mpumalanga. There were significant (p < 0.0001) genotype effects indicating genetic variability. Significant (p < 0.01) environment effects showed that YSA damage in February was significantly (p < 0.05) higher than in December. The significant (p < 0.01) genotype by environment interaction indicated February as the best month to screen for YSA. Higher broad sense heritability (> 0.70) suggests selecting resistant genotypes would be effective. Data collected in February produced higher broad sense heritability (> 0.80) than in December (< 0.70) suggesting February as the preferred month to score for damage. The proportion of resistant genotypes was 16.5% (range 2–34%), indicating the presence of resistant in South African advanced genotype populations. Evaluation of released cultivars showed N36, N49 and N71 are resistant while N57 and N73 are susceptible.

Genome sequence of the sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae).

The sugarcane aphid, Melanaphis sacchari (Zehntner, 1897), is an agricultural pest that causes damage to plants in the Poaceae (the grasses) family, such as sorghum and sugarcane. Here, we used Nanopore long reads and Hi-C interaction map to generate a chromosome-level assembly with a total length of 356.1 Mb, of which 85.5% (304.6 Mb) is contained within the three autosomes and the X chromosome. Repetitive sequences accounted for 16.29% of the chromosomes and a total of 12,530 protein-coding genes were annotated, achieving 95.8% benchmarking universal single-copy orthologs (BUSCO) gene completeness. This offers a substantial improvement compared to previous low-quality genomic resources. Phylogenomic analysis by comparing M. sacchari with twenty-four published aphid genomes representing three aphid tribes reveals that M. sacchari belongs to the tribe Aphidini and maintained a conserved chromosome structure with other Aphidini species. The high-quality genomic resources reported in this study will be useful for understanding the evolution of aphid genomes and studying pest management of M. sacchari.

Management of Sorghum Aphids in Early and Late‐Planted Grain Sorghum With an In‐Furrow Insecticide Application

AbstractThe sorghum aphid (Melanaphis sorghi), also known as the sugarcane aphid, has become a significant pest in the southern United States since its detection in Texas and Louisiana in 2013, now affecting 25 states and impacting sorghum yields. Management strategies, such as resistant cultivars and insecticide applications, are employed, but further research is needed to optimize these methods and evaluate the combined effects of insecticide application and planting dates on aphid control and sorghum yield. The objective of this study was to evaluate the impact of insecticide applications and planting dates on M. sorghi infestations and grain sorghum yield over three growing seasons in Tifton, GA. Earn 1.0 CEU in Integrated Pest Management by taking the quiz for the article at https://web.sciencesocieties.org/Learning‐Center/Courses.

Melanaphis sacchari/sorghi complex: current status, challenges and integrated strategies for managing the invasive sap-feeding insect pest of sorghum.

Melanaphis sacchari (Zehntner;Hemiptera: Aphididae), sugarcane aphid (SCA), is an invasive phloem-feeder found worldwide with a wide host range of economically important plants including sorghum and sugarcane. Given its high reproductive capacity and ability to rapidly spread over long distances, SCA presents challenges for effective control, leading to substantial economic losses. Recent studies have identified two multiloci SCA genotypes specialized in feeding on sugarcane (MLL-D) and sorghum (MLL-F) in the USA, which raises concerns as the USA is the second largest sorghum-producing country. This has encouraged research towards identifying these two biotypes where some research has stated them as two species; MLL-D clade to be M. sacchari and MLL-F clade to be M. sorghi Theobald (Hemiptera: Aphididae), sorghum aphid (SA). This review aims at compiling research progress that has been made on understanding the SCA/SA species complex. Furthermore, this review also highlights a wide range of management strategies against SCA/SA that includes both biological and chemical methods. In addition, the review emphasizes studies examining host plant resistance to understand and evaluate the role of R-genes and phytohormones such as jasmonic acid, salicylic acid and ethylene against SCA. Beside this, plant volatiles and other secondary metabolites such as flavonoids, terpenes and phytanes are also explored as potential control agents. Being an invasive pest, a single management tactic is inadequate to control SCA population and hence, integrated pest management practices incorporating physical, cultural and biological control methods should be implemented with exclusive chemical control as a last resort, which this review examines in detail. © 2024 The Author(s). Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Effects of Conventional and Organic Fertilization on the Chemical Profile of Sorghum bicolor and the Preference of Sugarcane Aphids (Melanaphis sacchari)

Melanaphis sacchari is a cosmopolitan pest that causes losses in sorghum crops, so new management methods are needed. In addition, the type of fertilization used influences plant compositions and pest infestation, and allelochemicals are a promising method for the possible management of M. sacchari. In this work, we measured the preference of M. sacchari through chemical stimuli towards sorghum plants grown under greenhouse conditions without fertilization (F0), conventional fertilization (CF), and organic fertilization (OF). Leaves were collected from sorghum plants fertilized with 200 kg N ha−1 using ammonium sulfate and poultry manure. Extracts were obtained using Soxhlet extraction, and the compounds were identified using a gas chromatograph coupled with mass spectrometry (GC-MS). Sorghum extracts were individually tested through bioassays to determine M. sacchari preference. The abundance and number of compounds in sorghum differed depending on the type of fertilization used. M. sacchari showed a preference for the extract from CF sorghum plants (76.66%) over the extract from OF plants (23.34%). Therefore, the type of fertilization can be used as a tactic to prevent higher infestations of M. sacchari. The biological activity of the compounds identified here with M. sacchari should be determined for future pest management strategies using allelochemicals, given that the sugarcane aphid uses chemical signals to locate its host plant.

Invasive sorghum aphid: A decade of research on deciphering plant resistance mechanisms and novel approaches in breeding for sorghum resistance to aphids

AbstractDuring the last decade, the sorghum aphid (Melanaphis sorghi), previously identified as sugarcane aphid (Melanaphis sacchari), became a serious pest of sorghum, spreading to all sorghum‐producing regions in the United States, Mexico, and South America, where crop losses of 50%–100% have been reported. Developing sorghum cultivars with resistance to this insect is the most sustainable strategy for long‐term pest management. To design cultivars with aphid resistance, comprehensively understanding the mechanisms underlying aphid survival, host plant resistance, and aphid–sorghum interactions is critical. In this review, we summarize the comprehensive efforts to characterize the aphid populations as well as their interaction with sorghum plants via hormonal pathways that trigger various genes including leucine rich repeats, WRKY transcription factors, lipoxygenases, calmodulins, and others. We discuss efforts made during the last decade to identify specific genomic regions and candidate genes that confer aphid resistance, as well as describe recent successes and potential challenges in breeding for aphid resistance. Furthermore, we discuss the use of disruptive technologies like high‐throughput phenotyping, artificial intelligence, or machine learning for developing aphid resistant sorghum cultivars. Integration of these new technologies has the potential to accelerate the development and design of novel traits that confer durable aphid resistance in new sorghum cultivars to defend sorghum against new aphid genotype development.

Physiological response as a tolerance mechanism to yellow sugarcane aphid (YSA) (S. Flava Forbes) herbivory on selected commercial sugarcane varieties (S. Officinarum)

Physiological response as a tolerance mechanism to yellow sugarcane aphid (YSA) (S. Flava Forbes) herbivory on selected commercial sugarcane varieties (S. Officinarum)

Integrated transcriptomic and pathway analyses of sorghum plants revealed the molecular mechanisms of host defense against aphids.

Sugarcane aphid has emerged as a major pest of sorghum recently, and a few sorghum accessions were identified for resistance to this aphid so far. However, the molecular and genetic mechanisms underlying this resistance are still unclear. To understand these mechanisms, transcriptomics was conducted in resistant Tx2783 and susceptible BTx623 sorghum genotypes infested with sugarcane aphids. A principal component analysis revealed differences in the transcriptomic profiles of the two genotypes. The pathway analysis of the differentially expressed genes (DEGs) indicated the upregulation of a set of genes related to signal perception (nucleotide-binding, leucine-rich repeat proteins), signal transduction [mitogen-activated protein kinases signaling, salicylic acid (SA), and jasmonic acid (JA)], and plant defense (transcription factors, flavonoids, and terpenoids). The upregulation of the selected DEGs was verified by real-time quantitative PCR data analysis, performed on the resistant and susceptible genotypes. A phytohormone bioassay experiment showed a decrease in aphid population, plant mortality, and damage in the susceptible genotype when treated with JA and SA. Together, the results indicate that the set of genes, pathways, and defense compounds is involved in host plant resistance to aphids. These findings shed light on the specific role of each DEG, thus advancing our understanding of the genetic and molecular mechanisms of host plant resistance to aphids.

Characterization of sequences, expression profiling, and natural allelic variation analysis of the MYC gene family in sorghum (Sorghum bicolor)

Sorghum aphid (Melanaphis sacchari) and head smut fungi (Sporisorium reilianum) infesting sorghum cause delayed growth and development, and reduce yield and quality. This study use bioinformatics and molecular biological approaches to profile the gene expression pattern during sorghum development and under pest infestation, and analyzed the natural allelic DNA variation of sorghum MYC gene family. The findings provide insights for potential application in breeding the stress resistant and high productivity sorghum varieties. The results indicated that there are 28 MYC genes identified in sorghum genome, distributed on 10 chromosomes. The bHLH_MYC_N and HLH domains are the conserved domains of the MYC gene in sorghum. Gene expression analysis showed that SbbHLH35.7g exhibited high expression levels in leaves, SbAbaIn showed strong expression in early grains, and SbMYC2.1g showed high expression levels in mature pollen. In anti-aphid strains at the 5-leaf stage, SbAbaIn, SbLHW.4g and SbLHW.2g were significantly induced in leaves, while SbbHLH35.7g displayed the highest expression level in panicle tissue, which was significantly induced by the infection of head smut. Promoter cis-element analysis identified methyl jasmonate (MJ), abscisic acid (ABA), salicylic acid (SA) and MYB-binding sites related to drought-stress inducibility. Furthermore, genomic resequencing data analysis revealed natural allelic DNA variations such as single nucleotide polymorphism (SNP) and insertion-deletion (INDEL) for the key SbMYCs. Protein interaction network analysis using STRING indicated that SbAbaIn interacts with TIFYdomain protein, and SbbHLH35.7g interacts with MDR and imporin. SbMYCs exhibited temporal and spatial expression patterns and played vital roles during the sorghum development. Infestation by sugarcane aphids and head smut fungi induced the expression of SbAbaIn and SbbHLH35.7g, respectively. SbAbaIn modulated the jasmonic acid (JA) pathway to regulate the expression of defensive genes, conferring resistance to insects. On the other hand, SbbHLH35.7g participated in detoxification reactions to defend against pathogens.

Entomophthoralean and hypocrealean fungal pathogens of the sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae), on sorghum in Georgia

The sugarcane aphid, Melanaphis sacchari, is a widely distributed insect that attacks grasses in different genera including Miscanthus, Saccharum, and Sorghum. The invasive aphid superclone was first discovered in the U.S. attacking grain sorghum in Texas in 2013. Since then, it has been found in at least 25 states including Georgia. We conducted a survey of naturally occurring fungal pathogens of sugarcane aphids on five farms in Georgia, and identified a hypocrealean fungus, Akanthomyces dipterigenus, and two entomophthoralean fungi, Neoconidiobolus spp. From 2018 to 2020, fungal activity differed across farms but at one farm both major fungal species, A. dipterigenus and N. thromboides, were found each of the 3 years infecting sugarcane aphids, attacking adults, both alatae and apterae, and nymphs.

Disruption of the sorghum circadian clock impacts sorghum-sugarcane aphid interaction dynamics and aphid feeding behavior

Circadian clocks play a pivotal role in orchestrating metabolic rhythms in response to environmental stress. Sorghum bicolor (sorghum), a multipurpose cereal crop, suffers severe growth and yield reduction due to feeding by sugarcane aphids (SCA; Melanaphis sacchari), which are phloem-feeding pests. Previously, it has been shown that sorghum utilizes a multitude of defense mechanisms to curb SCA colonization. However, our understanding of the impact of circadian clock on sorghum-aphid interaction dynamics is limited. To explore this, a time-series transcriptomics was conducted on sorghum plants in disrupted circadian rhythm with and without SCA infestation. Transcriptomic analysis revealed a total of 2,873 differentially expressed genes (DEGs) and weighted gene co-expression network analysis (WGCNA) identified four modules with distinct expression patterns unique to night-time. Further, a total of 946 sorghum circadian genes were identified and among those, 328 circadian genes were unique to SCA-uninfested control groups that belonged to defense responses to insects and wounding. The circadian genes upregulated during the night-time after SCA infestation were related to MYB transcription factors, primary metabolism, and transporters, suggesting that SCA feeding modulates host defenses during the night-time. Aphid feeding modulation of sorghum defense genes during the night-time is in alignment with the electrical monitoring of SCA feeding behavior analysis, which revealed that the SCA spent significantly more time in the salivation phase during the night-time feeding. Our study provides novel insights into the circadian response of sorghum-aphid interaction dynamics and identified sorghum circadian genes in response to SCA infestation.

Influence of Microbes in Mediating Sorghum Resistance to Sugarcane Aphids

Gut microbiomes profoundly influence insect health and mediate interactions between plant hosts and their environments. Insects, including aphids, harbour diverse obligate symbionts that synthesize essential nutrients and facultative symbionts that enhance host fitness in specific ecological contexts. Sorghum (Sorghum bicolor) is a significant cereal crop cultivated worldwide that has been negatively affected by the presence of an invasive piercing-sucking insect pest, the sugarcane aphid (SCA; Melanaphis sacchari). We previously identified SC265 and SC1345 as the resistant and susceptible sorghum lines, respectively, among the founder nested association mapping (NAM) population. Here, using these resistant and susceptible lines, we explored variations in the SCA gut microbiome when they feed on two different sorghum lines with varied resistance levels. Analyses after excluding the obligate endosymbiont Buchnera aphidicola from the dataset showed a significant difference in microbial diversity and composition between resistant and susceptible sorghum lines 7- and 14 days post aphid infestation. Our results indicate that the SCA fed on susceptible and resistant sorghum lines had Pseudomonadaceae and Rhizobiaceae, respectively, as the most abundant bacterial families. Differences in gut microbial community composition were underscored by alpha diversity metrics and beta diversity compositional analyses. These findings contribute to our understanding of the intricate interplay between plant and aphid microbiomes, shedding light on potential avenues to bolster sorghum resistance to SCA.

Tithonia diversifolia: beneficial companion plant to control Yellow Aphids on sugarcane fields in Tanzania

To find sustainable ways to protect its sugarcane areas from the key pest Sipha flava (Hemiptera: Aphididae) in north Tanzania, the local company TPC Limited funded a 6 months project in coordination with the French Agricultural Research Centre for International Development (CIRAD) to assess different agroecological practices, such as the use of companion plants around sugarcane fields. In this study, the influence of the flowering species Tithonia diversifolia located at the field edges as a potential banker plant for conservation biological control of the yellow sugarcane aphid was evaluated. Predatory species were identified by direct capture and/or regular observations and the intensity of aphid damage was evaluated through number of colonies. Twenty-four aphid predator species were identified being hosted by T. diversifolia, and the vicinity of this plant reduced by 86% the number of S. flava colonies in the sugarcane edges. These species belonged mostly to family Coccinellidae (ladybugs), Syrphidae (hoverflies), Chrysopidae (green lacewings), Dolichopodidae (long legged flies). This is the first paper evaluating T. diversifolia’s potential as a banker plant in sugarcane crops for pest control.

The Characterization of Melanaphis sacchari Microbiota and Antibiotic Treatment Effect on Insects.

Insects are under constant selective pressure, which has resulted in adaptations to novel niches such as crops. This is the case of the pest Melanaphis sacchari, the sugarcane aphid, native to Africa and currently spreading worldwide. The aphid undergoes successful parthenogenesis, causing important damage to a variety of crops and leading to important economic losses for farmers. A natural M. sacchari population grown in sorghum was studied to identify its microbiome through the sequencing of its 16S rDNA metagenome. A high proportion of Proteobacteria, followed by Firmicutes, Bacteroidetes, and Actinobacteria, was observed. We also detected Wolbachia, which correlates with the asexual reproduction of its host. M. sacchari was challenged in a bioassay with the antibiotics oxytetracycline and streptomycin, resulting in a dose-dependent decay of its survival rate. The possibility of controlling this pest by altering its microbiota is proposed.

Registration of three sweet sorghum lines with high tolerance to sorghum aphid (Melanaphis sorghi)

AbstractSweet sorghum [Sorghum bicolor (L.) Moench] stalks contain sugary juice, which is used to produce syrup and has potential for biofuel production. Since 2013, the sorghum aphid (Melanaphis sorghi, previously known as sugarcane aphid, M. sacchari) has become a major pest of sorghum in North America. GTS1903 (Reg. no GP‐945, PI 702423), GTS1904 (Reg. no. GP‐946, PI 702424), and GTS1905 (Reg. no. GP‐947, PI 702425) represent the first publicly released sorghum aphid‐tolerant sweet sorghum germplasm. All three derive from the initial cross A1N109 × No. 5 Gambela. In four environments GTS1903, GTS1904, and GTS1905 sustained less aphid damage than the check cultivar ‘Top 76‐6’, and in one environment they harbored significantly fewer aphids than Top 76‐6. Under sorghum aphid infestation the juice Brix, an estimate of sugar content, averaged 17.0, 15.9, and 17.0 °Bx for GTS1903, GTS1904, and GTS1905, respectively, all greater than Top 76‐6 (12.7 °Bx). The juice of these three lines also contains greater trans‐aconitic acid concentration (26.8–37.1 mM) than Top 76‐6 (5.5 mM), which may contribute to sorghum aphid tolerance. GTS1903, GTS1904, and GTS1905 flower approximately 74, 89, and 76 days after planting, respectively. GTS1905 is the tallest, averaging 279 cm. All three lines have shown resistance to leaf anthracnose (caused by Colletotrichum sublineola). Genetic markers confirmed that all three lines contain the region of SBI‐06 from PI 257599 that is associated with sorghum aphid resistance.

Dipha aphidivora as Bio-agent to Sugarcane Aphids in Gopalganj District under Field Conditions

The Aphids cause significant damage with relent losses in crops especially in sugarcane farming worldwide, and, presently it is needful to appreciate eco-friendly compatible management strategies for sustainable and low-invested feasible master plan for insect-pest management which cannot be preceded without natural control through parasitoids. This review paper has been drive to emphasize the connection of various aphidophagous natural opponent (predators, parasitoids and pathogens) for their better implementation with maximal expression in natural and harmless pest management.

Temporal transcriptomic profiling elucidates sorghum defense mechanisms against sugarcane aphids

BackgroundThe sugarcane aphid (SCA; Melanaphis sacchari) has emerged as a key pest on sorghum in the United States that feeds from the phloem tissue, drains nutrients, and inflicts physical damage to plants. Previously, it has been shown that SCA reproduction was low and high on sorghum SC265 and SC1345 plants, respectively, compared to RTx430, an elite sorghum male parental line (reference line). In this study, we focused on identifying the defense-related genes that confer resistance to SCA at early and late time points in sorghum plants with varied levels of SCA resistance.ResultsWe used RNA-sequencing approach to identify the global transcriptomic responses to aphid infestation on RTx430, SC265, and SC1345 plants at early time points 6, 24, and 48 h post infestation (hpi) and after extended period of SCA feeding for 7 days. Aphid feeding on the SCA-resistant line upregulated the expression of 3827 and 2076 genes at early and late time points, respectively, which was relatively higher compared to RTx430 and SC1345 plants. Co-expression network analysis revealed that aphid infestation modulates sorghum defenses by regulating genes corresponding to phenylpropanoid metabolic pathways, secondary metabolic process, oxidoreductase activity, phytohormones, sugar metabolism and cell wall-related genes. There were 187 genes that were highly expressed during the early time of aphid infestation in the SCA-resistant line, including genes encoding leucine-rich repeat (LRR) proteins, ethylene response factors, cell wall-related, pathogenesis-related proteins, and disease resistance-responsive dirigent-like proteins. At 7 days post infestation (dpi), 173 genes had elevated expression levels in the SCA-resistant line and were involved in sucrose metabolism, callose formation, phospholipid metabolism, and proteinase inhibitors.ConclusionsIn summary, our results indicate that the SCA-resistant line is better adapted to activate early defense signaling mechanisms in response to SCA infestation because of the rapid activation of the defense mechanisms by regulating genes involved in monolignol biosynthesis pathway, oxidoreductase activity, biosynthesis of phytohormones, and cell wall composition. This study offers further insights to better understand sorghum defenses against aphid herbivory.

TOXICITY OF Argemone mexicana (L.) EXTRACTS AND IMIDACLOPRID ON Chrysoperla carnea (Stephens)

In sorghum (Sorghum bicolor L. Moench) cultivation, the main pest is the sugarcane aphid (Melanaphis sacchari Zehntner (Hemiptera: Aphididae)). The insecticide imidacloprid is frequently used to control this insect, and in some cases, it is complemented with the release of lacewings of the species Chrysoperla carnea Stephens (Neuroptera: Chrysopidae). The insecticide has been shown to be harmful to non-target insects, such as the natural enemies of this aphid, so it is necessary to find other less harmful products. The objective of this study was to evaluate the toxicity of aqueous and oily extracts of chicalote (Argemone mexicana L.) on C. carnea and to contrast it with that of imidacloprid, with the hypothesis that extracts of A. mexicana applied to the developmental stages of C. carnea generate less mortality on the predator than imidacloprid. The aqueous and oily extracts had a concentration of 30 g L-1. For imidacloprid, the recommended dose for sugarcane aphid control (0.35 g L-1) was used. Mortality and the treatments effect were evaluated by exposure methods: T1) topical on larvae, T2) egg immersion, T3) treated Sitotroga cerealella eggs, and T4) liquid ingestion in adults. Mortality, hatching and emergence variables were analyzed with a one-way ANOVA, followed by Tukey’s comparison of means (p ≤ 0.05). Treatments were classified according to the toxicity levels proposed by the International Organization for Biological Control. The aqueous and oily extracts were in toxicity class 1 for C. carnea, except in eggs treated with the oily extract (class 4). Imidacloprid was classified in class 4 when applied topically and by ingestion in adults and in class 2 in ingestion of treated S. cerealella eggs. In general, extracts of A. mexicana could be used as selective insecticides, while imidacloprid can be considered incompatible with releases of this predator.

Detecting common coccinellids found in sorghum using deep learning models

Increased global production of sorghum has the potential to meet many of the demands of a growing human population. Developing automation technologies for field scouting is crucial for long-term and low-cost production. Since 2013, sugarcane aphid (SCA) Melanaphis sacchari (Zehntner) has become an important economic pest causing significant yield loss across the sorghum production region in the United States. Adequate management of SCA depends on costly field scouting to determine pest presence and economic threshold levels to spray insecticides. However, with the impact of insecticides on natural enemies, there is an urgent need to develop automated-detection technologies for their conservation. Natural enemies play a crucial role in the management of SCA populations. These insects, primary coccinellids, prey on SCA and help to reduce unnecessary insecticide applications. Although these insects help regulate SCA populations, the detection and classification of these insects is time-consuming and inefficient in lower value crops like sorghum during field scouting. Advanced deep learning software provides a means to perform laborious automatic agricultural tasks, including detection and classification of insects. However, deep learning models for coccinellids in sorghum have not been developed. Therefore, our objective was to develop and train machine learning models to detect coccinellids commonly found in sorghum and classify them according to their genera, species, and subfamily level. We trained a two-stage object detection model, specifically, Faster Region-based Convolutional Neural Network (Faster R-CNN) with the Feature Pyramid Network (FPN) and also one-stage detection models in the YOLO (You Only Look Once) family (YOLOv5 and YOLOv7) to detect and classify seven coccinellids commonly found in sorghum (i.e., Coccinella septempunctata, Coleomegilla maculata, Cycloneda sanguinea, Harmonia axyridis, Hippodamia convergens, Olla v-nigrum, Scymninae). We used images extracted from the iNaturalist project to perform training and evaluation of the Faster R-CNN-FPN and YOLOv5 and YOLOv7 models. iNaturalist is an imagery web server used to publish citizen’s observations of images pertaining to living organisms. Experimental evaluation using standard object detection metrics, such as average precision (AP), AP@0.50, etc., has shown that the YOLOv7 model performs the best on the coccinellid images with an AP@0.50 as high as 97.3, and AP as high as 74.6. Our research contributes automated deep learning software to the area of integrated pest management, making it easier to detect natural enemies in sorghum.

Response of sorghum commercial hybrids to sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae) and threshold-based chemical management in Guanajuato, Mexico

The sugarcane aphid, Melanaphis sacchari (Hemiptera: Aphididae) (SCA) affects grain sorghum, Sorghum bicolor (Poaceae) production. The response of sorghum hybrids to SCA was evaluated during 2017 in Guanajuato, Mexico. Experiments were established under strip-plot designs with two factors (hybrids, threshold-based chemical management -TBCM- treatments) and under irrigated or dryland conditions. Experiments were established on two sowing dates at Celaya and Valle de Santiago (irrigated) using the SCA-tolerant hybrids APACHE, BRS-70, MEZQUITE, SCAP-618, and SCA-susceptible UPM-219. Dryland experiments were established at Celaya, Valle de Santiago, and Pénjamo using MEZQUITE, and SCAP-618 (tolerant), and lines UPM-219, SHORTER, and MAJESTIC-355 (susceptible). The TBCM strategies were a) with TBCM (seed treatment with thiamethoxam; flupyradifurone or sulfoxaflor applied to foliage), and b) without TBCM (control). Significant differences (p &lt; 0.05) between treatments under irrigated and dryland conditions for the number of aphids per leaf and grain yield were found. APACHE, BRS-70, and MEZQUITE had the highest grain yields under both TBCM and no-TBCM. UPM-219 was competitive under TBCM conditions, but without TBCM showed total yield losses. The yield–aphid cumulative density linear regressions were negatively significant (p ≤ 0.05) to sorghum cultivated without TBCM. Irrigation increased 64 % grain yields compared with dryland experiments. TBCM increased grain yield (50 % in irrigated and 100 % in dryland conditions). TBCM increased grain yields and reduced cumulative SCA populations under irrigated or rainfed conditions, mainly for susceptible sorghum. Resistant germplasm and TBCM could control SCA in sorghum cultivated in Guanajuato, mainly at late sowings frequently carried out under dryland conditions.