Multiple Insect Research Articles

Untapped Sources of Dual Resistance to Hessian Fly and Greenbug in Synthetic Hexaploid Wheats.

The Hessian fly (Hf) and greenbugs (Gb) are major pests of wheat, causing severe economic losses globally. Deploying resistant wheat is the most effective strategy for managing these destructive insects. However, the resistance is not effective against all Hf or Gb biotypes and can impose selection pressure on insects, resulting in the development of virulent biotypes. These challenges must be met through the discovery of new and novel sources of resistance to these pests. Synthetic Hexaploid Wheat (SHW)-developed cultivars are a rich source of resistance against a diverse array of pathogens and pests. In this study, 80 SHW lines were evaluated for their resistance to Hf and Gb under controlled environmental conditions. Of these, a total of 36 SHW lines showed resistance independently to Hf biotype L and Gb biotype E, while 27 lines showed combined resistance to both Hf and Gb. Further, a subset of 10 SHW lines showed resistance to additional Hf biotypes, Great Plains and vH13. The identification of SHW lines resistant to multiple insects and biotypes offers an invaluable resource to breeders who are looking to stack resistance traits to develop elite cultivars as a strategy to alleviate economic impacts upon global wheat production.

Hail netting excludes key insect pests and protects from fruit damage in a commercial Minnesota apple orchard.

Exclusion netting in some European and North American apple (Malus domestica Borkhausen, Rosaceae, Rosales) orchards has been documented to be an effective method of control for multiple insect pest species. By minimizing reliance on insecticides, these orchards have reduced costs, risks to the environment and non-target species, and reduced the risk of insecticide resistance. This study examined the use of commercially available hail netting (DrapeNet®; Prosser, WA) as a pest exclusion strategy under conditions in Minnesota, USA. In 2021 and 2022, we assessed the efficacy of hail netting as a tool for pest suppression in orchards by monitoring pest species in netted and open plots crossed with and without insecticide applications. Our findings show that both of the major pest species in Minnesota, the codling moth (Cydia pomonella L.; Lepidoptera: Tortricidae) and the apple maggot (Rhagoletis pomonella Walsh; Diptera: Tephritidae), were significantly reduced inside the netting compared to open plots by 94% and 96%, respectively. For a secondary pest, the red-banded leafroller (Argyrotaenia velutinana Walker; Lepidoptera: Tortricidae), moth populations were reduced by 56%. We also found that insecticide application alone did not significantly reduce pest pressure in these species. Additionally, we investigated the subsequent effects of hail netting on fruit quality and yield. The use of hail netting and insecticide application resulted in significantly higher proportions of high-quality fruit at harvest. However, netting did not significantly influence yield. These findings suggest that hail netting can be used to control Midwest apple insect pests with limited insecticide applications while maintaining high fruit quality.

Hail netting: an economically competitive IPM alternative to insecticides for Midwest apple production.

Apple orchards are highly managed agricultural ecosystems where growers typically rely on insecticides to minimize the risk of pest-related fruit losses. Apple growers practicing integrated pest management require cost-effective alternatives to conventional insecticides for control of major pests such as codling moth (Cydia pomonella L.) and apple maggot (Rhagoletis pomonella Walsh). Exclusion netting has been shown to effectively control multiple insect pest species, limit fruit damage and reduce the use of insecticides while also conferring consumer and environmental benefits. In this study, partial budgeting was applied to explore the financial efficacy of using a hail netting (DrapeNet®) system as a sustainable pest management strategy for Midwest U.S. apple (Malus x domestica). The cost of the hail netting was compared to a common Midwest insecticide spray regimen for apples using yield and quality data from a field study at two Minnesota apple orchards in 2021-2022. The PB analysis indicated that the netting system was an economically competitive alternative to conventional insecticide applications. The economic results were robust across a range of apple prices and yields suggesting that Minnesota apple growers can benefit economically from the application of hail netting for sustainable pest management.

Silicon and Epichloë‐endophyte defences in a model temperate grass diminish feeding efficiency and immunity of an insect folivore

Abstract Plants deploy diverse anti‐herbivore defences which reduce feeding and performance of herbivores. Temperate grasses use silicon (Si) accumulation and Epichloë‐endophytes for physical and chemical (i.e. endophytic‐alkaloids) defence against insect herbivores. Recent studies suggest that Epichloë‐endophytes increase Si accumulation in their host grass. It is unknown, however, how this affects Si‐deposition on the leaf surface, their impacts on insect herbivore feeding efficiency and their immunity to potential infection/parasitism. To address this knowledge gap, we grew tall fescue (Festuca arundinacea) hydroponically with and without Si, in the absence or presence of the novel AR584 Epichloë‐strain. We exposed plants to Helicoverpa armigera (Lepidoptera: Noctuidae) in both in situ (intact leaves) and ex situ (excised leaves) feeding trials and determined the effects of Si and endophyte defences on herbivore feeding efficiency, growth rates and immunity against potential infection/parasitism. Endophytic plants supplied with Si showed 110% and 143% increases in leaf silica density and leaf Si concentrations, respectively, when exposed to herbivory, compared to non‐endophytic plants that were herbivore‐free. Despite the endophyte‐mediated increases in Si concentrations, H. armigera was only affected by Si supply; growth rates decreased by 87% and most feeding efficiency indices decreased by at least 30%. Si supply also increased mandibular wear by 16%, which was negatively correlated with H. armigera growth rates. Cellular and humoral immunity of H. armigera were negatively affected by both Si and endophytes. Endophytic‐loline alkaloid concentrations were unaffected by Si supply or herbivory, whereas herbivory increased peramine concentrations by 290%. To our knowledge, this is the first report of Si defences and Epichloë‐endophyte derived alkaloids compromising insect immunity via reduced melanisation response. Using tall fescue and H. armigera, our study suggests that deploying both physical (i.e. Si accumulation) and chemical (i.e. endophytic‐alkaloids) defences acting against multiple insect herbivore traits, including feeding efficiency, growth and immunity, may be a successful defence strategy in temperate grasses. This multi‐faceted defence may be particularly difficult for insect herbivores to overcome. Read the free Plain Language Summary for this article on the Journal blog.

Silvicultural treatments improve pest and disease conditions of white pine (Pinus strobus) residual trees and regeneration

Managing multiple forest insect pests and diseases is challenging. For example, in eastern white pine (Pinus strobus) stands whereas partial shading and high seedling density is encouraged to reduce damage by white pine blister rust (Cronartium ribicola) and white pine weevil (Pissodes strobi), dense conditions in the understory may increase damage by foliar diseases such as brown spot needle blight (Lecanosticta acicola) and Caliciopsis canker (Caliciopsis pinea). We evaluated the effect of silvicultural treatments, shelterwoods (residual basal area < 18 m2 ha−1), low density thinnings (residual basal area ≤ 14 m2 ha−1), patch cuts (1.2 ha openings), and untreated controls on damage by these insect pest and diseases in residual overstory trees and regeneration. Shelterwoods and low density thinnings provided a good balance of some shading and reduced stem density, which resulted in less weevil damage and foliar disease severity. Crown condition and quality of regeneration was better in all treatments compared to unmanaged controls. Shelterwoods, low density thinnings and patch cuts have the added benefit on increasing seral habitat, resulting in greater songbird diversity.

A two-step approach to monitoring changes in susceptibility to sulfuryl fluoride in red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and its implication for the industry

Sulfuryl fluoride (SF) is an inorganic fumigant, currently being used widely to disinfest various postharvest commodities and processed products. Though SF has been used in treating stored commodities for more than two decades, so far, no information is available in relation to monitoring the changes in susceptibility levels to SF in stored product insects. In this study, we characterized dose mortality responses to SF in multiple field insect populations and phosphine-resistant reference strains of red flour beetle, Tribolium castaneum, towards establishing a discriminating dose for detection of resistance. Adult beetles, after two weeks of eclosion, were exposed to a series of SF concentrations (0.05–2.5 mg L−1) over 48 h (2.4–120 g hm−3). Mortality response in each population/strain was evaluated after 7 days and subjected to probit analysis. A two-step approach was adopted, both based on the key toxicity parameters, LC values, response ratio, and confidence intervals. Firstly, LC95 of the most susceptible population, 0.84 mg L−1 over 48 h (40 g hm−3) was identified as the baseline dose and proposed to monitor changes in susceptibility levels to SF in freshly collected field populations of T. castaneum. Then the discriminating dose was derived, 1.7 mg L−1 over 48 h by multiplying LC95 of the most susceptible population by a factor of 2, which could potentially be used to identify genetically resistant individuals to SF. Dose mortality responses of T. castaneum populations/strains from Australia revealed low-level (1.8-fold) region-wide variations in basal tolerance to SF, emphasizing the importance of adopting a two-dose approach to monitor resistance to SF. Overall, our results hold enormous potential for researchers and stakeholders in Australia and across the globe towards its use in the early detection of resistance to SF in T. castaneum and its management.

Variation of Helicoverpa armigera symbionts across developmental stages and geographic locations.

Cotton bollworm (Helicoverpa armigera) poses a global problem, causing substantial economic and ecological losses. Endosymbionts in insects play crucial roles in multiple insect biological processes. However, the interactions between H. armigera and its symbionts have not been well characterized to date. We investigated the symbionts of H. armigera in the whole life cycle from different geographical locations. In the whole life cycle of H. armigera, Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria were the dominant bacteria at the phylum level, while Enterococcus, Enterobacter, Glutamicibacter, and Bacillus were the four dominant bacteria at the genus level. Furthermore, high similarity in symbiotic bacterial community was observed in different stages of H. armigera, which were dominated by Enterococcus and Enterobacter. In fields, the dominant bacteria were Proteobacteria and Bacteroidetes, whereas, in the laboratory, the dominant bacteria were Proteobacteria. At the genus level, the dominant bacteria in cotton bollworm eggs of wild populations were Enterobacter, Morganella, Lactococcus, Asaia, Apibacter, and Enterococcus, and the subdominant bacteria were Bartonella, Pseudomonas, and Orbus. Moreover, the symbionts varied with geographical locations, and the closer the geographical distance, the more similar the microbial composition. Taken together, our study identifies and compares the symbiont variation along with geographical gradients and host development dynamic and reveals the high flexibility of microbiome communities in H. armigera, which probably benefits for the successful survival in a complicated changing environment.

Identification of phytoplasmas associated with grapevine ‘bois noir’ and flavescence dorée in inter-row groundcover vegetation used for green manure in Franciacorta vineyards

‘Bois noir’ (BN) and flavescence dorèe (FD), the two main diseases of the grapevine yellows complex associated with genetically distinct phytoplasmas, have a complex epidemiology including multiple insect vectors and reservoir plants. This study investigated the presence of BN and FD phytoplasmas in nine groundcover plant species commonly utilized for inter-row vineyard green manure in Franciacorta (North Italy). The activities conducted in 2020 included monitoring and sampling groundcover plant species and symptomatic grapevines in September, and phytoplasma identification and typing by amplification and sequence analyses of stamp and map genes. Molecular analyses identified BN phytoplasma (strains carrying the stamp gene sequence variants St5, St19, St30) and FD phytoplasma (strains carrying the map gene sequence variant M54) in 72% and 28% of symptomatic grapevines, respectively. BN phytoplasma strains St5 and St30 were found also in Eruca sativa, Vicia sativa, and Polygonum fagopyrum. FD phytoplasma strain M54 was found also in Vicia faba, Trifolium incarnatum, and Polygonum fagopyrum. These results reinforced the evidence of the increasing range of BN and FD phytoplasma alternative plant hosts and suggested a criterium for the selection of the groundcover plant species utilized for green manure, excluding the ones putatively involved in BN and FD diffusion.

Hybrid breeding for fall armyworm resistance: Combining ability and hybrid prediction

AbstractFall armyworm (FAW, Spodoptera frugiperda) emerged as a major lepidopteran pest destroying maize in sub‐Saharan Africa. A diallel mating design was used to generate 210 experimental hybrids from 21 lines. Experimental hybrids and four checks were evaluated in two locations. Commercial checks suffered higher foliar and ear damage compared to the top 15 hybrids. Mean squares associated with the genotypic variation were higher than genotype‐by‐environment interactions for foliar and ear damage traits. Heritabilities were moderate to high. Significant correlations were observed between grain yield (GY) with ear rot (−0.54) and ear damage (−0.45). Positive and significant GCA effects were observed for GY in seven parental lines, which were developed from multiple insect resistance breeding programmes. CKSBL10153 has the highest GCA value for GY and shows significant GCA effects for foliar and ear damage traits. These lines were identified as the ideal combiners for GY and FAW resistance and are therefore recommended for utilization as testers in the development of FAW‐resistant three‐way cross‐hybrid maize with correlated response for increased GY. GCA and marker‐based prediction correlations of GY were 0.79 and 0.96, respectively. Both GCA effects and marker‐based models were effective in predicting hybrid performance for FAW resistance.

Single-Cell RNA sequencing of leaf sheath cells reveals the mechanism of rice resistance to brown planthopper (Nilaparvata lugens).

The brown planthopper (BPH) (Nilaparvata lugens) sucks rice sap causing leaves to turn yellow and wither, often leading to reduced or zero yields. Rice co-evolved to resist damage by BPH. However, the molecular mechanisms, including the cells and tissues, involved in the resistance are still rarely reported. Single-cell sequencing technology allows us to analyze different cell types involved in BPH resistance. Here, using single-cell sequencing technology, we compared the response offered by the leaf sheaths of the susceptible (TN1) and resistant (YHY15) rice varieties to BPH (48 hours after infestation). We found that the 14,699 and 16,237 cells (identified via transcriptomics) in TN1 and YHY15 could be annotated using cell-specific marker genes into nine cell-type clusters. The two rice varieties showed significant differences in cell types (such as mestome sheath cells, guard cells, mesophyll cells, xylem cells, bulliform cells, and phloem cells) in the rice resistance mechanism to BPH. Further analysis revealed that although mesophyll, xylem, and phloem cells are involved in the BPH resistance response, the molecular mechanism used by each cell type is different. Mesophyll cell may regulate the expression of genes related to vanillin, capsaicin, and ROS production, phloem cell may regulate the cell wall extension related genes, and xylem cell may be involved in BPH resistance response by controlling the expression of chitin and pectin related genes. Thus, rice resistance to BPH is a complicated process involving multiple insect resistance factors. The results presented here will significantly promote the investigation of the molecular mechanisms underlying the resistance of rice to insects and accelerate the breeding of insect-resistant rice varieties.

Performance of Bemisia tabaci MEAM1 on soybean and resistance traits of cultivars

Bemisia tabaci MEAM1, known as whitefly, poses a significant threat to soybean crops worldwide. To develop effective pest management strategies, it is crucial to understand how this insect pest performs on different soybean cultivars and identify resistance traits in these cultivars. This study aimed to assess the biological development of B. tabaci MEAM1 and the performance of five consecutive whitefly generations on various soybean cultivars to determine the stability of resistance across multiple insect generations. Additionally, the study aimed to estimate genetic parameters associated with resistance traits. To conduct the experiment, twenty individuals of B. tabaci were released and confined within cages attached to soybean leaf petioles. The experiment followed a completely randomized design with eleven treatments and five replicates. The emerging insects from the bioassay were confined to plants of their respective cultivars. This process was repeated for five consecutive generations of whiteflies to evaluate the cultivars' ability to exhibit resistance across multiple generations of the pest. The results showed that the cultivars M 8808 and AS 3810 had a negative impact on B. tabaci oviposition. Additionally, the cultivar BRS 9280 influenced the development of the insect. Based on the selection index, cultivars BRS 9280, AS 3810, M 8808, and BRS 8383 exhibited resistance traits. Furthermore, cultivars BRS 9280, AS 3810, and M 8808 demonstrated resistance characteristics consistently over five generations when subjected to whitefly pressure. These cultivars can be considered valuable sources of resistance against B. tabaci MEAM1 for breeding programs aimed at developing resistant soybean cultivars.

Emergence of terpene chemical communication in insects: Evolutionary recruitment of isoprenoid metabolism.

Insects have evolved a chemical communication system using terpenoids, a structurally diverse class of specialized metabolites, previously thought to be exclusively produced by plants and microbes. Gene discovery, bioinformatics, and biochemical characterization of multiple insect terpene synthases (TPSs) revealed that isoprenyl diphosphate synthases (IDS), enzymes from primary isoprenoid metabolism, are their likely evolutionary progenitors. However, the mutations underlying the emergence of the TPS function remain a mystery. To address this gap, we present the first structural and mechanistic model for the evolutionary emergence of TPS function in insects. Through identifying key mechanistic differences between IDS and TPS enzymes, we hypothesize that the loss of isopentenyl diphosphate (IPP) binding motifs strongly correlates with the gain of the TPS function. Based on this premise, we have elaborated the first explicit structural definition of isopentenyl diphosphate-binding motifs (IBMs) and used the IBM definitions to examine previously characterized insect IDSs and TPSs and to predict the functions of as yet uncharacterized insect IDSs. Consistent with our hypothesis, we observed a clear pattern of disruptive substitutions to IBMs in characterized insect TPSs. In contrast, insect IDSs maintain essential consensus residues for binding IPP. Extending our analysis, we constructed the most comprehensive phylogeny of insect IDS sequences (430 full length sequences from eight insect orders) and used IBMs to predict the function of TPSs. Based on our analysis, we infer multiple, independent TPS emergence events across the class of insects, paving the way for future gene discovery efforts. This article is protected by copyright. All rights reserved.

Abundance, occurrence and time series: long-term monitoring of social insects in a tropical rainforest

The magnitude of worldwide insect decline is hotly debated, with multiple examples of stable or increasing insect populations. In addition, time series data for tropical insects are scarce, notably in rainforests where insect diversity is poorly known but reaches a peak. Despite social insects (ants, termites, bees and allies) being key organisms in these habitats, long-term monitoring data for these groups are crucially lacking. For many of these insects, the difficulty of locating nests in rainforests could be one reason. In this context, species occurrence in samples is often used as a surrogate for abundance to evaluate species distribution in space/time, but the loss of information is difficult to assess. In a tropical rainforest in Panama, we employed various sampling methods to examine the time series of seven insect assemblages with differing degrees of sociality: termite workers and soldiers, termite alates, bess beetles, litter ant workers, army ant alates, orchid bees, and nocturnal sweat bees. We used five community variables and six models related to occurrence and abundance, to test for significant trends in assemblages over a 13-year period (2009–2021). While assemblages of bess beetles increased, those of termite workers and soldiers, army ant alates, and orchid bees remained relatively stable. Termite alate, litter ant worker, and nocturnal bee assemblages showed signs of decline, demonstrating the need for monitoring distinct assemblages. Significant trends in generalized additive mixed models (GAMM) were observed in three out of five assemblages that could be tested. Our study indicates that trends in assemblages may be more informatively reported with abundance than with occurrence. We recommend (1) monitoring multiple insect assemblages as ecological indicators responsible for diverse ecosystem services; and (2) reporting species richness, changes in faunal composition, occurrence, and, when possible, using time-explicit analyses (such as GAMM models) for evaluating population trends over time.

Opioid-Induced Doctor Dolittle Phenomenon

AbstractBackgroundThe Doctor Dolittle delusion, of animals conversing with the sufferer, has not heretofore been reported to occur with heroin intoxication.MethodsThis 23-year-old right-handed single male used heroin daily since the age of 19. For 2 years prior to presentation, 1 hour after injecting at least one bag of heroin IV, he developed hallucinations of animals talking to him. The voices would occur simultaneously with moving their mouths. Dogs would bark, cats would meow, and birds would squawk his name. Insects would engage him in friendly conversation. Different pitches of voice were produced from each animal; birds were high-pitched; squirrels, insects, and cats were lower-pitched; dogs were medium-pitched. As his intoxication resolved, the hallucinations also evaporated.ResultsMental Status Examination: Oriented x 1, able to recall five digits forwards and three digits backwards. Able to remember none of four objects in 3 minutes without reinforcement and three with reinforcement. Able to spell the word “world” forwards but not backwards.DiscussionThe hallucination of animals talking, coincident with their mouths moving, articulating the words, associated with intoxication with high doses of heroin, with resolution with elimination of heroin, suggests opioid intoxication is the causative factor. The mechanism of zoopsia in Parkinson’s disease has been attributed to dysfunction of the inferior longitudinal and inferior fronto-occipital fasciculi which relay visual information from the occipital cortex to the temporal and the orbitofrontal cortices. Heroin may have induced cortical inhibition, disinhibiting such pathways and thus facilitating these hallucinations. The simultaneous congruent auditory and visual hallucinations suggests a central origin of these, controlling both the auditory and visual system, such as the left superior and middle temporal gyrus, or possibly the cerebellar vermis. What is unique about the current description is that multiple animal and insect species were involved, and that the pitch of their voice was species specific (high-pitched in birds, and low-pitched in rodents and insects). The pitch may reflect the individual’s personal hedonics towards the type of animal or the individual’s interpretations of mass media’s representation of these animals (i.e., cartoons of Looney Toons high-pitched Tweety Bird or Disney’s low-pitched Jiminy Cricket). While it is possibly due to the opioids themselves, heroin is frequently adulterated with fillers which may contain hallucinogenic properties, any of which may have been the pathogenic factor. Autophobia, or the need for social contact, may be the nidus motivating such communicative anthropomorphism. Query as to the presence of such Doctor Dolittle hallucinations in those with heroin or other intoxicants may be revealing.FundingNo Funding

Development's Inaugural Outstanding Paper Prize.

Development's Inaugural Outstanding Paper Prize.

Segmental expression of two ecdysone pathway genes during embryogenesis of hemimetabolous insects

Signaling networks are redeployed across different developmental times and places to generate phenotypic diversity from a limited genetic toolkit. Hormone signaling networks in particular have well-studied roles in multiple developmental processes. In insects, the ecdysone pathway controls critical events in late embryogenesis and throughout post-embryonic development. While this pathway has not been shown to function in the earliest stage of embryonic development in the model insect Drosophila melanogaster, one component of the network, the nuclear receptor E75A, is necessary for proper segment generation in the milkweed bug Oncopeltus fasciatus. Published expression data from several other species suggests possible conservation of this role across hundreds of millions of years of insect evolution. Previous work also demonstrates a second nuclear receptor in the ecdysone pathway, Ftz-F1, plays a role in segmentation in multiple insect species. Here we report tightly linked expression patterns of ftz-F1 and E75A in two hemimetabolous insect species, the German cockroach Blattella germanica and the two-spotted cricket Gryllus bimaculatus. In both species, the genes are expressed segmentally in adjacent cells, but they are never co-expressed. Using parental RNAi, we show the two genes have distinct roles in early embryogenesis. E75A appears necessary for abdominal segmentation in B. germanica, while ftz-F1 is essential for proper germband formation. Our results suggest that the ecdysone network is critical for early embryogenesis in hemimetabolous insects.

Relatedness modulates reproductive competition among queens in ant societies with multiple queens.

Reproductive sharing in animal groups with multiple breeders, insects and vertebrates alike, contains elements of both conflict and cooperation, and depends on both relatedness between co-breeders, as well as their internal and external conditions. We studied how queens of the ant Formica fusca adjust their reproductive efforts in response to experimental manipulations of the kin competition regime in their nest. Queens respond to the presence of competitors by increasing their egg laying efforts, but only if the competitors are highly fecund and distantly related. Such a mechanism is likely to decrease harmful competition among close relatives. We demonstrate that queens of Formica fusca fine-tune their cooperative breeding behaviors in response to kinship and fecundity of others in a remarkably precise and flexible manner.

Greenbug feeding-induced resistance to sugarcane aphids in sorghum

Plants are attacked by multiple insect pest species and insect herbivory can alter plant defense mechanisms. The plant defense responses to a specific herbivore may also contribute to the herbivore growth/survival on plants. Feeding by one insect species can modulate the plant defenses, which can either facilitate or hamper the colonization of subsequent incoming insects. However, little is known about the effect of sequential herbivory on sorghum plants. In this study, we demonstrate that a specialist aphid, sugarcane aphid (SCA; Melanaphis sacchari) grows faster on sorghum than a generalist aphid species, greenbug (GB; Schizaphis graminum). We also determined how the pre-infestation of SCA on sorghum affected the invasion of GB and vice-versa. Our sequential herbivory experiments revealed that SCA reproduction was lower on GB-primed sorghum plants, however, the reverse was not true. To assess the differences in plant defenses induced by specialist vs. generalist aphids, we monitored the expression of salicylic acid (SA) and jasmonic acid (JA) marker genes, and flavonoid biosynthetic pathway genes after 48 h of aphid infestation. The results indicated that GB infestation induced higher expression of SA and JA-related genes, and flavonoid pathway genes (DFR, FNR, and FNSII) compared to SCA infestation. Overall, our results suggested that GB-infested plants activate the plant defenses via phytohormones and flavonoids at early time points and hampers the colonization of incoming SCA, as well as explain the reproductive success of SCA compared to GB.

Takotsubo cardiomyopathy following envenomation: An updated review.

Takotsubo cardiomyopathy (TTC) can be diagnosed in patients presenting with clinical features of acute coronary syndrome (ACS) by using Mayo clinic criteria. Multiple precipitators have been attributed to causing TTC. Rarely it has been reported to occur following an acute envenomation. This review describes the various patterns, mechanisms, and outcomes of envenomation induced TTC. In this review, we included all studies on "TTC" and "envenomation "published in the various databases before June 2022. To be included in the review articles had to have a distinct diagnosis of TTC and an envenomation. A total of 20 patients with envenomation induced TTC were identified. Most episodes of envenomation induced TTC were reported following a bee sting, scorpion sting, and snake envenomation. Fear and anxiety related to the sting, direct catecholamine toxicity and administration of exogenous beta-adrenergic agents have been commonly postulated to precipitate TTC in these patients. 95% of these patients presented with a clinical picture of ACS. Most of these patients also fulfill at least 3 out of 4 criteria of Mayo clinic criteria for TTC. Echocardiographic evidence of Apical TTC was noted in 72% of patients. 94% of these patients had clinical improvement following optimal management and 35% of these patients were treated with guideline directed medications for heart failure. Envenomation following multiple insect stings and reptile bites can precipitate TTC. Most reported envenomation related TTC has been due to bee stings and scorpion bites. Common mechanisms causing TTC were fear, anxiety, and stress of envenomation. Most of these patients present with clinical presentation of ACS, ST elevation, and elevated troponin. The most common type of TTC in these patients is Apical, which improved following medical management.

Genetic Variation, DIMBOA Accumulation, and Candidate Gene Identification in Maize Multiple Insect-Resistance.

Maize seedlings contain high amounts of 2,4-dihydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA), and the effect of DIMBOA is directly associated with multiple insect-resistance against insect pests such as Asian corn borer and corn leaf aphids. Although numerous genetic loci for multiple insect-resistant traits have been identified, little is known about genetic controls regarding DIMBOA content. In this study, the best linear unbiased prediction (BLUP) values of DIMBOA content in two ecological environments across 310 maize inbred lines were calculated; and their phenotypic data and BLUP values were used for marker-trait association analysis. We identified nine SSRs that were significantly associated with DIMBOA content, which explained 4.30-20.04% of the phenotypic variation. Combined with 47 original genetic loci from previous studies, we detected 19 hot loci and approximately 11 hot loci (in Bin 1.04, Bin 2.00-2.01, Bin 2.03-2.04, Bin 4.00-4.03, Bin 5.03, Bin 5.05-5.07, Bin 8.01-8.03, Bin 8.04-8.05, Bin 8.06, Bin 9.01, and Bin 10.04 regions) supported pleiotropy for their association with two or more insect-resistant traits. Within the 19 hot loci, we identified 49 candidate genes, including 12 controlling DIMBOA biosynthesis, 6 involved in sugar metabolism/homeostasis, 2 regulating peroxidases activity, 21 associated with growth and development [(auxin-upregulated RNAs (SAUR) family member and v-myb avian myeloblastosis viral oncogene homolog (MYB)], and 7 involved in several key enzyme activities (lipoxygenase, cysteine protease, restriction endonuclease, and ubiquitin-conjugating enzyme). The synergy and antagonism interactions among these genes formed the complex defense mechanisms induced by multiple insect pests. Moreover, sufficient genetic variation was reported for DIMBOA performance and SSR markers in the 310 tested maize inbred lines, and 3 highly (DIMBOA content was 402.74-528.88 μg g-1 FW) and 15 moderate (DIMBOA content was 312.92-426.56 μg g-1 FW) insect-resistant genotypes were major enriched in the Reid group. These insect-resistant inbred lines can be used as parents in maize breeding programs to develop new varieties.