Citrus Red Research Articles

Field Efficacy of Acaricides on Citrus Red Mite and Dissipation Study for Cyflumetofen and Pyridabin in Lemon Using QuEChERS Method and LC-ESI-MS

Field Efficacy of Acaricides on Citrus Red Mite and Dissipation Study for Cyflumetofen and Pyridabin in Lemon Using QuEChERS Method and LC-ESI-MS

A Shift Pattern of Bacterial Communities Across the Life Stages of the Citrus Red Mite, Panonychus citri

As one of the most detrimental citrus pests worldwide, the citrus red mite, Panonychus citri (McGregor), shows extraordinary fecundity, polyphagia, and acaricide resistance, which may be influenced by microbes as other arthropod pests. However, the community structure and physiological function of microbes in P. citri are still largely unknown. Here, the high-throughput sequencing of 16S rDNA amplicons was employed to identify and compare the profile of bacterial communities across the larva, protonymph, deutonymph, and adult stages of P. citri. We observed a dominance of phylums Proteobacteria and Firmicutes, and classes α-, γ-, β-Proteobacteria and Bacilli in the bacterial communities across the host lifespan. Based on the dynamic analysis of the bacterial community structure, a significant shift pattern between the immature (larva, protonymph, and deutonymph) and adult stages was observed. Accordingly, among the major families (and corresponding genera), although the relative abundances of Pseudomonadaceae (Pseudomonas), Moraxellaceae (Acinetobacter), and Sphingobacteriaceae (Sphingobacterium) were consistent in larva to deutonymph stages, they were significantly increased to 30.18 ± 8.76% (30.16 ± 8.75%), 20.78 ± 10.86% (18.80 ± 10.84%), and 11.71 ± 5.49% (11.68 ± 5.48%), respectively, in adult stage, which implied the important function of these bacteria on the adults’ physiology. Actually, the functional prediction of bacterial communities and Spearman correlation analysis further confirm that these bacteria had positively correlations with the pathway of “lipid metabolism” (including eight sublevel pathways) and “metabolism of cofactors and vitamins” (including five sublevel pathways), which all only increased in adult stages. In addition, the bacterial communities were eliminated by using broad-spectrum antibiotics, streptomycin, which significantly suppressed the survival and oviposition of P. citri. Overall, we not only confirmed the physiological effects of bacteria community on the vitality and fecundity of adult hosts, but also revealed the shift pattern of bacterial community structures across the life stages and demonstrated the co-enhancements of specific bacterial groups and bacterial functions in nutritional metabolism in P. citri. This study sheds light on basic information about the mutualism between spider mites and bacteria, which may be useful in shaping the next generation of control strategies for spider mite pests, especially P. citri.

Guide to Citrus Mite Identification

This document provides insights into the Citrus Rust Mite (CRM), detailing its morphology, behavior, and impact on citrus crops. CRM, characterized by its piercing-sucking mouthparts, targets epidermal cells of citrus leaves, fruit, and twigs, causing surface blemishes and potential reductions in fruit size and quality. The text also discusses other mites affecting citrus, such as the Pink Citrus Rust Mite (PCRM), Citrus Red Mite (RM), Texas Citrus Mite (TCM), and Six-Spotted Mite (SSM), outlining their distinctive features and damage patterns. Understanding these mites and their effects is crucial for effective pest management in citrus cultivation.

Food Color and Autism: A Meta-Analysis.

Autism has been increasing dramatically since its description by Leo Kanner in 1943. The Centers for Disease Control and Prevention (CDC) in 2018 has identified 1 in 59 children (1 in 37 boys and 1 in 151 girls) has autism spectrum disorder (ASD). Autistic spectrum disorders and ADHD are complex conditions in which nutritional and environmental factors play major roles. It is important to understand how food can have an impact on their current and future health. Appealing food colors stimulate the consumption of different food products. Since 2011, it is evident that dyes are linked to harmful effects in children. Artificial dyes have neurotoxic chemicals that aggravate mental health problems. Many families with autistic children avoid food dyes in their diet in order to avoid behavioral issues. A study reported that there is a correlation between yellow dye and sleep disturbance. Food colors Blue 1 and 2, Green 3, Red 3, Yellow 5 and 6, Citrus Red 2, and Red 40 can trigger many behaviors in most kids. Artificial food color usually contains petroleum and is manufactured in a chemical process that includes formaldehyde, aniline, hydroxides, and sulfuric acids. Most impurities in the food color are in the form of salts or acids. Sometimes lead, arsenic, and mercury may be present as impurities. The U.S. FDA is yet to study the effects of synthetic dyes on behavior in children. A study conducted at Southampton University in England found a link between food dyes and hyperactive behavior in children. The research does not prove that food coloring actually causes autism spectrum disorder, but there seems to be a link. This chapter attempts to provide a broad review of the available literature on food color and the epidemiology, etiology, prevention, and treatment of autistic spectrum disorder.

Effect of initial infestation on population fluctuation and spatial distribution of Panonychus citri (Acari: Tetranychidae) on Thomson navel orange in Ghaemshahr, Iran

Citrus red mite (CRM), Panonychus citri (McGregor) (Acari: Tetranychidae) is one of the important citrus pests in different parts of the world including northern Iran. Population fluctuation and spatial distribution pattern of this pest was studied in Ghaemshahr, northern Iran during 2016–2017 in different initial infestation treatments (paired-treatment and multiple-treatment experiments) that had been designed for crop loss assessment caused by CRM. Taylor's Power Law and Iwao's Patchiness Regression methods were used to determine the spatial distribution pattern of CRM. The results showed that the highest population density of the pest was during summer of 2016 and 2017 with an average of 127.3 and 91.15 CRM per leaf, respectively, and the population declined in the fall with an average of near zero mites per leaf. The spatial distribution pattern of CRM in both years and both methods was aggregated with an exception in which it was random. It could be concluded that initial infestion with different densities of the pest affected the population fluctuation of the pest during the growing season and somewhat the spatial distribution pattern of CRM.

Formulating a Natural Colorant Containing Wax for a One-step Color-add Application for Fresh Citrus

In Florida, early season citrus fruits usually reach full maturity in terms of internal quality while their peel often does not turn to orange color after degreening due to insufficient buildup of carotenoids. For huanglongbing (HLB)-affected orange trees, the fruit may never turn orange during the entire harvest season, despite any cold weather. Improvement of early season citrus peel color is important to the citrus industry to better meet consumer expectations. Occasionally, packinghouses apply a dye, Citrus Red No. 2 (CR2), to improve the surface color of oranges, temples, and tangelos before applying a fruit wax to impart shine, retain moisture, and slow fruit senescence. In a previous report, we determined that paprika and annatto extracts are comparable to CR2 as natural colorant alternatives. In this research, the goal was to formulate a natural colorant [annatto, paprika, or paprika oleoresin (PO)]-containing carnauba wax coating. The coatings were first evaluated for color, shine, moisture retention, respiration rate, ethylene production, and internal gas content. Control fruit were coated with carnauba wax alone, or dyed with CR2 then coated with carnauba wax. The effects were assessed under different temperature and light exposure conditions to simulate commercial storage and marketing. The results showed that a one-step application of paprika-containing carnauba wax was comparable to the two-step (“CR2 then wax”) applications in improving fruit appearance and modification of internal gas composition.

Citrus Red Mite Insecticide Trial and Effects on Predaceous Mites, 2016*

Citrus Red Mite Insecticide Trial and Effects on Predaceous Mites, 2016*

Evaluation of Natural Colorants and Their Application on Citrus Fruit as Alternatives to Citrus Red No. 2

Warm field temperatures can often result in poor peel color of some citrus varieties, especially early in the harvest season. Under these conditions, Florida oranges, temples, tangelos, and K-Early citrus fruit are allowed to be treated with Citrus Red No.2 dye (CR2) to help produce a more acceptable peel color. Unfortunately, CR2, the commercial colorant used in Florida, has been listed as a group 2B carcinogen by the European Union (EU) and the International Agency for Research on Cancer (IARC). Although not likely dangerous at levels used on citrus, and on a part of the fruit that is not ingested, there is a negative health perception, and thus, a need for natural or food grade alternative colorants to replace CR2 for use on citrus. This research demonstrated that three out of five oil-soluble natural red/orange colorants resulted in peel colors somewhat similar to the industry standard CR2. These three (annatto extract, paprika extract, and paprika oleoresin) were selected for further in vivo studies. The stability of the natural colorants along with CR2 was evaluated by applying them on test papers and then on fresh ‘Hamlin’ oranges. All natural colorants were found to be easily oxidized and faded when applied on test papers. However, coating the colored surfaces with carnauba wax apparently inhibited oxidation and the subsequent discoloration of the surface. When applying the natural colorants to ‘Hamlin’ oranges before waxing, the treatments retained the improved color after storage in the dark at 5 °C, simulating cold storage. However, only annatto extract maintained a stable color when subsequently stored in a simulated market condition, at 23 °C exposed to 300 lx of standard fluorescent white light.

Molecular characterization of vitellogenin and its receptor genes from citrus red mite, Panonychus citri (McGregor).

The production and uptake of yolk protein play an important role in the reproduction of all oviparous organisms. Vitellogenin (Vg) is the precursor of vitellin (Vn), which is the major egg storage protein, and vitellogenin receptor (VgR) is a necessary protein for the uptake of Vg into developing oocytes. In this paper, we characterize the full-length Vg and VgR, PcVg1 and PcVgR, respectively, of the citrus red mite Panonychus citri (McGregor). The PcVg1 cDNA is 5748 nucleotides (nt) with a 5553-nt open reading frame (ORF) coding for 1851 amino acids (aa), and the PcVgR is 6090 nt, containing an intact ORF of 5673 nt coding an expected protein of 1891 aa. The PcVg1 aa sequence shows a typical GLCG domain and several K/RXXR cleavage sites, and PcVgR comprises two ligand-binding domains, two epidermal growth factor (EGF)-like regions containing YWTD motifs, a transmembrane domain, and a cytoplasmic domain. An analysis of the aa sequences and phylogenetics implied that both genes were genetically distinct from those of ticks and insects. The transcriptional profiles determined by real-time quantitative PCR in different developmental stages showed that both genes present the same expressional tendencies in eggs, larvae, nymphs, and adults. This suggested that the biosynthesis and uptake of PcVg occurs coordinately. The strong reproductive capacity of P. citri has been hypothesized as an important factor in its resistance; consequently, understanding the molecular mechanisms regulating Vg and VgR are fundamental for mite control.

Determination of illegal dyes in eggs by liquid chromatography - tandem mass spectrometry

Abstract A multiresidue method for simultaneous determination of 10 dyes unauthorised for the use in laying hens was developed (Sudan I, Sudan II, Sudan III, Sudan IV, Sudan Red G, Sudan Orange G, Sudan Red 7B, Para-Red, Toluidine Red, Citrus Red). The dyes were extracted using liquid-liquid extraction with acetonitrile in the presence of anhydrous sodium sulphate, and cleaned using zirconium coated silica cartridges. After dilution with acetonitrile saturated with hexane:DMSO (8:2), samples were analysed using LC-MS/MS system with acetonitrile (A) and 0.1% formic acid (B) as a mobile phase in a gradient mode and C18 analytical column. The method was validated according to the requirements described in the Commission Decision 2002/657/EC: linearity (r ≥ 0.998), precision: repeatability (1.94%-10.02%), and within-laboratory reproducibility (4.66%-8.89%), recovery (97%-105%), decision limit CCα (5.33-6.50 μg/kg), and detection capability CCβ (6.18-7.50 μg/kg) were calculated. The developed method fulfilled all performance criteria and can be used in the official survey of dyes residues in food of animal origin.

Partial Purification and Properties of a Cysteine Protease from Citrus Red Mite Panonychus citri

Several studies have reported that the citrus red mites Panonychus citri were an important allergen of citrus-cultivating farmers in Jeju Island. The aim of the present study was to purify and assess properties of a cysteine protease from the mites acting as a potentially pathogenic factor to citrus-cultivating farmers. A cysteine protease was purified using column chromatography of Mono Q anion exchanger and Superdex 200 HR gel filtration. It was estimated to be 46 kDa by gel filtration column chromatography and consisted of 2 polypeptides, at least. Cysteine protease inhibitors, such as trans poxy-succinyl-L-leucyl-amido (4-guanidino) butane (E-64) and iodoacetic acid (IAA) totally inhibited the enzyme activities, whereas serine or metalloprotease inhibitors did not affect the activities. In addition, the purified enzyme degraded human IgG, collagen, and fibronectin, but not egg albumin. From these results, the cysteine protease of the mites might be involved in the pathogenesis such as tissue destruction and penetration instead of nutrient digestion.

Identification and Characterization of Seven Glutathione S-Transferase Genes from Citrus Red Mite, Panonychus citri (McGregor)

The citrus red mite, Panonychus citri (McGregor), is a global citrus pest, and has developed severe resistance to several types of acaricides. However, the molecular mechanisms of resistance in this mite remain unknown. In this study, seven full-length cDNAs encoding glutathione S-transferases (GSTs) genes were identified and characterized in P. citri. The effects of pyridaben and fenpropathrin exposure on the expression of these genes were also investigated. Phylogenetic analysis revealed that the seven GSTs genes in P. citri cloned in this study belong to three different cytosolic classes, including four in mu, two in delta and one in zeta. Among these seven GSTs genes, the relative expression level of PcGSTm1 was significantly higher in adult than in the other life stages (egg, larvae and nymph). Compared with the control, the mRNA levels of the seven GST genes did not change significantly following exposure to pyridaben at LC10. However, RT-qPCR results showed that, when exposed to LC10 of fenpropathrin, six GSTs gene (PcGSTm1, PcGSTm3, PcGSTm4, PcGSTd1, PcGSTd2 and PcGSTz1) transcripts increased in a time-dependent manner. This is the first insight into the molecular characteristics of GSTs gene cDNAs in P. citri. The elevated GSTs gene transcripts following exposure to fenpropathrin might be one of the mechanisms involved in detoxification of this acaricide.

Secret ingredients: who knows what's in your food?

British chef and food activist Jamie Oliver ignited a firestorm in January 2011 when he mentioned on the Late Show with David Letterman that castoreum, a substance used to augment some strawberry and vanilla flavorings, comes from what he described as “rendered beaver anal gland.”1 The next year, vegans were outraged to learn that Starbucks used cochineal extract, a color additive derived from insect shells, to dye their strawberry Frappuccino® drinks2 (eventually, the company decided to transition to lycopene, a pigment found in tomatoes3). Although substances like castoreum and cochineal extract may be long on the “yuck factor,”4 research has shown them to be perfectly safe for most people; strident opposition arose not from safety issues but from the ingredients’ origins. But these examples demonstrate that the public often lacks significant knowledge about the ingredients in foods and where they come from. This is not a new development; the public relationship to food additives has a long history of trust lost, regained, and in some cases lost again. The Federal Food, Drug, and Cosmetic (FD&C) Act of 19385 was passed shortly after the deaths of 100 people who took an untested new form of a popular drug, which contained what turned out to be a deadly additive.6 The new law was consumer oriented and intended to ensure that people knew what was in the products they bought, and that those products were safe. The law has been amended over the years in attempts to streamline and bring order to the sprawling task of assessing and categorizing the thousands of substances used in foods, drugs, and cosmetics. One result of this streamlining is that under current U.S. law, companies can add certain types of ingredients to foods without premarket approval from the thin-stretched Food and Drug Administration (FDA). In other words, there are substances in the food supply that are unknown to the FDA. In 2010 the Government Accountability Office (GAO) concluded that a “growing number of substances … may effectively be excluded from federal oversight.”7 Is this a problem? The answer depends on whom you ask.

Microwave‐Assisted Extraction and Determination of Citrus Red 2 Dye in Oranges and Orange Juice by Liquid Chromatography‐Tandem Mass Spectrometry

A fast, simple, low cost, and high-throughput method has been developed for the determination of citrus red 2 dye in orange and orange juice samples. The procedure is based on microwave-assisted extraction followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis. The method was optimized, and the analyte was efficiently extracted from the samples in 30 min using hexane/acetone (v/v, 3 : 1). The method was validated and showed good linearity and selectivity. The limits of quantification (LOQs) were 5 μg/kg (sample size of 2 g) for both orange and orange juice samples. The average recoveries, measured at 3 concentration levels (5, 10, and 20 μg/kg), were in the range 77.5% to 87.6% for the compound tested with relative standard deviations below 7.3%. The proposed method is rapid, accurate, and could be utilized for the routine analysis of citrus red 2 dye in orange and orange juice samples.

Toxicology of food dyes

Food dyes, synthesized originally from coal tar and now petroleum, have long been controversial because of safety concerns. Many dyes have been banned because of their adverse effects on laboratory animals or inadequate testing. This review finds that all of the nine currently US-approved dyes raise health concerns of varying degrees. Red 3 causes cancer in animals, and there is evidence that several other dyes also are carcinogenic. Three dyes (Red 40, Yellow 5, and Yellow 6) have been found to be contaminated with benzidine or other carcinogens. At least four dyes (Blue 1, Red 40, Yellow 5, and Yellow 6) cause hypersensitivity reactions. Numerous microbiological and rodent studies of Yellow 5 were positive for genotoxicity. Toxicity tests on two dyes (Citrus Red 2 and Orange B) also suggest safety concerns, but Citrus Red 2 is used at low levels and only on some Florida oranges and Orange B has not been used for several years. The inadequacy of much of the testing and the evidence for carcinogenicity, genotoxicity, and hypersensitivity, coupled with the fact that dyes do not improve the safety or nutritional quality of foods, indicates that all of the currently used dyes should be removed from the food supply and replaced, if at all, by safer colorings. It is recommended that regulatory authorities require better and independent toxicity testing, exercise greater caution regarding continued approval of these dyes, and in the future approve only well-tested, safe dyes.

Citrus Red Mite Pesticide Efficacy Trials, 1995, 1996

Abstract Acaricides for control of citrus red mite were evaluated in the spring of 1995 and 1996 on ≈20 year old ‘Washington navel’ orange trees at the Lindcove Research and Extension Center, Exeter, CA. The acaricides were compared for efficacy against citrus red mite as well as their impact on populations of a predatory mite, which feeds on citrus red mite in San Joaquin Valley orchards. The acaricides were applied on 19 May in 1995; and on 8 Apr in 1996 using a Bean hand-sprayer at 300 psi and approximately 300 gpa (3^1 gal/tree). Single tree treatments were assigned based on pretreatment sampling of citrus red mite conducted on 9 May 1995 and 7 Apr 1996. Samples consisted of five leaves from the periphery of four quadrants of each tree (20 leaves per tree). The number of all active stages of citrus red mite and predatory mites per leaf were recorded weekly.

Field Selection Experiments with Hexythiazox in the Citrus Red Mite, <i>Panonychus citri</i> (MCGREGOR)

柑橘園におけるミカンハダニのヘキシチアゾクス抵抗性発達の様相を把握し, 抵抗性対策を考えるため, 静岡県榛原郡の日本曹達株式会社榛原農業研究所内の24樹からなる柑橘園において淘汰試験を行なった. 6年間で18回のヘキシチアゾクス連用散布 (25ppm) で, LC50値が8000ppm以上の高いレベルに抵抗性が発達した. 連続散布という特殊な処理体系でありながら抵抗性発達速度は遅かった. 最初の4年間は年2～3回の散布でミカンハダニの密度抑制が可能であったが, 次の2年間では効果が低下し年4回もの散布を必要とした. また, 同一園内でも樹ごとにミカンハダニの発生密度が異なるだけでなく, ヘキシチアゾクスに対する感受性も異なり, ヘキシチアゾクス抵抗性は, 特定の樹に寄生するミカンハダニの集団で局所的に発達したと考えられた.

Present Status of Resistance of the Citrus Red Mite, Panonychus citri (McGregor), to Acaricides in Shizuoka Prefecture

Present Status of Resistance of the Citrus Red Mite, <i>Panonychus citri</i> (McGregor), to Acaricides in Shizuoka Prefecture

Development of Acaricide Resistance in the Citrus Red Mite, Panonychus citri (McGregor), in Shizuoka Prefecture

Development of Acaricide Resistance in the Citrus Red Mite, <i>Panonychus citri</i> (McGregor), in Shizuoka Prefecture

Feeding behavior ofEuseius stipulatus andTyphlodromus phialatus on the citrus red mitePanonychus citri [Acari: Phytoseiidae, Tetranychidae

Observations were made on the feeding behavior of the two main phytoseiid species in Spanish Citrus orchards,Euseius stipulatus (Athias-Henriot) andTyphlodromus phialatus Athias-henriot. The experiences were carried out by rearing the predatory mites on excised orange leaves, and always with an excess of the prey the Citrus Red Mite (=CRM)Panonychus citri (McGregor). In experiments with all stages of CRM, the number of prey killed per hour was 5.12 and 2.00, the percentage of successful attacks, 58% and 21%, and the mean time spent feeding on each prey was 5.1 and 12.2 minutes for starving females ofE. stipulatus andT. phialatus respectively.E. stipulatus feeds on all stages of the prey except eggs, andT. philatus, on all stages, except males. Both species attack much less successfully females ofP. citri rather than immatures. In experiments with adult females and eggs ofP. citri as prey, the mean number of prey killed daily was 4.51 females forE. stipulatus, and 2.01 females and 2.12 eggs forT. philatus. Considering this killing rate and the number of eggs laid by the predators in the same period, it can be concluded thatE. stipulatus consumes only 30% of the content of the preys killed, whereasT. philatus consumes a percentage of prey variable between individuals and ranging from 40% to 100%. These differences in feeding behavior between the two species could partly explain differences in their efficiency as biocontrol agents ofP. citri observed in the field.