Important Pest Research Articles

Transcriptome-Wide Evaluation Characterization of microRNAs and Assessment of Their Functional Roles as Regulators of Diapause in Ostrinia furnacalis Larvae (Lepidoptera: Crambidae).

microRNAs (miRNAs) function as vital regulators of diapause in insects through their ability to post-transcriptionally suppress target gene expression. In this study, the miRNA of Ostrinia furnacalis, an economically important global crop pest species, was characterized. For the included analyses, 9 small RNA libraries were constructed using O. furnacalis larvae in different diapause states (non-diapause, ND; diapause, D; diapause-termination, DT). The results identified 583 total miRNAs, of which 256 had previously been identified, whereas 327 were novel. Furthermore, comparison analysis revealed that 119 and 27 miRNAs were differentially expressed in the D vs. ND and DT vs. D, respectively. Moreover, the expression patterns of their miRNAs were also analyzed. GO and KEGG analysis of the target genes of differentially expressed miRNAs highlighted the importance of these miRNAs as diapause regulators in O. furnacalis, especially through metabolic processes, endocrine processes, 20-hydroxyecdysone, and circadian clock signaling pathways. In summary, this study highlighted the involvement of specific miRNAs in the control of diapause in O. furnacalis. To the best of our knowledge, this is the first study to identify miRNA expression patterns in O. furnacalis, thereby providing reference and novel evidence enhancing our current understanding of how small RNAs influence insect diapause.

Cave Myotis (Myotis velifer) consume diverse prey items and provide important ecosystem services

Abstract Insectivorous bats play an essential role as predators in natural ecosystems and contribute to pest control in agricultural landscapes. However, characterizing diets of specific bat species is difficult using conventional methods that cannot capture detailed dietary information. In this study, we used metabarcoding of the cytochrome oxidase I mitochondrial gene to analyze fecal samples of Myotis velifer and provide insight into the seasonal variation of diet from a colony located in the Chihuahuan Desert region of Texas. After filtering sequence reads, we recovered and analyzed 706 molecular operational taxonomic units (MOTUs) in the diet of M. velifer. We found 484 taxa (species and genus level) belonging to 11 insect orders in 66 fecal samples collected from March to October 2021. The orders containing the most MOTUs were Diptera (n = 353), Lepidoptera (n = 160), and Blattodea (n = 59). In their diet, we identified important insect crop pests, non-native insects, and substantial consumption of mosquitoes. Dietary composition shifted throughout seasons. Bats captured in summer months consumed the highest diversity of arthropod orders, and those captured in the spring consumed more diet items but were less diverse in arthropod orders. Our results uncovered 2 additional orders consumed by M. velifer, Blattodea and Odonata, that have not been previously described in their diet.

Local and landscape constraints of adult population of Anastrepha obliqua (Diptera: Tephritidae) in mango orchards

Introduction: The West Indian fruit fly, Anastrepha obliqua (Macquart), is one of the most economically important pests of mangoes in Mexico and the Neotropics. Objective: To analyze adult population patterns of A. obliqua and their relation to local and landscape factors. Methods: We selected 11 “Manila” mango orchards along the middle part of La Antigua River, which were characterized to determine their biophysical structure and landscape configuration considering their distance to six different land uses/land covers. Anastrepha obliqua population was estimated by collecting adult flies in colorless polyethylene plastic bottle traps baited with a protein for three weeks in June 2022. Results: A total of 1 869 adults of A. obliqua were trapped, of which 75 % were females and 25 % were males. Abundance varied from 68 to 490 adult flies per orchard, while capture frequency from 0.36 to 1.8 flies/trap/day. Abundance increased in highly shaded orchards, and capture frequency decreased in orchards with highly soil compaction. Abundance and the frequency of capture increased in orchards near isolated trees of Spondias spp. and decreased in orchards near sugarcane plantations. Shade management in mango orchards may be used as an effective strategy to promote biotic interactions to naturally regulate A. obliqua populations, meanwhile, soil compaction represents a limiting ecological condition, which might severely impact fruit fly larvae survival. Conclusions: Adult population of A. obliqua depends on several local and landscape factors because they indicate resource availability and ecological conditions. These findings could be considered for control strategies in the integrated management of this pest to promote protection and improve the fruit quality of mango crop.

Development of bait station to complement attract-and-kill agents of Zeugodacus tau (Diptera: Tephritidae).

Zeugodacus tau (Walker) (Diptera: Tephritidae) is an important agricultural pest currently managed primarily through the application of insecticides due to limited control strategies. Bait station devices are target specific and have emerged as a behaviorally based alternative to traditional insecticide sprays for managing Z. tau. In this study, we designed a bait station by integrating female-biased olfactory, visual, and gustatory elements, and a killing agent in a wax-matrix. Our results showed that the wax-matrix integrated with spinetoram showed the highest toxicity to immature and mature Z. tau females. Furthermore, the color and shape of the spinetoram bait station significantly influenced its attractiveness and toxicity to female Z. tau. Green sausage-shaped exteriors were the most effective color and shape examined. Subsequent experiments showed a length-dependent effect on mortality and visiting frequencies of Z. tau females when the bait stations were 9-13 cm long. The addition of the olfactory stimulus of 5% ammonium acetate to the bait station attracted a higher number of mature Z. tau females than the control. The killing efficacy of the weathered bait station was similar to that of the fresh station within an 8-week period (over 794 mm of rainfall). The bait station developed herein would provide new insight into the attract-and-kill strategy for Z. tau and alleviate the pressure of the actual management program for this pest.

Important Insect Pests on Cabbage in Lao PDR

This study was conducted in Xiengkhouang province, Vientiane province, Saravane province, Champasak province, Vientiane Capital, and Plant Protection Center, from January to March 2017. The aims of study were to investigate to major insect pests on cabbage and compared the efficacy of Jeevatu, Jeevatu+botanical pesticide and chemical pesticide to control Diamondback moth in laboratory condition. The study was divided into two treatments: 1) survey important insect pests of cabbage in 3 purposive sampling areas (field)/village, 10 points/rai, and 3 cabbages/point to identify insect pests and survey the life cycle of Diamondback moth of cabbage, and 2) conduct the efficacy experiment of Jeevatu, Jeevatu+botanical pesticide and chemical pesticide to Diamondback moth in laboratory. The experiment was done by Completely Randomized Design (CRD) with 5 treatments and 4 replications. The survey showed that there are 8 species of insect pests on cabbage and the most important species is Diamondback moth (Plutella xylostella) which was found in all provinces that had been survey than followed by striped flea beetle (Phyllotreta striolata), cabbage aphid (Brevicoryne brassicae), cabbage butterfly (Pieris rapae), taro caterpillar (Spodoptera litura), cabbage webworm (Hellula undalis), cabbage looper (Trichoplasia ni) and flea beetle (phyllotreta cruciferae). Life cycle of Diamondback moth was investigated in that laboratory, and it showed that the total of life cycle took about 14-21 days that included 3-5 days for egg stage, 8-12 days for lavae stage, 3-4 days for pupae stage, and 13-31 days of bebeing mature. The efficacy of Jeevatu+Sugar apple leaf extracts, Jeevatu+Neem extracts, and Jeevatu with water for control Diamondback moth indicated that after 5 days sprayed, the mortality percentage was up to 90%, 80% and 57% respectively. For chemical sprayed for 2 days, the mortality percentage was up to 100%. The results of this study showed that the Jeevatu+botanical pesticide can be used as a substitute for substituting chemical in preventing the control Diamondback moth.

Nanoparticle LDH enhances RNAi efficiency of dsRNA in piercing-sucking pests by promoting dsRNA stability and transport in plants

Piercing-sucking pests are the most notorious group of pests for global agriculture. RNAi-mediated crop protection by foliar application is a promising approach in field trials. However, the effect of this approach on piercing-sucking pests is far from satisfactory due to the limited uptake and transport of double strand RNA (dsRNA) in plants. Therefore, there is an urgent need for more feasible and biocompatible dsRNA delivery approaches to better control piercing-sucking pests. Here, we report that foliar application of layered double hydroxide (LDH)-loaded dsRNA can effectively disrupt Panonychus citri at multiple developmental stages. MgAl-LDH-dsRNA targeting Chitinase (Chit) gene significantly promoted the RNAi efficiency and then increased the mortality of P. citri nymphs by enhancing dsRNA stability in gut, promoting the adhesion of dsRNA onto leaf surface, facilitating dsRNA internalization into leaf cells, and delivering dsRNA from the stem to the leaf via the vascular system of pomelo plants. Finally, this delivery pathway based on other metal elements such as iron (MgFe-LDH) was also found to significantly improve the protection against P. citri and the nymphs or larvae of Diaphorina citri and Aphis gossypii, two other important piercing-sucking hemipeteran pests, indicating the universality of nanoparticles LDH in promoting the RNAi efficiency and mortality of piercing-sucking pests. Collectively, this study provides insights into the synergistic mechanism for nano-dsRNA systemic translocation in plants, and proposes a potential eco-friendly control strategy for piercing-sucking pests.Graphical

Chromosome-level genome assembly of Oriental chestnut gall wasp (Dryocosmus kuriphilus)

Dryocosmus kuriphilus, commonly known as the chestnut gall wasp, belongs to the family Cynipidae and is native to China. It is a highly invasive insect species causing serious damage to chestnut trees and has rapidly spread to various continents, including Europe, North America, and Oceania. The D. kuriphilus has become one of the important pests of chestnut plants in the world and is listed as a quarantine object by the European and Mediterranean Plant Protection Organization (EPPO). In this study, we used PacBio long reads, Illumina short reads, and Hi-C sequencing data to construct a chromosome-level assembly of the D. kuriphilus genome. The assembled genome includes 14,729 contigs with a total length of 2.28 Gb and a contig N50 of 0.8 Mb. With Hi-C technology, 2.17 Gb (95.02%) of contigs were anchored and oriented into the 10 pseudochromosomes with the scaffold N50 of 198.8 Mb and the scaffold N90 of 158.8 Mb. In total, 24,086 protein-coding genes were predicted in the assembled D. kuriphilus genome as the reference gene set. A total of 1.82 Gb repeats (occupying 79.7% of the genome), including 1.42 Gb of transposable elements and 0.40 Gb of tandem repeats, were identified in D. kuriphilus genome. In the evaluation of completeness, the BUSCO analysis determined a level of 98.1% completeness for the assembled genome sequences based on the Insecta database (OrthoDB version 10). The high-quality genome assembly of D. kuriphilus will not only provide a valuable reference for the study of its evolutionary history and genetic structure but also facilitate the research of host-pest interactions and invasiveness. Moreover, this genome assembly will promote in the development of effective management strategies to mitigate the economic and ecological impacts of this invasive pest on chestnut trees and ecosystems.

Prevention of resistance to spinosad by a combination of spinosad and Bacillus thuringiensis subsp. israelensis in Culex quinquefasciatus (Diptera: Culicidae).

Spinosad consists of spinosyn A and spinosyn D that are produced by the soil-dwelling actinomycete Saccharopolyspora spinosa. It has been used to control a wide variety of arthropod pests of economic importance. Formulations of spinosad have been used to control larval mosquitoes since approximately 2010. However, the target site- and metabolism-based resistance to this neurotoxin has been reported since 2000 in agricultural pests The current studies aim to further evaluate resistance risk and develop resistance prevention tactics in the southern house mosquito Culex quinquefasciatus. The first comparison group involved selection at lethal concentration, 75% (LC75) of technical spinosad for 30 generations, resulting in baseline resistance ratios (RRs) of 51.1-fold at LC50 and 45.4-fold at LC90 in Cx. quinquefasciatus. However, under the same conditions, selection by a combination of spinosad and Bacillus thuringiensis subsp. israelensis (B.t.i.), negated resistance development to spinosad, RRs ranging 1.00-1.75-fold at LC50 and 0.83-1.76-fold at LC90. At the same time, the selected population remained susceptible to the combination throughout the selection process, RRs fluctuating 0.74-1.38-fold at LC50 and 0.63-1.23-fold at LC90. Combination of spinosad and B.t.i. negates resistance development to spinosad, as opposed to spinosad alone in Cx. quinquefasciatus. Moreover, the species tested does not develop resistance to this combination upon repeated exposures, implying the potential for further developing this combination as a viable product for larval mosquito control. © 2024 Society of Chemical Industry.

UJI KONSENTRASI EKSTRAK DAUN SIRIH HUTAN BERPELARUT ORGANIK TERHADAP WERENG COKLAT

Rice is one of the priority food crop in Indonesia. The main problem faced by rice cultivation is the attack of brown planthopper (Nilaparvata lugens Stall.), this pest is one of the most important pest in rice cultivation, because it can cause a production decrease up to 100% by causing hopperburn symptoms and becoma a desease vector. Botanical pesticide of spiked pepper (Piper aduncum L.) can be the safe alternative to controling brown planthopper. This research aims to obtain effective concentration to controling brown planthopper. The research was conducted at The Plant Pest Laboratory Faculty of Agriculture and Organic Chemistry and Natural Materials Laboratory Faculty of Engineering, Riau University, from November 2020 to Januari 2021, using completely randomized design (CRD) consist of 6 treatments 4 replications. The treatment application consisted of concentrations of 0%, 0.20%, 0.40%, 0.60%, 0.80%, and 100% spiked pepper leaf methanol solvent extract. The result showed that different concentration significantly affected to the death of brown planthopper. Concentrations starting from 0.20% has good performance in killing pest, but the effective concentration to control brown planthoppers is 0.60% concentration of spiked pepper leaf methanol extract, with a total mortality of 82.50%, initial time of death 3.25 hours, and 50% time of death at 10 hours after application.

Study on susceptibility differences of Tetranychus cinnabarinus (Boisduval) males and females to acaricides

The carmine spider mite, Tetranychus cinnabarinus (Boisduval), is an important agricultural arthropod pest. This study investigated acaricide susceptibility differences between sexes to determine the biochemical mechanisms potentially involved in these differences. The susceptibility of females and males to seven acaricides (pyridaben, cyflumetofen, abamectin, chlorpyrifos, propargite, profenofos and fenpropathrin) was compared with laboratory bioassays. Males were more susceptible than females for each acaricide. Differences in the lethal concentration 50 % (LC50) values between the sexes were observed to range from 2.04-fold to 6.05-fold. The surface area was markedly greater for females than males (by 1.87-fold) and the weight was significantly greater for females compared to males (by 4.67-fold). The specific surface area of male was 2.61-fold higher than that of female. There were no differences in the cuticle structure, whereas the thickness of females was 1.63-fold than that of males. The penetration rate of males was statistically significantly higher than that of females, both in pyridaben and cyflumetofen. Synergism experiments and biochemical assays suggested the involvement of the three detoxification enzyme systems in the sexual susceptibility of T. cinnabarinus. The activities of cytochrome P450 monooxygenases (P450s) (p < 0.01), glutathione-S-transferase (GSTs) (p < 0.05) and carboxylesterase (CarEs) (p < 0.05) in females were significantly higher than that in males. The results reveal that the individual size (specific surface area), cuticle thickness, and detoxification enzyme activity were involved in the sexual susceptibility to acaricides of T. cinnabarinus.

Zeta class glutathione S-transferase is involved in phoxim tolerance and is potentially regulated by the transcription factor CncC in Agrotis ipsilon (Lepidoptera: Noctuidae)

The black cutworm, Agrotis ipsilon (Lepidoptera: Noctuidae), is an important agricultural pest. Phoxim is an organophosphate insecticide that has been widely used to control A. ipsilon. The extensive application of phoxim has resulted in a reduction in phoxim susceptibility in A. ipsilon. However, the molecular mechanisms underlying phoxim tolerance in A. ipsilon remain unclear. In this work, we report the involvement of AiGSTz1, a zeta class glutathione S-transferase, in phoxim tolerance in A. ipsilon. Exposure to a sublethal concentration (LC50) of phoxim dramatically upregulated the transcription level of the AiGSTz1 gene in A. ipsilon larvae, and this upregulation might be caused by phoxim-induced oxidative stress. The recombinant AiGSTz1 protein expressed in Escherichia coli was able to metabolize phoxim. Furthermore, AiGSTz1 displayed antioxidant activity to protect against oxidative stress. Knockdown of AiGSTz1 by RNA interference significantly increased the mortality rate of A. ipsilon larvae in response to phoxim. In addition, the transcription factor AiCncC can bind to the cap ‘n’ collar isoform C: muscle aponeurosis fibromatosis (CncC:Maf) binding site in the putative promoter of the AiGSTz1 gene. Silencing of AiCncC resulted in a dramatic downregulation of AiGSTz1. These results indicated that AiGSTz1 is involved in phoxim tolerance and is potentially regulated by AiCncC. These findings provide valuable insights into the defense mechanisms used by A. ipsilon against phoxim.

Predicting the Potential Global Distribution of the Plum Fruit Moth Grapholita funebrana Treitscheke Using Ensemble Models.

The plum fruit moth, Grapholita funebrana Treitschke, is one of the most significant borer pests, often causing huge economic losses in fruit production. However, the potential distribution range of this economically important pest is still poorly understood. For this study, we simulated an ensemble species distribution model to predict the spatiotemporal distribution pattern of G. funebrana at a global scale. The results show that the suitable habitats for this moth, under current environmental conditions, are mainly distributed in Europe; East Asia, including China and Japan; Central Asia; and some parts of America. In future projections, the suitable habitats are predicted to generally expand northward, while the suitable area will remain unchanged overall. However, the area of highly suitable habitat will decrease to only 17.49% of that found under current conditions. None of the nine factors used were revealed to be predominant predictors in terms of contributing to the model, suggesting that the integrated effects of these variables shape G. funebrana's distribution. In this study, the distribution range that has been predicted, especially for the regions with a highly suitable habitat, poses a high risk of G. funebrana outbreaks, highlighting the urgency of pest management. Moreover, in the United States of America (USA) and Japan (for which G. funebrana distributions were not previously recorded), especially in areas highly suitable for this moth, monitoring and quarantine measures should be strengthened to prevent the colonization and further dispersal of this pest, as seen with its close relative G. molesta, which has become a cosmopolitan pest species, migrating from its native region (East Asia) to other continents, including the Americas.

Bioefficacy and molecular characterization of Bacillus thuringiensis strain NBAIR BtGa against greater wax moth, Galleria mellonella L.

Galleria mellonella, the greater wax moth has always been an important pest against honeybees and has remained a nightmare for beekeeping farmers. Management of G. mellonella in live honeybee colonies is very difficult because most current management practices can destroy whole honeybee colonies. In the present study, experiments were conducted to isolate and characterize Bacillus thuringiensis from infected greater wax moth cadavers and to evaluate their biocontrol ability against G. mellonella. The bioefficacy of these isolates has been evaluated against greater wax moth along with the standard strain HD-1. Among all the strains tested, NBAIR BtGa demonstrated higher efficacy compared to other strains, with an LC50 value of 125.17µg/ml, whereas HD-1 exhibited a significantly higher LC50 value of 946.61µg/ml. Considering the economic importance of NBAIR BtGa we performed whole genome sequencing of this strain resulting in the identification of a genome size of 5.96Mb consisting of 6888 protein-coding genes. Gene ontology analysis categorized these genes into three groups based on their roles, i.e., biological functions (2169 genes), cellular components (1900 genes), and molecular functions (2774 genes). Through insecticidal toxicity-related genes (ITRG) profiling of our strain across the genome by Bt toxin scanner and cry processor resulted in the identification of several Cry proteins namely Cry1Ab11, Cry1Ia44, Cry1Aa2, Cry2Af1, Cry1Da2, Cry1Eb1, Cry1Ab5, Cry1Cb2, Cry1Ac2. Besides Cry proteins, other ITRG genes, viz. Vip3Bb2, Zwittermicin A resistance proteins, Chitinase C, Mpp46Ab1, immune inhibitor A, Bmp1, Vpb4Ca1, and Spp1Aa1 were also reported, which show toxicity against lepidopteran pests. The studies were also conducted to test the biosafety of Bt toxins against honeybee larvae and adults, which showed strain NBAIR BtGa was more than 99% safer for honeybee larvae as well as adults. Thus, the data generated ascertains its effectiveness as a biocontrol agent and it can be used further for the development of bio formulation for the management of G. mellonella in honeybee colonies.

Goatweed Flower Extract (Ageratum conyzoides L.) as A Botanical Insecticide for Pest Control Crocidolomia binotalis Z.

Crocidolomia binotalis Z. is an important cabbage plant pest in Indonesia. Nevertheless, pest control strategies depend on synthetic pesticides, negatively impacting ecosystems.Therefore, developing an effective organic pesticide approach to controlling C. binotalis is necessary. This research aimed to test the effectiveness of goatweed flower extract (Ageratum conyzoides L.) in controlling pest C. binotalis. The research consisted of two sets of experiments with two methods: the stomach and contact poison. Each experimental set was arranged in a completely randomized design (CRD) with three replications. The treatments were six levels of extract concentration at 0%, 15%, 30%, 45%, 60%, and 75%. The results showed that the application of A. conyzoides flower extract using the stomach and contact poison methods significantly increased the percentage of larval mortality 24 hours after application (haa) and the percentage of total larval mortality. The flower extract treatment of A. conyzoides significantly reduced the percentage of leaf area eaten, increased larval mortality, inhibited pupation and imago emergency, and shortened the larval stage's duration. The percentage of larval mortality through contact poison was higher than stomach poison.

CRISPR/Cas12a ribonucleoprotein mediated editing of tryptophan 2,3-dioxygenase of Spodoptera frugiperda.

In insect genome editing CRISPR/Cas9 is predominantly employed, while the potential of several classes of Cas enzymes such as Cas12a largely remain untested. As opposed to Cas9 which requires a GC-rich protospacer adjacent motif (PAM), Cas12a requires a T-rich PAM and causes staggered cleavage in the target DNA, opening possibilities for multiplexing. In this regard, the utility of Cas12a has been shown in only a few insect species such as fruit flies and the silkworm, but not in non-model insects such as the fall armyworm, Spodoptera frugiperda, a globally important invasive pest that defies most of the current management methods. In this regard, a more recent genetic biocontrol method known as the precision-guided sterile insect technique (pgSIT) has shown successful implementation in Drosophila melanogaster, with certain thematic adaptations required for application in agricultural pests. However, before the development of a controllable gene drive for a non-model species, it is important to validate the activity of Cas12a in that species. In the current study we have, for the first time, demonstrated the potential of Cas12a by editing an eye color gene, tryptophan 2,3-dioxygenase (TO) of S. frugiperda by microinjecting ribonucleoprotein complex into pre-blastoderm (G0) eggs. Analysis of G0 mutants revealed that all five mutants (two male and three female) exhibited distinct edits consisting of both deletion and insertion events. All five edits were further validated through in silico modeling to understand the changes at the protein level and further corroborate with the range of eye-color phenotypes observed in the present study.

Metarhizium caribense sp. nov., a Novel Species of Entomopathogenic Metarhizium Fungi Associated with Weevils Impairing Coffee, Sugar Cane and Sweet Potato Cultivation.

(1) Background: Insect pathogenic fungi of the genus Metarhizium are under study and in application as highly solicited, more eco-system friendly substitutes for chemical insecticides in many countries and in different agricultural contexts. In Cuba and Florida, Metarhizium strains have previously been isolated from economically important coffee and sugar cane pests. (2) Methods: Unambiguous species delineation within the Metarhizium anisopliae species complex is methodologically challenging. Recently, a species-discriminating PCR approach has been developed based on ribosomal intergenic spacer (rIGS) sequences that covered the prominent four "PARB" species within the complex. This approach is combined here with further genetic markers and is extended to a further species. (3) Results: Metarhizium isolates from Cuba, found to be more naturally associated with the coffee berry borer, Hypothenemus hampei, were morphologically, microscopically and molecular taxonomically characterized. Multilocus sequence analysis based on 5TEF, MzIGS3 and rIGS markers delineated these weevil-associated strains from all previously established Metarhizium species. (4) Conclusions: The isolates under study represent a new fungal taxon proposed to be designated Metarhizium caribense. The rIGS-based species-discriminating diagnostic PCR is a suitable tool for the identification of new Metarhizium species and can be productively combined to approaches using further genetic markers.

Biology of Citrus long-horned beetle, Anoplophora chinensis (Forster, 1771) (Coleoptera: Cerambycidae) on hazelnut

Anoplophora chinensis (Forster, 1771) (Coleoptera: Cerambycidae) is an important quarantine pest causing significant economic losses. It was detected in hazelnut orchards in Trabzon province in 2017 and an eradication program continues. In this study, the population level and biology of the pest were determined by rearing it and conducting periodic surveys in hazelnut orchards in Trabzon province Maçka district between 2020 and 2021. It has been revealed that the adult emergence of A. chinensis takes place in the last weeks of June and adults are found in nature until the end of August. The oviposition period continued from the end of June to the beginning of September and the larval stage of A. chinensis was observed throughout the year. The pupal stage was observed in May and June. With this study, the biology of A. chinensis in Türkiye has been revealed in detail for the first time and obtained data guides the eradication and surveillance studies.

Recurrent Selection as a Basis for the Widespread Dissemination and Cultivation of Onions: Examples From Northeastern Brazil

Goal: This study aimed to review phenotypic recurrent selection (PRS) in the onion development for northeastern Brazil. Theoretical Framework: Domesticated in the Central Asia (35°N and 50°N), onion is one of the main vegetable species widely cultivated around the globe. PRS methods are efficient for genetic gains (GG), maintaining variability in the population. Method: Cultivars of two onion-breeding programs for the Brazil Northeast region were analyzed to evaluate the PRS efficiency. Results and discussion: 1. PRS resulted in the development of cultivars Valeouro Ipa 11 and Franciscana IPA 10, at Belém do São Francisco (08°45'S, 38°57'W), replacing 70% of imported cultivars. 2. PRS for resistance to Thrips tabaci (09°09’S, 40°22’W), a pest of global importance, in the 'BRS Alfa São Francisco' resulted in GG of 6%/cycle, with a bulb yield of 32.1 ton.ha-1, contrasting with 15.9 and 14.0 ton.ha-1 of 'Alfa Tropical' and 'IPA 10', respectively (p&lt;0.01). In direct planting and high population density, BRS Alfa São Francisco produced 60 ton.ha-1 in the second semester. 3. The PRS for external brownish or purplish cataphylls and greater thickness (09°09’S, 40°22’W), in the CNPH 6400, resulted in GG/cycle of 6.83% and 11.54% in the brownish population and 7.84% and 10.92% in the purplish population, evaluated in two locations. Research implications: These examples emphasize the efficiency of PRS for accumulating favorable alleles, allowing the recommendation of onion cultivars in areas different from the domestication region. Originality/Value: The adopted approach have distinguished the massal selection from recurrent selection.

Toxic Effects of Bt-(Cry1Ab+Vip3Aa) Maize (“DBN3601T’’ Event) on the Asian Corn Borer Ostrinia furnacalis (Guenée) in Southwestern China

Asian corn borer (ACB), Ostrinia furnacalis, is an important agricultural pest affecting maize production in southwestern China, but knowledge of the toxic effect of Bt maize on the pest has been insufficient until now. In this study, we determined the susceptibility of ACB to Cry1Ab, Vip3Aa, and their complex proteins and evaluated the efficacy of Chinese domestic Bt-(Cry1Ab+Vip3Aa) maize (“DBN3601T” event) against the pest in Yunnan Province of southwestern China. The susceptible bioassay indicated that the LC50 values of the Cry1Ab and Cry1Ab+Vip3Aa proteins expressed by the Bt maize varieties against ACB larvae were 51.42 and 46.85 ng/g, respectively; however, the ACB larva was insensitive to the Vip3Aa protein. The Cry1Ab+Vip3Aa protein contents in V6–V8 leaves, VT tassels, R1 silks, R2 kernels, R3 stalks and R3 cobs of the Bt-(Cry1Ab+Vip3Aa) maize were 114.20, 30.69, 3.77, 8.92, 11.09 and 10.99 μg/g, respectively. The larval feeding test indicated that the Bt-(Cry1Ab+Vip3Aa) maize was more toxic to the early instar larvae, and the survival time of larvae fed on the leaves was the shortest, while it survived the longest on stalks. The identification of maize resistance levels in the field showed that both larval density and plant damage score of Bt-(Cry1Ab+Vip3Aa) maize were significantly lower than those in conventional maize. It is concluded that the Bt-(Cry1Ab+Vip3Aa) maize can be used for control of the ACB in southwestern China.

Physiological Status of Rice Leaf-Roller Cnaphalocrocis medinalis (Lepidoptera: Crambidae) Adults Trapped by Sex Pheromone and Floral Odor.

The rice leaf-roller Cnaphalocrocis medinalis is an important migratory pest of rice. We conducted a study to determine the physiological status of adults trapped by a sex pheromone and floral odor. In the immigrant group, the number of males trapped by the floral odor was greater than the number caught by sex pheromone trapping. The volume of testes was similar in the above two trapping methods but was smaller than in the sweep net method. The ovary developmental grade, mating rate, and number of matings of females caught in floral odor trap were higher than in those caught in the sweep net. In the local breeding group, the number of males trapped by sex pheromones was greater than the number trapped by the floral odor. The volume of testes was smaller in the floral odor trap compared to the pheromone trap group, with the largest in the sweep net group. The ovarian developmental grade, mating rate, and number of matings of females were significantly higher in the floral odor trap group than in the sweep net group. In the emigrant group, the adult olfactory response to the sex pheromone and floral odor was low. The volume of testes was larger in the sweep net group compared to the moths caught by floral odor trapping. The number of eggs laid by female immigrants trapped by the floral odor and sweep net was similar, while the number in the local breeding group was greater in moths caught with the sweep net in comparison with those caught by the floral odor trap. The difference in egg hatchability between the two trapping methods in both immigrants and local breedings was not significant.