scholarly journals First Report on the Mechanisms of Insecticide Resistance in Field Populations of the Small Hive Beetle in Florida

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 559
Author(s):  
Lambert H. B. Kanga ◽  
Walker Marechal ◽  
Anthony Ananga

The small hive beetle (Aethina tumida Murray) is a serious threat to beekeeping and crops that rely on honeybees for pollination. The small hive beetle not only causes significant damage to honeybees by feeding on pollen and honey, attacking bee brood and causing stored honey to ferment, but also might serve as a vector of diseases. In addition, the small hive beetle has developed resistance to the pyrethroid and organophosphate insecticides registered for control of honeybee pests in the United States. The development of resistance in small hive beetle populations is a great concern to the beekeeping industry; thus, there is an urgent need for strategies to manage that resistance. Therefore, we used synergist probes to determine the mechanisms of resistance in a small hive beetle population to these insecticides. Our studies on the toxicity of insecticides alone or with the synergists piperonyl butoxide (PBO) and S,S,S,-tributyl phosphorotrithionate (DEF) suggested that mixed-function oxidases and esterases were the major resistance factors to these insecticides in a studied population of the small hive beetle. In contrast, there was no synergism with diethyl maleate (DEM), triphenyl phosphate (TPP) and formamidine. Therefore, glutathione-S-transferase, carboxylesterase and target site were not involved in insecticide resistance in the small hive beetle. Rotation of classes of insecticides (with different modes of action) and metabolic synergists were suggested for the development of successful resistance management programs. To the best of our knowledge, this is the first study of the mechanisms of resistance in small hive beetle populations in Florida and suggests an urgent need for alternative control strategies for these serious pests of honeybee colonies.

2015 ◽  
Vol 105 (4) ◽  
pp. 424-432 ◽  
Author(s):  
Dolores Fernández-Ortuño ◽  
Anja Grabke ◽  
Xingpeng Li ◽  
Guido Schnabel

Gray mold, caused by the fungal pathogen Botrytis cinerea, is one of the most destructive diseases of small fruit crops and control is largely dependent on the application of fungicides. As part of a region-wide resistance-monitoring program that investigated 1,890 B. cinerea isolates from 189 fields in 10 states of the United States, we identified seven isolates (0.4%) from five locations in four different states with unprecedented resistance to all seven Fungicide Resistance Action Committee (FRAC) codes with single-site modes of action including FRAC 1, 2, 7, 9, 11, 12, and 17 registered in the United States for gray mold control. Resistance to thiophanate-methyl, iprodione, boscalid, pyraclostrobin, and fenhexamid was based on target gene mutations that conferred E198A and F200Y in β-tubulin, I365N/S in Bos1, H272R/Y in SdhB, G143A in Cytb, and T63I and F412S in Erg27. Isolates were grouped into MDR1 and MDR1h phenotypes based on sensitivity to fludioxonil and variations in transcription factor mrr1. MDR1h isolates had a previously described 3-bp deletion at position 497 in mrr1. Expression of ABC transporter atrB was increased in MDR1 isolates but highest in MDR1h isolates. None of the isolates with seven single resistances (SR) had identical nucleotide variations in target genes, indicating that they emerged independently. Multifungicide resistance phenotypes did not exhibit significant fitness penalties for the parameters used in this study, but MDR1h isolates produced more sclerotia at low temperatures and exhibited increased sensitivity to salt stress. In this study we show that current resistance management strategies have not been able to prevent the geographically independent development of resistance to all seven site-specific fungicides currently registered for gray mold control in the United States and document the presence of MDR1h in North America.


1998 ◽  
Vol 353 (1376) ◽  
pp. 1757-1767 ◽  
Author(s):  
I. Denholm ◽  
M. Cahill ◽  
T. J. Dennehy ◽  
A. R. Horowitz

For many key agricultural pests, successful management of insecticide resistance depends not only on modifying the way that insecticides are deployed, but also on reducing the total number of treatments applied. Both approaches benefit from a knowledge of the biological characteristics of pests that promote or may retard the development of resistance. For the whitefly Bemisia tabaci (Gennadius), these factors include a haplodiploid breeding system that encourages the rapid selection and fixation of resistance genes, its breeding cycle on a succession of treated or untreated hosts, and its occurrence on and dispersal from high–value crops in greenhouses and glasshouses. These factors, in conjunction with often intensive insecticide use, have led to severe and widespread resistance that now affects several novel as well as conventional control agents. Resistance–management strategies implemented on cotton in Israel, and subsequently in south–western USA, have nonetheless so far succeeded in arresting the resistance treadmill in B. tabaci through a combination of increased chemical diversity, voluntary or mandatory restrictions on the use of key insecticides, and careful integration of chemical control with other pest–management options. In both countries, the most significant achievement has been a dramatic reduction in the number of insecticide treatments applied against whiteflies on cotton, increasing the prospect of sustained use of existing and future insecticides.


2016 ◽  
Vol 154 (4) ◽  
pp. 742-753 ◽  
Author(s):  
B.-Z. ZHANG ◽  
F.-C. KONG ◽  
R.-K. CUI ◽  
X.-N. ZENG

SUMMARYThe B-biotype of Bemisia tabaci (Homoptera: Aleyrodidae) has become extremely resistant to commonly used insecticides in China. To further explore the mechanisms of resistance to diafenthiuron, the diafenthiuron induction profiles of carboxylesterase (COE1), glutathione S-transferase (GST) and seven cytochrome P450 genes in both resistant (R-DfWf) and susceptible (S-Lab) strains were characterized. The detoxification genes GST, CYP6CX4, CYP6DW3, CYP6DZ6 and CYP9F, which are known to be constitutively over-expressed in the R-DfWf strain, were significantly upregulated in R-DfWf and S-Lab strains exposed to diafenthiuron at LC50 compared with their levels in strains treated with distilled water (controls); however, CYP6CX1, another detoxification gene, was not upregulated. The upregulation was more pronounced in the R-DfWf strain than in the S-Lab strain exposed to different concentrations of diafenthiuron (LC10 or LC50). Interestingly, COE1, CYP6CM1 and CYP6A, which are not constitutively over-expressed in the R-DfWf strain, were all significantly upregulated after exposure to diafenthiuron. Similarly, significant differences in the expression of these detoxification genes, with the exception of CYP6CM1 in the S-Lab strain, were also observed after exposure to diafenthiuron. However, the induction of CYP6A and COE1 was more pronounced in the S-Lab strain than in the R-DfWf strain after treatment with diafenthiuron at both concentrations, indicating that diafenthiuron induction of CYP6CM1 is specific to the R-DfWf strain, while diafenthiuron induction of the other genes is common to both the R-DfWf and S-Lab strains. These results demonstrate that multiple detoxification genes are co-upregulated in the R-DfWf strain through both constitutive over-expression and induction mechanisms. This knowledge will be useful for rational selection of insecticides for use in resistance management and control of this species.


2020 ◽  
Vol 113 (3) ◽  
pp. 1411-1418
Author(s):  
Lino Bittencourt Monteiro ◽  
Luis Gustavo Witt ◽  
Izonete Cristina Guiloski ◽  
Regis Silvori Silva dos Santos ◽  
Helena C Silva de Assis

Abstract The oriental fruit moth, Grapholita molesta (Busk, 1916), is one of the most important pests in apple orchards in southern Brazil. Chemical control is still the most commonly used strategy for pest control. The aim of this study was to determine the resistance evolution of seven South Brazilian populations to four insecticides (chlorantraniliprole, lufenuron, chlorpyrifos, and fenitrothion). Bioassays were paired with metabolic analyses of glutathione-S-transferase (GST), carboxylesterases (α-NA and β-NA), and acetylcholinesterase (AChE) to understand the possible role with phytosanitary strategies in the insects’ susceptibility. Insect populations were collected in the municipalities of Campo do Tenente, Lapa and Porto Amazonas, Fraiburgo, São Joaquim, and Vacaria and multiplied in the laboratory. Two susceptible and two resistant populations were used as references. The bioassays showed that five populations were considered more resistant to organophosphates, six to lufenuron and two to chlorantraniliprole when compared with the sensitive population. None of the field populations had greater resistance than the resistant laboratory population. The enzymatic activity of AChE and GST was elevated in most of the populations that were less susceptible to organophosphates and lufenuron. The populations originating from orchards that used sexual confusion techniques had the greatest susceptibility based on toxicological and biochemical bioassays. Populations under pressure from various compounds had high GST, α and β-NA activity. There is evidence that a diversity of control strategies can provide better resistance management.


2016 ◽  
Vol 10 (3) ◽  
pp. 115
Author(s):  
Sutrisno Sutrisno

<p>The rice<br />brown planthopper (BPH), Nilaparvata lugens (Stål) is a<br />major insect pest of rice and their infestations occur every<br />year in several locations in Indonesia. The use of<br />insecticides often fails to control the BPH so their<br />populations are still high that cause rice crops show<br />hopperburn and the farmer loses the yields. The<br />development of insecticide resistant in BPH population is<br />one of the factors to contribute to the failure of insecticides<br />control. We have detected the development of field<br />population BPH resistance to BPMC, carbofuran, MIPC, and<br />imidacloprid, but we do not know yet the development of<br />resistance to other insecticides to control BPH in Indonesia.<br />This paper will review several cases on BPH resistance to<br />insecticides in Indonesia and other countries that include<br />aspects of the development of resistance in the field and in<br />the laboratory, the mechanism of resistance, inheritance of<br />resistance, genomics of resistance, and resistance<br />management. A policy and further study is also suggested for<br />insecticide resistance management in Indonesia.</p>


Pathogens ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 372
Author(s):  
Antonio Nanetti ◽  
James D. Ellis ◽  
Ilaria Cardaio ◽  
Giovanni Cilia

Knowledge regarding the honey bee pathogens borne by invasive bee pests remains scarce. This investigation aimed to assess the presence in Aethina tumida (small hive beetle, SHB) adults of honey bee pathogens belonging to the following groups: (i) bacteria (Paenibacillus larvae and Melissococcus plutonius), (ii) trypanosomatids (Lotmaria passim and Crithidia mellificae), and (iii) viruses (black queen cell virus, Kashmir bee virus, deformed wing virus, slow paralysis virus, sacbrood virus, Israeli acute paralysis virus, acute bee paralysis virus, chronic bee paralysis virus). Specimens were collected from free-flying colonies in Gainesville (Florida, U.S.A.) in summer 2017. The results of the molecular analysis show the presence of L. passim, C. mellificae, and replicative forms of deformed wing virus (DWV) and Kashmir bee virus (KBV). Replicative forms of KBV have not previously been reported. These results support the hypothesis of pathogen spillover between managed honey bees and the SHB, and these dynamics require further investigation.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Abdou Talipouo ◽  
Konstantinos Mavridis ◽  
Elysée Nchoutpouen ◽  
Borel Djiappi-Tchamen ◽  
Emmanouil Alexandros Fotakis ◽  
...  

AbstractCulex mosquitoes particularly Culex quinquefasciatus are important arboviral and filariasis vectors, however despite this important epidemiological role, there is still a paucity of data on their bionomics. The present study was undertaken to assess the insecticide resistance status of Cx. quinquefasciatus populations from four districts of Yaoundé (Cameroon). All Culex quinquefasciatus populations except one displayed high resistance to bendiocarb and malathion with mortalities ranging from 0 to 89% while high resistance intensity against both permethrin and deltamethrin was recorded. Molecular analyses revealed high frequencies of the ACE-1 G119S mutation (ranging from 0 to 33%) and kdr L1014F allele (ranging from 55 to 74%) in all Cx. quinquefasciatus populations. Significant overexpression was detected for cytochrome P450s genes CYP6AA7 and CYP6Z10, as well as for Esterase A and Esterase B genes. The total cuticular hydrocarbon content, a proxy of cuticular resistance, was significantly increased (compared to the S-lab strain) in one population. The study confirms strong insecticide resistance mediated by different mechanisms in Cx. quinquefasciatus populations from the city of Yaoundé. The expansion of insecticide resistance in Culex populations could affect the effectiveness of current vector control measures and stress the need for the implementation of integrated vector control strategies in urban settings.


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