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Simple Summary: The fall armyworm, Spodoptera frugiperda, represents a major threat to cereal crops. Therefore, this study aimed to detect the resistance of the second-instar larvae of S. frugiperda in two Egyptian field strains to eight insecticides. The results showed that emamectin benzoate, had the highest toxicity against the susceptible and the two field populations of S. frugiperda larvae followed by spinosad > lufenuron > diflubenzuron > cypermethrin > profenfos > methoxyfenozide > Bacillus thuringiensis. Additionally, resistance to cypermethrin followed by spinosad and lufenuron was observed in Fayoum field population. Thus, the combined use of synergists with cypermethrin, spinosad, and lufenuron showed synergistic effects against S. frugiperda larvae. This study underscores the need for pest management strategies based on regional resistance profiles and biochemical characteristics. Spodoptera frugiperda (J.E. Smith) (Noctuidae: Lepidoptera) is a notable insect pest that invades major cereal crops, causing significant damage and loss. Resistances of 2nd instar larvae of two Egyptian field populations of S. frugiperda, collected from the Fayoum and Giza governments, were measured against eight insecticides, including traditional insecticides (profenofos and cypermethrin), bio-insecticides (emamectin benzoate, spinosad, and Bacillus thuringiensis), and insect growth regulators (IGRs) (lufenuron, diflubenzuron, and methoxyfenozide). In addition, the synergistic effects of three synergists (Piperonyl butoxide (PBO), diethyl maleate (DEM), and triphenyl phosphate (TPP) were assessed, and the activities of detoxification enzymes (acetylcholine esterase (AChE), cytochrome P-450 (CYP-450), carboxylesterase (CarE), and glutathione-s-transferase (GST) were also determined. Resistance surveillance revealed that the Fayoum field population showed moderate resistance to cypermethrin (RR = 5.75-fold), followed by spinosad (RR = 2.62-fold), and lufenuron (2.01-fold). On the other hand, the Giza population exhibited significant resistance to cypermethrin only (RR = 3.65-fold). Our results revealed that emamectin benzoate was the most effective insecticide, with an LC50 value of 0.003 mg/L for the Fayoum population and 0.001 mg/L for the Giza population, compared to the susceptible strain (0.005 mg/L). Among the biological insecticides, Bacillus thuringiensis was the least toxic insecticide of all the tested strains. Synergism assays indicated that DEM and TPP had the most synergistic effect on spinosad (SR = 8.00-fold for both), followed by PBO (SR = 5.71-fold) for the Fayoum population, compared with spinosad alone. The assay of detoxification enzymes showed that GST activity significantly (p < 0.05) increased in the two field strains compared to the susceptible strain. However, no significant changes were observed among the tested strains in CYP-450, CarE, or AChE. The findings of this study provide substantial insights into tracking and managing the development of insecticide resistance in S. frugiperda in Egypt. [ABSTRACT FROM AUTHOR]

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Spodoptera frugiperda (J.E. Smith) (Noctuidae: Lepidoptera) is a notable insect pest that invades major cereal crops, causing significant damage and loss. Resistances of 2nd instar larvae of two Egyptian field populations of S. frugiperda, collected from the Fayoum and Giza governments, were measured against eight insecticides, including traditional insecticides (profenofos and cypermethrin), bio-insecticides (emamectin benzoate, spinosad, and Bacillus thuringiensis), and insect growth regulators (IGRs) (lufenuron, diflubenzuron, and methoxyfenozide). In addition, the synergistic effects of three synergists (Piperonyl butoxide (PBO), diethyl maleate (DEM), and triphenyl phosphate (TPP) were assessed, and the activities of detoxification enzymes (acetylcholine esterase (AChE), cytochrome P-450 (CYP-450), carboxylesterase (CarE), and glutathione-s-transferase (GST) were also determined. Resistance surveillance revealed that the Fayoum field population showed moderate resistance to cypermethrin (RR = 5.75-fold), followed by spinosad (RR = 2.62-fold), and lufenuron (2.01-fold). On the other hand, the Giza population exhibited significant resistance to cypermethrin only (RR = 3.65-fold). Our results revealed that emamectin benzoate was the most effective insecticide, with an LC50 value of 0.003 mg/L for the Fayoum population and 0.001 mg/L for the Giza population, compared to the susceptible strain (0.005 mg/L). Among the biological insecticides, Bacillus thuringiensis was the least toxic insecticide of all the tested strains. Synergism assays indicated that DEM and TPP had the most synergistic effect on spinosad (SR = 8.00-fold for both), followed by PBO (SR = 5.71-fold) for the Fayoum population, compared with spinosad alone. The assay of detoxification enzymes showed that GST activity significantly (p < 0.05) increased in the two field strains compared to the susceptible strain. However, no significant changes were observed among the tested strains in CYP-450, CarE, or AChE. The findings of this study provide substantial insights into tracking and managing the development of insecticide resistance in S. frugiperda in Egypt.

[Objective] To study the effects of four synergists on surface tension of common chemical pesticides in tobacco, so as to provide technical support for the application of synergists in the reduction and enhancement of chemical pesticides in tobacco. [Method] By measuring the surface tension values of nine common tobacco chemical pesticides with the applications of four synergists, and taking the critical surface tension of tobacco leaves as the judgment criterion, the types and doses of synergists that could be suitable for different chemical pesticides were selected. [Result] The critical surface tension of tobacco leaves was 30.52 mN/m, except for 5% carbaryl chloride microemulsion and 10% bromocyanamide dispersible oil suspension, the surface tension values of the recommended dose of the other seven common chemical pesticides in tobacco were significantly higher than the critical surface tension value of tobacco leaves. The critical surface tension values of the four synergists including GY-Tmax, 007, GY-T1602, and S903 were 32.38, 27.62, 26.82 and 20.77 mN/m, respectively. Such four synergists could reduce the surface tension of pesticides and made it close to the critical surface tension of tobacco leaves, and the dosage of different syn- ergists varied with the types of pesticides. [Conclusion] The proper applications of four synergists such as GY-Tmax, 007, GY-T1602, and $903 can reduce the surface tension of common chemical pesticides in tobacco and improve the wet distribution performance of pesticides on tobacco leaves. [ABSTRACT FROM AUTHOR]

The control of the Mediterranean fruit fly (Medfly), Ceratitis capitata, in citrus orchards in Spain is mainly based in three insecticides (spinosad, lambda-cyhalothrin and deltamethrin) and the liberation of sterile males. However, Medfly control is compromised by the development of lambda-cyhalothrin resistance and the detection of spinosad-resistant alleles in field populations. We report here, for the first time, resistance to deltamethrin in populations collected in fields under different management strategies, including MagnetMed™ traps coated with this insecticide and/or spinosad and lambda-cyhalothrin used as bait sprays, and even in populations obtained from non-treated fields. Two deltamethrin-resistant strains (BP-delta and Rfg-delta) were generated from the descendants of some of the field populations that showed lower susceptibility to deltamethrin. Both strains showed low susceptibility to MagnetMed™ traps, moderate susceptibility to Ceratipack traps, and lacked cross-resistance to spinosad and lambda cyhalothrin. Our data suggest that deltamethrin resistance was mediated by P450 enzymes, since bioassays with synergists showed that PBO reverted resistance in a field population and the laboratory strains, whereas the effect of DEF and DEM was minor and no mutations were found in the VGSC gene. The inheritance of resistance for both strains was completely recessive, autosomic and did not fit the mortality expected for a recessive character under a monogenic or digenic model. We also found that deltamethrin resistance presented a fitness cost in terms of males' weight, males' and females' longevity and lifetime fecundity, with a more pronounced effect in the BP-strain than in the Rfg-delta strain. Our results highlight the need to implement insecticide resistance management strategies to prevent control failures. [ABSTRACT FROM AUTHOR]

The ever increasing power demand has forced the power sector companies to increase their generation, transmission and distribution in turn increasing the number of power transformers in the system where necessary. Depending on the nature of operations, the transformers are chosen as either dry-type or liquid-cooled and the preference is mostly liquid cooled. Naphthenic oils have been the primary choice over the years and alternative solutions in the form of natural esters are researched extensively due to the environmental effects of Mineral Oil (MO). One such ester, Marula is presented in this research. The experiment places its focus on measurement of electrical, physical, chemical and thermal characteristics as per the standards of ASTM and IEC. The results prove the superior dielectric performance of MAO over MO. The antioxidant rich MAO exhibits superior dielectric properties and restores faster than MO after the instances of breakdown phenomena. The antioxidants show stability at both the low and high temperatures, and temperature causes minimum damage to antioxidants. In addition to that the use of such dielectric coolant minimizes the winding damage inside the transformer tank. Thus, it can be said that MAO is an excellent coolant and improves the efficiency of the transformer without the requirements of additional cooling devices.

Introduction The Colorado potato beetle (CPB), I Leptinotarsa decemlineata i (Say) (Coleoptera: Chrysomelidae), is the most damaging insect pest of potato and many other members of Solanaceae globally [[1]]. The actual reason behind CPB insecticide resistance development is the evolution of this insect with diverse phytochemicals in Solanaceous plants, which has been combined with heavy insecticide applications every year for its control since 1864 [[8]]. Keywords: Leptinotarsa decemlineata; environmental concerns; input cost; synergists; resistance management EN Leptinotarsa decemlineata environmental concerns input cost synergists resistance management N.PAG N.PAG 16 09/27/22 20220901 NES 220901 1. Current Status of Resistance in the CPB The CPB was the first insect on which insecticide spray was used on a larger scale in 1864 [[8]]. 26071812 113 Wan P.J., Shi X.Q., Kong Y., Zhou L.T., Guo W.C., Ahmat T., Li G.Q. Identification of cytochrome P450 monooxygenase genes and their expression profiles in cyhalothrin-treated Colorado potato beetle, Leptinotarsa decemlineata. [Extracted from the article]

Copyright of MESO is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Evolved resistance and regulatory deregistration have severely limited farmers' pesticide options. Many potential new pesticide target sites have been elucidated using targeted gene suppression and mutational tools, but few small molecules could be found that inhibit the target enzymes; the targets were considered 'undruggable'. Some organisms from all biological kingdoms use toxic peptides to ward off or kill enemies, and the agrochemical industry has used a few peptide analogs (glufosinate and bialophos) for field application. Conversely, pharmaceutical scientists have been using three‐dimensional target protein structure to discover and synthesize short peptides that bind tightly to the surfaces of, and inhibit previously undruggable targets. New computational tools to quickly elucidate 3‐D protein structure from amino acid sequence have just emerged. They replace crystallizing target proteins and performing X‐ray crystallography to elucidate 3‐D structure. These new tools allow prediction of peptides that will bind to the target proteins. They have further modified such peptides to enhance penetration, translocation and temperature stability. There is reason to assume that the same pioneering techniques can be used to develop peptide pesticides as well as pesticide synergists that act against undruggable targets and have excellent environmental and toxicological profiles. © 2022 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

To study the synergistic effects and synergistic mechanism of three synergists on bentazon, glufosinate-ammonium and haloxyfop-P-methyl, and screen out the synergist with the best performance, the static surface tension (SST), dynamic surface tension (DST), dynamic dryness and contact angle of herbicides, synergists and synergists-added herbicides were investigated and adhesion force and adhesion work were calculated. The physicochemical performance tests revealed that the synergist based on isomeric alcohol ethoxylates performed best in reducing SST, accelerating the reduction of DST and reducing the contact angle, and the synergist based on penetrant T was the second most effective, while the synergist based on methyl oleate had a slight effect and was the worst. The data of adhesion force and adhesion work showed that the herbicide solution containing isomeric alcohol ethoxylates based synergist had stronger adhesion on the leaves and was easier to retain and wet the leaf epidermis. Meanwhile, the results of the indoor efficacy evaluations also confirmed that the synergist isomeric alcohol ethoxylates that had the best physicochemical performance exhibited the best control efficacy when added to herbicides as the main component of a synergist. [ABSTRACT FROM AUTHOR]

Abstract With the rapid development and spread of resistance to insecticides among anopheline malaria vectors, the efficacy of current World Health Organization (WHO)-approved insecticides targeting these vectors is under threat. This has led to the development of novel interventions, including improved and enhanced insecticide formulations with new targets or synergists or with added sterilants and/or antimalarials, among others. To date, several studies in mosquitoes have revealed that the 20-hydroxyecdysone (20E) signaling pathway regulates both vector abundance and competence, two parameters that influence malaria transmission. Therefore, insecticides which target 20E signaling (e.g. methoxyfenozide and halofenozide) may be an asset for malaria vector control. While such insecticides are already commercially available for lepidopteran and coleopteran pests, they still need to be approved by the WHO for malaria vector control programs. Until recently, chemicals targeting 20E signaling were considered to be insect growth regulators, and their effect was mostly studied against immature mosquito stages. However, in the last few years, promising results have been obtained by applying methoxyfenozide or halofenozide (two compounds that boost 20E signaling) to Anopheles populations at different phases of their life-cycle. In addition, preliminary studies suggest that methoxyfenozide resistance is unstable, causing the insects substantial fitness costs, thereby potentially circumventing one of the biggest challenges faced by current vector control efforts. In this review, we first describe the 20E signaling pathway in mosquitoes and then summarize the mechanisms whereby 20E signaling regulates the physiological processes associated with vector competence and vector abundance. Finally, we discuss the potential of using chemicals targeting 20E signaling to control malaria vectors.

The ever increasing power demand has forced the power sector companies to increase their generation, transmission and distribution in turn increasing the number of power transformers in the system where necessary. Depending on the nature of operations, the transformers are chosen as either dry-type or liquid-cooled and the preference is mostly liquid cooled. Naphthenic oils have been the primary choice over the years and alternative solutions in the form of natural esters are researched extensively due to the environmental effects of Mineral Oil (MO). One such ester, Marula is presented in this research. The experiment places its focus on measurement of electrical, physical, chemical and thermal characteristics as per the standards of ASTM and IEC. The results prove the superior dielectric performance of MAO over MO. The antioxidant rich MAO exhibits superior dielectric properties and restores faster than MO after the instances of breakdown phenomena. The antioxidants show stability at both the low and high temperatures, and temperature causes minimum damage to antioxidants. In addition to that the use of such dielectric coolant minimizes the winding damage inside the transformer tank. Thus, it can be said that MAO is an excellent coolant and improves the efficiency of the transformer without the requirements of additional cooling devices. [ABSTRACT FROM AUTHOR]

With the rapid development and spread of resistance to insecticides among anopheline malaria vectors, the efficacy of current World Health Organization (WHO)-approved insecticides targeting these vectors is under threat. This has led to the development of novel interventions, including improved and enhanced insecticide formulations with new targets or synergists or with added sterilants and/or antimalarials, among others. To date, several studies in mosquitoes have revealed that the 20-hydroxyecdysone (20E) signaling pathway regulates both vector abundance and competence, two parameters that influence malaria transmission. Therefore, insecticides which target 20E signaling (e.g. methoxyfenozide and halofenozide) may be an asset for malaria vector control. While such insecticides are already commercially available for lepidopteran and coleopteran pests, they still need to be approved by the WHO for malaria vector control programs. Until recently, chemicals targeting 20E signaling were considered to be insect growth regulators, and their effect was mostly studied against immature mosquito stages. However, in the last few years, promising results have been obtained by applying methoxyfenozide or halofenozide (two compounds that boost 20E signaling) to Anopheles populations at different phases of their life-cycle. In addition, preliminary studies suggest that methoxyfenozide resistance is unstable, causing the insects substantial fitness costs, thereby potentially circumventing one of the biggest challenges faced by current vector control efforts. In this review, we first describe the 20E signaling pathway in mosquitoes and then summarize the mechanisms whereby 20E signaling regulates the physiological processes associated with vector competence and vector abundance. Finally, we discuss the potential of using chemicals targeting 20E signaling to control malaria vectors. [ABSTRACT FROM AUTHOR]

A resistant strain (MRS) of Sitobion miscanthi was cultured by continuous selection with malathion for over 40 generations. The MRS exhibited 32.7-fold resistance to malathion compared to the susceptible strain (MSS) and 13.5-fold, 2.9-fold and 4.8-fold cross-resistance for omethoate, methomyl and beta-cypermethrin, respectively. However, no cross-resistance was found to imidacloprid in this resistant strain. The realized heritability for malathion resistance was 0.02. Inhibitors of esterase activity, both triphenyl phosphate (TPP) and S,S,S,-tributyl phosphorotrithioate (DEF) as synergists, exhibited significant synergism to malathion in the MRS strain, with 11.77-fold and 5.12-fold synergistic ratios, respectively, while piperonyl butoxide (PBO) and diethyl maleate (DEM) showed no significant synergism in the MRS strain. The biochemical assay indicated that carboxylesterase activity was higher in MRS than in MSS. These results suggest that the increase in esterase activity might play an important role in S. miscanthi resistance to malathion. Imidacloprid could be used as an alternative for malathion in the management of wheat aphid resistance.

Abstract Background Dengue is a serious public health problem worldwide, including in Selangor, Malaysia. Being an important vector of dengue virus, Aedes aegypti are subjected to control measures which rely heavily on the usage of insecticides. Evidently, insecticide resistance in Ae. aegypti, which arise from several different point mutations within the voltage-gated sodium channel genes, has been documented in many countries. Thus, this robust study was conducted in all nine districts of Selangor to understand the mechanisms of resistance to various insecticides in Ae. aegypti. Mosquitoes were collected from dengue epidemic and non-dengue outbreak areas in Selangor. Methods Using the Center for Disease Control and Prevention (CDC) bottle assays, the insecticide resistance status of nine different Ae. aegypti strains from Selangor was accessed. Synergism tests and biochemical assays were conducted to further understand the metabolic mechanisms of insecticide resistance. Polymerase chain reaction (PCR) amplification and sequencing of the IIP-IIS6 as well as IIIS4-IIIS6 regions of the sodium channel gene were performed to enable comparisons between susceptible and resistant mosquito strains. Additionally, genomic DNA was used for allele-specific PCR (AS-PCR) genotyping of the gene to detect the presence of F1534C, V1016G and S989P mutations. Results Adult female Ae. aegypti from various locations were susceptible to malathion and propoxur. However, they exhibited different levels of resistance against dichlorodiphenyltrichloroethane (DDT) and pyrethroids. The results of synergism tests and biochemical assays indicated that the mixed functions of oxidases and glutathione S-transferases contributed to the DDT and pyrethroid resistance observed in the present study. Besides detecting three single kdr mutations, namely F1534C, V1016G and S989P, co-occurrence of homozygous V1016G/S989P (double allele) and F1534C/V1016G/S989P (triple allele) mutations were also found in Ae. aegypti. As per the results, the three kdr mutations had positive correlations with the expressions of resistance to DDT and pyrethroids. Conclusions In view of the above outcomes, it is important to seek new tools for vector management instead of merely relying on insecticides. If the latter must be used, regular monitoring of insecticide resistance should also be carried out at all dengue epidemic areas. Since the eggs of Ae. aegypti can be easily transferred from one location to another, it is probable that insecticide-resistant Ae. aegypti can be found at non-dengue outbreak sites as well.

The Colorado potato beetle (CPB), Leptinotarsa decemlineata (Say), is the most notorious insect pest of potato globally. Injudicious use of insecticides for management of this pest has resulted in resistance to all major groups of insecticides along with many human, animal health, and environmental concerns. Additionally, the input cost of insecticide development/discovery is markedly increasing because each year thousands of chemicals are produced and tested for their insecticidal properties, requiring billions of dollars. For the management of resistance in insect pests, synergists can play a pivotal role by reducing the application dose of most insecticides. These eco-friendly synergists can be classified into two types: plant-based synergists and RNAi-based synergists. The use of plant-based and RNAi-based synergists in resistance management of insect pests can give promising results with lesser environmental side effects. This review summarizes the resistance status of CPB and discusses the potential advantage of plant-based and RNAi-based synergists for CPB resistance management. It will motivate researchers to further investigate the techniques of using plant- and RNAi-based synergists in combination with insecticides.

The house fly, Musca domestica L. is an important mechanical vector of different pathogens of medical and veterinary importance. It is an organism well-known for its ability to develop insecticide resistance. In the current study, we investigated the genetic basis and mechanism of chlorantraniliprole resistance in a field strain of house fly by selecting it artificially in the laboratory with a commercial formulation of chlorantraniliprole (CTPR-SEL). After seven generations of consecutive selection with chlorantraniliprole, CTPR-SEL strain developed a 644-fold resistance compared with the Susceptible strain and a 3-fold resistance compared with the field strain. Reciprocal crossing between the CTPR-SEL and Susceptible homozygous strains revealed an autosomal and incomplete dominant mode of resistance to chlorantraniliprole. A direct test using a monogenic inheritance model based on chi-square analysis revealed that the resistance was governed by more than one gene. Bioassays with synergists indicated that esterases might be involved in the resistance of house fly to chlorantraniliprole. These findings may be helpful to the development of an improved strategy for chlorantraniliprole resistance management in house fly. [ABSTRACT FROM AUTHOR]

Malaria vector control interventions rely heavily on the application of insecticides against anopheline mosquitoes, in particular the fast-acting pyrethroids that target insect voltage-gated sodium channels (VGSC). Frequent applications of pyrethroids have resulted in resistance development in the major malaria vectors including Anopheles funestus, where resistance is primarily metabolic and driven by the overexpression of microsomal cytochrome P450 monooxygenases (P450s). Here we examined the pattern of cross-resistance of the pyrethroid-resistant An. funestus strain FUMOZ-R towards transfluthrin and multi-halogenated benzyl derivatives, permethrin, cypermethrin and deltamethrin in comparison to the susceptible reference strain FANG. Transfluthrin and two multi-fluorinated derivatives exhibited micromolar potency - comparable to permethrin - to functionally expressed dipteran VGSC in a cell-based cation influx assay. The activity of transfluthrin and its derivatives on VGSC was strongly correlated with their contact efficacy against strain FUMOZ-R, although no such correlation was obtained for the other pyrethroids due to their rapid detoxification by the resistant strain. The low resistance levels for transfluthrin and derivatives in strain FUMOZ-R were only weakly synergized by known P450 inhibitors such as piperonyl butoxide (PBO), triflumizole and 1-aminobenzotriazole (1-ABT). In contrast, deltamethrin toxicity in FUMOZ-R was synergized > 100-fold by all three P450 inhibitors. The biochemical profiling of a range of fluorescent resorufin and coumarin compounds against FANG and FUMOZ-R microsomes identified 7-benzyloxymethoxy-4-trifluoromethylcoumarin (BOMFC) as a highly sensitive probe substrate for P450 activity. BOMFC was used to develop a fluorescence-based high-throughput screening assay to measure the P450 inhibitory action of potential synergists. Azole fungicides prochloraz and triflumizole were identified as extremely potent nanomolar inhibitors of microsomal P450s, strongly synergizing deltamethrin toxicity in An. funestus. Overall, the present study contributed to the understanding of transfluthrin efficacy at the molecular and organismal level and identified azole compounds with potential to synergize pyrethroid efficacy in malaria vectors.

Background: Despite remarkable success obtained with current malaria vector control strategies in the last 15 years, additional innovative measures will be needed to achieve the ambitious goals for malaria control set for 2030 by the World Health Organization (WHO). New tools will need to address insecticide resistance and residual transmission as key challenges. Endectocides such as ivermectin are drugs that kill mosquitoes which feed on treated subjects. Mass administration of ivermectin can effectively target outdoor and early biting vectors, complementing the still effective conventional tools. Although this approach has garnered attention, development of ivermectin resistance is a potential pitfall. Herein, we evaluate the potential role of xenobiotic pumps and cytochrome P450 enzymes in protecting mosquitoes against ivermectin by active efflux and metabolic detoxification, respectively. Methods: We determined the lethal concentration 50 for ivermectin in colonized Anopheles gambiae; then we used chemical inhibitors and inducers of xenobiotic pumps and cytochrome P450 enzymes in combination with ivermectin to probe the mechanism of ivermectin detoxification. Results: Dual inhibition of xenobiotic pumps and cytochromes was found to have a synergistic effect with ivermectin, greatly increasing mosquito mortality. Inhibition of xenobiotic pumps alone had no effect on ivermectin-induced mortality. Induction of xenobiotic pumps and cytochromes may confer partial protection from ivermectin. Conclusion: There is a clear pathway for development of ivermectin resistance in malaria vectors. Detoxification mechanisms mediated by cytochrome P450 enzymes are more important than xenobiotic pumps in protecting mosquitoes against ivermectin. [ABSTRACT FROM AUTHOR]

Understanding how multiple insecticide resistance mechanisms occur in malaria vectors is essential for efficient vector control. This study aimed at assessing the evolution of metabolic mechanisms and Kdr L995F/S resistance alleles in Anopheles gambiae s.l. from North Cameroon, following long-lasting insecticidal nets (LLINs) distribution in 2011. Female An. gambiae s.l. emerging from larvae collected in Ouro-Housso/Kanadi, Be-Centre, and Bala in 2011 and 2015, were tested for susceptibility to deltamethrin + piperonyl butoxide (PBO) or SSS-tributyl-phosphoro-thrithioate (DEF) synergists, using the World Health Organization’s standard protocol. The Kdr L995F/S alleles were genotyped using Hot Ligation Oligonucleotide Assay. Tested mosquitoes identified using PCR-RFLP were composed of An. arabiensis (68.5%), An. coluzzii (25.5%) and An. gambiae (6%) species. From 2011 to 2015, metabolic resistance increased in Ouro-Housso/Kanadi (up to 89.5% mortality to deltametnrin+synergists in 2015 versus p < 0.02), while it decreased in Be-Centre and Bala (>95% mortality in 2011 versus 42–94% in 2015; p < 0.001). Conversely, the Kdr L995F allelic frequencies slightly decreased in Ouro-Housso/Kanadi (from 50% to 46%, p > 0.9), while significantly increasing in Be-Centre and Bala (from 0–13% to 18–36%, p < 0.02). These data revealed two evolutionary trends of deltamethrin resistance mechanisms; non-pyrethroid vector control tools should supplement LLINs in North Cameroon.

The incidence of mosquito-borne disease poses a significant threat to human and animal health throughout the world, with effective chemical control interventions limited by widespread insecticide resistance. Recent evidence suggests that gut bacteria of mosquitoes, known to be essential in nutritional homeostasis and pathogen defense, may also play a significant role in facilitating insecticide resistance. This study investigated the extent to which bacteria contribute to the general esterase and cytochrome P450 monooxygenase (P450)-mediated detoxification of the insecticides propoxur and naled, as well as the insecticidal activity of these chemistries to the yellow fever mosquito, Aedes aegypti. Experiments conducted using insecticide synergists that reduce general esterase and P450 activity demonstrate a role for both groups of enzymes in the metabolic detoxification of propoxur and naled. Furthermore, reduction of bacteria in mosquito larvae using broad-spectrum antibiotics was found to decrease the metabolic detoxification of propoxur and naled, suggesting that the bacteria themselves may be contributing to the in vivo metabolic detoxification of these insecticides. This was supported by in vitro assays using culturable gut bacteria isolated from mosquito larvae which demonstrated that the bacteria were capable of reducing insecticide toxicity. More work is needed, however, to fully elucidate the contribution of bacteria in Ae. aegypti larvae to the metabolic detoxification of insecticides. Unlabelled Image • Efficacy of insecticides naled and propoxur in mosquitoes increased by synergists. • General esterase and P450 enzymes contribute to metabolism of naled and propoxur. • Efficacy of naled and propoxur in mosquitoes increased by antibiotics. • Antibiotic treatment decreases metabolic detoxification of insecticides. • Cultured bacteria from mosquito larvae reduced insecticide toxicity. [ABSTRACT FROM AUTHOR]

Copyright of Glasnik Zastite Bilja is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Dengue is a serious public health problem worldwide, including in Selangor, Malaysia. Being an important vector of dengue virus, Aedes aegypti are subjected to control measures which rely heavily on the usage of insecticides. Evidently, insecticide resistance in Ae. aegypti, which arise from several different point mutations within the voltage-gated sodium channel genes, has been documented in many countries. Thus, this robust study was conducted in all nine districts of Selangor to understand the mechanisms of resistance to various insecticides in Ae. aegypti. Mosquitoes were collected from dengue epidemic and non-dengue outbreak areas in Selangor. Methods: Using the Center for Disease Control and Prevention (CDC) bottle assays, the insecticide resistance status of nine different Ae. aegypti strains from Selangor was accessed. Synergism tests and biochemical assays were conducted to further understand the metabolic mechanisms of insecticide resistance. Polymerase chain reaction (PCR) amplification and sequencing of the IIP-IIS6 as well as IIIS4-IIIS6 regions of the sodium channel gene were performed to enable comparisons between susceptible and resistant mosquito strains. Additionally, genomic DNA was used for allele-specific PCR (AS-PCR) genotyping of the gene to detect the presence of F1534C, V1016G and S989P mutations. Results: Adult female Ae. aegypti from various locations were susceptible to malathion and propoxur. However, they exhibited different levels of resistance against dichlorodiphenyltrichloroethane (DDT) and pyrethroids. The results of synergism tests and biochemical assays indicated that the mixed functions of oxidases and glutathione S-transferases contributed to the DDT and pyrethroid resistance observed in the present study. Besides detecting three single kdr mutations, namely F1534C, V1016G and S989P, co-occurrence of homozygous V1016G/S989P (double allele) and F1534C/V1016G/S989P (triple allele) mutations were also found in Ae. aegypti. As per the results, the three kdr mutations had positive correlations with the expressions of resistance to DDT and pyrethroids. Conclusions: In view of the above outcomes, it is important to seek new tools for vector management instead of merely relying on insecticides. If the latter must be used, regular monitoring of insecticide resistance should also be carried out at all dengue epidemic areas. Since the eggs of Ae. aegypti can be easily transferred from one location to another, it is probable that insecticide-resistant Ae. aegypti can be found at non-dengue outbreak sites as well. [ABSTRACT FROM AUTHOR]

Activity spectrum of detoxification enzymes was systematically assessed in tobacco caterpillar, Spodoptera litura collected from four locations in Kerala, India, to decipher the mechanism of insecticide resistance. Using the susceptible check ICAR-NBAIR strain, specific activity profiles of acetylcholine esterase (AChE) were found to be 16.16-, 10.71- and 4.88-fold higher in the Kovilnada, Palappur and Kanjikuzhi populations respectively. Specific activities of mixed function oxidase (MFO) were also found to be 19.24-, 17.11-, 6.08-fold higher in the same populations respectively, indicating the predominance of AChE and MFO towards imparting resistance. Carboxylesterase (CarE) and glutathion-S-transferase (GST) specific activity profiles were 3.62- and 3.37-fold higher in the Kovilnada population, followed by 2.89- and 2.98-fold higher in the Palappur population and as 2.10- and 1.15-fold higher in the Kanjikuzhi population, indicating their partial role in resistance development. Suppression of specific activities in synergism bioassays with AChE in chlorpyriphos + TPP treatment (9.32-fold), GST in chlorpyriphos + DEM (4.78-fold) and CarE in quinalphos + TPP (5.15-fold) highlighted the involvement of multiple detoxification enzymes conferring resistance to organophosphates. Reduced activity of MFO in case of lambda-cyhalothrin + PBO (5.35-fold), CarE in case of cypermethrin + TPP (7.36-fold) and 3.60-fold reduction in MFO in case of cypermethrin + PBO highlighted the role of esterases and MFOs towards resistance development against synthetic pyrethroids. [ABSTRACT FROM AUTHOR]

Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Spodoptera litura (Fabricius) (Lepidoptera: Noctuidae) is one of the most destructive insect pests owned strong resistance to different insecticides. Indoxacarb as a novel oxadiazine insecticide becomes the main pesticide against S. litura. DIMBOA [2,4-dihydroxy-7-methoxy-2 H-1,4-benz-oxazin-3(4 H)-one] is involved in important chemical defense processes in corn plants. However, the insects' adaptation mechanism to insecticides when exposed to defensive allelochemicals in their host plants remains unclear. Here, we assessed multi-resistance, and resistance mechanisms based on S. litura life history traits. After 18 generations of selection, indoxacarb resistance was increased by 61.95-fold (Ind-Sel) and 86.06-fold (Dim-Sel) as compared to the Lab-Sus. Also, DIMBOA-pretreated larvae developed high resistance to beta-cypermethrin, chlorpyrifos, phoxim, chlorantraniliprole, and emamectin benzoate. Meanwhile, indoxacarb (LC 50) was applied to detect its impact on thirty-eight detoxification-related genes expression. The transcripts of SlituCOE073, SlituCOE009, SlituCOE074 , and SlituCOE111 as well as SlGSTs5, SlGSTu1 , and SlGSTe13 were considerably raised in the Ind-Sel strain. Among the twenty-three P450s, CYP6AE68, CYP321B1, CYP6B50, CYP9A39, CYP4L10 , and CYP4S9v 1 transcripts denoted significantly higher levels in the Ind-Sel strain, suggesting that CarEs, GSTs and P450s genes may be engaged in indoxacarb resistance. These outcomes further highlighted the importance of detoxification enzymes for S. litura gene expression and their role in responses to insecticides and pest management approaches. [Display omitted] • Indoxacarb resistance ratio in S. litura larvae over 18 generations was studied. • Detoxifying enzyme mechanisms of P450s, GSTs, and CarEs were explored. • DIMBOA enhanced resistance of S. litura to indoxacarb. • PBO significantly synergized indoxacarb toxicity in S. litura larvae. • The longevity of adults was significantly shorter in the Dim-Sel Strain. [ABSTRACT FROM AUTHOR]

Insecticides have played and still fulfil a very important role in sustainable production of food, animal feed and also as protection against disease vectors. They act to suppress insect populations and, as a consequence of their use, insecticide resistance has evolved. An overview of insecticide resistance mechanisms in insects is given, focusing on the metabolic systems involved in xenobiotic metabolism in the class Insecta. Several enzyme families (e.g., esterases, mixed function oxidases, glutathione S-transferases) are involved in insecticide detoxification, sequestration and excretion and have differing relative importance within the various taxonomic groups. A brief discussion of their impact on control strategies is given.

Two-spotted spider mite, Teranychus urticae (Acari: Tetranychide), is one of the most important agricultural pests throughout the world. The high reproductive potential, short life cycle, combined with frequent acaricide applications has resulted in resistance development to a wide range of acaricides. Resistance to acaricides has an important role in inefficiency of chemical control of this pest. In the present study, the susceptibility of two populations of two-spotted spider mite collected from Karaj (KrS) and Mahallat (MhR) to spirodiclofen was investigated. The bioassay was conducted using a leaf-dip method on same-age protonymphs. Bioassay results showed that there was a significant difference between LC50 values of KrS and MhR populations. The resistance ratio was obtained as 22.19. The synergistic effects of triphenyl phosphate (TPP), piperonyl butoxide (PBO) and diethyl maleate (DEM) were assessed using residual contact vial (RCV) bioassay method. Results of the synergistic studies showed significant differences between LC50 values of spirodiclofen with spirodiclofen + PBO and spirodiclofen + TPP in MhR population. The most synergistic effect in MhR population was related to PBO. The results of enzyme assays revealed that the most ratio activity in MhR population to KrS population was related to cytochrome P450 monoxygenase (3.02) and the lowest ratio activity was related to glutathione S-transferase (GST) (1.40). These results confirmed that esterase and cytochrome P450 monoxygenase are probably involved in resistance of T. urticae to spirodiclofen. [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: A population of Amaranthus tuberculatus (var. rudis) was confirmed resistant to 4‐hydroxyphenylpyruvate dioxygenase (HPPD)‐inhibitor herbicides (mesotrione, tembotrione, and topramezone) in a seed corn/soybean rotation in Nebraska. Further investigation confirmed a non‐target‐site resistance mechanism in this population. The main objective of this study was to explore the role of cytochrome P450 inhibitors in restoring the efficacy of HPPD‐inhibitor herbicides on the HPPD‐inhibitor resistant A. tuberculatus population from Nebraska, USA (HPPD‐R). RESULTS: Enhanced metabolism via cytochrome P450 enzymes is the mechanism of resistance in HPPD‐R. Amitrole partially restored the activity of mesotrione, whereas malathion, amitrole, and piperonyl butoxide restored the activity of tembotrione and topramezone in HPPD‐R. Although corn was injured through malathion followed by mesotrione application a week after treatment, the injury was transient, and the crop recovered. CONCLUSION: The use of cytochrome P450 inhibitors with tembotrione may provide a new way of controlling HPPD‐inhibitor resistant A. tuberculatus, but further research is needed to identify the cytochrome P450 candidate gene(s) conferring metabolism‐based resistance. The results presented here aid to gain an insight into non‐target‐site resistance weed management strategies. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Copyright of Glasnik Zastite Bilja is the property of Zadruzna Stampa D.D. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Insecticide resistance is a major challenge in successful insect pest control as the insects have the ability to develop resistance to various widely used insecticides. Butene-fipronil is a novel compound with high toxicity to insects and less toxicity to the non-target organisms. In the present study, the effect of butene-fipronil alone and in combination with three enzyme inhibitors, piperonyl butoxide (PBO), diethyl maleate (DEM), and triphenyl phosphate (TPP), was carried out on larvae and adults of Drosophilia melanogaster. Our results indicated that the co-toxicity indices of butene-fipronil + PBO, butene-fipronil + TPP, and butene-fipronil + DEM mixtures were 437.3, 335.0, and 210.3, respectively, in the second-instar larvae, while 186.6, 256.2, and 238.5, respectively, in the adults, indicating synergistic effects. Interestingly, butene-fipronil increased the expression of CYP28A5 in the larvae; CYP9F2, CYP304A1, CYP28A5, and CYP318A1 in the female adults; and CYP303A1 and CYP28A5 in the male adults. Furthermore, high-level expression of Est-7 was observed in the female adults compared to larvae and male adults. Our results suggest that there is no difference in butene-fipronil metabolism in larvae and male and female adults of D. melanogaster. [ABSTRACT FROM AUTHOR]

Bradysia odoriphaga is a major pest that causes damage to chive production, and which has developed resistance to highly toxic chemical insecticides. Entomopathogenic nematodes (EPN) show a high potential for B. odoriphaga control. This study aimed to develop an effective management method against B. odoriphaga larvae, using EPN with low-toxicity insecticides. Fourteen selected insecticides had no significant effects on the survival and infectivity of Steinernema feltiae SN and Heterorhabditis indica LN2. Synergistic interactions were observed for imidacloprid and osthole with S. feltiae SN against B. odoriphaga larvae. Steinernema feltiae SN was more effective than H. indica LN2 against B. odoriphaga at 15 and 20 °C, and the addition of imidacloprid at 1/10 recommended concentration (RC) significantly increased the efficacy of S. feltiae SN. The year-round occurrence of the B. odoriphaga larvae in chive fields treated by EPN and imidacloprid at 1/10 RC was studied. Results showed that the application of EPN with imidacloprid at 1/10 RC successfully suppressed larval populations of B. odoriphaga in chive fields, thus significantly increasing the yield of chive. The practical method of applying EPN−imidacloprid combinations provided a cost-effective and environmental safety strategy for controlling B. odoriphaga larvae in chive production, which can reduce the usage of toxic chemical insecticides.

In this study we measured in vitro honey bee enzyme activities in presence of the synergist piperonyl butoxide (PBO) and some new benzodioxole and dihydrobenzofuran derivatives through absorbance and fluorescence spectrophotometric assays, to determine if and to what extent detoxification systems and acetylcholinesterases are affected by these compounds. Both Italian (Italy) and Carniolan (Czech Republic) honey bees were tested. In the case of Italian honey bees the esterase activity was partially but significantly inhibited by almost all the tested products. In Carniolan honey bees only the dihydrobenzofuran derivative EN16-41 significantly inhibited esterases. Other enzymatic systems, such as cytochrome P450 monooxygenases (P450s) and glutathione S-transferases (GSTs), often involved in xenobiotics detoxification, as well as acetylcholinesterases (AchEs) seem not to be targeted by the studied synergists. These data seem to suggest that some of the investigated PBO analogues could not be detrimental to honey bees. [ABSTRACT FROM AUTHOR]

BACKGROUND Investigating the impact of pesticides on non-target organisms is essential for sustainable integrated pest management programs. We therefore assessed the toxicity of ten insecticides to the brassica caterpillar Ascia monuste and its ant predator Solenopsis saevissima and examined the effect that the insecticide synergists had on toxicity to the predator. We also assessed the residual period of control and impact of the insecticides during the brassica growing cycle. RESULTS All insecticides except flubendiamide exhibited mortality above the threshold required by Brazilian legislation (80%). Chlorantraniliprole, cyantraniliprole, indoxacarb and spinosad exhibited lower toxicity to the ant predator than they did to the brassica caterpillar. The results obtained for synergized insecticides suggest that selectivity to the predator was due the involvement of cytochrome P450-dependent monooxygenases. Chlorfenapyr and cyantraniliprole exhibited the highest residual periods of control to the brassica caterpillar, whereas malathion had the greatest impact on the predator. CONCLUSION Most of the insecticides efficiently controlled the brassica caterpillar, but not all exhibited selectivity to the predator. Therefore, due to the distinctive responses of organisms with respect to residual periods of control and the impact of the insecticides, spraying frequency must be strongly considered in integrated pest management programs. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Background: Malaria is common in hilly, forested areas along national borders in Southeast Asia. Insecticide resistance in malaria vectors has been detected in a few countries in the Greater Mekong sub-region (GMS), representing a threat to malaria control and prevention. This study aims to determine the insecticide resistance status of Anopheles mosquitoes in Ubon Ratchathani province, northeastern Thailand, where increasing number of malaria cases were reported recently. Methods: Mosquitoes were collected in 2013-2015 using human landing and cattle bait collections in six sites during both the rainy and dry seasons. Mosquitoes were first morphologically identified to species and their susceptibility status to deltamethrin (0.05%), permethrin (0.75%) and DDT (4%) investigated, according to WHO guidelines. Bioassays with the synergists PBO and DEF were carried out to address the role of detoxifying enzymes in insecticide resistance. DNA sequencing of a fragment of the voltage-gated sodium channel gene was carried out to detect knock-down resistance (kdr) substitutions at position 1014 in resistant species. Results: Due to low vector abundance, complete bioassays (n ≥ 100 mosquitoes) were only achieved for Anopheles hyrcanus s.l., which was resistant to all insecticides tested (mortality ranged from 45 to 87%). Suspected resistance to DDT was found in Anopheles barbirostris s.l. (mortality 69%), but it was susceptible to deltamethrin (mortality 97-100%) and permethrin (mortality 100%). Although insufficient number of primary vectors were collected, results showed that Anopheles dirus s.l. and Anopheles maculatus s.l. were susceptible to deltamethrin (mortality 100%). Anopheles nivipes and Anopheles philippinensis were susceptible to all three insecticides. PBO significantly increased mortality to deltamethrin and permethrin in pyrethroid-resistant An. hyrcanus s.l. None of the sequenced specimens presented the L1014F or L1014S mutation. Discussion: This study shows that insecticide resistance is present in potential malaria vectors in northeastern Thailand. The absence of kdr mutations in all Anopheles species tested suggests that metabolic resistance is the main mechanism of pyrethroid resistance. This study provides new findings about insecticide susceptibility status of potential malaria vectors in northeastern Thailand that are deemed important to guide malaria vector control. [ABSTRACT FROM AUTHOR]

The pollen beetle, Meligethes aeneus F. (Coleoptera: Nitidulidae) and the cabbage seed weevil, Ceutorhynchus assimilis (Payk.) (Coleoptera: Curculionidae) are two most dangerous winter rape pests in Europe, which frequently co-occur on fields. Difficulties in controlling both pest species stem not only from their resistance to various active ingredients of insecticides, but also from significant differences in their susceptibility to the same active ingredients. The aim of our research was to establish the level of susceptibility of the pests to deltamethrin, a pyrethroid, and indoxacarb, an oxadiazine, and to determine enzymatic mechanisms of resistance to indoxacarb in the cabbage seed weevil, using pesticide synergists that block particular groups of enzymes. The results have shown that the pollen beetle was highly resistant to deltamethrin and highly susceptible to indoxacarb, while the cabbage seed weevil was highly susceptible to deltamethrin and highly resistant to indoxacarb. Studies of resistance mechanisms to indoxacarb in the cabbage seed weevil have not indicated participation of oxidative enzymes blocked by piperonyl butoxide, esterases blocked by S,S,S-tributylphosphorotrithioate or glutathione transferases blocked by diethyl malonate in the metabolism of this substance. Thus, further research on mechanisms behind the resistance of the cabbage seed weevil to indoxacarb is necessary. [ABSTRACT FROM AUTHOR]

A resistant strain of Aphis craccivora Koch was selected with pirimicarb for 12 generations. The selected strain exhibited 47-fold resistance compared to the susceptible laboratory strain. The resistant strain also showed cross-resistance to carbosulfan, malathion, chlorpyrifos methyl and thiamethoxam. Low resistance to fenitrothion and acetamiprid was also observed. Bioassays in combination with biochemical synergist studies revealed that the higher inhibition of carboxylesterase using the synergist tributyl phosphorotrithioate (DEF) was associated with increased toxicity of pirimicarb in the resistant strain. On the other hand, piperonyl butoxide (PBO) and diethyl maleate (DEM) had less inhibitory effect on mixed function oxidases (MFO) and glutathione-S-transferase (GST) in the resistant strain. The activity of carboxylesterase was 29-fold greater in the resistant strain, whereas the activity of MFO and GST in the resistant strain was only 5.5 and 1.7- fold greater, respectively. The activity of acetylcholine esterase (AChE) in the resistant strain was 2 fold higher than in the susceptible strain. The I 50 (the concentration of pirimicarb that inhibit 50% of the enzyme activity) ratio of R-strain to S-strain was 12.6. Molecular studies using real-time quantitative PCR showed that the transcription level of Ace 2 gene in the resistant strain was 3.4-fold higher than that in the susceptible strain. In conclusion, mechanism of resistance in the pirimicarb resistant strain of A. craccivora may include overexpression of Ace2 gene and higher activity of the detoxification enzymes esterases and partly MFO. [ABSTRACT FROM AUTHOR]

The relationship between the acute toxicity and feeding deterrent activity of ten compounds occurring commonly in essential oils was explored in order to determine whether they are acute toxins or antifeedants against stored-grain pests. Simultaneously, the objective was also to demonstrate the comparative efficacy against three post-harvest stored-grain pests. Thymol, carvacrol, eugenol and trans-anethole were specifically toxic, and linalool was a generalist feeding deterrent against all three species studied. Thymol was most toxic to Tribolium castaneum and Rhyzopertha dominica compared to carvacrol and eugenol but was least toxic to Sitophilus oryzae. Similarly, linalool deterred feeding of S. oryzae (FI = 0.025 mg/g of the wafer diet), T. castaneum (FI = 0.207 mg/g of the wafer diet) and R. dominica (FI = 0.482 mg/g of the wafer diet) at different concentrations; R. dominica beetles required about 20 times the concentration to deter feeding compared to S. oryzae and more than twice compared to T. castaneum. Comparison of toxicity and deterrent activity with respective artificial blends as binary mixtures revealed that synergism was not a generalized phenomenon, and the variations were both species as well as blend specific. Individual compound efficacy correlations were not ascertained, which suggests that artificial blends could be prepared to obtain potential mixtures for substantial control of stored-grain insect pests. The present study also implies that the compounds are mostly acute toxins, and whatever inhibition in feeding was obtained could be due to physiological toxicity rather than any interaction with gustatory receptors. [ABSTRACT FROM AUTHOR]

Connective tissue formation following muscle injury and remedial surgery may involve changes in the stiffness and configuration of the connective tissues linking adjacent muscles. We investigated changes in mechanical interaction of muscles by implanting either a tissue-integrating mesh ( n = 8) or an adhesion barrier ( n = 8) to respectively increase or decrease the intermuscular connectivity between soleus muscle ( SO) and the lateral gastrocnemius and plantaris complex ( LG+ PL) of the rat. As a measure of mechanical interaction, changes in SO tendon forces and proximal-distal LG+ PL force differences in response to lengthening LG+ PL proximally were assessed 1 and 2 weeks post-surgery. The extent of mechanical interaction was doubled 1 week post-implantation of the tissue-integrating mesh compared to an unaffected compartment ( n = 8), and was more than four times higher 2 weeks post-surgery. This was found only for maximally activated muscles, but not when passive. Implanting the adhesion barrier did not result in a reduction of the mechanical interaction between these muscles. Our findings indicate that the ratio of force transmitted via myofascial, rather than myotendinous pathways, can increase substantially when the connectivity between muscles is enhanced. This improves our understanding of the consequences of connective tissue formation at the muscle boundary on skeletal muscle function. [ABSTRACT FROM AUTHOR]