Discrimination of Rhizobium japonicum,Rhizobium lupini,Rhizobium trifolii,Rhizobium leguminosarum and of bacteriods by uptake of 2-ketoglutaric acid,glutamic acid and phosphate

Rhizobium strains (one each of Rh.japonicum, Rh. lupini, Rh. leguminosarum) take up 2-ketoglutaric acid in general much faster and from lower concentrations in the medium than strains of Escherichia coli, Bacillus subtilis and Chromobacterium violaceum. A strain of Enterobacter aerogenes, however, is more similar to some Rhizobium strains. The same strains of Rhizobium take up also phosphate much faster and from lower concentrations than the other bacteria tested. 4 strains of Rh. lupini proved to be significantly different from 4 strains of Rh. trifolii in taking up l-glutamic acid from three to ten times lower concentration within 5 h. A similar difference was noticed between 5 strains of Rh. leguminosarum and 2 strains of Rh. japonicum for the uptake of 2-ketoglutaric acid and of l-glutamic acid. Isolated bacteriods from nodules of Glycine max var. Chippeway have a reduced uptake capacity for glutamic acid and for 2-ketoglutaric acid during the first 10–12 h, but reach the same value after 24 h as free living Rh. japonicum cells. The differences in the uptake kinetics are independent of cell concentration. The group II Rhizobium strains (Rh. japonicum and Rh. lupini, slow growing Rhizobium) are characterized by a rapid uptake of glutamic acid to a lowremaining concentration of 1–3×10^-7 M and an uptake of 2-ketoglutaric acid to a remaining concentration of 2–5×10^-7 M. The group I Rhizobium strains (Rh. trifolii and Rh. leguminosarum, fast growing Rhizobium), can be characterized by a much slower uptake of both substances with a more than ten times higher concentration of both metabolites remaining in the medium after the same time.     

Antigenic affinities of the root-nodule bacteria of legumes

Antisera prepared against 58 strains of root-nodule bacteria and against 16 strains belonging to the genusAgrobacterium were tested against 113 strains ofRhizobium, 20 strains ofAgrobacterium and 20 strains of other, possibly related, bacteria.Three serologically distinct groups of root-nodule bacteria were noted: (1)Rh. trifolii, Rh. leguminosarum andRh. phaseoli; (2)Rh. lupini, Rh. japonicum andRhizobium spp.; (3)Rh. meliloti. Strains ofRh. meliloti showed serological affinities withA. radiobacter andA. tumefaciens. All groups showed wider flagellar than somatic agglutination, and many different serotypes were apparent.The groupings obtained from this investigation are compared with those derived from other taxonomic studies, and the use of serological methods in rhizobial classification is discussed.     

Pesticide Concentrations in Matrices Collected in the Perinatal Period in a Population of Pregnant Women and Newborns in New Jersey,USA

Gestational exposure to pesticides may adversely affect fetal development and birth outcomes. However, data on fetal exposure and associated health effects in newborns remain sparse. We measured a variety of pesticides and metabolites in maternal urine, maternal serum, cord serum, amniotic fluid, and meconium samples collected at the time of cesarean delivery from 150 women in central New Jersey, USA. Women who used pesticides at home had higher concentrations of pesticides or metabolites in cord serum [e.g., dacthal (p = .007), diethyltoluamide (p = .043), and phthalimide (p = .030)] than those who did not use pesticides, suggesting that residential use of pesticides may contribute to overall exposure as assessed by biomonitoring. Except for orthophenylphenol, the concentrations of most pesticides in biological matrices of this study population were either comparable to or lower than the levels reported in previous studies and in the U.S. general population. The daily exposure estimates of two representative organophosphorus insecticides (chlorpyrifos and diazinon) were lower than most regulatory protection limits (USEPA oral benchmark dose₁₀/100, USEPA reference oral dose, or ATSDR minimal risk levels); however, they were near or at the USEPA's population-adjusted doses for children and women. No abnormal birth outcomes or other clinical endpoints were noted in those newborns who had higher concentrations of orthophenylphenol during the perinatal period.     

Toxicity of a number of pesticides to strains ofTyphlodromus pyri andAmblyseius andersoni (Acari: Phytoseiidae)

Side effects of ten pesticides used in orchards and vineyards were tested with a laboratory method on several Dutch and Italian strains of the predatory mitesTyphlodromus pyri Scheuten andAmblyseius andersoni (Chant). Resistant and susceptible strains of both species were studied. Results showed that a test which evaluates mortality of various developmental stages and fecundity of adult females is better than one that measures only survival of adult females. A definite resistance to certain pesticides was found in ItalianT. pyri andA. andersoni. The level of resistance to parathion, azinphos-methyl and carbaryl was particularly high in some strains ofA. andersoni. The high level of resistance to certain pesticides was often associated with a marked reduction in fecundity.      

UV-induced mutability in repair-deficientrad6-1 strains ofSaccharomyces cerevisiae is caused by a suppressor gene

TheRAD6 gene is a multifunctional gene required for DNA repair, induced mutagenesis and sporulation. The survival and revertibility of two loci in fourrad6-1 mutant strains of different origin after UV irradiation were followed. As expected, all therad6-1 strains tested were more sensitive to UV radiation in comparison withRAD6 strains. The reversion frequency per survivor intrpl-289 andarg4–17 alleles was significantly higher in all fourrad6-1 mutant strains than in wild-type strains after equal doses of UV radiation. On the basis of genetic analysis we suggest that the phenomenon of increased frequency of induced mutagenesis is caused by a suppressor gene.     

Phylogeny and physiology of Drosophila opsins

Phylogenetic and physiological methods were used to study the evolution of the opsin gene family in Drosophila. A phylogeny based on DNA sequences from 13 opsin genes including representatives from the two major subgenera of Drosophila shows six major, well-supported clades: The blue opsin clade includes all of the Rhl and Rh2 genes and is separated into two distinct subclades of Rhl sequences and Rh2 sequences; the ultraviolet opsin clade includes all Rh3 and Rh4 genes and bifurcates into separate Rh3 and Rh4 clades. The duplications that generated this gene family most likely took place before the evolution of the subgenera Drosophila and Sophophora and their component species groups. Numerous changes have occurred in these genes since the duplications, including the loss and/or gain of introns in the different genes and even within the Rhl and Rh4 clades. Despite these changes, the spectral sensitivity of each of the opsins has remained remarkably fixed in a sample of four species representing two species groups in each of the two subgenera. All of the strains that were investigated had R1-6 (Rhl) spectral sensitivity curves that peaked at or near 480 nm, R7 (Rh3 and Rh4) peaks in the ultraviolet range, and ocellar (Rh2) peaks near 420 nm. Each of the four gene clades on the phylogeny exhibits very conservative patterns of amino acid replacement in domains of the protein thought to influence spectral sen sitivity, reflecting strong constraints on the spectrum of light visible to Drosophila.     

一株3-苯氧基苯甲酸降解菌的筛选及其协同Bacillus licheniformis G-04降解高效氯氰菊酯的研究

【目的】从长期受拟除虫菊酯类农药污染的白菜根系土壤分离1株3-苯氧基苯甲酸(3-phenoxybenzoic acid, 3-PBA)降解菌,并探究其与Bacillus licheniformis G-04协同作用对高效氯氰菊酯(beta-cypermethrin,Beta-CP)的降解及污染土壤的生物修复,为土壤农药残留危害处理提供优良菌种。【方法】采用富集驯化、筛选纯化方法,筛选3-PBA降解菌,并通过形态和生理生化特征以及16S rRNA序列分析进行鉴定。利用Origin 8.0分析3-PBA降解菌与B. licheniformis G-04的生长降解动力学过程。同时,采用高效液相色谱法评估两菌株协同降解Beta-CP的能力及其对受Beta-CP污染土壤的修复作用。【结果】筛选得到1株3-PBA高效降解菌HA516,48 h对3-PBA (100 mg/L)的降解率达到87.73%,经鉴定为皮特不动杆菌(Acinetobacter pittii);构建了该菌株和B. licheniformis G-04的生长降解动力学方程,结果表明模型与实验数据能较好拟合;以6.7∶3.3的接种比例先接种B. licheniformis G-04,24 h后再接入A. pittii HA516协同作用,在48 h,Beta-CP (50 mg/L)的降解率达78.37%,较单菌株(B. licheniformisG-04)的降解率(40.47%)提高了37.90%,半衰期从58.39h缩短为24.51h。土壤修复实验表明,第7天协同组对Beta-CP(30mg/kg)的降解率较单菌株提高了33.26%,达到79.27%。【结论】A.pittiiHA516是1株3-PBA高效降解菌,能与B. licheniformis G-04协同增效降解Beta-CP,可作为修复3-PBA或拟除虫菊酯类农药污染的优良微生物资源。     

Assessment of pesticide susceptibility for <Emphasis Type="Italic">Typhlodromus exhilaratus</Emphasis> and <Emphasis Type="Italic">Typhlodromus phialatus</Emphasis> strains (Acari: Phytoseiidae) from vineyards in the south of France

Two species of Phytoseiidae predominated in and around vineyards in an experimental site in the south of France: Typhlodromus exhilaratus is the dominant species on grapes, whereas T. phialatus occurs in the uncultivated areas surrounding these crops. To help understand their distribution, this study aims to determine their susceptibility to a fungicide (dimethomorph + mancozeb) and an insecticide (chlorpyriphos-ethyl), which have been widely used at the experimental site for at least four years. The hypothesis tested is that the effects of these two pesticides differ between T. exhilaratus and T. phialatus. Two populations of T. exhilaratus, one collected on a vine crop where the two pesticides were applied and the other in an unsprayed orchard of Sorbus domestica, and one population of T. phialatus collected on Viburnum tinus from uncultivated areas adjacent to the vine crop, were tested under laboratory conditions. The fungicide seems to affect the females of T. phialatus more than those of T. exhilaratus from vine. However, at the recommended field concentration the female mortality rates of the three strains were low and female fecundities were not significantly different. Conversely, mortality rates were very high for the three strains at the recommended field concentration of chlorpyrifos-ethyl. The strain of T. exhilaratus from vine seems to be more tolerant and 20% of females survived the recommended field rate. This suggests better survival after insecticide application than females of T. phialatus (100% mortality at a lower concentration than the recommended rate). As extrapolation of laboratory results to the field is often irrelevant, these differences could be just one of several factors affecting the spatial segregation of the two species in the agrosystem considered. Possible explanations other than pesticides for the poor settlement of T. phialatus in vine plots are discussed.     

Molecular phylogeny and detailed morphological analysis of two freshwater Rhizoclonium strains from contrasting spring types in Egypt and Italy

Two Rhizoclonium strains thriving in contrasting spring types (slightly hot spring/ambient, shaded pool spring) and biogeographic areas (El-Farafra Oasis in the Western Desert of Egypt/River-Po Plain in Northern Italy) were studied in depth based on field and cultured material, bright-field and fluorescence microscopy, and phylogenetic molecular analyses (SSU and LSU rRNA gene sequences). This polyphasic approach revealed that the two Rh. strains clearly belonged to the Rhizoclonium clade but differed in some of their key diagnostic features. The Egyptian Rhizoclonium strain, isolated from the spring-fed (Ain El-Balad) agricultural ditch in El-Farafra Oasis, was described with the working name ‘Rhizoclonium sp. 10.6 μm from a desert, slightly-hot spring’ based on its smaller cell diameter, ecological and phylogenetic molecular traits compared to allied morphospecies. Moreover, it was highlighted that the L/D ratio can be more than 3.0 within this group. The Italian Rhizoclonium strain, collected from the Fontanile Valle Re-shaded, pool ambient spring (Emilia-Romagna Region), was virtually identical to other strains identified as Rh. hieroglyphicum from China and Japan, due to its highly supported congruence in morphological characteristics and phylogenetic position. This study provided the first partial LSU and SSU rRNA gene sequences for European Rh. hieroglyphicum based on available literature. Phenotypic plasticity of rhizoid formation was also observed in both Rhizoclonium strains studied using culturing approaching techniques. Our investigation also confirms that a lot of work with a variety of approaches is still needed to assess the ecological preferences, morphological plasticity, and phylogenetics of freshwater Rhizoclonium taxa worldwide.     

Genetic structure of endangered Rhodiola sachalinensis

Rh. sachalinensis is a perennial,medicinal herb. The species is rare with apatchy distribution. Due to heavy disturbanceby human activities, it is now endangered.Allozyme analysis was employed to estimate itsgenetic diversity. Nineteen loci encoding 12enzyme systems were used. Rh.sachalinensis has a lower genetic variationwithin patches and higher differentiationbetween patches than other endangered, endemicspecies with limited distributions. The geneticdifferentiation between patches withingeographic regions is lower than that amonggeographic regions. Genetic drift is likely adominant factor contributing to the observedpattern of genetic structure. Because a higherdegree of genetic differentiation existsbetween patches in Rh. sachalinensis,more populations should be protected insitu, and samples from more populations shouldbe collected for ex situ conservation.     

Semi‐field evaluation of the effects of sub‐lethal doses of pesticides,with and without adult Schistocerca gregaria pheromone,on hoppers

Previously, we reported a chain of effects induced by phenylacetonitrile, the gregarious‐phase adult cohesion pheromone of the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), on conspecific hoppers. Specifically, the nymphs became hyperactive and displayed high levels of intraspecific predation, as surviving individuals gradually shifted to the solitary phase. The findings suggested that the pheromone could induce a significant level of mortality of the nymphs and predispose them to greater sensitivity to lower doses of insecticides. In this study, we compared the effects of the pheromone and various doses of three pesticides (fipronil, malathion, and carbosulfan) to pheromone‐exposed and unexposed crowd‐reared hoppers in semi‐field enclosures. The pheromone on its own displayed a high level of cumulative mortality of the nymphs (89%). Although combinations with fractional pesticide doses gave control efficiencies that were, in most cases, higher than with individual pesticides, pheromonal and pesticidal effects were only partially complementary, probably because of the feeding‐deterrent effects of the pesticides and the resulting reduction in cannibalism. However, our results demonstrate the possibility of significantly reducing the levels of pesticides used in hopper control and, thus, their negative environmental effects.     

Biodegradation of chlorpyrifos by bacterial consortium isolated from agriculture soil

Organophosphorous pesticides are widely used in agriculture to control major insect pests. Chlorpyrifos is one of the major organophosphorous pesticides which is used to control insects including termites, beetles. The widespread use of these pesticides is hazardous to the environment and also toxic to mammals, thus it is essential to remove the same from the environment. From the chlorpyrifos contaminated soil nine morphologically different bacterial strains, one actinomycete and two fungal strains were isolated. Among those isolates four bacterial strains which were more efficient were developed as consortium. The four bacterial isolates namely Pseudomonas putida (NII 1117), Klebsiella sp., (NII 1118), Pseudomonas stutzeri (NII 1119), Pseudomonas aeruginosa (NII 1120) present in the consortia were identified on the basis of 16S rDNA analysis. The intracellular fractions of the consortium exhibited more organophosphorus hydrolase activity (0.171 ± 0.003 U/mL/min). The degradation studies were carried out at neutral pH and temperature 37°C with chlorpyrifos concentration 500 mg L⁻¹. LC-mass spectral analysis showed the presence of metabolites chlopyrifos-oxon and Diethylphosphorothioate. These results highlight an important potential use of this consortium for the cleanup of chlorpyrifos contaminated pesticide waste in the environment.     

Comparison of the reversibility of locipet23 andlys2 after UV irradiation in the standard and UV-sensitive strains ofSaccharomyces cerevisiae

Reversibility of the respiration-deficient locuspet23 and auxotrophic locuslys2 was followed in the standard (RAD1) and UV sensitive (rad1–2) strains ofSaccharomyces cerevisiae, both after identical doses of UV radiation and at identical survival. When comparing the reversibility after the treatment with identical doses of UV radiation a much higher reversibility of both loci in strainrad1–2 could be detected. When comparing the reversibility of the loci in question at identical survival of both strains it could be found that the reversibility of thepet23 locus is again much higher in strainrad1–2, whereas the reversibility of thelys2 locus is roughly identical in the two strains. Thus, the function of geneRAD1 in repair processes is apparently associated with the “error-free” repair, both at low and high doses of ultraviolet radiation.     

Resistance to chlorpyriphos in the predatory mite Kampimodromus aberrans

The predatory mite Kampimodromus aberrans (Oudemans) is a key biocontrol agent in vineyards in Italy and Southern Europe. Its susceptibility to common pesticides (e.g., organophosphates) has been considered an important factor in preventing successful biocontrol of phytophagous mites. Nevertheless, populations of K. aberrans apparently resistant to organophosphates (OPs) have been reported to occur in Northern Italian vineyards. The resistance of K. aberrans to fungicides (e.g., mancozeb) has been demonstrated in the laboratory in France, but little is known about the toxicity of insecticides towards K. aberrans. Of these pesticides, the OP chlorpyriphos is extensively used in viticulture to control lepidopterans and homopterans. The present study investigated the dose–response effect of chlorpyriphos in four K. aberrans strains characterized by different levels of exposure to OP insecticides in the past: from never to frequently exposed. Resistance to chlorpyriphos is demonstrated for populations collected from vineyards and apple orchards. Resistance factors exceeded 145,000× for the three strains collected in vineyards and orchard. LC₅₀ values for resistant strains were 1.85–6.83 times higher than the recommended field dose of chlorpyriphos for vineyards and orchards (525 mg a.i./l).     

Chemical analysis of exocellular, acid polysaccharides from seven Rhizobium strains

A comparative, chemical analysis of the acid exopolysaccharides from seven Rhizobium strains, involving the taxonomic groups Rhizobium meliloti, Rh. trifolii, Rh. phaseoli, and Rh. leguminosarum, is presented. Apart from the polysaccharide from Rh. meliloti, which is known to lack uronic acid, no significant differences in the carbohydrate composition were found. The two non-nitrogen-fixing strains [infective (Coryn), and non-infective (Bart A)] gave polysaccharides which differ from those produced by the infective and nitrogen-fixing strains in the detailed structural features. This difference is expressed in the pattern of periodate oxidation and cation-binding capacity.     

噻虫嗪和噻虫胺对鸟类的急性毒性与风险评估

[目的]明确噻虫嗪与噻虫胺2种新烟碱农药对鸟类的风险。[方法]采用经口灌胃法测定98%噻虫嗪或噻虫胺原药、30%噻虫嗪或20%噻虫胺悬浮剂、42%噻虫嗪或46%噻虫胺种子处理悬浮剂对日本鹌鹑的毒性等级。根据供试农药对鸟类的毒性数据,结合田间用药信息,开展了2种农药对鸟类的初级风险评估。[结果]98%噻虫嗪原药、30%噻虫嗪悬浮剂和42%噻虫嗪种子处理悬浮剂对日本鹌鹑的半致死剂量(7 d-LD₅₀)分别为1500、481和266 mg·kg^-1,毒性等级分别为低毒、中毒、中毒,悬浮剂和种子处理悬浮剂的毒性高于原药。98%噻虫胺原药、20%噻虫胺悬浮剂和46%噻虫胺种子处理悬浮剂对日本鹌鹑的7 d-LD₅₀分别为369、397和1569 mg·kg^-1,毒性等级分别为中毒、中毒和低毒,种子处理悬浮剂的毒性最低。噻虫嗪和噻虫胺的悬浮剂在水稻田间使用时,对鸟类急性、短期和长期暴露的风险商值均小于1,风险可接受;噻虫嗪和噻虫胺的种子处理悬浮剂在玉米田应用时,对鸟类急性、短期和长期暴露的风险商值均大于1,风险不可接受。[结论]噻虫嗪和噻虫胺的悬浮剂在田间应用时对鸟类相对安全,2种农药的种子处理悬浮剂可能对鸟类产生危害。在种子处理场景中,播种后尽可能覆土或覆膜,减少种子直接暴露被鸟类取食;在鸟类保护区域,应避免使用噻虫嗪和噻虫胺的种子处理悬浮剂,以减轻农药施用对鸟类的危害。     

Biological and molecular characteristics of Beauveria bassiana isolates from California Lygus hesperus (Hemiptera: Miridae) populations

Lygus hesperus is an important pest of many crops grown in the Western US. In addition, other species of Lygus cause damage in other parts of the world. To date, no selective pesticide exists for the control of Lygus spp. and broad spectrum pesticides that also kill natural enemies may lead to secondary pests. Entomopathogenic fungi may offer an alternative to chemical pesticides. Isolates of Beauveria bassiana collected from San Joaquin Valley of California (SJV) L. hesperus populations were screened for their ability to grow at high temperatures and for their ability to infect and kill L. hesperus adults and nymphs under laboratory conditions. No isolate grew at 37 or 35 °C but most isolates were able to grow at 32 °C. In addition, one L. hesperus isolate was more efficacious at higher doses than the commercial isolate. Microsatellite markers were used to determine that selected isolates could be distinguished from other isolates. Preliminary information suggested 82 SJV isolates of B. bassiana were closely related to each other but distantly related to the commercial isolate.     

Production of Trichoderma strains with pesticide-polyresistance by mutagenesis and protoplast fusion

The sensitivity of two cold-tolerant Trichoderma strains belonging to the species T. harzianum and T.␣atroviride was determined to a series of pesticides widely used in agriculture. From the 16 pesticides tested, seven fungicides: copper sulfate, carbendazim, mancozeb, tebuconazole, imazalil, captan and thiram inhibited colony growth of the test strains significantly with minimal inhibitory concentrations of 300, 0.4, 50, 100, 100, 100 and 50 g/ml, respectively. Mutants resistant to carbendazim and tebuconazole were produced from both wild type strains by means of UV-mutagenesis. The cross-resistance capabilities and in␣vitro antagonistic properties of the mutants were determined. Carbendazim-resistant mutants showed total cross-resistance to benomyl and thiabendazole at a concentration of 20 g/ml. Intraspecific protoplast fusion was carried out between carbendazim- and tebuconazole-resistant mutants of both parental strains, and putative haploid recombinants with stable resistance to both pesticides were produced in the case of T.␣atroviride. These pesticide-polyresistant progenies are potential candidates for application in an integrated pest management system.This work was presented as an oral lecture in section ‘Agriculture, Soil, Forest Microbiology’ at the BioMicroWorld2005 conference.     

The rhizobia of lupinus densiflorus Benth., with some remarks on the classification of root nodule bacteria

Summary Four strains of rhizobia from Lupinus densiflorus Benth. were found to differ from the normal slow-growing strains of Rhizobium lupini by a rapid growth on agar medium, a somewhat different pattern of carbon metabolism, good growth in simple synthetic media, and also in their host plant relationships. Three strains had subpolar flagella like other lupine rhizobia, and the same was found to be predominant in a fourth strain previously described as having peritrichous flagellation.Two strains formed effectively nitrogen-fixing root nodules in Lotus corniculatus and Anthyllis vulneraria where the other two formed semieffective or ineffective nodules. All four strains formed ineffective nodules in Lotus uliginosus and Ornithopus sativus. The slow-growing strains of Rh. lupini mostly produce ineffective nodules in Lotus corniculatus but have now been seen to be effective in Lotus uliginosus.Instead of trying to define Rh. lupini as a cross-inoculation group it seems preferable to abandon it as a species and to transfer the fastgrowing strains to Rhizobium leguminosarum sensu Graham (1964) and De Ley and Rassel (1965), in spite of their predominantly subpolar flagellation. The familiar slow-growing strains would remain in the broad group of slow-growing root nodule bacteria with purely subpolar flagellation, called Phytomyxa japonica by Graham (1964) and Rhizobium japonicum by De Ley and Rassel (1965).     

Deltamethrin‐induced feeding plasticity in pyrethroid‐susceptible and ‐resistant strains of the maize weevil,Sitophilus zeamais

Phenotypic plasticity contributes to the adaptative evolution of populations exposed to new or altered environments. Feeding plasticity is a component of phenotypic plasticity not usually considered in insect strains adapted to insecticide‐altered environments, but which may either accentuate or mitigate insecticide resistance. This is a concern in the pyrethroid‐resistant strains of the maize weevil Sitophilus zeamais Motsch. (Col., Curculionidae), and the reason for this study. A pyrethroid‐susceptible and two pyrethroid‐resistant strains of maize weevil were subjected to free‐choice and no‐choice tests with maize grains sprayed with increasing doses of the pyrethroid, deltamethrin. The insects from the pyrethroid‐resistant strains exhibited higher feeding avoidance with increased deltamethrin doses than insects from the susceptible strain when subjected to free‐choice tests. The strains of maize weevil physiologically resistant to pyrethroids were also behaviourally resistant to deltamethrin – an additional management concern. The resistant strains avoid deltamethrin‐sprayed grains and are less nutritionally affected by this compound, with divergent responses from the susceptible strain with increased doses of deltamethrin. Furthermore, the higher relative growth rate and consequently higher efficiency of food conversion observed in the insecticide‐resistant strains were significant even without insecticide exposure, indicating that these traits are stimulus‐independent and may persist even without further insecticide selection, potentially limiting the options available for their management.