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Abstract The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, is a devastating insect-pest of 29 plants including date palm. It feeds inside the tree bark thus it is difficult to manage using insecticides. Only a few insecticides have been found effective against RPW. Among these insecticide, emamectin benzoate (EMB) is widely used. This insecticide can pose threat human and environmental health as it is used in the form of tree injection. Thus, keeping in view its possible, its sublethal effect on RPW was studied using Age-stage, two sex life table. Life table parameters of the progeny of exposed larvae to LC10, LC25, and LC50 of EMB were computed. Statistically higher fecundity (161.12 per female) was observed in control treatment, while less fecundity was observed in LC50 treatment. Significantly higher values for intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (R o ) (0.0376, 1.0383, and 67.13 per day, respectively) were recorded for the control treatment. Contrarily, lower values for r, R o , and λ i.e. 0.0318, 23.82, and 1.0324 per day, respectively were recorded in the LC50 treatment. Decreased population parameters suggest that EMB can be successfully used in for the management of RPW.

BACKGROUND: The citrus red mite, Panonychus citri is a serious pest of the citrus industry and has developed resistance to many acaricides. Broflanilide is a novel meta‐diamide insecticide that binds to a new site on the γ ‐aminobutyric acid receptor with high potency against pests. However, little information has been reported about its effect on the citrus red mite. RESULTS: Broflanilide exhibited higher toxicity to female adults and eggs of a laboratory strain of P. citri The median lethal concentration (LC50), 9.769 mg/L and 4.576 mg/L, respectively) than other commonly used acaricides and was also toxic to two P. citri field strains. Broflanilide treatment with LC10, LC20, and LC30 significantly decreased the fecundity and longevity of female adults of F0P. citri compared with the control. The duration of larva, protonymph, deutonymph and adult, and total life span in the F1 generation were significantly reduced after treatment of F0 with broflanilide. Population parameters, including the intrinsic rate of increase (r) and finite rate of increase (λ), were significantly increased, and the mean generation time (T) of F1 progeny was significantly reduced in the LC20 treatment. The predicted population size of F1 increased when parental female adults were treated with sublethal concentrations. CONCLUSION: Broflanilide had high acaricidal activity toward P. citri, and exposure to a sublethal concentration significantly inhibited the population growth of F0. The transgenerational hormesis effect is likely to cause population expansion of F1. More attention should be paid when broflanilide is applied to control P. citri in citrus orchards. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

The red palm weevil (RPW), Rhynchophorus ferrugineus Olivier, is a devastating insect-pest of 29 plants including date palm. It feeds inside the tree bark thus it is difficult to manage using insecticides. Only a few insecticides have been found effective against RPW. Among these insecticide, emamectin benzoate (EMB) is widely used. This insecticide can pose threat human and environmental health as it is used in the form of tree injection. Thus, keeping in view its possible, its sublethal effect on RPW was studied using Age-stage, two sex life table. Life table parameters of the progeny of exposed larvae to LC10, LC25, and LC50 of EMB were computed. Statistically higher fecundity (161.12 per female) was observed in control treatment, while less fecundity was observed in LC50 treatment. Significantly higher values for intrinsic rate of increase (r), finite rate of increase (λ), and net reproductive rate (Ro) (0.0376, 1.0383, and 67.13 per day, respectively) were recorded for the control treatment. Contrarily, lower values for r, Ro, and λ i.e. 0.0318, 23.82, and 1.0324 per day, respectively were recorded in the LC50 treatment. Decreased population parameters suggest that EMB can be successfully used in for the management of RPW. [ABSTRACT FROM AUTHOR]

BACKGROUND: The citrus red mite, Panonychus citri (McGregor) is a globally distributed agricultural pest. Of late, resistance to common acaricides has raised concerns that chemical control of P. citri is an inefficient means of control. Fluralaner, a highly toxic isoxazoline insecticide used to treat various ectoparasites, presents one potential alternative. However, little information has been reported about the effect of fluralaner on the citrus red mite. This study aims to evaluate the toxicity, sublethal and transgenerational effects of fluralaner on P. citri. RESULTS: In both laboratory and field populations of P. citri, we found fluralaner to be more toxic than conventional alternatives, including fenpropathrin, bifenazate, azocyclotin and chlorpyrifos. Interestingly, fluralaner proved more toxic to female adults than to the eggs of P. citri, with median lethal concentrations (LC50) of 2.446 and 122.7 mg L−1, respectively. Exposure to sublethal concentrations of fluralaner (LC10, LC20 and LC30) significantly reduced the fecundity and longevity of female adults P. citri individuals. Although concentrations of fluralaner applied to the parental female adults (F0) led to some changes in the developmental parameters, there were no significant changes in most of the life table parameters or population growth of the F1 generation. CONCLUSION: Our results indicate that fluralaner is highly toxic to P. citri, and a significant sublethal effect on F0 could suppress the population growth of P. citri, but not for F1. Fluralaner may be considered as a pesticide for the future management of the citrus red mite. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Eretmocerus hayati is an effective biocontrol agent against whitefly Bemisia tabaci. Thiamethoxam, abamectin, and sulfoxaflor are the commonly used insecticides for whitefly control. We explored the sublethal and transgenerational effects of these insecticides on E. hayati in laboratory by exposing the parental pupae to the maximum field-recommended concentration of each insecticide. The adult longevity and host control efficiency of F0 generation treated with insecticides decreased significantly compared with control. Demographic characteristics, parasitism and host-feeding rate of E. hayati F1 progeny was analyzed using the age-stage, two-sex life table, and the CONSUME-MSChart computer program. The results indicated that most life traits of E. hayati F1 generation, including the development duration of immature, longevity of female adults, oviposition days and fecundity were negatively affected by thiamethoxam. However, except for the prolonged development duration of pupae, no significant negative effect on other demographic parameters or population parameters of E. hayati F1 generation were observed in both abamectin and sulfoxaflor groups. The net host-feeding rate and whitefly-killing rate (parasitism + host-feeding) of E. hayati F1 females were adversely affected by thiamethoxam but not affected by abamectin and sulfoxaflor. Thiamethoxam had the most severe sublethal and transgenerational effects on E. hayati of the three insecticides tested. However, abamectin was more compatible with release of E. hayati, especially when applied during the E. hayati pupal stage. These findings provide insights into comprehensively understanding of the effects of insecticides used in whitefly control as well as the integrate management of B. tabaci. [ABSTRACT FROM AUTHOR]

Thrips hawaiiensis (Morgan) (Thysanoptera: Thripidae) is a sap-sucking pest that seriously damages several crops and reduces their economic value. Exposure to low concentrations of insecticides may have a sublethal effect on surviving insects. In order to provide a reference for the rational application of emamectin benzoate, its sublethal effects on the development and reproduction of T. hawaiiensis were evaluated. Pupal development time was significantly shorter in T. hawaiiensis treated with sublethal concentrations of emamectin benzoate (LC10 and LC20) than in control. Female adult longevity and female total longevity were significantly longer following LC20 treatment than in the control and LC10 treatment groups. Nevertheless, male adult longevity and male total longevity were significantly shorter in the LC10 treatment group than in the control and LC20 treatment groups. The sublethal concentration of emamectin benzoate (LC20) significantly shortened the preadult stages and the mean generation. Meanwhile, it significantly increased the finite rate of increase, intrinsic rate of increase, and net reproductive rate. The fecundity was significantly higher after LC20 treatment than after LC10 and control treatments. Compared with the control group, the LC10 and LC20 groups of T. hawaiiensis adults showed a significantly higher expression of the vitellogenin (Vg) and vitellogenin receptor (VgR) genes, which played a key role in increasing their fecundity. These findings suggest that short-term exposure to sublethal concentrations of emamectin benzoate may lead to a resurgence and secondary outbreak of T. hawaiiensis infestation. The results have practical applications for the management of this important and noxious pest. [ABSTRACT FROM AUTHOR]

Tetranychus urticae Koch (Acari: Tetranychidae) is a notorious crop pest with a worldwide distribution that has developed resistance to a wide range of acaricides. Combined tactics of pest management have special significance not only for a reduction in pesticide residues but also to maintain the natural enemy activity, which is an objective of IPM programs. Here, we investigated the effect of low-lethal concentrations of bifenazate at LC10, LC20, and LC30 on development and reproduction parameters of Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae). Lethal and sub-lethal concentrations were estimated using leaf dip bioassay method. The crude data were analyzed based on age-stage, two-sex life table analysis. Toxicological assays showed bifenazate treatments gradually decreased the longevity and total life span of both sexes. Our results indicated that reproductive and total fecundity of the next generation were also affected by sublethal concentrations. All concentrations caused a significant decline in oviposition days, compared to the control. The intrinsic rate of increase (rm) varied from 0.1344 to 0.1151 day-1 for the mites treated with distilled water and LC30 treatments, respectively. The finite rate of increase (λ) was affected by the acaricide concentration (lowest at LC30 concentration: 1.1221 day-1). Bifenazate concentration (LC10, LC20 and LC30) treatments gradually reduced the gross reproduction rate (GRR) and net reproductive rate (R0). Based on obtained results from current study, bifenazate is not a favorable acaricide with A. swiriskii and cannot be recommended to use with this predatory mite in integrated management. [ABSTRACT FROM AUTHOR]

Nanotechnology is a new field in the pesticide industry. Nanopesticides represent an emerging technological tool that offers a range of benefits including increased efficacy, durability, and reduction in the amounts of used active ingredients. However, due to the lack of studies on the toxicity and the sublethal effects on pests and natural enemies, the extent of action and fate of these nanopesticdes is still not fully understood limitting thus their wide use. In this study, we encapsulated the pirimicarb insecticide using nanostructured lipid carriers (NLC) and investigated the toxicity and sublethal effects (LC25) of the resulting nanocapsules against the cabbage aphid, Brevicoryne brassicae (Linnaeus) (Hemiptera: Aphididae) and its natural enemy the green lacewings Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae). Nanoencapsulation of pirimicarb enhanced 12.6-fold its toxicity to cabbage aphids compared to its commercial formulation. Furthermore, analysis of the age-stage, two-sex life table showed that negative effects on the B. brassicae aphid population growth were observed on F0 and F1 generations when aphids of parental (F0) generation were exposed to subelethal dose (LC25) of both formulations of pirimicarb. However, negative effects from sublethal exposure to the commercial and nanoformulated pirimicarb resulted in significant reduction on the net reproductive rate, intrinsic rate of natural increase, and finite rate of increase of the green lacewings C. carnea. Our findings indicate that the approaches and assumptions used to assess the risks of conventional insecticides may not apply for nanopesticides. Further research is still needed to better understand the environmental impact of these compounds. [ABSTRACT FROM AUTHOR]

A combination of pesticides and biological control agents is frequently necessary to achieve successful pest management requiring the assessment of their compatibility for the intended purpose. Aphidius flaviventris Kurdjumov is one of the parasitoids of the cotton aphid Aphis gossypii Glover, whose susceptibility to pesticides was not yet investigated. Accordingly, we investigated the lethal and sublethal effects of the commonly utilized insecticide mixture thiacloprid + deltamethrin on the cotton aphid and its parasitoid wasp Aphidius flaviventris. The estimated LC50 for the aphid was 14.1 mg ai/l; the effects of sublethal exposure at LC10 (2.80 mg ai/l) and LC30 (7.28 mg ai/l) on the aphid life-table parameters led to significantly increase on the development time of third- and fourth-instar nymphs and preadult. Sublethal exposure to the insecticide mixture compromised aphid longevity, fecundity, and life-table parameters (r , R 0, and T). Moreover, population growth and parasitism rate of the parasitoid were significantly compromised at both concentrations of the insecticide mixture under sublethal exposure. These results not only indicate the efficacy of thiacloprid + deltamethrin against the cotton aphid, but also raise concerns regarding its negative impacts on the parasitoid Aphidius flaviventris and caution against its use in pest management programs. [ABSTRACT FROM AUTHOR]

BACKGROUND: Two‐spotted spider mite (TSSM), Tetranychus urticae Koch is a serious agricultural pest and has developed high levels of resistance to many acaricides. Hence, screening new acaricides is important in the control of TSSM. Fluralaner, a novel isoxazoline, has high activity against agricultural and ectoparasitic pests; however, little information is available about its effects on agricultural mites. Lethal and sublethal effects of fluralaner towards TSSM eggs and female adults were therefore evaluated in this study. RESULTS: Fluralaner exhibited higher activity towards TSSM female adults (LC50, 0.49 mg L−1) compared with commercial acaricides including fenpyroximate, pyridaben and hexythiazox, and also excellent activity towards eggs (LC50, 0.36 mg L−1). The results of a sublethal effect study showed a significant reduction in the duration and fecundity of female adults with increases in the tested concentrations. The net reproductive rate (R0) decreased to 67.34 ± 3.96 and 50.29 ± 3.40 offspring per individual in LC10 and LC30 treatments compared with control (108.31 ± 7.61 offspring per individual). The intrinsic rate of increase (r) and finite rate of increase (λ) in the controls (0.30 and 1.36 d−1) were significantly higher than in the LC30 treatment (0.25 and 1.29 d−1); whereas, they were almost identical to values for the LC10 treatment. No change in mean generation time (T) was observed at sublethal concentrations treatments. CONCLUSION: Our results demonstrated that fluralaner has high acaricidal activity and could be considered a potential acaricide for TSSM management. © 2019 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

• A sublethal concentration of abamectin (LC 25) increased longevity of Nilaparvata lugens F 0 females. • Abamectin inhibited the fecundity of F 1 brachypterous N. lugens. • Abamectin stress (LC 25) can affect the wing morphs of F 1 N. lugens. The brown planthopper Nilaparvata lugens negatively affects rice yield by sucking nutrients from the rice stem and spreading viruses. In this study, the effects of sublethal concentrations of abamectin on development, fecundity, and wing morphs of N. lugens were investigated. Treatment with sublethal concentrations of abamectin showed no significant effects on the developmental period of F 0 nymphs. Although LC 10 and LC 25 treatments resulted in 10% and 25% mortality, the LC 25 treatment significantly prolonged the lifespan of macropterous and brachypterous females. Abamectin-treated brachypterous females showed significantly lower fecundity than control females. Furthermore, abamectin treatment showed no significant effects on the developmental period of F 1 nymphs. However, LC 25 treatment significantly inhibited the fecundity of brachypterous F 1 females and significantly reduced the proportion of macropterous F 1 females and brachypterous F 1 males. LC 25 treatment showed no significant effects on the fecundity of macropterous F 1 females. Considering the proportion of macropterous and brachypterous F 1 females, the relative fitness of the macropterous F 1 nymphs in the control, LC 10 , and LC 25 treatment groups was 1, 1.02, and 0.84, respectively, and that of brachypterous F 1 nymphs was 1, 0.79, and 0.93, respectively. Sublethal concentrations of abamectin inhibited N. lugens emergence. The present findings indicate the potential of abamectin for N. lugens field control. [ABSTRACT FROM AUTHOR]

The whitefly, Aleuroclava jasmini (Takahashi) (Hemiptera: Aleyrodidae), is an important pest on paper mulberry Broussonetia papyrifera (L.) Vent. (Moraceae) plants in green spaces of Tehran, Iran. The predator mite Amblyseius swirskii Athias-Henriot is one of the most common species found in paper mulberry landscape and it is a major biological control agent of this pest. Knowledge of the impact of insecticides on predatory mites is crucial for integrated management programs of this whitefly. This study assessed, under laboratory conditions, the sublethal effect of acetamiprid on the life table parameters of A. swirskii fed on A. jasmini. The sublethal concentrations LC10, LC20 and LC30 were obtained based on a dose-effect test. Exposure to the sublethal concentrations of acetamiprid had significant effects on the total immature periods of both males and females. The total fecundity and oviposition period decreased with an increase in concentration. The estimated life table parameters indicated that sublethal concentrations of acetamiprid caused greater reduction in r, λ and R0 of A. swirskii compared to the control. Therefore, the use of acetamiprid to control of A. jasmini may have serious implications for integrated pest management programs that aimed at exploiting A. swirskii biological control in paper mulberry landscape. [ABSTRACT FROM AUTHOR]

Sogatella furcifera (Horváth) is one of the most important migratory pests of rice in Asia. When normal concentrations of deltamethrin are applied to control lepidopteran pests of rice in the field, it is likely that S. furcifera will be exposed to sublethal concentrations of this chemical. Therefore, we examined the sublethal effects of deltamethrin on the development and reproduction of S. furcifera using the rice stem dipping method. The results showed that exposure of 3rd instar S. furcifera to LC10 and LC25 deltamethrin significantly increased the emergence rates compared with the F0 generation control group, but there was no significant difference in the nymphal stage duration, adult longevity and female fecundity. Nymphal duration of the F1 generation was significantly prolonged under both treatments. Female fecundity also increased in this generation, with a significant difference between the LC25 treatment group and controls. The relative fitness of the LC10 and LC25 treatment groups was 0.84 and 0.80, respectively. The results showed that sublethal concentrations of deltamethrin stimulate the reproduction of S. furcifera, but decrease the relative fitness of the population. These results provided a reference point for the application of insecticides to control S. furcifera. [ABSTRACT FROM AUTHOR]

The cosmopolitan pest Aphis gossypii (Glover) causes considerable economic losses on various crops by its feeding damage and transmitting diseases around the world. Flupyradifurone is a novel butenolide pesticide; its toxicity on A. gossypii parent generation (F0) was estimated following treatment with LC25 concentration for 48 h. The adult longevity and fecundity of the F0 individuals treated by flupyradifurone showed no significant decrease in comparison with the control. Life table method was used to evaluate the sublethal effects on progeny population (F1). Results showed that the development time of the fourth instar and the preadult as well as the total pre-reproductive period were significantly prolonged, while their fecundity was significantly decreased compared with the control. Additionally, the intrinsic rate of increase (r), the finite rate of increase (λ), and the net reproductive rate (R 0) of F1 were all significantly lower in the group treated by LC25 than in the control group. These results reveal that the sublethal concentration of flupyradifurone could suppress the population growth of A. gossypii and indicate that this novel insecticide may be as a useful tool in pest management. [ABSTRACT FROM AUTHOR]

Myzus persicae (Sulzer) is an important agricultural pest worldwide that imparts substantial damage to various horticultural and agricultural crops. Broflanilide is a newly developed insecticide that exhibits high activity against crop pests such as M. persicae. Nevertheless, the effects of sublethal levels of broflanilide on M. persicae fitness and population growth remain unclear. We assessed the sublethal and transgenerational effects of broflanilide on M. persicae performance using an age-stage, two-sex life table. Our results reveal that broflanilide is highly toxic to M. persicae with a 72-h LC 50 of 2.541 mg/L. The LC 25 of broflanilide significantly reduced the longevity and fecundity of the F 0 and F 1 generations, and the LC 10 and LC 25 of broflanilide significantly prolonged the developmental period of the third instar nymph in the F 1 generation. The net reproductive rate (R 0), intrinsic rate of increase (r), and finite rate of increase (λ) were significantly lower in the LC 25 -treated aphids. LC 25 broflanilide treatment significantly downregulated the reproduction-related genes ERR and Vg and significantly upregulated JHEH expression in the F 0 generation. LC 25 and LC 10 broflanilide treatments significantly upregulated the detoxification-related genes CarE and CYP6CY3 , respectively, which may be related to broflanilide resistance in M. persicae. These results showed that broflanilide LC 25 exhibited a significant inhibitory effect on M. persicae populations, which can persist in the F 1 generation. Our study facilitates the understanding of the sublethal effect of broflanilide on aphid performance and helps develop methods and programs for controlling M. persicae using low broflanilide doses. • Broflanilide exhibits relatively high toxicity to M. persicae. • The LC 25 concentration of broflanilide significantly inhibited the growth of M. persicae in the F 0 and F 1 generations. • The dosage of broflanilide should be considered when it is used for controlling M. persicae. [ABSTRACT FROM AUTHOR]

The white-backed planthopper, Sogatella furcifera (Horváth) (Hemiptera: Delphacidae), is a major rice pest in some Asia-Pacific countries. Buprofezin is an insect growth regulator with relatively low mammalian toxicity but high efficacy to many rice pests. In this study, we estimated the toxicity of buprofezin against 3rd-instar nymphs of S. furcifera using the rice-stem dipping method. The results showed that the LC 50 of buprofezin to 3rd-instar nymphs were 0.89 mg/L. When 3rd-instar nymphs were exposed to the LC 10 and LC 25 (0.10 and 0.28 mg/L) of buprofezin, the duration of juvenile development was significantly prolonged in the F 0 and F 1 generations. The fecundity (eggs per female) of the F 1 females was reduced by 5.29% and 12.34%, respectively, in addition to the survival rate, emergence rate, copulation rate, and hatchability were decreased by treatment with buprofezin at LC 10 and LC 25 , compared with the control group. The relative fitness of S. furcifera in LC 10 and LC 25 treatments was reduced by 47% and 63%, respectively. Furthermore, real-time quantitative PCR analyses revealed increased the expressions of SfCHS1 and its two variants following the exposure of nymphs to buprofezin. Increased these genes mRNA levels associated with reduced chitin biosynthesis may result from the inhibition of chitin synthase activity, and thereby leading to a higher mortality of S. furcifera . Overall, sublethal concentrations of buprofezin suppressed the population growth of S. furcifera . [ABSTRACT FROM AUTHOR]

Sogatella furcifera (Horváth) (white-backed planthopper, WBPH) is one of the most important pests on rice in Asia. It seriously impacts rice production by sucking phloem from the rice plant and transmitting southern rice black-streaked dwarf virus (SRBSDV). In the current study, we examined the sublethal effects of imidacloprid on the development, reproduction, and susceptibility of S . furcifera in the laboratory using the rice stem dipping method. The results showed that exposure of third-instar S . furcifera nymphs to sublethal concentrations (LC 10 and LC 25 ) of imidacloprid inhibited the rate of nymphal development in the F 0 and F 1 generations, and there was a significant difference between the LC 25 treated group and the control group. The fecundity (eggs per female) of the F 1 generation showed significant declines of 22.05% and 38.56% following exposure to LC 10 and LC 25 , respectively compared with the control group. Emergence rate, copulation rate, and hatchability were significantly lower in the LC 25 -treated group. The relative fitness of S . furcifera treated with LC 10 and LC 25 imidacloprid was 0.46 and 0.22, respectively. These results showed that exposure to imidacloprid impacted the next generation of S . furcifera , thus affecting the population growth of this species. After third-instar S . furcifera nymphs were exposed to sublethal concentrations of imidacloprid LC 10 and LC 25 , S . furcifera showed reduced susceptibility to treatment with thiamethoxam and buprofezin. Although the susceptibility of S . furcifera to chlorpyrifos was decreased after the exposure of third-instar nymphs to imidacloprid LC 25 , S . furcifera populations that had been exposed to imidacloprid LC 10 showed enhanced susceptibility to chlorpyrifos. These results provided a reference point for the application of insecticides to control S . furcifera . [ABSTRACT FROM AUTHOR]

In order to evaluate the sublethal effects of cyantraniliprole on Sogatella furcifera (Horváth), the rice stem dipping method was used in this study and the S. furcifera 3rd instar nymph was treated with the cyantraniliprole of LC10 and LC25 concentrations. Then the change of developmental duration, fecundity and female longevity were studied and the time specific life table of F1 generation population was established. Results showed that the number of the female fecundity of the F0 generation treated with LC10 and LC25 is significantly different from the control group, which is reduced by 40.41% and 41.36%, respectively. After the treatment of cyantraniliprole, no significant differences on the female ratio (Fr) and hatchability (Ha) of the F1 generation were observed compared with the control group. However, the fecundity was reduced by 14.41% and 16.31%, respectively. Besides, the predicted number of offspring (N) and population trend index (I) were lower than that of the control. After treated with cyantraniliprole of the LC10 and LC25 concentrations, the relative fitness of S. furcifera were 0.78 and 0.64, respectively. The results of the study indicated that using cyantraniliprole for rice pests control in the field will not only have a lethal effect on the existing S. furcifera, but also have a certain inhibiting effect on the next generation. [ABSTRACT FROM AUTHOR]

The green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), is an agricultural pest that seriously infests many crops worldwide. This study used electrical penetration graphs (EPGs) and life table parameters to estimate the sublethal effects of cyantraniliprole and imidacloprid on the feeding behavior and hormesis of M. persicae. The sublethal concentrations (LC30) of cyantraniliprole and imidacloprid against adult M. persicae were 4.933 and 0.541 mg L-1, respectively. The feeding data obtained from EPG analysis indicated that the count probes and number of short probes (<3 min) were significantly increased when aphids were exposed to LC30 of imidacloprid-treated plants. In addition, the phloem-feeding behavior of M. persicae was significantly impaired on fed tobacco plants treated with cyantraniliprole and imidacloprid at LC30. Analysis of life table parameters indicated that the growth and reproduction of F1 generation aphids were significantly affected when initial adults were exposed to LC30 of cyantraniliprole and imidacloprid. The nymphal period, female longevity, total preoviposition period, and mean generation time were significantly prolonged when initial adults were exposed to LC30 of imidacloprid. By comparison, these parameters were prolonged but not significantly in the cyantraniliprole treatment. The fecundity and gross reproductive rate were significantly increased in the treated groups. Similarly, the net reproductive rate was greater in the treated group than the control group. Our results indicate that treatment with LC30 of imidacloprid and cyantraniliprole would lead to a hormetic response of M. persicae, with higher likelihood of occurrence when initial adults were exposed to LC30 of cyantraniliprole. [ABSTRACT FROM AUTHOR]

The chive maggot, Bradysia odoriphaga (Diptera: Sciaridae), is the major pest that damages Chinese chive in China. Benzothiazole is a volatile compound derived from microorganisms secondary metabolites and has fumigant activity against B. odoriphaga. However, the sublethal effects of benzothiazole need to be evaluated before registration and application, to fully understand the potential for control of this pest. Laboratory investigations showed that sublethal concentrations (LC and LC) of benzothiazole decreased the survival rate and the fecundity of B. odoriphaga compared with control. However, the developmental times of eggs, larvae and pupae, and the total preoviposition period were prolonged. Additionally, population parameters were significantly affected in the treated groups. The intrinsic rate of increase ( r) decreased to 0.1391 (LC) and 0.1140 (LC) day compared with the control population (0.1589 day). The net reproductive rate ( R) in the control was 54.39 offspring/individual, whereas the R decreased to 41.80 and 25.08 offspring/individual in the LC and LC treatments, respectively. This study demonstrated that sublethal concentrations of benzothiazole adversely affected the developmental time, fecundity and life table parameters of B. odoriphaga. Therefore, benzothiazole has the potential to be exploited as a natural derived fumigant for the control of this pest. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

The green peach aphid, Myzus persicae (Sulzer), is an important insect pest of many crops around the world. Pesticide-induced hormesis may be an alternative mechanism for pest resurgence. In this study, life table parameters were applied to the estimation of sulfoxaflor-induced hormesis of adult M. persicae following 2-d LC25 concentration exposure. Leaf-dip bioassays showed that the sulfoxaflor possessed high toxicity against M. persicae, with an LC50 of 0.059mg/liter. The results indicated that the exposure of the parent generation of M. persicae to sublethal sulfoxaflor induced increase in reproduction and prolongation of immature development duration in the first progeny generation. Both R0 and GRR of aphids for treatment group were significantly higher than for the control in F1 generation, and the mean generation time was significantly postponed in treated group. These results suggest a hormesis induced by lower concentration of sulfoxaflor in M. persicae. It would be useful for assessing the overall effects of sulfoxaflor on M. persicae. [ABSTRACT FROM AUTHOR]

We assessed effects of parental exposure to Beauveria bassiana on life history traits of subsequent generations of western flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae). Progeny from individuals that survived fungal exposure as second instars had significantly shorter egg stages, but longer prepupal development times than corresponding untreated controls. However, survivorship to adulthood of these progeny groups did not differ. Although fecundities of the parental types did not differ, the sex ratio of progeny from fungal-treated parents was male-biased, whereas sex ratio of progeny from untreated control parents was even. We calculated life table parameters for the progeny and found that all parameters, except for generation time, were significantly less for the progeny of fungal-treated parents than for progeny of untreated parents. The intrinsic rate of increase, finite rate of increase, net reproductive rate, mean generation time, and gross reproductive rate were 0.199 d-1, 1.229 d-1, 21.84, 15.48 d, and 27.273, respectively, for progeny of treated thrips, and 0.266 d-1, 1.316 d-1, 52.540, 14.92 d, and 70.64, respectively, for progeny of control thrips. Consequently, population projections demonstrated that offspring of parents exposed to B. bassiana would increase their population more slowly than those from untreated parents. These results demonstrate that B. bassiana has sublethal effects that reduce the reproductive success of F. occidentalis and these effects should be taken into account when evaluating its use in management programs for F. occidentalis. [ABSTRACT FROM AUTHOR]

Cyantraniliprole has been widely used in China for controlling many pests, including the small brown planthopper (SBPH) Laodelphax striatellus (Fallén), which is a major pest of rice. Sublethal effects of cyantraniliprole on SBPH have not yet been examined. In this study, 3rd instar nymphs of SBPH were exposed to the LC 10 , LC 20 , and LC 30 (3.17, 6.07, and 9.70 mg/L) of cyantraniliprole, which led to reductions in survival rate and hatchability of the F 0 generation. Compared with the control, sublethal concentrations of cyantraniliprole significantly prolonged the development time of the 4th and 5th instar nymphs of the F 1 generation. In the LC 10 , LC 20 , and LC 30 treatment groups, the nymphal duration was prolonged by 1.98, 0.99, and 2.54 d, respectively. In addition, the sublethal concentrations of cyantraniliprole shortened the adult preoviposition period. The activities of cytochrome P450 monooxygenases and carboxylesterase in SBPH were promoted after treatment with sublethal concentrations of cyantraniliprole. The increase in insecticide resistance may be due to the increase in the activity of detoxification enzymes. Therefore, this research can provide a theoretical reference for the treatment of resistant SBPH. [Display omitted] • The LC 30 concentration of cyantraniliprole significantly decrease the hatchability of the F 0 generation of SBPH. • The sublethal concentrations of cyantraniliprole significantly prolong the nymph duration in F 1 generation of SBPH. • The sublethal concentrations of cyantraniliprole significantly increase the CarE and P450s enzyme activities of SBPH. [ABSTRACT FROM AUTHOR]

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Effects of the entomopathogenic fungus Beauveria bassiana were studied on life table parameters of two-spotted spider mite, Tetranychus urticae feeding on bean and cucumber under laboratory conditions. The developmental periods for all immature stages were not affected by fungal infection on each host plant but the duration of larval stage was significantly longer on bean. The female and male longevity, oviposition period and fecundity were significantly lower on fungus-treated mites but were not different between two host plants. Significant reductions were found on the intrinsic rate of increase (r m ), the net reproductive rate (R 0), the finite rate of increase (λ), the mean generation time (T c ) and the population doubling time (D t ) as a result of mycosis. Only the mean generation time (T c ) was influenced considering the effect of host plant, which was shorter on cucumber. [ABSTRACT FROM PUBLISHER]

Habrobracon hebetor Say is one of the most important ectoparasitoids of the larval stage of many invasive agricultural pests such as noctuid and pyralid moths. Lethal and sublethal effects of carbaryl and abamectin were assessed on the ectoparasitoid H. hebetor in laboratory conditions. Dose-response bioassays were carried out on immature and adult stages by using dipping and contact residue methods, respectively. LC (lethal concentration for 50%) values of carbaryl and abamectin were 31.19 and 4.16 mg a.i. l on larval stage and 12.6 and 4.42 mg a.i. l on adults, respectively. In order to assess the sublethal effects, adult wasps were exposed to an LC of each insecticide and then the demographic parameters of live wasps were studied. The results showed that the intrinsic rate of increase ( r), finite rate of increase (λ), net reproductive rate (R) and gross reproductive rate (GRR) were significantly affected by the insecticides. The highest and the lowest r values were 0.23 and 0.17 in control and carbaryl-treated insects, respectively. The sex ratio of H. hebetor offspring was not significantly affected by either insecticide. The results showed that carbaryl had more adverse effects on population parameters of the parasitoid compared to abamectin. Field studies are needed to determine the total effects of the pesticides on H. hebetor. [ABSTRACT FROM AUTHOR]

The green peach aphid, Myzus persicae (Sulzer), is a cosmopolitan agricultural pest and causes great damages each year. Afidopyropen is a novel insecticide with high efficacy against even the insecticides resistant M. persicae. However, the sublethal and transgenerational effects of afidopyropen on M. persicae is not clear. In the present paper, sublethal and transgenerational effects of afidopyropen on biological traits of M. persicae were determined based on the age-stage, two-sex life table theory. The afidopyropen was more toxic against M. persicae than other widely used insecticides, with LC 50 of 0.086 mg/L. The treatment with LC 5 , LC 15 and LC 25 concentrations of afidopyropen remarkably reduced the longevity and fecundity of F 0 M. persicae by 15.9–64.4% and 24.3–76.7%, respectively, compared with those of the control. The life history traits of F 1 generation including the pre-adult development time, mean total longevity, pre-adult survival rate, total pre-oviposition period and fecundity were significantly affected after treatment of the F 0 with afidopyropen, and the population parameters, including the net reproductive rate (R 0), intrinsic rate of increase (r) and finite rate of increase (λ) were also remarkably decreased, while the mean generation time (T) was extended by 6.94%. Among four development and reproduction related genes investigated, JHEH was downregulated by 31.8–38.0% in the afidopyropen treated F 0 generation, while the EcR and JHAMT were overexpressed and the Vg was significantly downregulated in F 1 generation compared to the control group. All these data indicated that the afidopyropen had significant sublethal and transgenerational effects on M. persicae. These results provide insights into comprehensively understanding of the insecticidal effects of afidopyropen on M. persicae as well as the management of resistant M. persicae. [Display omitted] [ABSTRACT FROM AUTHOR]

The small brown planthopper (SBPH) is a destructive agricultural pest, which causes economic losses to various crops, including rice, corn, wheat, and oats. Triflumezopyrim (TFM) is a new mesoionic insecticide used to control SBPH in China. However, the sublethal effects of TFM on the growth and fecundity of SBPH are unknown and require further study. In this study, the age-stage life table and physiological parameters were used to assess the TFM's sublethal effects on SBPH. We found that sublethal doses of TFM significantly changed the life table parameters of SBPH. The oviposition and fecundity of female SBPH decreased significantly after treatment with different sublethal doses, as did the emergence rate of adults. In contrast, insects treated with sublethal doses of TFM had longer developmental durations and adult life spans than the control group. The activities of carboxylesterase (CarE) and glutathione- S -transferase (GST) in the treatment group showed inhibitory effects. Mixed-function oxidase (MFO) showed an induction effects at 24 and 48 h after treated. The results showed that the sublethal doses of TFM had negative effects on the population development of SBPH. These results can provide a theoretical basis for population control and resistance management. [Display omitted] • Triflumezopyrim showed sublethal effects on adults of the small brown planthopper. • Low doses (LD 10 -LD 30) of triflumezopyrim can inhibit the fecundity of small brown planthopper significantly. • S doses of triflumezopyrim can increase the developmental duration and adult longevity of small brown planthopper. • The sublethal doses of triflumezopyrim can induce the change of detoxification enzyme activity. [ABSTRACT FROM AUTHOR]