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Fall armyworm (FAW) Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a global pest causing damage to several crops. However, its management using chemical control is a challenge due to its capacity to evolve resistance to insecticides. After 6 generations of selection with lambda-cyhalothrin, the LC50 for the insecticide-resistant strain (Lambda-Sel) was 486 ppm, higher than that of the field strain (FAW-MUL) (7.5 ppm), susceptible laboratory strain (Lab-PK) (0.46 ppm), and laboratory unselected strain (UNSEL) (5.26 ppm). Laboratory selection with lambda-cyhalothrin increased resistance from 16.3- to 1056.52-fold and 1.43- to 92.4-fold to lambda-cyhalothrin compared to Lab-PK and UNSEL strains, respectively. The selected strain of S. frugiperda (Lambda-Sel) presented low cross-resistance to chlorpyrifos, moderate to deltamethrin and indoxacarb, very low to spinosad, and no cross-resistance to emamectin benzoate. The realized heritability (h2) of lambda-cyhalothrin resistance in the Lambda-Sel strain was very high (0.88). The reciprocal cross progenies of F1 (Lambda-Sel ♀ × Lab-PK ♂), F1' (Lambda-Sel ♂ × Lab-PK ♀), BC1 (F1 ♀ × Lambda-Sel ♂), and BC2 (F1 ♀ × Lab-PK ♂) showed high resistance ratios of 545.64-, 396.52-, 181.18-, and 146.54-fold, respectively compared to Lab-PK. The degree of dominance values for lambda-cyhalothrin in F1 and F1' indicates incompletely dominant resistance. The difference between observed and expected mortality in backcross populations (BC1 and BC2) revealed a polygenic resistance. In conclusion, the resistance to lambda-cyhalothrin was autosomal, incompletely dominant, and polygenic. These findings provide new insights for insect resistance management strategies to mitigate the occurrence of resistance in this global pest., (© The Author(s) 2024. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com.)

Extensive fumigation of synthetic pesticides to control the mosquito vector during each post-monsoon season in Pakistan significantly enhanced the environmental contamination and extinction of beneficial insects from the urban ecosystems. In this context, the present study examined the larvicidal efficacy of green synthesized iron nanoparticles (IONPs), using an aqueous leaf extract of Grevillea robusta against the early 2nd and 4th instar larvae of Aedes aegypti and Anopheles stephensi in Pakistan. The prepared IONPs were characterized by UV-Vis spectrum, FTIR, X-ray diffraction, scanning electron microscopy, and energy-dispersive diffraction. Larvicidal bioassay was conducted at various concentrations (80, 160, 240, 320, and 400 ppm) of IONPs prepared from leaf extract of G. robusta, and readings were taken-every 12 h for two consecutive days. In vitro, larvicidal assay, G. robusta leaf extract IONPs exhibited high mortalities of 64-96% (LC 50  = 259.07 ppm; LC 90  = 443.92 ppm) for the second instar and 65-98% (LC 50  = 238.05 ppm; LC 90  = 433.93 ppm) for the fourth instar of Ae. aegypti, while in the case of An. stephensi 56-84% (LC 50  = 297.96 ppm; LC 90  = 528.69 ppm) for the second and 56-88% (LC 50  = 292.72 ppm; LC 90  = 514.00 ppm) mortality for fourth larvae at 12-48 h post-exposure times were observed respectively. Significant (p < 0.05) dose-dependent and exposure time-dependent trends were observed among the 2nd and 4th larvalinstar of An. stephensi and Ae. aegypti. However, both species showed similar response and observed no significant (p > 0.05) difference in percentage mortality between the vector mosquitoes An. stephensi and Ae. aegypti. Overall, this study demonstrates that the larvicidal efficacy of green synthesized IONPs at low concentrations can be an ideal eco-friendly and cost-effective biocontrol of vector mosquitoes' larvae of An. stephensi and Ae. aegypti., Competing Interests: Declaration of competing interest All authors declare they don't have any competing financial and technical, or personal conflicts of interest regarding the article's work and data., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Biomonitoring of people exposed to hazardous materials provides opportunities for early identification of several diseases, particularly in those individuals who are constantly exposed to pesticides, such as pesticide operators and workers in pesticide manufacturing industry. However, data on this hot topic are limited in Pakistan. In this study, insecticide toxic effects and biochemical alterations (i.e., damage in DNA and enzyme activity) were studied in blood samples of occupationally exposed individuals from Punjab, Pakistan. Eight out of twenty-seven blood samples (29.6%) of the pesticide operators were found positive in five insecticides, with the maximum concentration found for chlorpyrifos-methyl (0.039 μg/mL). Eleven out of twenty-seven blood samples (40.7%) of the pesticide industry workers were found positive in eight insecticides, with the maximum concentration found for endosulfan (0.051 μg/mL). Comet tail length was 16.88 ± 4.57 μm in pesticide industry workers and 16.33 ± 3.78 μm in pesticide operators, which were significantly higher (P < 0.01) than that recorded in the control group (4.84 ± 2.21 μm). Values of serum cholinesterase (SChE) concentration were slightly lower (P > 0.05) in exposed individuals, whereas values of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) concentration were significantly higher (P < 0.01) in exposed individuals compared with control group. Exposure duration and total insecticide concentration in blood samples were positively associated with comet tail length, ALT activity, AST activity, and ALP activity, but negatively with SChE. DNA damage was higher in smokers vs. non-smokers. Also, a positive association was found between comet tail length and number of cigarettes per day. Overall, occupational exposure to insecticides can pose serious health risks to pesticide operators and workers in pesticide manufacturing industry, highlighting the necessity of personal protection in those groups for preventing exposure and resultant health disorders., (Copyright © 2018. Published by Elsevier B.V.)

Insecticides, essential for crop protection measures, leave behind several toxic residues that can result in a series of human health disorders. Therefore, this study was planned for the determination of residues and adverse effects of insecticides in blood samples of sprayers, pesticide-industry workers and controls by using blood parameters of these individuals as biomarkers. Optimized analytical methods using GC-MS and HPLC for the simultaneous detection of 22 currently used insecticides were adopted. Eight of twenty-seven (22.22%) sprayers' blood samples were found positive for five different insecticides. Eleven of twenty-seven (40.74%) pesticide-industry workers were found positive for eight different insecticides. The blood samples of both the exposed groups, sprayers and industry workers had significantly (P < 0.001; Mann-Whitney U-tests) low hemoglobin-Hb concentrations (12.17 ± 2.13 and 12.22 ± 2.37 g/dl respectively) than the average value of the control group with 14.23 ± 2.37 g/dl. The erythrocyte sedimentation rates (ESRs) in sprayers and insecticide industry workers (28.78 ± 20.72 and 28.17 ± 25.14 mm/1st h respectively) were greater significantly (P < 0.001; Mann-Whitney U test) than the control blood samples (9.53 ± 3.34 mm/1st h). These results indicate that the exposed individuals have experienced significant hemotoxic effects during insecticide exposure. The study also predicts the risk to exposed individuals in developing countries like Pakistan and demands realization of safety measures to prevent such dangerous effects of pesticide exposures., (Copyright © 2018 Elsevier Inc. All rights reserved.)

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). After a thorough investigation, the Editors have concluded that the acceptance of this article was partly based upon the positive advice of two illegitimate reviewer reports. The reports were submitted from email accounts which were provided by the corresponding author Christos A. Damalas as suggested reviewers during the submission of the article. Although purportedly real reviewer accounts, the Editors have concluded that these were not of appropriate, independent reviewers. This manipulation of the peer-review process represents a clear violation of the fundamentals of peer review, our publishing policies, and publishing ethics standards. Apologies are offered to the reviewers whose identity was assumed and to the readers of the journal that this deception was not detected during the submission process., (Copyright © 2018 Elsevier B.V. All rights reserved.)

The cotton mealybug, Phenacoccus solenopsis is an important polyphagous sucking pest of ornamentals, horticultural and fiber crops worldwide. Some P. solenopsis populations have developed insecticide resistance. This study evaluated cross-resistance, stability of insecticide resistance and life history traits affected by chlorpyrifos resistance in P. solenopsis. After nine generations selected with chlorpyrifos, P. solenopsis exhibited a 539.76-fold resistance level compared to an unselected population (UNSEL Pop). Chlorpyrifos selected population (Chlor-SEL Pop) displayed moderate cross-resistance to profenofos, nitenpyram and high cross-resistance to lambda-cyhalothrin. Biological parameters of P. Solenopsis were affected by chlorpyrifos resistance. The Chlor-SEL Pop had a significant reduction in fitness (relative fitness=0.10), along with significant decreases in pupal weight, fecundity, egg hatching %, intrinsic rate of natural population increase, biotic potential, and mean relative growth rate. It is concluded that selection with chlorpyrifos had marked effect on resistance development in P. solenopsis and upon removal of selection pressure chlorpyrifos resistance declined significantly indicating unstable resistance. Development of resistance led to high fitness costs for the chlorpyrifos-selected strain. These findings should be helpful for better and more successful resistance management of P. solenopsis., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The green lacewing, Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) is a major generalist predator employed in integrated pest management (IPM) plans for pest control on many crops. Nitenpyram, a neonicotinoid insecticide has widely been used against the sucking pests of cotton in Pakistan. Therefore, a field green lacewing strain was exposed to nitenpyram for five generations to investigate resistance evolution, cross-resistance pattern, stability, realized heritability, and mechanisms of resistance. Before starting the selection with nitenpyram, a field collected strain showed 22.08-, 23.09-, 484.69- and 602.90-fold resistance to nitenpyram, buprofezin, spinosad and acetamiprid, respectively compared with the Susceptible strain. After continuous selection for five generations (G1-G5) with nitenpyram in the laboratory, the Field strain (Niten-SEL) developed a resistance ratio of 423.95 at G6. The Niten-SEL strain at G6 showed no cross-resistance to buprofezin and acetamiprid and negative cross-resistance to spinosad compared with the Field strain (G1). For resistance stability, the Niten-SEL strain was left unexposed to any insecticide for four generations (G6-G9) and bioassay results at G10 showed that resistance to nitenpyram, buprofezin and spinosad was stable, while resistance to acetamiprid was unstable. The realized heritability values were 0.97, 0.16, 0.03, and -0.16 to nitenpyram, buprofezin, acetamiprid and spinosad, respectively, after five generations of selection. Moreover, the enzyme inhibitors (PBO or DEF) significantly decreased the nitenpyram resistance in the resistant strain, suggesting that resistance was due to microsomal oxidases and esterases. These results are very helpful for integration of green lacewings in IPM programs., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The cotton mealybug, Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae) has gained recognition as a key pest due to its invasive nature throughout the world. The P. solenopsis has a wide range of host plants and damages the cotton crop in various parts of the world. In view of the economic importance of this pest, a study on selection, inheritance and mechanism of spinosad resistance was conducted on P. solenopsis. Selection of field collected P. solenopsis for seven generations with spinosad resulted in a high resistance ratio of 282.45-fold. Genetic studies of spinosad resistance in P. solenopsis indicated that maternal effects are not involved in spinosad resistance; and resistance development is an autosomal and incompletely dominant trait. The number of genes involved in spinosad resistance was determined to be more than one, suggesting that resistance is controlled by multiple loci. The realized heritability (h (2)) value for spinosad resistance was 0.94. Synergism bioassays of spinosad with piperonyl butoxide and S,S,S-tributyl phosphorotrithioate showed that spinosad resistance in P. solenopsis could be due to esterase only. The study provides the basic information for implementation of effective resistance management strategies to control P. solenopsis.

Cotton mealybug, Phenacoccus solenopsis Tinsley, is a serious pest of cotton and other crops and infestation by this pest results in yield losses that affect the economy of Pakistan. Various groups of insecticides have been used to control this pest but resistance development is a major factor that inhibits its control in the field. Chlorpyrifos is a common insecticide used against many pests including P. solenopsis. The present experiment was designed to assess the genetics and mechanism of chlorpyrifos resistance and to develop a better resistance management strategy and assess the genetics and mechanism of chlorpyrifos resistance. Before selection, the field strain showed 3.1-fold resistance compared to the susceptible strain (CSS). After 8 rounds of selection with chlorpyrifos, a selected population developed a 191.0-fold resistance compared to the CSS. The LC50 values of F1 (CRR ♀ × CSS ♂) and F1(†) (CRR ♂ × CSS ♀) strains were not significantly different and dominance (DLC) values were 0.42 and 0.55. Reciprocal crosses between chlorpyrifos susceptible and resistant strains indicated that resistance was autosomal and incompletely recessive. The monogenic model of fit test and calculation of number of genes segregating in the chlorpyrifos resistant strain demonstrated that resistance is controlled by multiple genes. A value of 0.59 was calculated for realized heritability for chlorpyrifos resistance. Synergism bioassays with piperonyl butoxide and S, S, S-butyl phosphorotrithioate showed that chlorpyrifos resistance was associated with microsomal oxidases and esterases. It was concluded that chlorpyrifos resistance in P. solenopsis was autosomally inherited, incompletely recessive and polygenic. These findings would be helpful to improve the management of P. solenopsis., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Background: Acetamiprid is a neonicotinoid insecticide that is effective against both soil and plant insects, including insects of the orders Lepidoptera, Coleoptera, Homoptera and Thysanoptera. In order to estimate the effects associated with insecticide exposure and devise better pest management tactics, a field population of Phenacoccus solenopsis was exposed to acetamiprid in the laboratory. Subsequently, cross-resistance and the effects of acetamiprid on the biological parameters of P. solenopsis were investigated., Results: Following five rounds of selection with acetamiprid, P. solenopsis developed a 315-fold greater resistance to this chemical compared with an unexposed control population. The selected population also demonstrated very high to moderate cross-resistance to other tested insecticides. Furthermore, acetamiprid resistance remained unstable when the acetamiprid-selected population was not exposed for a further five generations. The acetamiprid-selected population had a relative fitness of 0.22, with significantly lower survival rate, pupal weight, fecundity, percentage hatching, net reproductive rate, intrinsic rate of natural increase, biotic potential and mean relative growth rate, with prolonged male and female nymphal duration, developmental time from egg to female adult and male and female longevity compared with the control population., Conclusion: P. solenopsis biological parameters are greatly affected by acetamiprid, and it is of significant cost for the insects to counter these effects. This study will be a valuable source of information for further understanding of acetamiprid resistance and for assisting the development of resistance management programmes., (© 2014 Society of Chemical Industry.)

The Asian citrus psyllid (ACP) Diaphorina citri Kuwayama vectors pathogens that cause huanglongbing (HLB) or citrus greening devastating and economically important disease present in most citrus growing regions. Young citrus shoots are required for psyllid reproduction and development. During winter citrus trees produce little or no new growth. Overwintering adults reproduce in spring on newly emerging shoots also attractive to other pests and beneficial insects. Botanicals and relatively selective insecticides could help to conserve beneficial insects and reduce pest resistance to insecticides. Sprays of Azadirachtin (Neem), Tropane (Datura), Spirotetramat, Spinetoram, and broad-spectrum Imidacloprid were evaluated to control ACP in spring and summer on 10-year-old "Kinow" Citrus reticulata Blanco trees producing new growth. Psyllid populations were high averaging 5-9 nymphs or adults per sample before treatment application. Nymphs or adults were significantly reduced to 0.5-1.5 per sample in all treatments for 3 weeks, average 61%-83% reduction. No significant reduction in ladybeetles Adalia bipunctata, Aneglei scardoni, Cheilomenes sexmaculata, and Coccinella septempunctata was observed. Syrphids, spiders and green lacewings were reduced in treated trees except with Tropane. Studies are warranted to assess impact of these predators on ACP and interaction with insecticides. Observed reduction in ACP populations may not be enough considering its reproductive potential and role in the spread of HLB. Follow-up sprays may be required to achieve additional suppression using rotations of different insecticides., (© 2014 Institute of Zoology, Chinese Academy of Sciences.)

Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is a pest with an economic impact on various crops and ornamental plants. Different classes of insecticides have been used for P. solenopsis control but rise in resistance is a major concern. Previously resistant selected field populations of P. solenopsis with chlorpyrifos (RR = 15,292-fold), acetamiprid (RR = 10,631-fold), emamectin benzoate (RR = 280-fold), and spinosad (RR = 15,233.84-fold) were used to study the biochemical mechanisms of insecticide resistance in the laboratory. Enzyme assays were performed using P. solenopsis adults in all these resistant populations to determine the activities of different detoxification enzymes associated to different resistance mechanisms to these chemicals. The results revealed that oxidases activity was increased significantly in all selected strains compared with the susceptible strain. The glutathione-S-transferase (GST) activity nevertheless showed a significant change. The esterases (EST) activity was significantly higher in all the selected strains except the emamectin benzoate selected strain compared to the susceptible strain. These results confirm the contribution of oxidases and esterases in detoxification of the tested insecticides in P. solenopsis. This information would help to formulate resistance management strategies for this pest. [ABSTRACT FROM AUTHOR]

Dusky cotton bug Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae) has been found to infesting cotton and other plants in Pakistan and some other countries. However, in Pakistan the increasing infestation of O. hyalinipennis was controlled with different insecticides, but some degree of resistance has been reported. Inheritance and cross-resistance of dimethoate resistance selection have not been documented in O. hyalinipennis previously. Therefore, this study for the first time characterized dimethoate resistance in O. hyalinipennis by inducing it in the laboratory for six generations. The selected population was 9.70- and 157-fold resistant compared with the field and laboratory population, respectively. The dimethoate resistance selection did not bring about any cross-resistance with lambda-cyhalothrin (1.47-fold) but had a very low cross-resistance with chlorfenapyr (3.03-fold) and acephate (2.21-fold) compared with the field population. The overlapping in 95% confidence limits of LC50 ratios of F1 (R♀ × S♂) and F1' (R♂ × S♀) indicated the lack of maternal effects, whereas their degree of dominance of 0.54 and 0.51 suggested an incompletely dominant resistance inheritance. Multiple factors were involved in dimethoate resistance as implied from Chi-square analyses of backcrosses. In conclusion, O. hyalinipennis develops easily resistance to dimethoate due to selection. Lack of/or very low cross-resistance with lambda-cyhalothrin, chlorfenapyr and acephate implies that these insecticides can be used in rotation. Moreover, dimethoate resistance inheritance was incompletely dominant, autosomal and polygenic which implies that resistance to dimethoate can be delayed by using it in rotations, alterations, mosaics and combinations. [ABSTRACT FROM AUTHOR]

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The armyworm, Spodoptera litura Fab. (Lepidoptera: Noctuidae) is an economically important insect pest of vegetables, ornamentals and other agricultural crops. Synthetic insecticides have remained primary means for the management of S. litura than any other management tool. We tested the effectiveness of some insecticides against different larval instars of S. litura in laboratory as well as in field on the prevailing instars in two fodder crops lucern/alfalfa, Medicago sativa L. and jantar/sesbania, Sesbania sesban L. In the laboratory, emamectin benzoate provided the most control 69-91% followed by lufenuron 70-85% of all larval instars after 48 hours of application. In the lucern field, emamectin benzoate reduced the larval population of S. litura up to 79.32% and with the application of lufenuron 73.55% reduction occurred. Similarly, in jantar crop, lufenuron and emamectin benzoate proved to be more toxic against S. litura population. The abundance of ladybird beetle, Coccinella septempunctata L. (Coleoptera; Coccinellidae), honeybee, Apis mellifera L. (Hymenoptera; Apidae) and green lacewing, Chrysoperla carnea Stephen (Neuroptera; Chrysopidae) were found higher in emamectin and lufenuron treated plots compared to methoxyfenozide and chlorpyrifos. These results indicate that new chemistry insecticides; emamectin benzoate and lufenuron have a potential for the management of S. litura and are relatively safer for beneficial insects as compared to conventional insecticides, methoxyfenozide, and chlorpyrifos. [ABSTRACT FROM AUTHOR]

Diaphorina citri Kuwayama (Hemiptera: Liviidae) is one of the devastating pests of citrus orchards in different regions of the world and its management depends upon the use of insecticides. The work was conducted to evaluate the toxicities and resistance levels to various insecticides in a field collected population of citrus psylla from an area of Pakistan. The field population was also kept under selection pressure with thiamethoxam for several generations to study the impact of selection on thiamethoxam resistance development. The resistant population was then studied for cross-resistance with insecticides from different groups and realized heritability of thiamethoxam resistance was determined to assess the potential of resistance development. Selection of D. citri from G 1 -G 7 with thiamethoxam produced 229-fold resistant strain in the laboratory. Selected strain exhibited very low cross-resistance with flonicamid, buprofezin, and spirotetramat; low cross-resistance with diafenthiuron and fenpropathrin, moderate cross-resistance with nitenpyram and pyriproxyfen, and a very high cross-resistance with acephate and methomyl. The estimated realized heritability of thiamethoxam resistance was 0.36. This study provides information on the impact of selection on resistance development and its management by restoring the susceptibility of D. citri through rotation of insecticides with low level of cross-resistance. • Selection of D. citri from G 1 -G 7 with thiamethoxam produced 229-fold resistant strain in the laboratory. • Selection induced very high cross-reistance with acephate and methomyl. • Moderate cross-reistance with nitenpyram and pyriproxyfen was observed. • The estimated realized heritability of thiamethoxam resistance was 0.36. • The number of generations predicted for 10-fold increase in thiamethoxam resistance would be 4.16. [ABSTRACT FROM AUTHOR]

Mango mealybug Drosicha mangiferae (Pseudococcidae: Hemiptera) is one of the most damaging insect pests of a wide range of horticultural crops. This sap-feeding insect pest causes substantial loss to different fruit crops, particularly to citrus. For its management, citrus farmers rely on extensive and irrational applications of synthetic insecticides. Due to which, D. mangiferae have attained resistance against most these chemicals. This laboratory study was aimed to determine the toxicity of some selected conventional insecticidal formulations concurrently being used by the farmers against D. mangiferae infestation. Using standard twig-dip method, toxicity bioassays were conducted against 2nd instar nymphs of D. mangiferae. Treatments included nine conventional synthetic insecticides from three insecticidal groups. Results revealed that both treatments i.e. insecticidal formulations (F9,245 = 93.05, P < 0.001) and time intervals (F9,245 = 158.72, P < 0.01) and their 9, 245 4, 245 interaction (F36,245 = 5.73, P < 0.001) had a significant impact on the mortality of 2nd instar 36, 245 mealybug nymphs. The most effective synthetic insecticides against D. mangiferae individuals were lambda-cyhalothrin, methidathion, profenofos and deltamethrin with mean mortality and LT50 values of 45.00±4.57% and 49.01 h, 44.67±3.96% and 49.83 h, 50 40.00±4.07% and 58.98 h and 35.67±4.11% and 74.86 h, respectively. These insecticides may be incorporated in future pest management programs against D. mangiferae mealybugs. [ABSTRACT FROM AUTHOR]

The honeybees (Apis mellifera L.) are broadly renowned beneficial organisms with respect to biological, ecological and scientific significance by generating economically important products like royal jelly, pollen, propolis, honey and wax. These critical pollinators are being affected by the chemical compounds used for controlling the insects -pests of agricultural crops. We performed experiments by sowing of sunflower crop at (500 sq. m) field and applied the pesticides early in the morning at flowering stage on crop and the bees were exposed to the pesticides this way. Here we hypothesized that insecticide's exposure affects the colony strength parameters of honey bees. To test this hypothesis we examined the effects of different chemical compounds from different groups (Nitenpyram @10%SL/acre), (Cyhalothrin @200ml/acre-), (Emamectin benzoate @ 200ml/acre) on the adult bees, guard bees, forager bees, honey production, egg presence, egg hatching, larval duration, pupal period and adult lifespan. The data for the, forager bees was recorded two times a day 11:00 am and 2:00 pm and guard bees were collected once a day at 12:00 pm while he data for honey production was done after one month. The adult bees, guard bees and forager bees were observed dying greatly due to emamectin benzoate as compared to the other insecticides. The honey production in the treated colonies was being affected more by the insecticide cyhalothrin. The nitenpyram and cyhalothrin were more toxic for the egg presence and eggs hatching. The emamectin benzoate and cyhalothrin found toxic for pupal stage of honey bees. The timely adult emergence, new emerging bees and adult longevity were being affected extensively by nitenpyram. [ABSTRACT FROM AUTHOR]

Pink stem borer Sesamia inferens (Walker) (Lepidoptera: Noctuidae) is a major pest of sugarcane and rice frequently controlled by the use of insecticides, including fipronil. This study focused on fipronil resistance characterization in S. inferens by selecting a population (called Fipro-SEL Pop) with fipronil for 14 generations. Fipro-SEL Pop population showed 106.00- and 22.71-fold resistance to fipronil when compared to unselected (UNSEL) and Field strains, respectively. Fipro-SEL strain showed no cross-resistance to chlorpyrifos, lambda-cyhalothrin and spinosad. Reciprocal crosses between Fipro-SEL and UNSEL strains revealed an autosomal and incompletely recessive nature of resistance to fipronil. The F 1 and F 1 ' showed similar LC 50 values against fipronil and their dominance values were 0.46 and 0.53, respectively. Chi-square goodness of fit test suggested that fipronil resistance was polygenic. Realized heritability value was 0.25 for fipronil resistance. These outcomes would be useful for effective management of S. inferens. • Sesamia inferens showed 106- and 22.71-fold resistance to fipronil when compared to UNSEL and Field strains. • Fipro-SEL strain showed no cross-resistance to other tested insecticides. • Resistance to fipronil in Sesamia inferens was autosomal, incompletely recessive and polygenic. • Realized heritability (h 2 ) value was 0.25. [ABSTRACT FROM AUTHOR]

Citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) is a destructive insect pest of citrus nurseries as well as orchards in Pakistan. The aim of this study was to assess the effectiveness of some synthetic insecticides and essential oils against citrus leafminer larvae. Two laboratory bioassays, leaf dip bioassay (LDB) and topical bioassay (TB) were developed to check the efficacy of tested chemicals and essential oils. As seen from results, abamectin showed significant mortality (63.5%) of CLM larvae when topical bioassay was performed. Similarly, the percent mortality of CLM larvae was 53.8% after application of abamectin, when leaf dip bioassay technique was used. However, among tested botanicals, Azadirachta indica oil showed better results with percent CLM mortality of 35.6%, through topical bioassay and 31.8% through leaf dip bioassay. In the case of A. indica, the LC50 value was also observed lower (1.88±0.37, 1.73±0.29) in LDB and TB, respectively, as compared to other botanicals. So, our study suggested that abamectin gave better management of citrus leafminer larvae. However, higher concentrations of A. indica oil can be used to control CLM larvae. [ABSTRACT FROM AUTHOR]

Abstract The subterranean termite Heterotermes indicola (Blattodea: Rhinotermitidae) is a serious pest to wood in service causing significant annual economic loss in Southeast Asia. In the present study, silver oak (Grevillea robusta A. Cunn.) (Proteaceae) leaf extract was investigated for its termiticidal properties against the termite H. indicola in laboratory tests. An ethanol-solvent system was used to remove the extract from dry leaf powder via Soxhlet apparatus. A dose-dependent foraging response and mortality was observed after continuous exposure to a dose range of 1–20 mg/mL of extract based on dry extract weight. Results indicated that maximum (>90%) termite mortality occurred at 20 mg/mL along with a significant reduction in termite tunneling activity. An LC 50 was calculated at 5.47 mg/mL using the concentration series data. In filter paper antifeeding and repellency bioassays, a significant reduction in the total population of gut protozoa compared to untreated and negative controls (solvent) was observed. After 2 weeks of no-choice continuous feeding on filter paper treated at 20 mg/mL, hindgut protozoan population was reduced by 62.90%. The extract conveyed resistance to the non-durable cotton wood and chir pine after vacuum pressure treatment. At the highest concentration tested, 100% mortality was recorded after exposing termites to cotton wood and chir pine treated with silver oak leaf extract. HPLC-DAD-ESI-MS results of the extract showed high level of phenolic compound, alkyl-resorcinol. Results indicated that silver oak leaf extract has termiticidal properties and could be of value in the development of botanical insecticides for termite control in wood products. Graphical abstract Image 1 Highlights • Silver oak leaf extract showed termiticidal activities against Heterotermes indicola. • Anti-tunneling, antifeeding and termite mortality increased with increasing extract concentration. • Silver oak extract showed increased protozoacidal activity in a dose dependent response. • A repellent and toxicity bioassay exhibited the silver oak extract as a suitable repellent and wood protective agent. • HPLC-MS analysis of extractidentified major components of silver oak leaf extractand discussed relevant results. [ABSTRACT FROM AUTHOR]

Coccinellids beetles are considered one of the potential predators of the canola and mustard aphids. But the application of insecticides in field to manage aphids cause impairment of several key biological traits of the exposed coccinellids through physiological and behavioral effects. It is crucial to understand the effects of insecticides on the coccinellids. The current research was aimed at determining the intraguild predation (IGP) of different life stages combinations of Coccinella septempunctata and Coccinella transversalis in the presence and absence of prey and the impact of sublethal concentrations of insecticides on intra-guild predation (IGP) and aphid consumption by coccinellids. Data revealed that in the absence of prey larvae of C. septempunctata exhibited more predation on C. transversalis while the predation of C. septempunctata on C. transversalis was relatively less in the presence of prey. The larvae of C. septempunctata were found stronger and competitive than larvae and adults of C. transversalis during IGP. Higher IGP of C. septempunctata on C. transversalis was linked to its larger body size. Moreover, sublethal concentrations of insecticides (lambda-cyhalothrin, cypermethrin, thiamethoxam, imidacloprid, profenophos and chlorpyriphos) significantly affected the IGP of coccinellids beetles and their aphid consumption. The effect of insecticides was concentration dependent. None of the tested insecticides was found completely harmless to coccinellids. Imidacloprid was found relatively safe to coccinellids and hence, recommended for use in canola field. It is concluded that C. septempunctata is a stronger predator showing high value of IGP and the presence of prey affects the predation of C. septempunctata on C. transversalis. Sublethal concentrations of all test insecticides exert a negative impact on IGP and aphid consumption by both these coccinellids species. Imidacloprid is relatively safe for aphid control. [ABSTRACT FROM AUTHOR]

Subterranean termites cause considerable damage to a wide number of agricultural crops, tree plantations and wooden infrastructures all over the world including Pakistan. This study was aimed to evaluate the comparative efficacy of 10 commercial formulations of new-chemistry insecticides against Odontotermes obesus (Isoptera: Termitidae), one of the most economic subterranean termite species in Indo-Pak region. Label-recommended dose rates of insecticides were tested against worker termites using modified filter paper disc method according to completely randomized design. All insecticides caused significant mortality of termites as compared to control treatment. Formulations of chlorantraniliprole, chlorfenapyr and pyriproxyfen exhibited maximum termite mortality, ranging from 31.18±5.67, 28.33±7.03 and 21.67±4.01%, respectively at 3 h post-exposure to 100% at 24 h, followed by triflumuron (81.67±3.07%) and indoxacarb (63.33±5.58%). Moreover, chlorantraniliprole, chlorfenapyr, pyriproxyfen, emamectin, indoxacarb and triflumuron showed LT50 values of 15.62 h (10.66 – 20.58), 18.48 h (14.72 – 22.93), 27.34 h (22.34 – 33.97), 28.22 h (23.37 – 34.53), 31.91 h (26.68 – 38.90) and 32.82 h (28.03 – 39.11), respectively. On the contrary, spirotetramat, pymetrozine and spinosad were least effective against O. obesus termites. Conclusively, based on the results of this study, chlorantraniliprole, chlorfenapyr, pyriproxyfen, triflumuron and indoxacarb are recommended to be incorporated in future integrated pest management programs against subterranean termites. [ABSTRACT FROM AUTHOR]

The efficacy of five insecticides containing a.i. bifenthrin, dimethoate, spinosad, spinetoram and chlorfenapyr was evaluated following RCBD against Thrips tabaci in farmer's field for two consecutive years. The data were recorded before and after 24 h, 48 h, 72 h and 7 days of spraying. The results showed that all the insecticides reduced thrips populations compared to controls. However, the maximum reduction in thrips population and highest onion bulb yield (34.07 t/ha) was obtained with dimethoate 40EC followed by bifenthrin 10EC (33.14 t/ha). The minimum onion bulb yield (25.71 t/ha) was obtained in the control, where no insecticide was applied against thrips. If onion thrips are not controlled, the damage they cause can reduce bulb yields by 9-25%. The highest incremental return over the control (Rs.83, 600/ha), net income (Rs.82, 913/ha) and maximum cost benefit ratio were also obtained in the treatment with dimethoate 40EC. [ABSTRACT FROM AUTHOR]

Insecticides, indispensable in crop-protection, leave behind the toxic residues of various kinds, which may lead to a variety of metabolic and systemic dysfunctions in man and other non-target organisms through dietary intake. Therefore, this study was conducted in the Department of Entomology, University of Sargodha, Sargodha, Pakistan during the year 2015. to evaluate the residual level of insecticides. Optimized analytical methods using gas chromatography-mass spectrometry (GC-MS) and high performance liquid chromatography (HPLC) were adopted for the simultaneous screening of roughly 22 insecticides in fruits, vegetables, pollen, nectar and water samples in three zones of Punjab Pakistan. Out of total of 143 samples analyzed (59 fruits & vegetables, 36 pollen, 36 nectar and 27 water samples), 50 samples (34.96%) were found positive for one or more insecticides. Fruits and vegetables 24(40.67%), pollen 8(22.22%) and nectar 6(16.66%) and water 18(66.67%) samples were found positive. Total 13 insecticides were detected in 27 water-samples of three zones of Punjab (Pakistan) ranging from 0.02 to 0.8 µg/L. Different insecticides including carbosulfan, profenofos, cypermethrin, endosulfan sulfate and chlorpyriphos-methyl were frequently detected in the fruit and vegetable samples. The results suggest that consumers of Punjab province are exposed to the lower concentrations of insecticides that can cause long-lasting disorders. [ABSTRACT FROM AUTHOR]

False flax, German sesame and Siberian oilseed are the names used for oil seed crop, Camelina sativa L. Crantz of the family Brassicaceae. Camelina sativa is a flexible, summer annual oilseed crop that can be raised in different climatic and soil conditions. The objectives of this study were to test the efficacy of different insecticides against aphid, Lipaphis erysimi on Canadian and Australian Camelina sativa varieties. Insecticides were tested at their field recommended doses using knapsack sprayer. The data on adult mortality of Lipaphis erysimi were recorded after 24, 48, 72, 96 and 120 h. Acetamiprid and mospilon were found more effective in controlling aphid. For Canadian variety, after 5 days of application, maximum mortality was recorded for acetamiprid (98.70%) while least was observed for diafenthiuron (53.52%). In case of Australian camelina, maximum mortality (98.26%) of aphid were found using acetamiprid. Acetamiprid was the most effective insecticide to control aphid in both varieties of Camelina sativa. [ABSTRACT FROM AUTHOR]

The study was conducted during 2013 on spring sown crop, which remained in the field from March to September using brinjal variety Nirala. The Experiment was laid out in a Split Plot Design with three replications having insecticides as main plot factor and application interval as a sub plot factor. Two insecticides, Tracer (spinosad) and Timer (emamectin benzoate) were applied at three application intervals using a knapsack hand operated sprayer. All plots were sprayed uniformly on May 01 for the first insecticide application. Subsequent sprays were done at 4, 8 and 12 days after first application (DAFA). All the marketable fruit was plucked 1 day before first insecticide application. Infested and healthy fruit was separated and counted. For subsequent sprays, marketable fruit washarvested in the morning and spray applied in the evening of same day. Number and weight of healthy and infested fruit was recorded. Benefit cost ratio (BCR) was calculated to evaluate the economics of insecticide application at different intervals. [ABSTRACT FROM AUTHOR]

The dusky cotton bug, Oxycarenus hyalinipennis (Costa) (Hemiptera: Lygaeidae) is a serious pest of cotton and damages cotton seed by reducing the oil content. In Pakistan, O. hyalinipennis is managed by using various insecticides and has developed resistance to several insecticides. In this study, O. hyalinipennis was selected with bifenthrin for 12 generations (G 1 to G 12) and developed a 55.64-fold resistance when compared with an unselected population (Unsel Pop). Bifenthrin resistance declined from 55.64 to 24.93-fold when selected population was removed from bifenthrin selection pressure for four generations (G 13 to G 16). Bifenthrin selected (Bifen-Sel) population showed a very low cross-resistance to profenofos (2.82-fold), deltamethrin (2.35-fold) and acetamiprid (2.21-fold) when compared with a field population (Field Pop). The bifenthrin resistance was incomplelety dominanat and autosomal. The relative fitness (Rf) of Bifen-Sel population was 0.58 along with significant decreases in average nymphal survival, fecundity, egg hatchability, intrinsic rate of population increase (r m), net reproductive rate (Ro) and biotic potential (Bp). The Rf of Cross 1 and Cross 2 was 1.07 and 1.22, respectively. The high fitness costs, instable resistance and a very low cross-resistance with other insecticides might be useful in slowing down the evolution of bifenthrin resistance by implementing an insecticide rotation plan. Image 1 • Selection for 12 generations with bifenthrin induced 55.64-fold resistance in DCB. • Relaxing from selection pressure reverted bifenthrin resistance to 24.93-fold. • No obvious cross-resistances were observed with all tested insecticides. • Bifenthrin-selected population was low in fitness. • Bifenthrin resistance was incompletely dominant and autosomal. [ABSTRACT FROM AUTHOR]

Abstract: One of the emerging threats to citrus industry in Pakistan is the infestation of mealybug Drosicha mangiferae (Pseudococcidae: Hemiptera), a damaging insect pest of a large number of agricultural and horticultural crops in South East Asia. In spite of extensive applications of conventional synthetic pesticides, citrus farmers are unable to get rid of this pest. In order to find out alternate biorational pesticides, this laboratory study was carried out to evaluate few selected novel chemistry insecticidal formulations against 2nd instar nymphs of D. mangiferae using standard twig-dip bioassay method according to Completely Randomized Design. Results showed that both factors i.e. insecticidal treatments (F 9, 245 = 146.90, P < 0.001) and time (F 4, 245 = 445.75, P < 0.01) and their interaction (F 36, 245 = 9.20, P < 0.001) had a significant effect on the mortality of mealybug nymphs. The most effective novel chemistry insecticides against D. mangiferae mealybugs were sulfoxaflor, spirotetramat, thiamethoxam and pyriproxyfen with mean mortality and LT50 values of 64.00±3.50% and 31.67 h, 62.67±2.64% and 34.42 h, 53.01±4.10% and 45.84 h, and 51.00±3.97% and 48.10 h, respectively. Based on these results, the above mentioned novel chemistry insecticides are recommended to be incorporated in future pest management programs against D. mangiferae mealybugs. [ABSTRACT FROM AUTHOR]