Impact of insect growth regulators on biology and behavior of Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae)

Ecotoxicology - This study investigated the effects of four insect growth regulators (IGRs) on biology and behavior of Chrysoperla carnea. IGRs were sprayed on eggs, larvae (~24-h old), and pupae...     

Residual action of five insecticides on larvae and adults of the neotropical predators Chrysoperla externa (Neuroptera: Chrysopidae) and Eriopis connexa (Coleoptera: Coccinellidae)

This work aimed to evaluate the residual action of five insecticides on larvae and adults of the predators Chrysoperla externa (Hagen) and Eriopis connexa (Germar). The insecticides gamma-cyhalothrin, imidacloprid+beta-cyfluthrin, methomyl, thiamethoxam, and thiamethoxam+lambda-cyhalothrin were sprayed in pod bean plants until the point of runoff. Weekly, at 3, 10, 17, 24, and 31 days, first instar larvae and adults of both predators were exposed to leaves containing dry residues of the insecticides. Based on the mortality observed throughout the bioassays, the insecticides were classified according to the scale of the residual effects proposed by the International Organization for Biological and Integrated Control (IOBC). Except for thiamethoxam+lambda-cyhalothrin, which was moderately persistent (class 3) to larvae of C. externa and E. connexa, all other tested insecticides were persistent (class 4) to larvae of both species. Gamma-cyhalothrin, imidacloprid + beta-cyfluthrin, and methomyl were persistent (class 4) to C. externa adults, while thiamethoxam was moderately persistent (class 3) and thiamethoxam + lambda-cyhalothrin was slightly persistent (class 2) to the adult stage. As for E. connexa adults, imidacloprid + beta-cyfluthrin and methomyl were persistent (class 4) and gamma-cyhalothrin, thiamethoxam, and thiamethoxam + lambda-cyhalothrin were moderately persistent (class 3). Thus, due to extended residual effect, these insecticides must be avoided when larvae and adults of both predators are active in the crop.

     

Lethal and sublethal effects of pesticides on <Emphasis Type="Italic">Chrysoperla carnea</Emphasis> larvae (Neuroptera: Chrysopidae) and the influence of rainfastness in their degradation pattern over time

The predator Chrysoperla carnea is a model species for the study of non-target effects of pesticides under different scenarios: registration of plant protection products under the European Union and effects of the Bt toxin. Laboratory and persistence studies were carried out with six pesticides currently used in corn crops in Spain that were applied at their maximum field recommended concentrations. The assessed end-points were larval mortality, survivorship until adult stage, duration of the larval and pupal periods, fecundity, fertility and sex ratio of the emerged adults. Based on the total effect (lethal and sublethal) caused to L₃ larvae in contact with fresh residues in the laboratory, pendimethalin was harmless (IOBC 1), lambda-cyhalothrin, abamectin, and hexythiazox were slightly harmful (IOBC 2), deltamethrin was moderately harmful (IOBC 3) and chlorpyrifos was harmful (IOBC 4). Afterwards, the residues of the two most toxic pesticides in the lab (deltamethrin and chlorpyrifos) were aged under greenhouse conditions (22 ± 2 °C, 40 ± 10 % R.H., 16.9 μmol m^?2 s^?1 UV radiation) in the presence and absence of artificial rainfall (10 l m^?2 h^?1, applied 24 h after pesticide application). Deltamethrin was classified as short lived (IOBC A) in both cases. However, degradation of chlorpyrifos residues was accelerated in the presence of rainfall, leading to the classification as slightly persistent (IOBC B), while in absence of rainfall it behaved as persistent (IOBC D). Every pesticide can be recommended for inclusion in corn IPM programs where the predator is present except chlorpyrifos that exhibited high direct toxicity in the lab and prolonged residual action even in the presence of rainfall.     

Toxicity of three aphicides to the generalist predators <Emphasis Type="Italic">Chrysoperla carnea</Emphasis> (Neuroptera: Chrysopidae) and <Emphasis Type="Italic">Orius insidiosus</Emphasis> (Hemiptera: Anthocoridae)

Recent widespread infestations of the invasive sugarcane aphid, Melanaphis sacchari (Zehntner) (Hemiptera: Aphididae), in sorghum fields in the southern USA have created demand for insecticides that will provide effective control of sugarcane aphid, while conserving those beneficial species that contribute to biological control of the pest. We tested the susceptibility of both adult and immature stages of two aphid predators, the green lacewing, Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), and the insidious flower bug, Orius insidiosus (Say) (Hemiptera: Anthocoridae), to three aphicides, flonicamid, sulfoxaflor and flupyradifurone. Flonicamid was innocuous to both species regardless of life stage or route of exposure. Lacewing adults were more susceptible to sulfoxaflor and flupyradifurone than were larvae, and had higher mortality when fed contaminated honey solution than when contacting residues on an inert surface. When laid in sunflower stems treated with these two materials, eggs of O. insidiosus hatched successfully, but nymphs experienced significant mortality when exposed to treated stems, likely due to phytophagous behavior that resulted in some insecticide ingestion. Despite these impacts, we conclude that both sulfoxaflor and flupyradifurone are likely to be relatively innocuous in comparison to more broad-spectrum insecticides and are thus potentially compatible with biological control and overall management of M. sacchari in grain sorghum.     

Impact of insect growth regulators on the predator <Emphasis Type="Italic">Ceraeochrysa cincta</Emphasis> (Schneider) (Neuroptera: Chrysopidae)

The generalist predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae) is an important biological control agent of several arthropod pests in different agroecosystems. This study assessed the lethal and sublethal effects of six insect growth regulators sprayed on first-instar larvae of C. cincta. Lufenuron and diflubenzuron were highly harmful to first-instar larvae of C. cincta, causing 100 % of mortality before they reached the second instar. Buprofezin caused ~25 % mortality of the larvae and considerably reduced the fecundity and longevity of the insects, but substantially increased the proportion of females in the surviving population of C. cincta. Methoxyfenozide and tebufenozide did not affect the duration and survival of the immature stages, but methoxyfenozide significantly reduced the fecundity and longevity of the insects. Pyriproxyfen reduced the survival of the larval stage by 19.5 %, but did not affect the development, survival and reproduction of the surviving individuals. Based on reduction coefficient, the insecticides diflubenzuron and lufenuron were considered harmful to C. cincta, whereas buprofezin and methoxyfenozide were slightly harmful and tebufenozide and pyriproxyfen were harmless. The estimation of life-table parameters indicated that buprofezin and methoxyfenozide significantly reduced the R _o , r and λ of C. cincta, whereas pyriproxyfen and tebufenozide caused no adverse effect on population parameters, indicating that these insecticides could be suitable for use in pest management programs towards the conservation and population increase of the predator in agroecosystems. However, more studies should be conducted to evaluate the compatibility of these insecticides with the predator C. cincta under semi-field and field conditions.     

Resistance of the house fly Musca domestica (Diptera: Muscidae) to lambda-cyhalothrin: mode of inheritance,realized heritability,and cross-resistance to other insecticides

Lambda-cyhalothrin, a pyrethroid insecticide, has been used frequently for the control of house flies, Musca domestica L., worldwide including Pakistan. To assess the resistance risk and design a resistance management strategy, a house fly population was exposed to lambda-cyhalothrin in the laboratory to assess inheritance and heritability, and cross-resistance to other insecticides, including different chemical classes. After 11 generations of selection, the population developed 113.57-fold resistance to lambda-cyhalothrin compared to the susceptible population. There was no cross-resistance to bifenthrin and methomyl, but very low cross-resistance to abamectin and indoxacarb in the lambda-cyhalothrin selected population compared to the field population. Synergism bioassay with piperonyl butoxide and S,S,S-tributylphosphorotrithioate indicated that lambda-cyhalothrin resistance was associated with microsomal oxidases and esterases. The LC₅₀ values of F₁ (Lambda-SEL ♀ × Susceptible ♂) and F′₁ (Lambda-SEL ♂ × Susceptible ♀) populations were not significantly different and dominance (D_LC) values were 0.68 and 0.62. The resistance to lambda-cyhalothrin was completely recessive (D_ML = 0.00) at highest dose and completely dominant at lowest dose (D_ML = 0.95). The monogenic model of inheritance showed that lambda-cyhalothrin resistance was controlled by multiple factors. The heritability values were 0.20, 0.04, 0.003, 0.07 and 0.08 for lambda-cyhalothrin, bifenthrin, methomyl, indoxacarb and abamectin resistance, respectively. It was concluded that lambda-cyhalothrin resistance in house flies was autosomally inherited, incompletely dominant and controlled by multiple factors. These findings would be helpful to improve the management of house flies.     

Physical fitness: a longitudinal study among Muslim children of Bijapur (Karnataka)

Aerobic capacity or maximum oxygen uptake capacity (VO2 max) has been widely considered to be reliable and valid measure of cardio respiratory fitness. Persons possessing higher values and have the capacity to yield larger amounts of energy, are capable of performing better in athletic and other field activities. Seventy school going children from the Muslim community of Bijapur (Karnataka) aged 12-16 years (means +/- SEM = 14.33 +/- 0.94), volunteered for this study. Their height (cm) and weight (kg) were measured as physical anthropometry and Body mass index (BMI) was calculated (kg/m2). VO2max (ml.kg-1.min-1) was determined by applying the step test study of Margaria et al. The Physical fitness index (PFI) of the subjects were assessed by Harvard Step Test. The physiological endurance measured as VO2max (ml.kg-1.min-1) was found to be 34.31 +/- 2.44 S.E.M, which is lower in comparison to their Caucasian counterparts but nearly similar when compared with their Indian counterparts. The present study reveals that VO2max significantly correlates with BMI and PFI score. The present study also reveals that 27.2%, 20.07%, 15.77%, 14.37% and 22.87% of the subjects are in excellent, very good, good, average and poor classifications of fitness level respectively.     

Physical fitness: a comparative study between students of residential (Sainik) and non-residential schools (aged 12-14 years)

Physical Fitness Index (PFI), of fifty Residential (Sainik) School children (Mean +/- SD, 13.18 +/- 0.48 yrs) and forty four Non-Residential school children (Mean +/- SD, 13.15 +/- 0.66 yrs) of Bijapur, Karnataka, was assessed by Harvard Step Test. Their height (cm), weight (kg), chest circumference (cm), and mid arm circumference (cm) were recorded as physical anthropometry. Body Mass Index (BMI) was also calculated (kg/m2). Results indicated that Non-Residential School children had poor physical anthropometry and showed a less PFI score (Mean +/- SD, 60.56 +/- 13.49), as compared to Residential (Sainik) School children (Mean +/- SD, 85.7 +/- 16.91). Regular physical activity with uniform diet and better physical composition attributed higher physical fitness in the children of Residential (Sainik) school in comparison to their sedentary Non-Residential counter part.     

Mitohormesis: Promoting Health and Lifespan by Increased Levels of Reactive Oxygen Species (ROS)

Increasing evidence indicates that reactive oxygen species (ROS), consisting of superoxide, hydrogen peroxide, and multiple others, do not only cause oxidative stress, but rather may function as signaling molecules that promote health by preventing or delaying a number of chronic diseases, and ultimately extend lifespan. While high levels of ROS are generally accepted to cause cellular damage and to promote aging, low levels of these may rather improve systemic defense mechanisms by inducing an adaptive response. This concept has been named mitochondrial hormesis or mitohormesis. We here evaluate and summarize more than 500 publications from current literature regarding such ROS-mediated low-dose signaling events, including calorie restriction, hypoxia, temperature stress, and physical activity, as well as signaling events downstream of insulin/IGF-1 receptors, AMP-dependent kinase (AMPK), target-of-rapamycin (TOR), and lastly sirtuins to culminate in control of proteostasis, unfolded protein response (UPR), stem cell maintenance and stress resistance. Additionally, consequences of interfering with such ROS signals by pharmacological or natural compounds are being discussed, concluding that particularly antioxidants are useless or even harmful.     

General characteristics of the insulin resistance syndrome: prevalence and heritability. European Group for the study of Insulin Resistance (EGIR)

It has recently been recommended by a WHO expert committee that the insulin resistance syndrome, a cluster of cardiovascular risk factors linked to insulin resistance, should be termed 'the metabolic syndrome'. Characterisation with data from 2 large databases [the European Group for the study of Insulin Resistance (EGIR) and the Danish Twin Register] has shown that insulin resistance correlates closely with the various components of the metabolic syndrome, and that the prevalence of the syndrome is approximately 16% among Caucasians. Both genetically determined and environmentally induced insulin resistance may precipitate onset of the metabolic syndrome, and increased levels of abdominal fat may be of primary importance in its development.     

Increased serum levels of progranulin (PGRN) in patients with haemophilic arthropathy

Haemophilia A and B are rarely occurring X chromosome‐linked congenital coagulation disorders dominated by spontaneous joint bleedings and chronic synovitis, leading to development of haemophilic arthropathy (HA). Progranulin (PGRN) is a growth factor with anti‐inflammatory and immunomodulatory properties. PGRN is an important molecule in the pathogenesis of osteoarthritis (OA) and rheumatological disorders. This study was aimed at investigating the potential role of PGRN in the mechanisms underlying the pathogenesis of HA. The serum levels of PGRN were measured by enzyme‐linked immunosorbent assay (ELISA) in patients with end‐stage knee joint HA (n = 20) and end‐stage primary knee joint OA (n = 20) who met the inclusion and exclusion criteria. The clinical and radiological assessment of disease severity was evaluated by the Knee Society Score (KSS) and Kellgren‐Lawrence scale. Median PGRN levels in HA patients was 349.1 ng/mL (232.8–415.6 ng/mL) and in OA patients 148.3 ng/mL (112.1‐275.3 ng/mL) with statistically significant differences between both groups (P < 0.015). Further analysis revealed no correlation between PGRN levels and any of the patient demographics and clinical parameters. This study demonstrates increased PGRN serum levels in patients with HA and provides new insights into the mechanisms underlying the pathogenesis of HA indicating a new potential target for therapeutic intervention.     

Effects of Cu+2 and pH on the fitness of Ceriodaphnia dubia (Richard 1894) (Crustacea, Cladocera) in microcosm experiments

An important disturbance of anthropogenic origin frequently occurring in freshwater ecosystems is a rise in the concentration of heavy metals in solution, among which copper stands out due to its known toxicity. However, the study of the chemical behavior of copper in solution is highly dependent on pH. In this study, the effect of ionic copper on the fitness of Ceriodaphnia dubia was assessed in microcosm experiments under different conditions of Cu+2 and pH. Two groups of experiments were conducted: effects on survival and fecundity, and effects on population dynamics. In the former, both pH and copper concentrations were manipulated. On the other hand, only the concentration of biologically available ionic copper was manipulated whereas pH was maintained constant in the population dynamics experiments. There was an agreement between both sets of experiments in terms of their results, showing important toxic effects of copper as evidenced through significant differences between controls and treatments in survival and fecundity. Mean age of first reproduction was delayed, and both the number of neonates produced per female and number of broods decreased with the increase in the concentration of copper. R0 was always lower at pH 6 than at pH 8 and was negatively related to the increment in the concentration of copper under either pH. A significant effect on population dynamics at 5 micrograms l-1 of copper sulfate was found and the extinction of the population at 20 micrograms l-1 of copper sulfate. New values of toxicity from copper are proposed, and the potential effects that an increment in copper could have on the communities that occupy a central position in aquatic food webs are discussed.     

Increased sensitivity to dopaminergic agonists after repeated electroconvulsive shock (ECS) in rats

The effects of single or repeated electroconvulsive shock (once daily for 7 days) on spontaneous locomotor activity and dopamine agonist-induced hyperactivity were investigated 1 hr, 1, 5 and 10 days after the last shock. Apomorphine-induced stereotyped behaviour was also measured. One hour after a single ECS both the spontaneous locomotor activity and locomotor stimulation produced by d-amphetamine or nomifensine were depressed but the stimulant effect of apomorphine was not altered. One hour, 1, 2, 3 and 5 days following repeated ECS, the rats displayed enhanced spontaneous loco- motor activity and d-amphetamine, nomifensine or apomorphine stimulated motor activity. This last effect was also observed 10 days after ECS was terminated. Apomorphine-induced stereotyped behaviour was not changed at these times. These results indicate that in rats repeated ECS increased behavioural sensitivity to dopaminergic stimuli in the mesolimbic system.     

Increased histidine decarboxylase (HDC) activity in human colorectal cancer: results of a study on ten patients

Following numerous reports of high histidine decarboxylase (HDC) activity in tumour-bearing animals, the present work was designed to determine the activity of this enzyme in normal and tumour tissues in a series of ten surgical patients with colorectal carcinoma. Significantly increased HDC activity, almost double that of normal tissues, was found in specimens from extirpated human tumours. These results, obtained under reliable sampling and measurement conditions indicated that changes in the enzymic activity of HDC may have a significant role in the development of colorectal tumour cells. Inhibition of the enzyme activity in human cancer subjects may retard or impede tumour growth and perhaps limit the spread of metastases.     

Increased adamantane resistance in influenza A(H3) viruses in Australia and neighbouring countries in 2005

The prevention and control of disease caused by seasonal and potential pandemic influenza viruses is currently managed by the use influenza vaccines and antivirals. The adamantanes (amantadine and rimantadine) were the first antivirals licensed for use against influenza A viruses and have been used extensively in some countries. Since the early 2000s increased resistance to these drugs has been reported especially in the A(H3) viruses. In this study we analysed recent human influenza A strains isolated in Australia and regionally for evidence of resistance to adamantanes and found evidence of significant resistant emerging during 2005.