Search

Honeybees are important insects, both economically and as pollinators. While foraging, bees can come in contact with environmental pollutants such as pesticides, possibly in combination with other xenobiotic compounds that may compromise bee health. Our current study investigated the acute exposure to nanosized titanium dioxide, a common additive in food, cosmetics, paints and agricultural products, along with deltamethrin (DLT), a well‐known pyrethroid pesticide. The effects of binary exposure to titanium dioxide nanoparticles (TiO2‐NPs) nanoparticles at concentrations of 25, 50, 75 and 100 μg/mL with DLT were noted on Apis mellifera brain histology along with their possible synergism. In DLT‐ and combined TiO2‐NP‐DLT treated bees, survival rates were lowered and several histological alterations were observed including an increased number of cells with pyknotic nuclei, along with cytoplasmic vacuolization, chromatin compaction and degeneration indicating autophagic activity and a decrease in the cross‐sectional area of nanoparticle‐treated mushroom body calyces. A synergistic relationship between TiO2‐NPs and DLT was revealed, while LD50 for combined TiO2‐NP‐DLT treatment was 0.101, 0.09 and 0.02 μg/bee at 24, 48 and 72 h, respectively. In summary, results demonstrate that TiO2‐NP and DLT co‐exposure can induce damage in bee brain structures at higher concentrations, which indicates an additional risk factor for bee health in the field. [ABSTRACT FROM AUTHOR]

Nanoparticles are defined as structures of size ranges from 1-100 nm in diameter in at least one direction. Metallic nanoparticles are considered the most potent agents in the modern world because they are used in every field of life, including the biotechnology, medical, textile, and food industries. Owing to their increased application, humans are constantly exposed to these nanoparticles. Their physiochemical characteristics, as their large surface to volume ratio might enhance their toxicity, increased surface area of NPs exhibit increased biological activity i.e reactive oxygen species generation when compared to large particles of the same mass. Consequently, their biosafety is a matter of major concern. The liver is the primary organ for detoxification and the major organ exposed to nanoparticles. After penetrating the body, nanoparticles enter the bloodstream and are internalized by hepatocytes. After penetration, they cause genotoxicity, oxidative stress and histopathology in hepatic tissues. [ABSTRACT FROM AUTHOR]

While nanoparticles (NPs) can be used as insecticides by themselves, they can also be carriers for insecticidal chemicals. Existing literature suggests that the smaller the NP size, the greater the toxicity and penetration into the insect's body. Nonetheless, there is a lack of literature pertaining to the mode of action within insects. This review article summarizes the currently available entomological studies on the mechanisms of NP–insect interactions. Externally, NPs affect pigmentation and integrity of the cuticle, while internally they induce immune responses and alter gene expression leading to altered protein, lipid, and carbohydrate metabolism along with cellular toxicity that impairs development and reproduction of the insect. Consequently, insects are incapacitated due to the disruption of the nutrient intake, production of reactive oxygen species and altered biochemical activity while some NPs can promote growth and development as well as diminish the effects of nontarget toxicity. [ABSTRACT FROM AUTHOR]

Termites Heterotermes indicola (Wasmann) are destructively dagamging insects that cause massive harm to timber, resulting in loss of billions of dollars in property damage. Various chemical antitermite solutions are available that cause environmental contamination and are also hazard to human health. Extracts from 3 plants Cedrus deodara (Pinaceae), Betula utilis (Betulaceae) and Syzygium cumini (Myrtaceae) were tested for repellent, antifeedant and their toxicity against Heterotermes indicola (Wasmann). Our results show that feeding and mean percentage mortality varied not only with the plant species, but alsowith the type of the extraction solvents. Hexane extract of C. deodara showed the highest termite mortality rate. H.indicola consumed more ethanolic extract treated/untreated filter paper than hexan treated untreated filter paper with various plant extracts.These results show that hexane extracts of the plants were comparatively more toxic and repellent against H.indicola (Wasmann), since insects consumed mimimum filter paper treated with all three plant extracts. Results show that for all three plants, hexane extracts had optimum anti-termite activity. [ABSTRACT FROM AUTHOR]

The article presents a study which investigates on the potential of antitermitic activities of eucalyptus oil concerning several termite species in Pakistan such as Heterotermes indicola (Wasmann), Mierotermes obesi (Holmgren) and Odontotermes obesus (Rambur). It mentions that the toxicity, repellency and fumigant activity tests were conducted to the laboratory assays from the essential oil from Eucalyptus (Eucalyptus citriodora). The study shows that eucalyptus oil was highly repellent against termites. The study suggests that eucalyptus oil can be considered to be the best at dose of methanol.

The study was carried out on 100 broiler birds to ascertain the effect of ammonia and different ammonia modifiers on various parameters. For this purpose, the birds were divided into five groups and different treatments were allotted including potassium aluminium sulphate, aluminium silicate and Yucca schidigera plant extract. A completely sealed environment was created to produce ammonia. Results showed that ammonia at 25 ppm did not affect the carcass weight, relative organs weight and antibody titer. Gross and histopathological changes like pale liver, congestion in lungs and necrosis in kidneys were observed in positive control group, while minor changes were seen in all treatment groups. Grossly, bursa of Fabricious appear smaller in size, while on histological examination it showed depletion of lymphocytes in positive control. The level of urea (18.53 mg/100 ml), creatinine (0.30/ mg/100 ml), AST (53.0 IU/L) and ALT (7.50 IU/L) were increased. The antibody titer (5.65 log²) was not affected by 25 ppm of ammonia however, it was 35% higher than both the control groups in aluminium silicate group (7.67 log²). A lower spleen weight (0.10 g) and kidney (0.73g) weight, while higher levels of urea (15.83 mg/100 ml) and creatinine (0.31 mg/100 ml) were observed in Yucca treated groups. The AST (53 IU/L) and ALT (8.26 IU/L) were found significantly (P<0.05) higher in alum treated groups than both control groups. All the treatments reduced the effects of ammonia in broilers, however, in overall aluminium silicate results were better than other treatments. The study concludes that, all the three amendments are useful in reducing the ammonia and improves the production and function of the broiler chicken. [ABSTRACT FROM AUTHOR]