Agricultural Insecticides Research Articles

Comparative susceptibility of two Neotropical predators, Eriopis connexa and Chrysoperla externa, to acetamiprid and pyriproxyfen: Short and long-term effects after egg exposure

Compatibility assessments between selective insecticides and the natural enemies of pests are essential for integrated-pest-management programs. Chrysoperla externa and Eriopis connexa are two principal Neotropical predators of agricultural pests whose conservation in agroecosystems requires a toxicity evaluation of pesticides to minimize the impact on those beneficial insects on the environment. The objective of this work was to evaluate the toxicity of the insecticides pyriproxyfen and acetamiprid on C. externa and E. connexa eggs exposed to the maximum recommended field concentrations of each along with three successive dilutions. The survival and the immature developmental time were assessed daily until adulthood and the mean survival time calculated over a 10-day period. The cumulative survival of E. connexa was reduced at all concentrations of both insecticides, while that of C. externa was significantly decreased by ≥50 mg L−1 of acetamiprid and ≥37.6 mg L−1 of pyriproxyfen. In both species, the reductions occurred principally on the eggs and first larval instar. Survival curves, in general, differed from those of the controls, with the mean survival time of E. connexa being significantly shorter in insecticides treatments than that of the controls. Certain concentrations of each of the insecticide lengthened the egg and first-larval-instar developmental periods of E. connexa and C. externa, respectively. Also, pyriproxyfen reduced the first-larval-instar period and lengthened the fourth of E. connexa. Acetamiprid was more toxic to E. connexa than to C. externa at the two highest concentrations. Conversely, at those same concentrations of pyriproxyfen, the relative toxicity to the two species was reversed. The present work represents the first investigation on the comparative susceptibility of two relevant Neotropical biological control agents to acetamiprid and pyriproxyfen. Also, it highlights the necessity of assessing long-term effects in the compatibility studies between natural enemies of agricultural pests and insecticides.

Monarch butterfly population decline in North America: identifying the threatening processes.

The monarch butterfly (Danaus plexippus) population in North America has sharply declined over the last two decades. Despite rising concern over the monarch butterfly's status, no comprehensive study of the factors driving this decline has been conducted. Using partial least-squares regressions and time-series analysis, we investigated climatic and habitat-related factors influencing monarch population size from 1993 to 2014. Potential threats included climatic factors, habitat loss (milkweed and overwinter forest), disease and agricultural insecticide use (neonicotinoids). While climatic factors, principally breeding season temperature, were important determinants of annual variation in abundance, our results indicated strong negative relationships between population size and habitat loss variables, principally glyphosate use, but also weaker negative effects from the loss of overwinter forest and breeding season use of neonicotinoids. Further declines in population size because of glyphosate application are not expected. Thus, if remaining threats to habitat are mitigated we expect climate-induced stochastic variation of the eastern migratory population of monarch butterfly around a relatively stationary population size.

The agricultural impact of pesticides on Physalaemus cuvieri tadpoles (Amphibia: Anura) ascertained by comet assay

ABSTRACT Amphibians inhabiting agricultural areas are constantly exposed to large amounts of chemicals, which reach the aquatic environment during the rainy season through runoff, drainage, and leaching. We performed a comet assay on the erythrocytes of tadpoles found in the surroundings of agricultural fields (soybean and corn crops), where there is an intense release of several kinds of pesticides in different quantities. We aimed to detect differences in the genotoxic parameters between populations collected from soybeans and cornfields, and between them and tadpoles sampled from non-agricultural areas (control group). Tadpoles collected from ponds located at soybean fields had significantly more DNA damage, followed by tadpoles collected from cornfields. In contrast, animals sampled from non-agricultural areas had the lowest incidence of DNA damage. In addition, we found a negative correlation between the parameters of the comet assay and the area of the ponds surrounding soybean. This correlation indicates a possible dilution effect in the concentration of pesticides. Finally, Physalaemus cuvieri Fitzinger, 1826 seems to be a good bioindicator for detecting the genotoxic effects of field agricultural insecticides; therefore, we suggest that this species should be used in environmental biomonitoring studies, since it is common and abundant where it occurs.

Feeding toxicity and impact of imidacloprid formulation and mixtures with six representative pesticides at residue concentrations on honey bee physiology (Apis mellifera).

Imidacloprid is the most widely used insecticide in agriculture. In this study, we used feeding methods to simulate in-hive exposures of formulated imidacloprid (Advise® 2FL) alone and mixtures with six representative pesticides for different classes. Advise, fed at 4.3 mg/L (equal to maximal residue detection of 912 ppb active ingredient [a.i.] in pollen) induced 36% mortality and 56% feeding suppression after 2-week feeding. Treatments with individual Bracket (acephate), Karate (λ-cyhalothrin), Vydate (oxamyl), Domark (tetraconazole), and Roundup (glyphosate) at residue level had a mortality range of 1.3–13.3%, statistically similar to that of control (P>0.05). The additive/synergistic toxicity was not detected from binary mixtures of Advise with different classes of pesticides at residue levels. The feeding of the mixture of all seven pesticides increased mortality to 53%, significantly higher than Advise only but still without synergism. Enzymatic data showed that activities of invertase, glutathione S-transferase, and acetylcholinesterase activities in imidacloprid-treated survivors were mostly similar to those found in control. Esterase activity mostly increased, but was significantly suppressed by Bracket (acephate). The immunity-related phenoloxidase activity in imidacloprid-treated survivors tended to be lower, but most treatments were statistically similar to the control. Increase of cytochrome P450 activity was correlated with Advise concentrations and reached significant difference at 56 mg/L (12 ppm a.i.). Our data demonstrated that residue levels of seven pesticide in pollens/hive may not adversely affect honey bees, but long term exclusive ingestion of the maximal residue levels of imidacloprid (912 ppb) and sulfoxaflor (3 ppm a.i.) may induce substantial bee mortality. Rotating with other insecticides is a necessary and practical way to reduce the residue level of any given pesticide.

Fate and transport of furrow-applied granular tefluthrin and seed-coated clothianidin insecticides: Comparison of field-scale observations and model estimates.

The transport of agricultural insecticides to water bodies may create risk of exposure to non-target organisms. Similarly, widespread use of furrow-applied and seed-coated insecticides may increase risk of exposure, yet accessible exposure models are not easily adapted for furrow application, and only a few examples of model validation of furrow-applied insecticides exist using actual field data. The goal of the current project was to apply an exposure model, the Pesticide in Water Calculator (PWC), to estimate the concentrations of two in-furrow insecticides applied to maize: the granular pyrethroid, tefluthrin, and the seed-coated neonicotinoid, clothianidin. The concentrations of tefluthrin and clothianidin in surface runoff water, sampled from a field in central Illinois (USA), were compared to the PWC modeled pesticide concentrations in surface runoff. The tefluthrin concentrations were used to optimize the application method in the PWC, and the addition of particulate matter and guttation droplets improved the models prediction of clothianidin concentrations. Next, the tefluthrin and clothianidin concentrations were calculated for a standard farm pond using both the optimized application method and the application methods provided in PWC. Estimated concentrations in a standard farm pond varied by a factor of 100 for tefluthrin and 50 for clothianidin depending on the application method used. The addition of guttation droplets and particulate matter to the model increased the annual clothianidin concentration in a standard farm pond by a factor of 1.5, which suggested that these transport routes should also be considered when assessing neonicotinoid exposure.

Identifying the landscape drivers of agricultural insecticide use leveraging evidence from 100,000 fields

Agricultural landscape intensification has enabled food production to meet growing demand. However, there are concerns that more simplified cropland with lower crop diversity, less noncrop habitat, and larger fields results in increased use of pesticides due to a lack of natural pest control and more homogeneous crop resources. Here, we use data on crop production and insecticide use from over 100,000 field-level observations from Kern County, California, encompassing the years 2005-2013 to test if crop diversity, field size, and cropland extent affect insecticide use in practice. Overall, we find that higher crop diversity does reduce insecticide use, but the relationship is strongly influenced by the differences in crop types between diverse and less diverse landscapes. Further, we find insecticide use increases with increasing field size. The effect of cropland extent is distance-dependent, with nearby cropland decreasing insecticide use, whereas cropland further away increases insecticide use. This refined spatial perspective provides unique understanding of how different components of landscape simplification influence insecticide use over space and for different crops. Our results indicate that neither the traditionally conceived "simplified" nor "complex" agricultural landscape is most beneficial to reducing insecticide inputs; reality is far more complex.

Lindane (Gamma‐Hexachlorocyclohexane) Exposure Impairs [Ca2+]i‐Mediated Vascular Reactivity

Gama hexacholorocyclohexane (γHCH; lindane), Gammallin is an organochlorine chemical that has been used as an agricultural insecticide as well as a pharmaceutical treatment for lice and scabies. It is reported to be neurotoxic, interfering with GABA neurotransmitter functions and other biological functions from brain to endocrine and cardiovascular systems. Despite being a banned persistent organic pollutant, it's still in use and can leach and contaminate our foods and water. We have investigated the effects and the mechanism(s) of lindane‐induced vascular dysfunctions in rat aorta. Rats treated with low dose of single pesticide Lindane (100 or 300 μmol/kg;1/5LD50; SP) or multiple pesticides (MP) (aldrin, endosulfan, lindane, 4,4‐DDT, and endrin: 1/100, 1/50, and 1/25 of the LD50, MP) orally or dermal application for 2 or 4 weeks showed significantly attenuated vascular relaxation (57 ± 5% to 36 ± 0.8%; ACh 10−3 M), MP attenuated relaxation (57 ± 5% to 19.8 ±5.8% and 19.0 ±4.0% respectively for 1/100 and 1/25 LD50). Paradoxically, 4 weeks SP enhanced relaxation to ACh (60.5 ± 4.6% to 83.5 ± 8.8%). In aorta from dermal group (SP), relaxation to ACh was significantly attenuated (59.4 ± 5.0 to 23.7 ± 6.0%). Vasoconstriction to PE (10−8 ‐10−3 M) were significantly attenuated by 4 weeks' treatment with oral SP or dermal MP reducing the contraction (0.64±0.06 to 0.15 ± 0.02gm or 0.49±0.01 gm; 10−3 M), but not for 2 weeks oral MP for PE‐induced contraction. Further investigation into the mechanism behind the observed vascular dysfunction reveals that in CHO cell line stably expressing M1‐ACh receptors, Lindane diminishes carbachol (10−8 to 10−3 M)‐induced increases in [Ca2+]i mediated by M1‐ACh receptor. Lindane diminishes Carbachol effects only at Carbachol's maximum activation and these results indicate that the vascular dysfunction by the pesticides could be due to disruption of intracellular Ca2+ regulation. Thus, 24‐hour Lindane exposure facilitates IP3‐mediated [Ca2+]i signaling. Month‐long Lindane exposure induces vascular dysfunction possibly via disruption of IP3‐mediated in [Ca2+]i signaling leading to dysregulated vasoresponsiveness to hormones/neurotransmitters contributing to cardiovascular dysfunctions.Support or Funding InformationThis research was supported by the National Heart, Lung, and Blood Institute (Grants HL03674 and HL070669) and by the use of TSU Research infrastructure support provided by grants G12RR003045 and CO6RR012537 awarded by the National Center for Research Resources, National Institutes of Health (NIH). The G12 program is now a part of the National Institute on Minority Health and Health Disparities (NIMHD) and the C06 program is in the Office of Research Infrastructure Programs in the Office of the Director, NIH.

Distribution of species and kdr gene frequency among Anopheles gambiae s.s. and Anopheles coluzzii populations in five agricultural sites in Côte d'Ivoire

The resistance of Anopheles gambiae s.l. to insecticides constitutes a concern for the programs of malaria control because it can be an obstacle to effective control of the vectors. The follow-up of this resistance is a priority to work out strategies of management and to preserve the means of that major malaria vector control activities. The general objective of this study is to identify the species within An. gambiae s.l., and to determine the frequency of the Kdr gene in An. gambiae s.s. and An. coluzzii in five agricultural sites in Ivory Coast: an urban site, two semirural sites (coffee-trees/cacao-trees, orchard) and two rural sites (rice site and a traditional village without agricultural insecticide). During this study, 2285 specimens of An. gambiae s.l. were analyzed for this purpose. An. gambiae s.s. (in the past called molecular form S) and An. coluzzii (in the past called molecular form M) were the only species of the complex An. gambiae identified in all the sites. The frequency of the Kdr mutation varied from 0.37 in the site without agricultural insecticide to 0.95 in the urban site where there is an intense use of insecticides. Three areas of these species distribution were observed: an area where the species An. gambiae s.s. is dominant (sites located in savanna), an area with predominance of An. coluzzii (in the southern forested area) and an intermediate area where the two species were in a same proportion (pre-forested site).The Kdr mutation was identified in the two species in all the sites in savanna and forest, except in the site without agricultural insecticide where only An. gambiae was resistant. It shows the increase of the receptive potential of An. gambiae s.l. with respect to the Kdr gene and the extension of the resistance to insecticide of this species in Ivory Coast.

Net Loss? Agrochemicals and Insecticide Resistance in the Fight against Malaria.

Net Loss? Agrochemicals and Insecticide Resistance in the Fight against Malaria.

First report of the East African kdr mutation in an Anopheles gambiae mosquito in Côte d’Ivoire

Background. The intensive use of insecticides in public health and agriculture has led to the development of insecticide resistances in malaria vectors across sub-Saharan Africa countries in the last two decades. The kdr target site point mutation which is among the best characterised resistance mechanisms seems to be changing its distribution patterns on the African continent. The 1014F kdr mutation originally described only in West Africa is spreading to East Africa while the 1014S kdr mutation originally described in East Africa, is spreading to West and Central Africa. However, the East- kdr mutation has not been reported in Côte d'Ivoire so far. Methods. Immature stages of Anopheles gambiae s.l. were collected from breeding sites at the outskirts of Yamoussoukro, Côte d'Ivoire. Emerging 3–5 day old adult female mosquitoes were tested for susceptibility to deltamethrin 0.05%, malathion 5%, bendiocarb 1% and dichlorodiphenyltrichloroethane (DDT) 4% according to WHO standard procedures. A total of 50 An. gambiae s.l. specimens were drawn at random for DNA extraction and identification down to the species level. A subsample of 30 mosquitoes was tested for the East-African kdr mutation using a Taqman assay. Results. The tested mosquito population appeared to be strongly resistant to deltamethrin (1.03% mortality), bendiocarb (38.46% mortality) and DDT (0% mortality) with probable resistance observed for malathion (92.47%). Among the 41 mosquitoes that were successfully characterized, An. coluzzii was predominant (68.3%) followed by An. gambiae s.s. (19.5%) and a few hybrids (7.3%). Out of 30 specimens genotyped for East- kdr, a single hybrid mosquito appeared to be heterozygous for the mutation. Conclusion. The present study revealed the presence of the East- kdr mutation in Côte d’Ivoire for the first time in An. gambiae and highlights the urgent need to start monitoring the allele and genotype frequencies.

First report of the East African kdr mutation in an Anopheles gambiae mosquito in Côte d'Ivoire.

Background. The intensive use of insecticides in public health and agriculture has led to the development of insecticide resistances in malaria vectors across sub-Saharan Africa countries in the last two decades. The kdr target site point mutation which is among the best characterised resistance mechanisms seems to be changing its distribution patterns on the African continent. The 1014F kdr mutation originally described only in West Africa is spreading to East Africa while the 1014S kdr mutation originally described in East Africa, is spreading to West and Central Africa. However, the East-kdr mutation has not been reported in Côte d'Ivoire so far. Methods. Immature stages of Anopheles gambiae s.l. were collected from breeding sites at the outskirts of Yamoussoukro, Côte d'Ivoire. Emerging 3-5 day old adult female mosquitoes were tested for susceptibility to deltamethrin 0.05%, malathion 5%, bendiocarb 1% and dichlorodiphenyltrichloroethane (DDT) 4% according to WHO standard procedures. A total of 50 An.gambiaes.l. specimens were drawn at random for DNA extraction and identification down to the species level. A subsample of 30 mosquitoes was tested for the East-African kdr mutation using a Taqman assay. Results. The tested mosquito population appeared to be strongly resistant to deltamethrin (1.03% mortality), bendiocarb (38.46% mortality) and DDT (0% mortality) with probable resistance observed for malathion (92.47%). Among the 41 mosquitoes that were successfully characterized, An.coluzzii was predominant (68.3%) followed by An.gambiae s.s. (19.5%) and a few hybrids (7.3%). Out of 30 specimens genotyped for East-kdr, a single hybrid mosquito appeared to be heterozygous for the mutation. Conclusion. The present study revealed the presence of the East-kdr mutation in Côte d'Ivoire for the first time in An.gambiae and highlights the urgent need to start monitoring the allele and genotype frequencies.

A beekeeper's perspective on the neonicotinoid ban.

Bees and agrochemicals have a long history. For example, the first volume of IBRA's journal Bee World in 1919 contains mention of poisoning of bees by spraying an orchard with lead arsenate. Bees being insects, it is self-evident that the use of insecticides to control crop pests poses a risk to them. Bee poisoning incidents became a very serious problem in the 1960s and 1970s with spraying of, in particular, oilseed rape with organophosphorus compounds. The introduction of carbamates and then especially synthetic pyrethroids reduced these problems. Data from the Wildlife Incident Investigation Scheme show that in recent years there have been very few poisoning incidents in the United Kingdom that can be attributed to agricultural insecticides. The introduction of neonicotinoid insecticides has, however, been very controversial. Almost as soon as they were introduced in the 1990s, French beekeepers blamed colony losses on imidacloprid used on sunflowers and maize, but restrictions on its use did not lead to a reduction in losses or to a reduction in beekeepers' concerns. Acute pesticide poisoning incidents by neonicotinoids in Germany and Italy in 2008 further sealed their reputation. Despite laboratory evidence showing their harm, field experience remains equivocal, and many commercial beekeepers continue to move their colonies to oilseed rape crops for honey production. The neonicotinoid moratorium has undoubtedly led to the increased use of older insecticides, and the effect of this on bee populations is unknown and unquantified. Many beekeepers are currently confused by the conflicting evidence. © 2016 Society of Chemical Industry.

Chlorpyrifos inhibits neural induction via Mfn1-mediated mitochondrial dysfunction in human induced pluripotent stem cells

Organophosphates, such as chlorpyrifos (CPF), are widely used as insecticides in agriculture. CPF is known to induce cytotoxicity, including neurodevelopmental toxicity. However, the molecular mechanisms of CPF toxicity at early fetal stage have not been fully elucidated. In this study, we examined the mechanisms of CPF-induced cytotoxicity using human induced pluripotent stem cells (iPSCs). We found that exposure to CPF at micromolar levels decreased intracellular ATP levels. As CPF suppressed energy production that is a critical function of the mitochondria, we focused on the effects of CPF on mitochondrial dynamics. CPF induced mitochondrial fragmentation via reduction of mitochondrial fusion protein mitofusin 1 (Mfn1) in iPSCs. In addition, CPF reduced the expression of several neural differentiation marker genes in iPSCs. Moreover, knockdown of Mfn1 gene in iPSCs downregulated the expression of PAX6, a key transcription factor that regulates neurogenesis, suggesting that Mfn1 mediates neural induction in iPSCs. Taken together, these results suggest that CPF induces neurotoxicity via Mfn1-mediated mitochondrial fragmentation in iPSCs. Thus, mitochondrial dysfunction in iPSCs could be used as a possible marker for cytotoxic effects by chemicals.

Degradation of imidacloprid insecticide in a binary mixture with propylene glycol by conventional fenton process

AbstractImidacloprid is one of the most widely used insecticides in agriculture. The fate of this highly recalcitrant pollutant and its by-product of incomplete degradation in water is of great concern due to the hazardous effects usually associated to pesticides. In the present manuscript, imidacloprid degradation by hydroxyl radical produced

A comparative assessment of cytotoxicity of commonly used agricultural insecticides to human and insect cells

The cytotoxic potential of 13 commonly used agricultural insecticides was examined using cell-based systems with three human HepG2, Hek293, HeLa cells and three insect Tn5B1-4, Sf-21, and Drosophila S2 cells. Data showed that (1) an enhancement of some insecticides (e.g. pyrethroids) on cells proliferation; (2) an inhibition of some insecticides on cells viability; (3) various levels of susceptibility of different cells to the same insecticide; and (4) the cell type dependent sensitivity to different insecticides. The degree of cytotoxicity of insecticides on human cells was significantly lower than that on insect cells (P<0.05). Methomyl, even 20μg/ml, showed little cytotoxicity at 24h exposure whereas emamectin benzoate possessed the strongest cytotoxic potential in a dose-dependent fashion. The results revealed comparable cytotoxic property of agricultural insecticides against intact cells.

A Landscape View of Agricultural Insecticide Use across the Conterminous US from 1997 through 2012.

Simplification of agricultural landscapes is expected to have positive effects on many crop pests and negative effects on their natural enemies, potentially leading to increased pest pressure, decreased crop yield, and increased insecticide use. While many intermediate links in this causal chain have empirical support, there is mixed evidence for ultimate relationships between landscape simplification, crop yield, and insecticide use, especially at large spatial and temporal scales. We explored relationships between landscape simplification (proportion of a county in harvested cropland) and insecticide use (proportion of harvested cropland treated with insecticides), using county-level data from the US Census of Agriculture and a variety of standard and spatiotemporal regression techniques. The best model indicated that insecticide use across the US has increased between 1997 and 2012, was strongly dependent on the crops grown in a county, increased with average farm income and size, and increased with annual growing degree days. After accounting for those variables, and other unidentified spatial and temporal structure in the data, there remained a statistically significant, moderate, positive relationship between insecticide use and landscape simplification. These results lend general support to the causal chain outlined above, and to the notion that a landscape perspective is useful for managing ecosystem services that are provided by mobile organisms and valuable to agriculture.

Current knowledge of detoxification mechanisms of xenobiotic in honey bees.

The western honey bee Apis mellifera is the most important managed pollinator species in the world. Multiple factors have been implicated as potential causes or factors contributing to colony collapse disorder, including honey bee pathogens and nutritional deficiencies as well as exposure to pesticides. Honey bees' genome is characterized by a paucity of genes associated with detoxification, which makes them vulnerable to specific pesticides, especially to combinations of pesticides in real field environments. Many studies have investigated the mechanisms involved in detoxification of xenobiotics/pesticides in honey bees, from primal enzyme assays or toxicity bioassays to characterization of transcript gene expression and protein expression in response to xenobiotics/insecticides by using a global transcriptomic or proteomic approach, and even to functional characterizations. The global transcriptomic and proteomic approach allowed us to learn that detoxification mechanisms in honey bees involve multiple genes and pathways along with changes in energy metabolism and cellular stress response. P450 genes, is highly implicated in the direct detoxification of xenobiotics/insecticides in honey bees and their expression can be regulated by honey/pollen constitutes, resulting in the tolerance of honey bees to other xenobiotics or insecticides. P450s is also a key detoxification enzyme that mediate synergism interaction between acaricides/insecticides and fungicides through inhibition P450 activity by fungicides or competition for detoxification enzymes between acaricides. With the wide use of insecticides in agriculture, understanding the detoxification mechanism of insecticides in honey bees and how honeybees fight with the xenobiotis or insecticides to survive in the changing environment will finally benefit honeybees' management.

Contamination of the Aquatic Environment with Neonicotinoids and its Implication for Ecosystems

The widespread use of systemic neonicotinoid insecticides in agriculture results first in contamination of the soil of the treated crops, and secondly in the transfer of residues to the aquatic environment. The high toxicity of these insecticides to aquatic insects and other arthropods has been recognised, but there is little awareness of the impacts these chemicals have on aquatic environments and the ecosystem at large. Recent monitoring studies in several countries, however, have revealed a world-wide contamination of creeks, rivers and lakes with these insecticides, with residue levels in the low μg/L (ppb) range. The current extent of aquatic contamination by neonicotinoids is reviewed first, and the findings contrasted with the known acute and chronic toxicity of neonicotinoids to various aquatic organisms. Impacts on populations and aquatic communities, mostly using mesocosms, are reviewed next to identify the communities most at risk from those that undergo little or no impact. Finally, the ecological links between aquatic and terrestrial organisms are considered. The consequences for terrestrial vertebrate species that depend mainly on this food source are discussed together with impacts on ecosystem function. Gaps in knowledge stem from difficulties in obtaining long-term experimental data that relates the effects on individual organisms to impacts on populations and ecosystems. The paper concludes with a summary of findings and the implications they have for the larger ecosystem.

Acephate exposure during a perinatal life program to type 2 diabetes.

Acephate has been used extensively as an insecticide in agriculture. Its downstream sequelae are associated with hyperglycemia, lipid metabolism dysfunction, DNA damage, and cancer, which are rapidly growing epidemics and which lead to increased morbidity and mortality rates and soaring health-care costs. Developing interventions will require a comprehensive understanding of which excess insecticides during perinatal life can cause insulin resistance and type 2 diabetes. A Wistar rat animal model suggests that acephate exposure during pregnancy and lactation causes alterations in maternal glucose metabolism and programs the offspring to be susceptible to type 2 diabetes at adulthood. Therapeutic approaches based on preventive actions to food contaminated with insecticides during pregnancy and lactation could prevent new cases of type 2 diabetes.

Mycoremediation of chlorpyrifos and lambda-cyhalothrin by two species of filamentous fungi

Chlorpyrifos and lambda-cyhalothrin are two of the most commonly used insecticides in agriculture. Their residues reach water courses, affecting aquatic fauna and subsequently human beings. Aspergillus viridinutans and Penicillium implicatum isolated from water drains at El-Giza and El-Ismailia governorates were grown in potato dextrose broth media supplemented with different concentrations of chlorpyrifos and lambda-cyhalothrin. Samples, taken at 0, 7 and 14 days, were analysed for pesticide residues by gas chromatography. The fungal species showed biodegradation potentials of 2.5, 5 and 20 ppm of chlorpyrifos and lambda-cyhalothrin. Degradation percentage reached 100% after 14 days of incubation of both pesticides (2.5 ppm) individually with the two tested fungal species. The values of degradation rate, besides the weights of dry fungal biomasses ensured that the optimum chlorpyrifos concentration for A. viridinutans and P. implicatum was 5 ppm, while the optimum lambda-cyhalothrin concentration for A. viridinutans was 5 ppm and 2.5 ppm for P. implicatum.