Muizen

Naturschützer warnen, dass das Insektensterben auch die Feldermäuse ausrotten könnte

Die Fledermäuse erwachen momentan aus dem Winterschlaf. Nachts gehen sie auf die Jagd, um ihre leeren Reserven aufzutanken. Doch sie finden kaum noch Futter. „Seit einiger Zeit beobachten wir einen alarmierenden Rückgang von Insekten“, sagt Karl Kugelschafter, Fledermausexperte vom Naturschutzbund (Nabu). Für die Fledermäuse geht es ums Überleben, denn sie ernähren sich fast ausschließlich von Insekten und müssen pro Tag ungefähr ein Drittel ihres Körpergewichtes an Nahrung zu sich nehmen. Hochgerechnet braucht ein einzelnes Tier also ungefähr ein Kilogramm Insekten in einem Sommer.

Chronic exposure to low levels of organophosphate insecticide may cause diabetes

A study by scientists at Madurai Kamaraj University, Tamil Nadu, has found evidence that chronic exposure to organophosphate insecticides induces diabetes and impaired glucose tolerance in both humans and mice. The researchers found that organophosphate-induced diabetes was mediated by gut bacteria. The results were published in the journal Genome Biology.

Induction of abnormal behaviours in mice after in utero and early postnatal exposure to imidacloprid

Imidacloprid (IMD), a neonicotinoid insecticide, is the most widely used insecticide on the planet. The purpose of this study was to examine the behavioural and biochemical effects of chronic in utero and early postnatal IMD exposure. Our treatment regimen entailed chronic exposure whereby pregnant mice were infused with 0.5 mg/kg/day of IMD via a subcutaneous osmotic mini-pump from gestational day 3 to postnatal day 21.

Feldhamster im Norden so gut wie ausgestorben

Schwarze Knopfaugen und dicke Bäckchen: Der Feldhamster sieht niedlich aus. Doch zu Gesicht bekommt den Nager im Norden kaum noch jemand, denn der Feldhamster (Cricetus cricetus) ist so gut wie ausgestorben. In Schleswig-Holstein und Mecklenburg-Vorpommern lebt nach Angaben der Deutschen Wildtier Stiftung kein einziger Feldhamster mehr. Und auch für Niedersachsen sieht es schlecht aus: Dort gibt es noch wenige Tiere rund um die die Hildesheimer Börde und Peine, aber auch hier schrumpft der Bestand. "Es ist fünf vor zwölf", sagt Biologe Peer Cyriacks von der Deutschen Wildtier Stiftung.

Pre- and Post-Natal Exposure To Acetamiprid Causes Neurological Abnormalities in Male Mice

Neonicotinoids, a widely used group of pesticides designed to selectively bind to insect nicotinic acetylcholine receptors, were considered relatively safe for mammalian species. However, they have been found to activate vertebrate nicotinic acetylcholine receptors and could be toxic to the mammalian brain.

The Battle Over the Most Used Herbicide Heats Up as Nearly 100 Scientists Weigh In

One year ago, an agency of the World Health Organization’s International Agency for Cancer Research (IARC) declared that glyphosate (or Roundup), the world’s most widely used herbicide, probably causes cancer. Then, in the fall, the European Food Safety Agency’s (EFSA) responded with an assessment that disagreed with the WHO’s findings. In response, 94 scientists came out in support of the IARC’s original findings. This week, the group—which includes scientists from around the world—released their article in the peer-reviewed Journal of Epidemiology and Community Health saying: The most appropriate and scientifically based evaluation of the cancers reported in humans and laboratory animals as well as supportive mechanistic data is that glyphosate is a probable human carcinogen. On the basis of this conclusion and in the absence of evidence to the contrary, it is reasonable to conclude that glyphosate formulations should also be considered likely human carcinogens. And their endorsement is no small matter. In fact, as the U.S. Environmental Protection Agency (EPA) reassesses the safety of glyphosate, and the U.S. Food and Drug Administration (FDA) plans to begin testing food for its residue, this volley has important implications.

Bestrijdingsmiddelen hebben een ware slachting aangericht bij diersoorten die van akkers afhankelijk zijn

Nederland bestaat voor een groot deel uit een agrarisch cultuurlandschap, waarvan ca. 800.000 ha in gebruik is als akkerland. Slechts op een kleine 1% is de akkerbouw biologisch. De afgelopen decennia is de akkerbouw in Nederland sterk van karakter veranderd. In de eerste helft van de 20e eeuw werden op de meeste akkers granen verbouwd of er was sprake van lokale teelten zoals vlas of boekweit. Nadien is het zwaartepunt verschoven naar de teelt van snijmaïs en hakvruchten (bieten en aardappelen). Naast de verschuiving in de geteelde gewassen is de akkerbouw ook verregaand gemechaniseerd en geïntensiveerd. De mechanisatie heeft ertoe geleidt dat grote akkers met minder mankracht kunnen worden bewerkt, wat geleid heeft tot o.a. schaalvergroting. Bovendien is tegenwoordig het aantal agrarische werkzaamheden gedurende het groeiseizoen beperkt, met name door het toepassen van gewasbeschermingsmiddelen. Soorten die voor een belangrijk deel van hun levenscyclus gebruik maken van akkers zijn bijvoorbeeld Geelgors (Emberiza citrinella), Grauwe gors (Emberiza calandra), Ortolaan (Emberiza hortulana), Veldleeuwerik (Alauda arvensis), Gele kwikstaart (Motacilla flava), Kwartel (Coturnix coturnix), Patrijs (Perdix perdix), Korhoen (Tetrao tetrix), Fazant (Phasianus colchicus), Grauwe kiekendief (Circus pygargus), Kievit (Vanellus vanellus), Hamster (Cricetus cricetus), Haas (Lepus europaeus), Kleine parelmoervlinder (Issoria lathonia), Koninginnepage (Papilio machaon) en Knoflookpad (Pelobates fuscus). Voor andere soorten, zoals Woelrat (Arvicola terrestris/shermani), Dwergmuis (Micromys minutus) of Kwartelkoning (Crex crex), kunnen akkers eveneens belangrijke biotopen zijn, als andere meer natuurlijke biotopen ontbreken. Vrijwel alle soorten die afhankelijk zijn van akkers zijn de afgelopen decennia door het gebruik van bestrijdingsmiddelen sterk in aantal en verspreiding achteruitgegaan of de soorten staan op het punt uit Nederland te verdwijnen. Met name door de toenemende toepassing van neonicotinoïde insecticiden is een enorme schaarste aan insecten ontstaan die een onmisbare eiwitbron vormen voor de meeste akkerland soorten.

Glyphosate, the active ingredient of Roundup herbicide, is a renal carcinogen

The EPA document attached shows how Monsanto tried to convince the EPA to ‘disappear’ toxicology data, which confirmed that 18 out of 100 test-mice developed a rare form of kidney tumour when fed glyphosate. EPA scientists were concerned that when 18% of mice developed ‘rare’ kidney tumours when fed glyphosate; moreover, this was not a case of ‘false positives’ as Monsanto was claiming. The tumors in question were real and also rare. The EPA refused to allow Monsanto to argue that ‘false positives’ argument should be used to ‘dilute’ the findings. The EPA regulators in question fought back - to protect the Public Health; evidently the EPA still had a sense of ethics and public service at that time. Since glyphosate is the most widely used pesticide in the world today it is clear that Monsanto ‘persuaded’ the EPA to suppress its concerns and give Glyphosate an unconditional license. Glyphosate was found in Warburtons Bread and Jordans Muesli in the UK in 2014.

Immunotoxic effects of imidacloprid following 28 days of oral exposure in BALB/c mice

The objective of the present study was to evaluate immunotoxic effects of imidacloprid in female BALB/c mice. Imidacloprid was administered orally daily at 10, 5, or 2.5 mg/kg over 28 days. Specific parameters of humoral and cellular immune response including hemagglutinating antibody (HA) titer to sheep red blood cells (SRBC; T-dependent antigen), delayed type hypersensitivity (DTH) response to SRBC, and T-lymphocyte proliferation in response to phytohemagglutinin (PHA) were evaluated. The results showed that imidacloprid at high dose, specifically suppressed cell-mediated immune response as was evident from decreased DTH response and decreased stimulation index of T-lymphocytes to PHA. At this dose, there were also prominent histopathological alterations in spleen and liver. Histopathological analysis of footpad sections of mice revealed dose-related suppression of DTH response. Imidacloprid at low dose of 2.5 mg/kg/day did not produce any significant alterations in cellular and humoral immune response and it seemed to be an appropriate dose for assessment of ‘no observable adverse effects level’ for immunotoxicity in BALB/c mice. The results also indicated that imidacloprid has immunosuppressive effects at doses >5 mg/kg, which could potentially be attributed to direct cytotoxic effects of IMD against T cells (particularly TH cells) and that long-term exposure could be detrimental to the immune system.

Impaired auditory discrimination learning following perinatal nicotine exposure or β2 nicotinic acetylcholine receptor subunit deletion

Maternal smoking during pregnancy can impair performance of the exposed offspring in tasks that require auditory stimulus processing and perception; however, the tobacco component(s) responsible for these effects and the underlying neurobiological mechanisms remain uncertain. In this study, we show that administration of nicotine during mouse perinatal development can impair performance in an auditory discrimination paradigm when the exposed animals are mature. This suggests that nicotine disrupts auditory pathways via nicotinic acetylcholine receptors (nAChRs) that are expressed at an early stage of development. We have also determined that mice which lack nAChRs containing the β2 subunit (β2* nAChRs) exhibit similarly compromised performance in this task, suggesting that β2* nAChRs are necessary for normal auditory discrimination or that β2* nAChRs play a critical role in development of the circuitry required for task performance. In contrast, no effect of perinatal nicotine exposure or β2 subunit knockout was found on the acquisition and performance of a differential reinforcement of low rate task. This suggests that the auditory discrimination impairments are not a consequence of a general deficit in learning and memory, but may be the result of compromised auditory stimulus processing in the nicotine-exposed and knockout animals