Dienstag, 22. Juli 2008 | Autor: Bernhard
ich habe bereits mehrfach die Ergebnisse der CCD workgroup angeführt. Bitte seht euch die Ergebnisse noch einmal genauer an. Siehe: http://www.ento.psu.edu/MAAREC/CCDPpt/WhatPesticidesToDoWithItJune08ABJ.pdf
Neben den Pestiziden aus der Landwirtschaft werden auch die Pestizide als Ursache herangezogen, die die Imker selbst in die Beuten bringen. Die zur Behandlung gegen die Varroa verwendeten Pestizide sind Akarizide. Und wirken daneben häufig insektizid. Genau wie die Pestizide aus der Landwirtschaft reichern sich die vom Imker verwendeten Pestizide im Bienenvolk an und bilden mit den Pestiziden aus der Landwirtschaft ein tödlichen oder subletalen Cocktail.
Da die Pestizide des Imkers direkt in das Volk gegeben werden, sind die Konzentrationen dieser Werte am höchsten von allen Pestiziden.
Einige Studien belegen bereits die insektizide Wirkung. Beispiele befinden sich im Anhang.
Diesen Ergebnissen nach ist daher nicht nur eine Änderung im Umgang mit Pestiziden in der Landwirtschaft, sondern auch in der Imkerei notwendig.
Cell death in honeybee (Apis mellifera) larvae treated
with oxalic or formic acid
Aleš GREGORCa*, Azra POGA CNIKa, Ivor D. BOWENb
a Veterinary Faculty of the University of Ljubljana, Gerbi ceva 60, 1000 Ljubljana, Slovenia
b Cardiff School of Biosciences, Preclinical Building, Cardiff University, PO Box 911, Cardiff, CF10 3US, UK (Received 3 June; revised 28 November 2003; accepted 16 December 2003)
Abstract – The effects of oxalic (OA) and formic acids (FA) on honeybee larvae in colonies were assessed and evaluated. Cell death was detected by the TUNEL technique for DNA labelling. In 3- and 5-day-old larvae exposed to OA, cell death was found in 25% of midgut epithelial cells 5 h after the treatment, using an “In situ cell death detection kit, AP” (Roche). The level of cell death increased to 70% by the 21st hour and the morphology of the epithelium remained unchanged. Fifty hours after the application, cell death was established in 18% of the epithelial cells of the 3-day-old larvae and had increased to 82% in the 5-day-old larvae. A “DeadEnd” apoptosis detection kit (Promega) showed sporadic cell death mainly in the larval fat body 5 h after treatment. Twenty-one hours after the OA application cell death was found in 4% of the larval midgut epithelial cells. Evaporated formic acid induced extensive apoptotic cell death in the peripheral, cuticular and subcuticular tissues that preceded the cell death of the entire larval body.
The Effects of Miticides on the Reproductive Physiology of Honey Bee (Apis mellifera L.) Queens and Drones
Lisa Marie Burley
The effects of miticides on the reproductive physiology of queens and drones were examined. The first study examined the effects of Apistan® (fluvalinate), Check Mite+ (coumaphos), and Apilife VAR® (74% thymol) on sperm production and viability in drones. Drones from colonies treated with each miticide were collected at sexual maturity. Sperm production was determined by counting the number of sperm in the seminal vesicles. Sperm for viability assays was analyzed by dual fluorescent staining. Apilife VAR® and coumaphos significantly lowered (P<0.0001) sperm production and coumaphos treatments caused a significant decrease (P<0.0001) in the sperm viability. The effects of miticides on queens was examined by treating queen-rearing colonies and examining the number and viability of sperm in the spermathecae of newly mated queens. Queens from each treatment group were collected after mating and the spermathecae were removed and analyzed. Colonies treated with coumaphos failed to provide viable queens and were excluded. Apilife VAR® was found to significantly decrease (P<0.0016) sperm viability. No significant differences in sperm numbers were found between treatments.
The effect of miticides on sperm viability over time was also examined. Drones were reared as described, but the spermatozoa were collected as pooled samples from groups of drones. The pooled samples from each treatment were subdivided and analyzed periods of up to 6 weeks. Random samples were taken from each treatment (n = 6 pools) over a period of 6 weeks. The exposure of drones to coumaphos during development significantly reduced sperm viability for all 6 weeks, and caused a large decline in week 6. The potential impacts of these results on queen performance and failure are discussed.