scholarly journals Combined Toxicity of Insecticides and Fungicides Applied to California Almond Orchards to Honey Bee Larvae and Adults

Insects ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 20 ◽  
Author(s):  
Andrea Wade ◽  
Chia-Hua Lin ◽  
Colin Kurkul ◽  
Erzsébet Ravasz Regan ◽  
Reed M. Johnson

Beekeepers providing pollination services for California almond orchards have reported observing dead or malformed brood during and immediately after almond bloom—effects that they attribute to pesticide exposure. The objective of this study was to test commonly used insecticides and fungicides during almond bloom on honey bee larval development in a laboratory bioassay. In vitro rearing of worker honey bee larvae was performed to test the effect of three insecticides (chlorantraniliprole, diflubenzuron, and methoxyfenozide) and three fungicides (propiconazole, iprodione, and a mixture of boscalid-pyraclostrobin), applied alone or in insecticide-fungicide combinations, on larval development. Young worker larvae were fed diets contaminated with active ingredients at concentration ratios simulating a tank-mix at the maximum label rate. Overall, larvae receiving insecticide and insecticide-fungicide combinations were less likely to survive to adulthood when compared to the control or fungicide-only treatments. The insecticide chlorantraniliprole increased larval mortality when combined with the fungicides propiconazole or iprodione, but not alone; the chlorantraniliprole-propiconazole combination was also found to be highly toxic to adult workers treated topically. Diflubenzuron generally increased larval mortality, but no synergistic effect was observed when combined with fungicides. Neither methoxyfenozide nor any methoxyfenozide-fungicide combination increased mortality. Exposure to insecticides applied during almond bloom has the potential to harm honey bees and this effect may, in certain instances, be more damaging when insecticides are applied in combination with fungicides.

2019 ◽  
Vol 14 (2) ◽  
pp. 476-491 ◽  
Author(s):  
Brendan A. Daisley ◽  
Andrew P. Pitek ◽  
John A. Chmiel ◽  
Kait F. Al ◽  
Anna M. Chernyshova ◽  
...  

Abstract American foulbrood (AFB) is a highly virulent disease afflicting honey bees (Apis mellifera). The causative organism, Paenibacillus larvae, attacks honey bee brood and renders entire hives dysfunctional during active disease states, but more commonly resides in hives asymptomatically as inactive spores that elude even vigilant beekeepers. The mechanism of this pathogenic transition is not fully understood, and no cure exists for AFB. Here, we evaluated how hive supplementation with probiotic lactobacilli (delivered through a nutrient patty; BioPatty) affected colony resistance towards a naturally occurring AFB outbreak. Results demonstrated a significantly lower pathogen load and proteolytic activity of honey bee larvae from BioPatty-treated hives. Interestingly, a distinctive shift in the microbiota composition of adult nurse bees occurred irrespective of treatment group during the monitoring period, but only vehicle-supplemented nurse bees exhibited higher P. larvae loads. In vitro experiments utilizing laboratory-reared honey bee larvae showed Lactobacillus plantarum Lp39, Lactobacillus rhamnosus GR-1, and Lactobacillus kunkeei BR-1 (contained in the BioPatty) could reduce pathogen load, upregulate expression of key immune genes, and improve survival during P. larvae infection. These findings suggest the usage of a lactobacilli-containing hive supplement, which is practical and affordable for beekeepers, may be effective for reducing enzootic pathogen-related hive losses.


Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 603
Author(s):  
Juyeong Kim ◽  
Kyongmi Chon ◽  
Bo-Seon Kim ◽  
Jin-A Oh ◽  
Chang-Young Yoon ◽  
...  

Rearing honey bee larvae in vitro is an ideal method to study honey bee larval diseases or the toxicity of pesticides on honey bee larvae under standardized conditions. However, recent studies reported that a horizontal position may cause the deformation of emerged bees. Accordingly, the purpose of this study was to evaluate the emergence and deformation rates of honey bee (Apis mellifera ligustica) larvae reared in horizontal and vertical positions. The study was conducted under the same laboratory conditions with three experimental groups, non-capped or capped horizontal plates and capped vertical plates. However, our results demonstrated that the exhibited adult deformation rates of the horizontal plates were significantly higher (27.8% and 26.1%) than those of the vertical plates (11.9%). In particular, the most common symptoms were deformed wings and an abnormal abdomen in the horizontal plates. Additionally, adults reared on horizontal plates were substantially smaller (10.88 and 10.82 mm) than those on vertical plates (11.55 mm). Considering these conclusions, we suggest that a vertical rearing method is more suitable when considering the deformation rates of the control groups to verify the sublethal effects of pesticides on honey bees.


2012 ◽  
Vol 24 (8) ◽  
pp. 1079 ◽  
Author(s):  
Brandon K. Hopkins ◽  
Charles Herr ◽  
Walter S. Sheppard

Much of the world’s food production is dependent on honey bees for pollination, and expanding food production will further increase the demand for managed pollination services. Apiculturists outside the native range of the honey bee, in the Americas, Australia and eastern Asia, have used only a few of the 27 described subspecies of honey bees (Apis mellifera) for beekeeping purposes. Within the endemic ranges of a particular subspecies, hybridisation can threaten native subspecies when local beekeepers import and propagate non-native honey bees. For many threatened species, cryopreserved germplasm can provide a resource for the preservation of diversity and recovery of endangered populations. However, although instrumental insemination of queen honey bees is well established, the absence of an effective means to cryopreserve honey bee semen has limited the success of efforts to preserve genetic diversity within the species or to develop repositories of honey bee germplasm for breeding purposes. Herein we report that some queens inseminated with cryopreserved semen were capable of producing a substantial number of fertilised offspring. These diploid female larvae were used to produce two additional sequential generations of new queens, which were then back-crossed to the same stock of frozen semen. Our results demonstrate the ability to produce queens using cryopreserved honey bee spermatozoa and the potential for the establishment of a honey bee genetic repository.


Animals ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 178
Author(s):  
Roksana Kruszakin ◽  
Paweł Migdal

So far, larval rearing in vitro has been an important method in the assessment of bee toxicology, particularly in pesticide risk assessment. However, natural products are increasingly used to control honey bee pathogens or to enhance bee immunity, but their effects on honey bee larvae are mostly unknown. In this study, laboratory studies were conducted to determine the effects of including selected aqueous plant infusions in the diet of honey bee (Apis mellifera L.) larvae in vitro. The toxicity of infusions from three different plant species considered to be medicinal plants was evaluated: tansy (Tanacetum vulgare L.), greater celandine (Chelidonium majus L.), and coriander (Coriandrum sativum L.). The impact of each on the survival of the larvae of honey bees was also evaluated. One-day-old larvae were fed a basal diet consisting of distilled water, sugars (glucose and fructose), yeast extract, and freeze-dried royal jelly or test diets in which distilled water was replaced by plant infusions. The proportion of the diet components was adjusted to the age of the larvae. The larvae were fed twice a day. The experiment lasted seven days. Significant statistical differences in survival rates were found between groups of larvae (exposed or not to the infusions of tansy, greater celandine, and coriander). A significant decrease (p < 0.05) in the survival rate was observed in the group with the addition of a coriander herb infusion compared to the control. These results indicate that plant extracts intended to be used in beekeeping should be tested on all development stages of honey bees.


2017 ◽  
Vol 12 (12) ◽  
pp. 1934578X1701201
Author(s):  
Gianluca Fichi ◽  
Matteo Mattellini ◽  
Elisa Meloni ◽  
Guido Flamini ◽  
Stefania Perrucci

The in vitro anthelmintic activity on sheep gastrointestinal strongyle (GIS) eggs and larvae of 0.5% aloin and 0.1% aloe-emodin was investigated. From fresh faecal samples collected by ewes naturally infected by Haemonchus, Trichostrongylus and Teladorsagia nematodes, GIS eggs were isolated and cultivated in Petri dishes (100 eggs/dish). For the in vitro evaluation of the anthelmintic activity of tested compounds, the Egg hatch test (EHT), the Larval development test (LDT) and the Larval mortality/paralysis test (LMT) were used. In each assay, the activity of tested compounds was compared to untreated and treated (0.1% thiabendazole, TBZ) controls. Six repetitions were made through the experiment. Obtained data were statistically elaborated using the X2 test. In EHT, 0.5% aloin gave highly significantly different (P<0.01) results from the untreated controls. In LDT, both 0.1% aloe-emodin and 0.5% aloin almost completely prevented the larval development from L1 to L3, showing no significant differences (P<0.01) when compared to TBZ. In LMT, larval mortality observed in 0.5% aloin treated plates was significantly higher (P<0.01) than that observed in TBZ treated controls. These results show the in vitro anthelmintic properties on sheep GIS of the examined plant secondary metabolites. In LDT and/or LMT, the activity of 0.5% aloin and 0.1% aloe-emodin was comparable to or higher than that of the reference drug.


Apidologie ◽  
1998 ◽  
Vol 29 (6) ◽  
pp. 569-578 ◽  
Author(s):  
Camilla J. Brødsgaard ◽  
Wolfgang Ritter ◽  
Henrik Hansen

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Matthieu Guichard ◽  
Vincent Dietemann ◽  
Markus Neuditschko ◽  
Benjamin Dainat

Abstract Background In spite of the implementation of control strategies in honey bee (Apis mellifera) keeping, the invasive parasitic mite Varroa destructor remains one of the main causes of colony losses in numerous countries. Therefore, this parasite represents a serious threat to beekeeping and agro-ecosystems that benefit from the pollination services provided by honey bees. To maintain their stocks, beekeepers have to treat their colonies with acaricides every year. Selecting lineages that are resistant to infestations is deemed to be a more sustainable approach. Review Over the last three decades, numerous selection programs have been initiated to improve the host–parasite relationship and to support honey bee survival in the presence of the parasite without the need for acaricide treatments. Although resistance traits have been included in the selection strategy of honey bees, it has not been possible to globally solve the V. destructor problem. In this study, we review the literature on the reasons that have potentially limited the success of such selection programs. We compile the available information to assess the relevance of selected traits and the potential environmental effects that distort trait expression and colony survival. Limitations to the implementation of these traits in the field are also discussed. Conclusions Improving our knowledge of the mechanisms underlying resistance to V. destructor to increase trait relevance, optimizing selection programs to reduce environmental effects, and communicating selection outcomes are all crucial to efforts aiming at establishing a balanced relationship between the invasive parasite and its new host.


Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 252
Author(s):  
Sarah C. Wood ◽  
Jocelyne C. Chalifour ◽  
Ivanna V. Kozii ◽  
Igor Medici de Mattos ◽  
Colby D. Klein ◽  
...  

Neonicotinoid and fungicide exposure has been linked to immunosuppression and increased susceptibility to disease in honeybees (Apis mellifera). European foulbrood, caused by the bacterium Melissococcus plutonius, is a disease of honeybee larvae which causes economic hardship for commercial beekeepers, in particular those whose colonies pollinate blueberries. We report for the first time in Canada, an atypical variant of M. plutonius isolated from a blueberry-pollinating colony. With this isolate, we used an in vitro larval infection system to study the effects of pesticide exposure on the development of European foulbrood disease. Pesticide doses tested were excessive (thiamethoxam and pyrimethanil) or maximal field-relevant (propiconazole and boscalid). We found that chronic exposure to the combination of thiamethoxam and propiconazole significantly decreased the survival of larvae infected with M. plutonius, while larvae chronically exposed to thiamethoxam and/or boscalid or pyrimethanil did not experience significant increases in mortality from M. plutonius infection in vitro. Based on these results, individual, calculated field-realistic residues of thiamethoxam and/or boscalid or pyrimethanil are unlikely to increase mortality from European foulbrood disease in honeybee worker brood, while the effects of field-relevant exposure to thiamethoxam and propiconazole on larval mortality from European foulbrood warrant further study.


2021 ◽  
Vol 1 ◽  
Author(s):  
Lina Zhang ◽  
Yanchun Deng ◽  
Hongxia Zhao ◽  
Ming Zhang ◽  
Chunsheng Hou

Honey bees play a vital role in providing pollination services for agricultural crops and wild flowering plants. However, the spillover risk of their pathogens to other pollinators or wild insects is becoming a cause for concern. There is some evidence that stingless bees can carry honey bee viruses, but little is known about the presence of honey bee viruses in stingless bees in China. Here, we investigate the occurrence of major honey bee pathogens including bacteria, fungi, and viruses in stingless bees (Apidae: sp.). Our results show that the stingless bees (Apidae: sp.) were mainly infected with DWV-A, but no DWV-B and DWV-C. Phylogenetic analysis on fragments of lp, RdRp, and VP3 of DWV-A indicated that genetic variation in VP3 might an important indicator for host-specific viruses, but it requires further study. Our results indicated that DWV-A is not only the major strain of virus currently circulating in managed bee colonies in China and globally, but in stingless bee species as a whole.


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