Piotr Medrzycki

• PhD
• Researcher at Council for Agricultural Research and Agricultural Economy Analysis

In honey bee diet, pollen is the primary source of proteins and essential nutrients. High pollen diversity and protein content support honey bee health, enhancing resistance to different stressors. Agroecosystem simplification, with few dominant species flowering for a limited period, can lead to a shortage of forage and a reduction in the variety...

Chronic bee paralysis virus (CBPV) is a Apis mellifera viral infectious disease, exhibiting dark and hairless abdomen in workers with tremors and ataxita. Clinical signs are also typically linked to adverse weather conditions and overcrowding in the hive. The disease occurs in spring but recently it has been observed cases increase and seasonality...

Infectious and parasitic agents (IPAs) and their associated diseases are major environmental stressors that jeopardize bee health, both alone and in interaction with other stressors. Their impact on pollinator communities can be assessed by studying multiple sentinel bee species. Here, we analysed the field exposure of three sentinel managed bee sp...

Sustainable agriculture requires balancing crop yields with the effects of pesticides on non-target organisms, such as bees and other crop pollinators. Field studies demonstrated that agricultural use of neonicotinoid insecticides can negatively affect wild bee species1,2, leading to restrictions on these compounds³. However, besides neonicotinoids...

Introduction Heterogeneity in composition and spatial configuration of landscape elements support diversity and abundance of flower-visiting insects, but this is likely dependent on taxonomic group, spatial scale, weather and climatic conditions, and is particularly impacted by agricultural intensification. Here, we analyzed the impacts of both asp...

To provide a complete portrayal of the multiple factors negatively impacting insects in agricultural landscapes it is necessary to assess the concurrent incidence, magnitude, and interactions among multiple stressors over substantial biogeographical scales. Trans-national ecological field investigations with wide-ranging stakeholders typically enco...

A reduction in floral resource abundance and diversity is generally observed in agro-ecosystems, along with widespread exposure to pesticides. Therefore, a better understanding on how the availability and quality of pollen diets can modulate honeybee sensitivity to pesticides is required. For that purpose, we evaluated the toxicity of acute exposur...

Single page summary of Vanderplank et al (2021) - contains a QR code for accessing the paper

Current global change substantially threatens pollinators, which directly impacts the pollination services underpinning the stability, structure and functioning of ecosystems. Among these threats, many synergistic drivers such as habitat destruction and fragmentation, increasing use of agrochemicals, decreasing resource diversity as well as climate...

The sulfoximine insecticide sulfoxaflor is regarded as a potential substitute for neonicotinoids that were recently banned in the EU due to their side effects on bees. Like neonicotinoids, sulfoxaflor acts as a competitive modulator of nicotinic acetylcholine receptors. In agricultural environments, bees are commonly exposed to combinations of pest...

Neonicotinoid insecticides have been signaled as an important driver of widespread declines in bee diversity and abundance. Neonicotinoids were registered in the 1990s and by 2010 accounted for one third of the global insecticide market. Following a moratorium in 2013, their use on open-field crops was completely banned in the EU in 2018. Pesticide...

Pesticide use is one of the main causes of pollinator declines in agricultural ecosystems. Traditionally, most laboratory studies on bee ecotoxicology test acute exposure to single compounds. However, under field conditions, bees are often chronically exposed to a variety of chemicals, with potential synergistic effects. We studied the effects of f...

When pollen is studied from nutritional point of view, it would be desirable to correct its raw palynological spectrum in order to express the mass contribution of each pollen type. Different approaches applied for this correction through volumetric coefficients are discussed, and a simple and reliable procedure is proposed.

Pollinators in agroecosystems are often exposed to pesticide mixtures. Even at low concentrations, the effects of these mixtures on bee populations are difficult to predict due to potential synergistic interactions. In this paper, we orally exposed newly emerged females of the solitary beeOsmia bicornis to environmentally realistic levels of clothi...

It is known that the palynological features, and consequently the nutritional quality, of bee-foraged pollen vary according to several factors such as sampling site and period of year. In our two year study, carried out as part of the COLOSS CSI Pollen study between April and September in the eastern province of Genova (Italy), we explored the rela...

The honey bee is a major pollinator whose health is of global concern. Declines in bee health are related to multiple factors, including resource quality and pesticide contamination. Intensive agricultural areas with crop monocultures potentially reduce the quality and quantity of available nutrients and expose bee foragers to pesticides. However,...

ESM Methods, ESM Tables, and ESM figures - Details concerning honey bee preparation, sugar diets, neonicotinoids, survival, sugar consumption, glucose and trehalose hemolymph levels, and statistical methods. Further details concerning our results in the ESM figure S1 and tables S1, S2, S3, S4, S5, and S6. 10.1098/rspb.2017.1711

Several anthropogenic contaminants, including pesticides and heavy metals, can affect honey bee health. The effects of mixtures of heavy metals and pesticides are rarely studied in bees, even though bees are likely to be exposed to these contaminants in both agricultural and urban environments. In this study, the lethal toxicity of Cr alone and in...

Bees are key participators to the fertility of plants and yet they are suffering from losses and disorders. In other studies, double the amount of fungicides were found in colonies showing disorders than in healthy ones, with boscalid among the most frequently detected residues. Boscalid was mainly found in bee bread, main ingredient of larvae food...

In the early 2000s, Italian beekeepers began to report bee mortality events linked to maize sowing. Evidence pointed to three neonicotinoids (imidacloprid, clothianidin, thiamethoxam) and a phenylpyrazole (fipronil) used for seed dressing that were dispersed in the environment during sowing. Following these events and based on the precautionary pri...

Vespa velutina Lepieltier, 1836 (Hymenoptera: Vespidae) is an invasive predator of honeybees accidentally introduced into Europe from eastern Asia. It was observed for the first time in southwest France in 2004 and in the following years it rapidly spread almost all over the country. In 2013 it was officially reported in Italy, in the region Liguri...

Pollen collected from flowers by forager bees is the only natural protein source for the hive. This nutritional compound is fundamental for the nurse bee and brood development, and for the queen activity. Pollen has a strong influence on colony health. It is also known that the pollen quality, in terms of the amino acid profile and total protein co...

Pollen is the only protein source for the honey bee colony. Its nutritional quality varies according to the floral origin. The total protein content is a very important information in many research fields. Nevertheless its interpretation may be falsified by the sugars which are the main component of pollen pellets. In this paper we provide a databa...

Background: Neonicotinoid insecticides have been identified as an important factor contributing to bee diversity declines. Nonetheless, uncertainties remain about their impact under field conditions. Most studies have been conducted on Apis mellifera and tested single compounds. However, in agricultural environments, bees are often exposed to mult...

In Italy a nation-wide monitoring network was established in 2009 in response to significant honey bee colony mortality reported during 2008. The network comprised of approximately 100 apiaries located across Italy. Colonies were sampled four times per year, in order to assess the health status and to collect samples for pathogen, chemical and poll...

Determination of pesticides in bee samples. (DOCX)

Municipality and region of the ApeNet apiaries. (DOCX)

Primer sequences. (DOCX)

Compounds investigated by LC-MS. (DOCX)

Percentage of samples positive to Nosema ceranae classified per year, macro area and period. (DOCX)

Percentage of colony losses per each monitored Italian region and year (N = number of apiaries per each region). (DOCX)

Compounds investigated by GC-ECD. (DOCX)

Percentage of samples positive for BQCV, SBV, ABPV, CBPV, DWV, KBV, IAPV and AIV classified per year, macro area and period. (DOCX)

Year 2010. Association between pathogens in sampling periods. (DOCX)

Percentage of proteins in bee-bread classified per year, macro area and period. (DOCX)

Percentage of samples positive for pesticides in three bee matrices: honey bees, bee-bread and beeswax. (DOCX)

Number of positive sample (N) for each compound and percentage of pesticide detection (%) in honey bees, beeswax and bee-bread samples from Italian bee colonies in 2009 and 2010. (DOCX)

Year 2009. Association between pathogens in sampling periods. (DOCX)

Pollen diet is essential to nurse bees to develop hypopharyngeal glands (HPGs) and produce royal jelly to feed larvae. The effect of different diet regimes combined with pesticide exposure on the development of HPGs in honeybees was studied. In particular, a high-quality pollen mixture (high pollen diversity and protein content) and a low-quality d...

In this paper we assessed, under laboratory conditions, the toxicity of an active substance on solitary bee larvae of Osmia cornuta (Hymenoptera: Megachilidae). A field-realistic dose of the systemic insecticide spirotetramat was applied to the mass provisions. The insecticide’s effects on several life-cycle parameters were studied in males and fem...

Neonicotinoids have been among the most frequently used insecticides in the cultivation of several crops and orchards. Till 2012, imidacloprid represented 41.5% of the whole neonicotinoid market and thiamethoxam was the second biggest neonicotinoid, followed by clothianidin. However, almost two years ago, a decision was made by the EC parliament to...

Il declino degli impollinatori selvatici e, in particolare, la mortalità delle api domestiche registrata negli ultimi anni hanno messo in evidenza il fondamentale ruolo delle api e degli altri insetti pronubi nell’impollinazione delle piante. L’accertamento delle cause di questi fenomeni non è di facile realizzazione, perché i fattori implicati pos...

Modern agriculture often involves the use of pesticides to protect crops. These substances are harmful to target organisms (pests and pathogens). Nevertheless, they can also damage non-target animals, such as pollinators and entomophagous arthropods. It is obvious that the undesirable side effects of pesticides on the environment should be reduced...

Adult honey bees are maintained in vitro in laboratory cages for a variety of purposes. For example, researchers may wish to perform experiments on honey bees caged individually or in groups to study aspects of parasitology, toxicology, or physiology under highly controlled conditions, or they may cage whole frames to obtain freshly emerged workers...

In Northern Italy from 2000 to 2008, many spring bee mortalities were clearly linked to sowing of maize seeds dressed with insecticides. In the present study, we investigated the effects on honey bees of clothianidinderived from maize seed-dressing (Poncho®) in laboratory (test by indirect contact) and in semi-field conditions. Despite the reducti...

APENET: monitoring and research in apiculture’, is a two year research project funded in 2009 by the Italian Ministry of Agriculture and completed in September 2011. The main objectives of APENET were: to give explanation about the colony losses and high bee mortalities reported in the recent years in many countries; to evaluate the efficacy of the...

The impact of pesticides on honey bees is an issue that has been studied for many years and is now being reconsidered because con-troversy still exists with the relationship of insecticides and Colony Collapse Disorder (CCD). It is insufficient to explain CCD with only bee pathology studies. Research must be conducted on a wider series of causes: i...

Dual choice feeding tests were performed to determine a preference of forager honeybees for specific amino acids. Artificial nectar containing proline was preferred over those containing only sugars. Nectar containing alanine was preferred on the first day, but preference was no longer significant thereafter. On the contrary, a negative response wa...

Honey bee and colony mortality have been reported for several years in many countries as well as in Italy. In the last years this phenomenon has become increasingly serious, and several hypotheses have been proposed to explain honey bee and colony losses. These hypotheses relate to pests and diseases, pesticides, apicultural practices, climate chan...

Adult honey bees (Apis mellifera) usually maintain colony brood rearing temperature between 34-35°C by thermoregulation. The brood may, however, also be subjected to suboptimal temperature. Here we investigated whether a decrease of brood rearing temperature may have effects on larval mortality, adult emergence, longevity, morphology and susceptibi...

The honeybee is a good biological indicator that quickly reflects chemical impairment of the environment by its high mortality and the presence of pollutants in its body or in beehive products. In this work the honeybee (Apis mellifera) and honey were used to detect the presence of polycyclic aromatic hydrocarbons (PAHs) in several areas with diffe...

Woodward M (2008): Chlorantraniliprole (DPX-E2Y45, DuPont™ Rynaxypyr, Coragen and Altacor insecticide) -a novel anthranilic diamide insecticide -demonstrating low toxicity and low risk for beneficial insects and predatory mites. WG Pesticides and Beneficial Organisms, Proceedings of the Meeting at Berlin, Germany, 10th -12th October 2007, Editors:...

The Experimental unit of entomology (INRA, France) developed a new in vitro method to assess effects of pesticides on honey bee larvae. The method consists in rearing bee larvae in plastic cells. The larvae are fed with diet containing 50% of fresh royal jelly and 50% of an aqueous sugar and yeast extract solution, and reared in an incubator at 35...

During last years several cases of bee losses have been reported during the period of corn sowing in different European countries. In Italy an institutional system for bee losses survey does not exist and therefore some Italian regions decided to organise an official network to collect data and analyse dead bee samples. Collected data indicate that...

A large amount of knowledge about honeybees exists and it is also rapidly increasing, converging from different scientific fields. Despite this availability, the integration of this knowledge for applied and research purposes is not quite easy. To overcome this problem, a model (ApiPop v. 2) for the simulation of the honeybee population dynamics an...

It has been recently demonstrated that honeybees can be used to monitor the presence of Erwinia amylovora in the environment. The monitoring protocol involves a number of stations (consisting of three hives each) located in infected areas, at the edges of infected areas, or in apparently non infected areas. From 2000 to 2002, over 500 samples of po...

The diversity of the Italian bee fauna was investigated over a four-year period at 52 sites in 8 Italian regions of Italy (Piedmont, Friuli-Venezia Giulia, Emilia-Romagna, Tuscany, Umbria, Molise, Sicily, and Sardinia). A previously agreed sampling method- ology was used, and the bee collection protocol was based upon the transept method. The sampl...

For several years, reports by French and Italian beekeepers have been suggesting a lethal effect of imidacloprid on honey bees; in particular, the molecule has been related to honey bee mortality and decrease of hive populations, affecting the orientation and ability of honey bees to return to the hive. In this paper we investigate the effects of s...

Under certain circumstances, the effects of imidacloprid on honey bees may not be immediately perceived. The aim of this study was to investigate if imidacloprid, provided in sub-lethal doses, could influence honey bee behaviour in the laboratory. Imidacloprid (supplied as Confidor®) was offered to bees in 50 % sucrose solution at two different con...

The ability of Lysiphlebus testaceipes (Cresson) females to discriminate between parasitised and unparasitised Aphis gossypii Glover, and the mechanisms of host discrimination was studied. By comparing the resting time of parasitoid females on leaves with parasitised and unparasitised aphids their ability to host discriminate was evidenced. Y-tube...