Gherardo Bogo

Council for Agricultural Research and Agricultural Economy Analysis | CREA

Nectar composition is an important driver of insect attractiveness. Although bumblebees prefer sucrose-rich nectar, they were found to be the main pollinators of Gentiana lutea, whose nectar is low on sucrose. Therefore, we tested the hypothesis that bumblebees are attracted to the amino acids proline and β-alanine, which are both naturally occurri...

Amino acids (AAs) are an abundant class of nectar solutes, and they are involved in the nectar attractiveness to flower visitors. Among the various AAs, proline is the most abundant proteogenic AA, and γ‐amino butyric acid (GABA) and β‐alanine are the two most abundant non‐proteogenic AAs. These three AAs are known to affect insect physiology, bein...

From the 1990s, the Southeast Asia native giant resin bee Megachile sculpturalis (Smith, 1853) was introduced first to North America, and then to many countries in Europe. Despite increasing studies on its invasive potential and geographical expansion, information on nesting behaviour of this species is still extremely scarce. To increase knowledge...

Flower nectar, a sugar‐rich solution containing amino acids as major secondary solutes, is the primary energy source for bees. Proline is one of the most abundant protein nectar amino acids, showing several effects on bee physiology. Mason bees are outstanding pollinators, often preferred to Apis mellifera for pollination of fruit trees. Among them...

In recent decades, hundreds of secondary metabolites have been found in floral nectar and many studies have demonstrated that they can play various roles in modulating the behaviour of floral visitors. However, temporal variations in nectar chemistry over extended flowering seasons have never been substantiated. Moreover, the effects of nectar chem...

Several studies on floral nectar demonstrated that the behaviour of visit performed by pollinators is influenced by nectar chemistry. Biogenic amines act as neurotransmitters in invertebrates and recently have been reported in the floral nectar of 15 plant species for the first time. However, both their occurrence in floral nectar and the effects o...

Pollinators are vitally important for the maintenance of ecosystems and the reproduction of most spontaneous and cultivated plants. However, in the last decades, they are suffering from an alarming decline, with the spread of pathogens and parasites being one of the main causes. Apis mellifera L. is the best-studied pollinator, and several studies...

The protocol for pollinator sampling was produced on the basis of the EU Pollinator Monitoring Scheme. We selected 12 sites in Emilia-Romagna, Italy: 11 in agricultural areas and 1 in a Natura2000 site (SAC-IT4050029). We carried out a sampling of pollinator insects through a variable transect by hand netting. Only pollinators on the flowers were r...

The giant resin bee, Megachile sculpturalis (Megachilidae), is a species alien to Europe that easily adopts bee hotels in city gardens. In Italy, we are carrying out a monitoring project at CREA bee hotel. Starting in 2016, we monitored emergence and defined nest structure and pollen; estimated the number of nests completed by each female, and reco...

Cuckoo bumblebees are a monophyletic group within the genus Bombus and social parasites of free-living bumblebees, upon which they rely to rear their offspring. Cuckoo bumblebees lack the worker caste and visit flowers primarily for their own sustenance and do not collect pollen. Although different flower-visiting behaviours can be expected between...

The bumblebee Bombus terrestris L. (Hymenoptera: Apidae) is an effective pollinator of both wild and cultivated plants and essential for the pollination of various important greenhouse crops. Because of its sex determination mechanism, homozygosity of the complementary sex determination (csd) locus due to inbreeding causes fertilized eggs to develo...

Diploid males represent a cost for the viability of populations in haplodiploid species with a single-locus complementary sex determination system. In such social species as bumble bees, their presence affects colony growth and reproduction, therefore, the detection of diploid males is an important aspect to implement conservation actions and for t...

Floral nectar is the primary reward directly consumed by floral visitors and its chemical composition affects their behaviour and fidelity. In turn, floral visitors are expected to alter floral nectar composition directly or indirectly through the introduction of external contaminants, such as pollen grains and microorganisms. To understand the eff...

Floral nectar is a chemically complex aqueous solution within which several secondary metabolites have been identified that affect attractiveness for pollinators. Understanding preferences and aversions to nectar quality in flower visitors is crucial since this may influence the patterns of insect floral visitation with consequences on the plant fi...

The decline of pollinators may alter the complex system of interactions that they establish with flowering plants, with potential negative consequences on both partners. Within this context, network analysis may be a useful tool to study ecological properties of plant-pollinator interactions and to evaluate the outcomes of conservation actions. Thr...

In bumble bee colonies, pollen is the only protein source for larval feeding and its shortage causes a distress in larval development. Adult bumble bees need pollen for the development of glands and the reproductive system. In bumble bee rearing, honey bee collected pollen is used as the main protein source, either as fresh-frozen or dried pellets,...

In the present study on the bumblebee Bombus terrestris, we investigated the influence of inbreeding on queen fitness by comparing diapause survival and egg‐laying success of queens mated with nestmate and non‐nestmate males. We then compared the early stage of colonies with or without diploid males and analysed colony characteristics to identify a...

Nectar mediates complex interactions between plants and animals. Recent research has focused on nectar secondary compounds that may play a role in regulating some of these interactions. These compounds may affect the behavior of nectar feeders by interacting with their neurobiology. Non-protein amino acids (NPAAs) can constitute a large portion of...

Megachile disjunctiformis Cockerell 1911 (Hymenoptera Megachilidae) is recorded for the first time in Europe. After previous observations in 2011 and 2016 near Bologna, Italy, three specimens (one female and two males) were captured in three different locations of the Bologna area in 2017 and identified. The species is known from China, Japan, Taiw...

To investigate the effects of two non‐protein amino acids, β‐alanine and γ‐amino butyric acid (GABA), on Osmia bicornis survival and locomotion, two groups of caged bees were fed with sugar syrup enriched with β‐alanine and GABA, respectively. A further control group was fed with sugar syrup. Five behavioural categories were chosen according to the...

Abstract Bees collect pollen as an important resource for offspring development while acting as pollen vectors for the plants visited. Foraging preferences of pollinators together with plant species availability shape the web of interactions at the local scale. In this study, we focused on the bee pollinator community of a population of the rare pr...

Inbreeding is caused by the mating of closely related individuals and may produce a decrease in the fitness of offspring and have deleterious consequences for adults. In haplodiploid social Hymenoptera inbreeding has a further negative effect due to the production of unviable or sterile diploid males. As a consequence, mechanisms of inbreeding avoi...

In many species, inbreeding avoidance mechanisms prevent mating between close relatives, but these mechanisms are poorly studied in bumble bees. The probability of inbred matings within a colony in eusocial insects may depend on the timing of gyne and male emergence and on their sex ratio. In this study, we compared the development of 35 colonies o...

Diapause control and colony initiation are among the major problems encountered in the rearing of bumble bee colonies in small-scale rearing. In this study, we used Bombus terrestris queens obtained from commercial colonies to investigate (1) the diapause survival in virgin and mated queens, (2) the diapause and colony initiation performance of mat...

Stopvelutina è la rete italiana che unisce enti di ricerca e apicoltori al fine di intercettare l'eventuale comparsa di Vespa velutina e monitorare l'ampliamento del suo attuale areale di distribuzione. In questo primo anno il sistema di segnalazioni ha permesso di individuare un nuovo sito di presenza di V. velutina in provincia di Rovigo. La prec...

Several biotic and abiotic factors affect the seasonal and daily activities of flower-visiting insects, which, ultimately, influence the composition and abundance of a pollinator community and the extent of their pollination service. The aim of this four-year study was to assess the effect of some abiotic and biotic factors on the abundance and act...

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...

An integrated approach was proposed for the conservation of the bee pollinators of the locally rare plant dittany Dictamnus albus. Based on previous studies that revealed the most efficient pollinators, we performed three related actions to improve their presence in the area: (i) we provided artificial nests for bumblebees and solitary bees; (ii) w...

The study of plant-pollinator relationship and the degree of their specialization is among the most lively and debated issues in plant biology and ecology. The fates of plants and bee pollinators are strictly connected: the severe decline lately encountered by wild Apoidea, which in turn results in a lower pollination rate, trigger the so-called “e...

The interplay between insect and plant traits outlines the patterns of pollen transfer and the subsequent plant reproductive fitness. We studied the factors that affect the pollination efficiency of a pollinator community of Dictamnus albus L. by evaluating insect behaviour and morphological characteristics in relation to flowering phenology. In or...

Technical handbook of PP-ICON - Plant-Pollinator Integrated CONservation approach: a demonstrative proposal / LIFE09 NAT/IT/000212 project

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 (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...