Bees are the most important pollinators of flowering plants and are necessary for pollinating both wild plants and many of the crops that produce the food we eat. There are many different species of bees, with about 20,000 species worldwide and 4,000 species in the United States. Even though bees are important pollinators, there is still much we do not know about how many species there are and their biology. In order to better understand the species and their biology, I performed three projects that help fill these gaps by reviewing the species of a poorly known bee group, examining the different ways bees carry pollen, and then reviewing how bees gather pollen from flowers. To better understand bee diversity, I examined a group of species in the subgenus Heteroperdita in the genus Perdita (Andrenidae). I described nine species that were new to science, found the opposite sex of three species, and found that one species was a duplicate of a previously described species. This work increased the number of species in Heteroperdita to 22 and increased the number of species in the genus Perdita to 636. I then explored how pollen is carried back to the nest in two distantly-related bee groups, the genera Perdita and Hesperapis (Melittidae). I found that different species can carry pollen in one of three different ways: moist, dry, or glazed. Interestingly, how the bees carry pollen appears to depend on the shape and stickiness of the pollen grains that the bees prefer. I then reviewed how bees gather pollen from flowers. I combined previous research and my own observations of bees to classify the different pollen gathering behaviors into seven different types. I then examined why bees use different pollen gathering behaviors and provided a set terminology to refer to each behavior. Overall, this dissertation advances our knowledge of the diversity of bees and their relationships with flowers, which will support efforts to understand and conserve these important pollinators.

La presente tesi fornisce un contributo originale al dibattito esistente tra gli economisti industriali sul rapporto tra concorrenza e asimmetrie informative. Infatti, l’obiettivo principale di questo lavoro consiste nell'investigare, da un punto di vista teorico (e supportato dall'evidenza empirica), come alcune barriere informative presenti nel mercato influenzano le strategie imprenditoriali in diversi contesti competitivi, fornendo implicazioni di policy per autorità garanti della concorrenza e a tutela del consumatore. Nello specifico, il primo capitolo esamina gli incentivi di una impresa dominante in un mercato a monte a offrire contratti di esclusiva ad un monopolista nel mercato a valle, quando vi è incertezza riguardo alla domanda finale dei consumatori. Nei capitoli seguenti, invece, l’analisi si caratterizza dalla presenza del concetto comportamentale di "avversione alla perdita", particolarmente rilevante nelle decisioni di acquisto dei cosiddetti "beni di esperienza". In questi mercati le imprese possono decidere liberamente di permettere test sui propri prodotti prima del loro acquisto, modificando quindi l’utilità attesa dei consumatori. Il secondo capitolo analizza le strategie di vendita per un monopolista. Il terzo capitolo, invece, esamina l’equilibrio di mercato in un contesto competitivo e come l’utilizzo di test sui prodotti possa essere adoperato come strumento collusivo. / This dissertation provides an original contribution to the existing debate between industrial economists on the relationship between competition and information asymmetries. Indeed, the main goal of this work consists in investigating, from a theoretical point of view (and supported by empirical evidence), how some informational frictions in the market affect firm’s strategies in different competitive environments, providing policy implications for competition and consumer protection authorities. Specifically, the first chapter looks at the incentives of a dominant firm in an upstream market to offer exclusive dealing contracts to a monopolist in the downstream market, when there is uncertainty about consumer demand. In the following chapters, instead, the analysis is characterized by the presence of the behavioral concept of "loss aversion", which is particularly relevant in the purchase decisions of the so-called "experience goods". In these markets, firms can freely decide to allow product experimentation before purchase, thus modifying the consumers' expected utility. The second chapter analyzes the monopolist's sales strategies. The third chapter, instead, examines the market equilibrium in a competitive environment and how product experimentation can be used as a collusive device.

Ogni ordinamento costituito, qualunque sia la sua forma politica, tenta di difendere se stesso. Ma in un ordinamento liberal-democratico le esigenze di protezione confliggono con quelle libertà il cui riconoscimento costituzionale esprime proprio la specificità della struttura politica liberal-democratica, giacché proprio le libertà democratiche possono divenire, per usare le parole di Karl Loewenstein, “the trojan horse by which the enemy enters the city”. È questo il problema della c.d. democrazia protetta. In ordine a tale questione, riferimento obbligato sono la Legge fondamentale tedesca e gli istituti suoi propri del Parteiverbot e della perdita dei diritti fondamentali. Il problema non è ignorato dall’ordinamento costituzionale italiano. Limiti alla revisione costituzionale, disciplina dei partiti antisistema, limitazione dei diritti fondamentali, poteri eccezionali ed organi di garanzia fanno della democrazia italiana una democrazia in fondo più “protetta” di quanto generalmente la si consideri. / Every constituted system, whatever its political form is, aims to protect itself. However, the needs of self protection in a liberal-democratic system conflict with those freedoms proper to this political structure, since these democratic freedoms can even become, quoting Karl Lowenstein’s words: “the trojan horse by which the enemy enters the city”. This is the issue of the so called protected democracy. With respect to this problem, the German Constitutional Law, with it’s typical institution of Parteiverbot and loss of fundamental rights, is an unavoidable reference. This problem is also treated in the Italian constitutional system. The limitation to the power of constitutional amendment, the regulation of the anticonstitutional parties, the restraint of fundamental rights, the emergency and the guardianship powers, make, after all, the Italian democracy more protected than what is generally thought.