@article {22011, title = {The long and the short of it: a global analysis of hawkmoth pollination niches and interaction networks}, journal = {Functional Ecology}, volume = {31}, year = {2017}, pages = {101-115}, chapter = {101}, abstract = {

\"1. Proboscis length has been proposed as a key dimension of plant pollination niches, but this niche space has not previously been explored at regional and global scales for any pollination system. Hawkmoths are ideal organisms for exploring pollinator niches as they are important pollinators in most of the biodiverse regions of the earth and vary greatly in proboscis length, with some species having the longest proboscides of all insects.
2. Using data sets for nine biogeographical regions spanning the Old and New World, we ask whether it is possible to identify distinct hawkmoth pollination niches based on the frequency distribution of proboscis length, and whether these niches are reflected in the depths of flowers that are pollinated by hawkmoths. We also investigate the levels of specialization in hawkmoth pollination systems at the regional and community level using data from interaction network studies.
3. We found that most regional hawkmoth assemblages have bimodal or multimodal distributions of proboscis length and that these are matched by similar distributions of floral tube lengths. Hawkmoths, particularly those with longer proboscides, are polyphagous and at the network level show foraging specialization equivalent to or less than that of bees and hummingbirds. In the case of plants, shorter-tubed flowers are usually visited by numerous hawkmoth
species, while those that are longer-tubed tend to exclude shorter-proboscid hawkmoths and thus become ecologically specialized on longer-proboscid hawkmoth species. Longer-tubed flowers tend to have greater nectar rewards, and this promotes short-term constancy by longproboscid hawkmoths.
4. Our results show that pollinator proboscis length is a key niche axis for plants and can account for the patterns of evolution in functional traits such as floral tube length and nectar volume. We also highlight a paradoxical trend for nectar resource niche breadth to increase according to proboscis length of pollinators, while pollinator niche breadth decreases according to the tube length of flowers.\"

}, keywords = {ADAPTATION, ADAPTIVE RADATION, BIOGEOGRAPHY, COEVOLUTION, COMMUNITY STRUCTURE, ECOLOGY, NECTAR SOURCES, POLLINATION, POLLINATOR SHIFT, POLLINATOR SPECIFICITY, SPHINGIDAE}, doi = {10.1111/1365-2435.12753}, author = {Johnson, S.D. and Mor{\'e}, M. and Amorim, F.W. and Haber, W.A. and Frankie, G.W. and Stanley, D.A. and Cocucci, A.A. and Raguso, R.A.} } @article {21313, title = {Wavelength discrimination and the role of ultraviolet vision in the feeding behaviour of hawkmoths}, journal = {Biotropica}, volume = {26}, year = {1994}, pages = {427-435}, chapter = {427}, abstract = {

\"Nocturnal Sphingidae (hawkmoths or sphinx moths) are important pollinators in tropical forests. Hawkmoth flowers are typically white to the human eye. As the retinas of hawkmoths contain ultraviolet-sensitive photoreceptors, flower patterns reflecting ultraviolet wavelengths (that are not visible to humans) might be significant to sphingid feeding behavior. The flowers of ten hawkmoth-pollinated species were examined with an ultraviolet sensitive video system in Monteverde, Costa Rica. All were found to lack ultraviolet reflectance. A common hawkmoth species, Manduca sexta, whose range extends to Costa Rica was then used in laboratory free choice experiments to determine which wavelengths elicited proboscis extension, probing and drinking of sugar water. When offered a choice between artificial flowers or backlighted filters, Manduca strongly preferred to feed at those reflecting or transmitting only wavelengths longer than 400 nm, avoiding those that also included ultraviolet wavelengths. That is, feeding behavior was best elicited by stimuli that mimicked the reflectance of typical hawkmoth flowers. Feeding behavior must be primarily activated by either the green- or violet-sensitive mechanisms (or both) of the hawkmoth visual system, while concurrent activation of the ultraviolet-sensitive mechanism interferes with it.\"

}, keywords = {COSTA RICA, MANDUCA, SPHINGIDAE, ULTRAVIOLET VISION, VISION}, url = {http://www.jstor.org/stable/2389237 }, author = {White, R.H. and Stevenson, R.D. and Bennett, R.R. and Cutler, D.E. and Haber, W.A.} } @article {18190, title = {A tropical hawkmoth community: Costa Rican dry forest Sphingidae}, journal = {Biotropica}, volume = {21}, year = {1989}, month = {1989}, pages = {155-172}, chapter = {155}, keywords = {COSTA RICA, DIVERSITY, PHENOLOGY, POLLINATION, POPULATION BIOLOGY, SPHINGIDAE}, doi = {10.2307/2388706}, url = {https://www.jstor.org/stable/2388706}, author = {Haber, W.A. and Frankie, G.W.} }