scholarly journals Floral Cues of Non-host Plants Attract Oligolectic Chelostoma rapunculi Bees

2021 ◽  
Vol 9 ◽  
Author(s):  
Hannah Burger ◽  
Nadine Joos ◽  
Manfred Ayasse

Oligolectic bees are highly dependent on the availability of the host plants to which they are specialized. Nevertheless, females of Chelostoma rapunculi have recently been monitored occasionally to visit Malva moschata and Geranium sanguineum flowers, in addition to their well-known Campanula spp. hosts. The questions therefore arise which floral cues promote visits to non-host plants. As host-specific floral cues are key attractants for oligolectic bees, we have studied the attractiveness of olfactory and visual cues of the established host Campanula trachelium in comparison to the non-host plants G. sanguineum and M. moschata in behavioral experiments. Chemical and electrophysiological analyses of the floral scent and spectral measurements of floral colors were used to compare and contrast host and non-host plants. The behavioral experiments showed that foraging-naïve bees, in particular, were attracted by olfactory cues of the non-host plants, and that they did not favor the Campanula host scent in choice experiments. Many electrophysiologically active floral volatiles were present in common in the studied plants, although each species produced an individual scent profile. Spiroacetals, the key components that enable C. rapunculi to recognize Campanula hosts, were detected in trace amounts in Geranium but could not be proved to occur in Malva. The visual floral cues of all species were particularly attractive for foraging-experienced bees. The high attractiveness of G. sanguineum and M. moschata flowers to C. rapunculi bees and the floral traits that are similar to the Campanula host plants can be a first step to the beginning of a host expansion or change which, however, rarely occurs in oligolectic bees.

2020 ◽  
Vol 46 (10) ◽  
pp. 987-996
Author(s):  
Brynn Cook ◽  
Alexander Haverkamp ◽  
Bill S. Hansson ◽  
T’ai Roulston ◽  
Manuel Lerdau ◽  
...  

Abstract Insect pollination is essential to many unmanaged and agricultural systems and as such is a key element in food production. However, floral scents that pollinating insects rely on to locate host plants may be altered by atmospheric oxidants, such as ozone, potentially making these cues less attractive or unrecognizable to foraging insects and decreasing pollinator efficacy. We demonstrate that levels of tropospheric ozone commonly found in many rural areas are sufficient to disrupt the innate attraction of the tobacco hawkmoth Manduca sexta to the odor of one of its preferred flowers, Nicotiana alata. However, we further find that visual navigation together with associative learning can offset this disruption. Foraging moths that initially find an ozone-altered floral scent unattractive can target an artificial flower using visual cues and associate the ozone-altered floral blend with a nectar reward. The ability to learn ozone-altered floral odors may enable pollinators to maintain communication with their co-evolutionary partners and reduce the negative impacts that anthropogenically elevated oxidants may have on plant-pollinator systems.


2011 ◽  
Vol 57 (2) ◽  
pp. 162-174 ◽  
Author(s):  
Rodrigo C. Vergara ◽  
Alejandra Torres-Araneda ◽  
Diego A. Villagra ◽  
Robert A. Raguso ◽  
Mary T. K. Arroyo ◽  
...  

Abstract The study of multi-modal communication has only recently been extended to innate and learned interactions between flowers and their animal visitors, and usually only to pollinators. Here we studied the relevance of floral scent and visual display of a night blooming, putatively hawkmoth-pollinated plant Oenothera acaulis (Onagraceae) in the attraction of non-native cockroaches Blatta orientalis (Blattodea: Blattidae), which function as facultative floral larcenists in coastal habitats of central Chile. We experimentally decoupled visual (corolla) and olfactory (fragrance) stimuli by presenting paper corollas and green mesh bags, with or without a freshly-picked natural flower inside. We then contrasted the behavioral responses of roaches in these treatments with those to the natural combination of traits in actual flowers and their respective control treatments, measuring the roaches’ frequency of first visits, mean and total residence time spent in each treatment. The roaches primarily used olfactory cues when approaching O. acaulis flowers at two biologically relevant spatial scales. In addition, the presence of conspecific roaches had a strong influence on recruitment to the experimental arena, increasing the statistical differences among treatments. Our results suggest a primacy of floral fragrance over visual stimuli in the foraging responses of B. orientalis. Olfactory cues were necessary and sufficient to attract the roaches, and the visual cues presented in our manipulations only marginally increased their attraction within a 20 cm diameter of the stimulus. The full spectrum of floral visitation behavior was not elicited by the artificial flowers, suggesting the need for additional tactile or contact chemosensory stimuli not provided by paper. Although the nitrogenous scent compounds that we found in O. acaulis flowers are almost exclusively found in hawkmoth-pollinated flowers, the attractiveness of these compounds to a non-native, facultative flower-visiting insect indicates that they do not function as pollinator-specific signals for hawkmoth attraction.


Neurology ◽  
2018 ◽  
Vol 90 (11) ◽  
pp. e977-e984 ◽  
Author(s):  
Motoyasu Honma ◽  
Yuri Masaoka ◽  
Takeshi Kuroda ◽  
Akinori Futamura ◽  
Azusa Shiromaru ◽  
...  

ObjectiveTo determine whether Parkinson disease (PD) affects cross-modal function of vision and olfaction because it is known that PD impairs various cognitive functions, including olfaction.MethodsWe conducted behavioral experiments to identify the influence of PD on cross-modal function by contrasting patient performance with age-matched normal controls (NCs). We showed visual effects on the strength and preference of odor by manipulating semantic connections between picture/odorant pairs. In addition, we used brain imaging to identify the role of striatal presynaptic dopamine transporter (DaT) deficits.ResultsWe found that odor evaluation in participants with PD was unaffected by visual information, while NCs overestimated smell when sniffing odorless liquid while viewing pleasant/unpleasant visual cues. Furthermore, DaT deficit in striatum, for the posterior putamen in particular, correlated to few visual effects in participants with PD.ConclusionsThese findings suggest that PD impairs cross-modal function of vision/olfaction as a result of posterior putamen deficit. This cross-modal dysfunction may serve as the basis of a novel precursor assessment of PD.


1998 ◽  
Vol 5 (3) ◽  
pp. 193-203
Author(s):  
Matthias Laska ◽  
Karin Metzker

Using a conditioned food avoidance learning paradigm, six squirrel monkeys (Saimiri sciureus) and six common marmosets (Callithrix jacchus) were tested for their ability to (1) reliably form associations between visual or olfactory cues of a potential food and its palatability and (2) remember such associations over prolonged periods of time. We found (1) that at the group level both species showed one-trial learning with the visual cues color and shape, whereas only the marmosets were able to do so with the olfactory cue, (2) that all individuals from both species learned to reliably avoid the unpalatable food items within 10 trials, (3) a tendency in both species for quicker acquisition of the association with the visual cues compared with the olfactory cue, (4) a tendency for quicker acquisition and higher reliability of the aversion by the marmosets compared with the squirrel monkeys, and (5) that all individuals from both species were able to reliably remember the significance of the visual cues, color and shape, even after 4 months, whereas only the marmosets showed retention of the significance of the olfactory cues for up to 4 weeks. Furthermore, the results suggest that in both species tested, illness is not a necessary prerequisite for food avoidance learning but that the presumably innate rejection responses toward highly concentrated but nontoxic bitter and sour tastants are sufficient to induce robust learning and retention.


2002 ◽  
Vol 205 (16) ◽  
pp. 2519-2523 ◽  
Author(s):  
Francesco Bonadonna ◽  
Vincent Bretagnolle

SUMMARY Many burrowing petrels are able to return to their nests in complete darkness. The well-developed anatomy of their olfactory system and the attraction that food-related odour cues have for some petrel species suggest that olfaction may be used to recognize the burrow. In contrast,surface-nesting petrels may rely on visual cues to recognise their nest. We performed experiments on nine species of petrel (with different nesting habits) rendered anosmic either by plugging the nostrils or by injecting zinc sulphate onto the nasal epithelium. Compared with shamtreated control birds,we found that anosmia impaired nest recognition only in species that nest in burrows and that return home in darkness. Therefore, petrels showing nocturnal activity on land may rely on their sense of smell to find their burrows, while petrels showing diurnal activity or surface nesters may disregard olfactory cues in favour of visual guidance.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1773 ◽  
Author(s):  
Yuan Yuan ◽  
Ye Sun ◽  
Yanchun Zhao ◽  
Chungui Liu ◽  
Xiulan Chen ◽  
...  

Bearded irises are ornamental plants with distinctive floral fragrance grown worldwide. To identify the floral scent profiles, twenty-seven accessions derived from three bearded iris, including Iris. germanica, I. pumila and I. pallida were used to investigate the composition and relative contents of floral scent components by headspace solid-phase microextraction (HS-SPME) and gas chromatography–mass spectrometry (GC-MS). A total of 219 floral scent components were detected in blooming flowers. The scent profile varied significantly among and within the three investigated species. Principal component analysis (PCA) indicated that terpenes, alcohols and esters contributed the most to the floral scent components and 1-caryophyllene, linalool, citronellol, methyl cinnamate, β-cedrene, thujopsene, methyl myristate, linalyl acetate, isosafrole, nerol, geraniol were identified as the major components. In a hierarchical cluster analysis, twenty-seven accessions could be clustered into six different groups, most of which had representative scent components such as linalool, citronellyl acetate, thujopsene, citronellol, methyl cinnamate and 1-caryophyllene. Our findings provide a theoretical reference for floral scent evaluation and breeding of bearded irises.


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