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Sodium (Na) concentrations are low in plant tissues, and its metabolic function in plants is minor; however, Na is a key nutrient for plant consumers. Previous studies have thus far focused on Na concentration. Nevertheless, a balanced potassium (K) to Na ratio (K:Na) is more important than Na concentration alone since food with high K:Na has detrimental effects on consumers irrespective of Na concentration. Therefore, plants may actively regulate K:Na in their tissues and products, shaping plant-insect interactions. Studies considering nutritional aspects of plant-insect interactions have focused on nonreproductive tissues and nectar. In this study, we consider pollen as serving a primary reproductive function for plants as well as a food of pollinivores. Plants might regulate K:Na in pollen to affect their interactions with pollinivorous pollinators. To investigate whether such a mechanism exists, we manipulated Na concentrations in soil and measured the proportion of K, Na, and 13 other nutrient elements in the pollen of two sunflower (Helianthus annuus) cultivars. This approach allowed us to account for the overall nutritional quality of pollen by investigating the proportions of many elements that could correlate with the concentrations of K and Na. Of the elements studied, only the concentrations of Na and K were highly correlated. Pollen K:Na was high in both cultivars irrespective of Na fertilization, and it remained high regardless of pollen Na concentration. Interestingly, pollen K:Na did not decrease as pollen increased the Na concentration. We hypothesize that high K:Na in pollen might benefit plant fertilization and embryonic development; therefore, a tradeoff might occur between producing low K:Na pollen as a reward for pollinators and high K:Na pollen to optimize the plant fertilization process. This is the first study to provide data on pollen K:Na regulation by plants. Our findings broaden the understanding of plant-bee interactions and provide a foundation for a better understanding of the role of the soil-plant-pollen-pollinator pathway in nutrient cycling in ecosystems. Specifically, unexplored costs and tradeoffs related to balancing the K:Na by plants and pollinivores might play a role in past and current shaping of pollination ecology. [ABSTRACT FROM AUTHOR]

Sodium (Na) concentrations are low in plant tissues, and its metabolic function in plants is minor; however, Na is a key nutrient for plant consumers. Previous studies have thus far focused on Na concentration. Nevertheless, a balanced potassium (K) to Na ratio (K:Na) is more important than Na concentration alone since food with high K:Na has detrimental effects on consumers irrespective of Na concentration. Therefore, plants may actively regulate K:Na in their tissues and products, shaping plant-insect interactions. Studies considering nutritional aspects of plant-insect interactions have focused on nonreproductive tissues and nectar. In this study, we consider pollen as serving a primary reproductive function for plants as well as a food of pollinivores. Plants might regulate K:Na in pollen to affect their interactions with pollinivorous pollinators. To investigate whether such a mechanism exists, we manipulated Na concentrations in soil and measured the proportion of K, Na, and 13 other nutrient elements in the pollen of two sunflower (Helianthus annuus) cultivars. This approach allowed us to account for the overall nutritional quality of pollen by investigating the proportions of many elements that could correlate with the concentrations of K and Na. Of the elements studied, only the concentrations of Na and K were highly correlated. Pollen K:Na was high in both cultivars irrespective of Na fertilization, and it remained high regardless of pollen Na concentration. Interestingly, pollen K:Na did not decrease as pollen increased the Na concentration. We hypothesize that high K:Na in pollen might benefit plant fertilization and embryonic development; therefore, a tradeoff might occur between producing low K:Na pollen as a reward for pollinators and high K:Na pollen to optimize the plant fertilization process. This is the first study to provide data on pollen K:Na regulation by plants. Our findings broaden the understanding of plant-bee interactions and provide a foundation for a better understanding of the role of the soil-plant-pollen-pollinator pathway in nutrient cycling in ecosystems. Specifically, unexplored costs and tradeoffs related to balancing the K:Na by plants and pollinivores might play a role in past and current shaping of pollination ecology.

Solitary, dioecious, and mostly endemic to Andean cloud forests, wax palms (Ceroxylon Bonpl. ex DC. spp.) are currently under worrisome conservation status. The establishment of management plans for their dwindling populations rely on detailed biological data, including their reproductive ecology. As in the case of numerous other Neotropical palm taxa, small beetles are assumed to be selective pollinators of wax palms, but their identity and relevance in successful fruit yield were unknown. During three consecutive reproductive seasons we collected data on population phenology and reproductive and floral biology of three syntopic species of wax palms native to the Colombian Andes. We also determined the composition of the associated flower-visiting entomofauna, quantifying the extent of the role of individual species as effective pollinators through standardized value indexes that take into consideration abundance, constancy, and pollen transport efficiency. The studied populations of C. parvifrons (Engel) H. Wendl., C. ventricosum Burret, and C. vogelianum (Engel) H. Wendl. exhibit seasonal reproductive cycles with marked temporal patterns of flower and fruit production. The composition of the associated flower-visiting entomofauna, comprised by ca. 50 morphotypes, was constant across flowering seasons and differed only marginally among species. Nonetheless, a fraction of the insect species associated with pistillate inflorescences actually carried pollen, and calculated pollinator importance indexes demonstrated that one insect species alone, Mystrops rotundula Sharp, accounted for 94%-99% of the effective pollination services for all three species of wax palms. The sequential asynchronous flowering of C. parvifrons, C. ventricosum, and C. vogelianum provides an abundant and constant supply of pollen, pivotal for the maintenance of large populations of their shared pollinators, a cooperative strategy proven effective by high fruit yield rates (up to 79%). Reproductive success might be compromised for all species by the population decline of one of them, as it would tamper with the temporal orchestration of pollen offer. [ABSTRACT FROM AUTHOR]

With 22 species, Ancognatha is the fourth most species-rich genus of Neotropical cyclocephaline scarabs (Melolonthidae, Cyclocephalini), an important group of anthophilous insects associated with palms (Arecaceae). Unlike other members of the tribe, which predominantly inhabit low-altitude ecosystems, Ancognatha spp. are most common in montane areas, at elevations of 1500 to over 4000 m a.s.l. In the cloud forests of the Andes of Colombia, we investigated the association between Ancognatha vulgaris and seven species of wax palms (Ceroxylon spp.) from 2009 to 2013. Male and female A. vulgaris can be characterized as specialized florivores recovered in abundances of up to 40 individuals at both male and female inflorescences of all studied species of wax palms, which they also used for shelter and as aggregation sites for mating. The night-active beetles preferably fed on the pollen released in high quantities by staminate flowers of male inflorescences, but were also observed gnawing on the pistillate flowers of female inflorescences. We hypothesize that wax palm inflorescences are a key resource for the maintenance of populations of A. vulgaris under the extreme environmental conditions of Andean montane ecosystems, an assumption supported by their overlapping biogeographical distributions. [ABSTRACT FROM AUTHOR]

The multicoloured Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae) may potentially exploit a range of "alternative" food sources. The nutritional value of three common non-prey food groups, i.e. fruit, fungi and pollen, is examined in this study. Development, reproduction and survival of the species were assessed in the laboratory on diets of apple, pear and raspberries and the fungi Oidium lycopersicum, Botrytis cinerea, Sclerotinia sclerotiorum and Rhizoctonia solani. When fed exclusively on these foods this ladybird failed to complete its development or reproduce. However, larval and adult survival was prolonged by 4 to 8 days and 55 to 67 days, respectively, when fruit was offered compared with only water. During a field study H. axyridis adults were collected monthly from March to October at two locations near Ghent, Belgium. Gut analysis demonstrated that, despite the continued presence of aphids, over 90% of all the adults collected contained pollen throughout the year. The pollen belonged to 53 different pollen types. Monthly average numbers of pollen grains in the gut varied from 5 to 233 grains. In contrast, there were about 35,000 grains in the guts of H. axyridis females that successfully developed and reproduced in the laboratory on diet that consisted of only pollen. This suggests that in the field in the majority of cases pollinivory mainly only provided complementary nutrients for this coccinellid. The use of alternative non-prey foods like pollen and fruit may play a role in sustaining populations of this coccinellid at times when the optimal prey is absent.

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We present the first evidence of mice actively searching and consuming the pollen of Bromeliaceae and describe this behavior for the first time based on video-recorded evidence in the wild. Following repeated observations of nocturnal florivory in several individuals of Tillandsia macropetala, mice of the genus Peromyscus were recorded consuming pollen from this bromeliad during the dry season in the tropical montane cloud forest of central Veracruz, Mexico. The mice first consumed the anthers and, although it also consumed part of the filaments, the majority of these were discarded once the mice had consumed the pollen. The mice seem to be opportunistic consumers of pollen in a season when other resources are possibly scarce. It would be of value to determine the proportion of the rodent diet represented by pollen and other floral products during periods of low food availability, as well as to determine the potential impact of such herbivory on plant reproductive success. [ABSTRACT FROM AUTHOR]

Amblydromalus limonicus Garman & McGregor (Acari: Phytoseiidae) is a generalist predatory mite with economic potential to control thrips and whiteflies in protected cultivation. We tested the development and reproduction of A. limonicus on three food sources with potential for use in laboratory production or to support its populations in a crop: fresh cattail pollen, Typha latifolia L. (Poales: Typhaceae), dry decapsulated cysts of the brine shrimp Artemia franciscana Kellogg (Branchiopoda: Artemiidae) and frozen eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae). The diets were tested both on an artificial substrate and on kidney bean leaves. In the absence of food, all larvae died on the artificial substrate, whereas they succeeded in reaching the protonymphal stage on bean leaves. Immature survival was high (>90 %) on all diet-substrate combinations, except when E. kuehniella eggs were offered on the artificial substrate (35 % survival). Both sexes showed the fastest development when offered E. kuehniella eggs on leaf discs, followed by A. franciscana cysts, whereas the slowest development was achieved on T. latifolia pollen. Fecundity and oviposition rate were higher on E. kuehniella and A. franciscana than on T. latifolia. Amblydromalus limonicus females lived longer on the leaf discs than on the artificial substrates. The intrinsic rate of increase (r) was highest when E. kuehniella eggs were offered on leaf discs (0.256 females per female per day), whereas the lowest rate (0.128 females per female per day) was obtained when the eggs were provided on artificial substrates. The intrinsic rate of increase on A. franciscana cysts was not affected by substrate and averaged 0.22 females per female per day. Diet significantly influenced the size of A. limonicus females as measured by the distance between specific setae on the dorsal shield of the idiosoma. The application of the investigated food sources to sustain a colony of predatory mites upon their release in a greenhouse crop is discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] The ladybird beetle Micraspis discolor is a potential biological control agent in the rice ecosystems of Asia. Besides attacking a range of arthropod prey the ladybird also feeds on pollen. To explore the mechanism of pollinivory of M. discolor , we compared the transcriptomes and microbiomes of the ladybird when fed rape pollen versus insect foods (the aphid Aphis craccivora , the mealybug Planococcus citri or eggs of the Mediterranean flour moth Ephestia kuehniella). We also set out to identify putative cellulase genes and cellulolytic bacteria that might aid in pollen digestion. From the genome of M. discolor , we only identified glycoside hydrolase family 1 genes as candidate cellulase genes. However, these genes were not differentially expressed under the pollen-fed treatment as compared to the other diets. Transcriptome comparison among different diet treatments of M. discolor showed that differentially expressed genes were mainly related to nutrient metabolism, indicating differences in nutrient and antinutrient composition among the different diets. When comparing the microbiomes of M. discolor under different diet treatments, cellulolytic bacteria, like Siphonobacter aquaeclarae , were detected as discriminative biomarkers of pollen feeding. The findings from transcriptome and microbiome analyses indicate that cellulolytic bacteria might play a more important role than endogenous genes in pollen digestion by this ladybird beetle. [ABSTRACT FROM AUTHOR]

The article discusses a study on the food consumed by phyllostomid bats and the similarity of their diets to six species from the Pantanal wetlands in Brazil. It offers information on the analysis of fecal specimen from 347 captive bats conducted in 2002 to 2007. It describes the Ficus and Piper fruit species that dominate their diet and the consumption of pollen source Bauhinia ungulata by ten species of bats. It offers information on the preference of phyllostomids for pollen and fruit species.

The article discusses a study which examined the impact of moisture source and diet on the development and reproduction of pirate bugs Orius thripoborus (Hesse) and Orius naivashae (Poppius) (Hemiptera: Anthocoridae) found in South Africa. The study also investigated the effect of two factitious foods and moist honey bee pollen on developmental and reproductive parameters of the pirate bugs. It found that Orius thripoborus performed better than Orius naivashae on tested diets.

The multicoloured Asian lady beetle Harmonia axyridis (Coleoptera: Coccinellidae) may potentially exploit a range of "alternative" food sources. The nutritional value of three common non-prey food groups, i.e. fruit, fungi and pollen, is examined in this study. Development, reproduction and survival of the species were assessed in the laboratory on diets of apple, pear and raspberries and the fungi Oidium lycopersicum, Botrytis cinerea, Sclerotinia sclerotiorum and Rhizoctonia solani. When fed exclusively on these foods this ladybird failed to complete its development or reproduce. However, larval and adult survival was prolonged by 4 to 8 days and 55 to 67 days, respectively, when fruit was offered compared with only water. During a field study H. axyridis adults were collected monthly from March to October at two locations near Ghent, Belgium. Gut analysis demonstrated that, despite the continued presence of aphids, over 90% of all the adults collected contained pollen throughout the year. The pollen belonged to 53 different pollen types. Monthly average numbers of pollen grains in the gut varied from 5 to 233 grains. In contrast, there were about 35,000 grains in the guts of H. axyridis females that successfully developed and reproduced in the laboratory on diet that consisted of only pollen. This suggests that in the field in the majority of cases pollinivory mainly only provided complementary nutrients for this coccinellid. The use of alternative non-prey foods like pollen and fruit may play a role in sustaining populations of this coccinellid at times when the optimal prey is absent. [ABSTRACT FROM AUTHOR]

Due to growing criticism over the use of non-indigenous coccineffids, the two-spot ladybird, Adalia bipunctata (L.), has enjoyed increasing attention for aphid biocontrol in Europe. In the current study, eggs of the Mediterranean flour moth, Ephestia kuehniella Zeller, whether or not supplemented with bee pollen, were evaluated as a factitious food for larvae and adults of A. bipunctata. The predator showed slower larval development and lower survival when reared on live pea aphids, Acyrthosiphon pisum (Harris), than on E. kuehniella eggs. Survival on gamma-irradiated eggs of E. kuehniella was superior to that on frozen flour moth eggs, but other developmental characteristics were similar. Adults of A. bipunctata reared on Ac. pisum were only half as fecund as those offered irradiated or frozen E. kuehniella eggs, but egg hatch was markedly better on live aphids than on flour moth eggs (61 versus 20-27%, respectively). However, when a diet of flour moth eggs was supplemented with frozen moist bee pollen, egg hatch of A. bipunctata was equally as good as on live aphids. Supplementing flour moth eggs with dry pollen did not yield satisfactory results. Only 10% of larvae reached adulthood on moist bee pollen alone and resulting adults weighed less than half as much as those obtained on flour moth eggs. Our findings indicate that A. bipunctata is able to compensate for a suboptimal diet of animal prey by supplementary feeding on flower pollen. It is concluded that pollinivory may be a crucial trait for both the rearing of this natural enemy and its use in biological control programmes. [ABSTRACT FROM AUTHOR]

1 Coleomegilla maculataDeGeer feeds on corn pollen in the field, but the degree to which this predator relies on corn pollen as part of its diet is not well understood. We quantified the amount of pollen consumed byC. maculatasecond, third and fourth instars and adults in the field.2 Laboratory experiments were conducted to determine the digestion rate and duration of different stadia or stages using temperature regimens that reflected field conditions during anthesis.Coleomegilla maculatalarvae and adults were collected from the field and the amount of pollen in their digestive tracts was determined gravimetrically. The rate of digestion, duration of each life stage and the field observations were used to estimate the amount of pollen consumed by second, third and fourth instars and adults.3 Our models estimate that larvae consume 0.66, 1.67 and 3.30 mg of pollen during the second, third and fourth stadia, respectively. Adults consumed an estimated 13.15 mg during anthesis.4 The relevance of our results to ecological risk assessment of transgenic insecticidal corn and predator life history strategies is discussed. The results presented here are a first attempt to quantify pollen consumption by a predator, and future areas of research are suggested. [ABSTRACT FROM AUTHOR]

We monitored numbers of Coleomegilla maculata DeGeer and Harmonia axyridis (Pallas) eggs, larvae, and adults in an Illinois cornfield during anthesis. Larvae and adults were collected from the field and their gut contents were examined. Also, daily pollen deposition was recorded over the sample period, and prey biomass per plant was calculated for each of four replicate plots of field corn. The numbers of egg clutches and adults per plant were compared with daily pollen deposition, and pre- and postanthesis daily pollen deposition, densities of egg clutches, and adult densities were compared Also we compared the numbers of larvae and adults collected per plot and pollen and prey densities in the plots. Finally, the proportions of larvae and adults that had fed on corn pollen or prey were compared between predator species. We found that the number of coccinellid egg clutches increased significantly after anthesis and that the densities of adults of both species were not significantly different pre- and postanthesis. Larval and adult populations of H. axyridis were significantly correlated with prey densities, but C. maculata were not. All instars of C. maculata and H. axyridis occurred in corn during anthesis, and corn pollen was found in the guts of all four instars and in adults of both species. Dissections revealed that the majority of C. maculata larvae and adults had pollen in their guts, and a minority of ri. axyridis larvae and a single adult had pollen in their guts. Conversely, the majority of H. axyridis larvae and adults had insect prey in their guts, and <40 of C. maculata larvae and adults had prey in their guts. Potential mechanisms for the numerical increases of coccinellids observed during anthesis and the implications of pollen feeding for risk assessment of transgenic insecticidal corn to C. maculata are discussed. [ABSTRACT FROM AUTHOR]

Spiders are usually thought to obtain their energy for growth, maintenance and reproduction from captured prey. However, not all spiders should be assumed to receive all of their energy from prey. Accumulated studies have documented nectarivory in a wide variety of hunting spiders. We report a Clubiona spider visiting flowers of the nectariferous orchid Neottianthe cucullata as an example of spider nectarivory. In addition, during the visitations by Clubiona spider, pollinia removal was observed. The impact of the Clubiona spider on the N. cucullata reproductive success is also discussed. [ABSTRACT FROM AUTHOR]

While Habenaria ( Orchidaceae) is a species-rich genus and the orchid diversification is considered to be tightly related to its diverse pollination system, floral visitors of few Habenaria spp. have been studied. Here, we investigated the diurnal floral visitors of Habenaria sagittifera. While Orthoptera have not been considered a regular floral visitor, we observed that juvenile katydid Ducetia japonica ( Tettigoniidae) regularly visited and consumed the pollinia and anther caps of H. sagittifera. The relationship between Habenaria and Ducetia would not be a tight mutualism. However, the regular visitation and pollinia consumption may showcase the evolutionary route to Orthoptera-orchid pollination mutualism. [ABSTRACT FROM AUTHOR]

Abstract Larvae and adults of certain species of predator lady beetles feed on pollen, guaranteeing their survival, and at times, reproduction in the absence of preferred prey. Palynology, therefore, may contribute in the investigation of botanical families visited by these predators in order to obtain this floral resource. There are records of the visitation of Apiaceae flowers by Coleomegilla maculata DeGeer, 1775 (Coleoptera, Coccinellidae), but not the ingestion of their pollen grains by this lady beetle. The external morphology of pollen grains of three Apiaceae aromatic species (Anethum graveolens L., Coriandrum sativum L., Foeniculum vulgare Mill.) was characterized, and it was evaluated the ingestion of these pollens by fourth instar larvae and adults of C. maculata upon confinement along with flowers of these Apiaceae for 24 and 48 hours. The pollen grains of those species presented similar external morphology. In the two times of exposure, the larvae ingested the same amount of pollen from the three Apiaceae species, and the amount of C. sativum pollen ingested was the same between larvae and adults. The amount of A. graveolens pollen grains ingested by the adults was significantly greater than the pollens of C. sativum and F. vulgare, in 24 hours, with the opposite occurring in 48 hours. In the first 24 hours, the adults ingested more A. graveolens pollen than the larvae, with the opposite occurring with F. vulgare. There was no significant difference in the amount of Apiaceae pollen ingested between larvae and adults in 48 hours. The results suggest that the pollen-eating habits of certain aphidophagous lady beetles may be crucial in their preservation within agro-ecosystems.

Pollinivory-the consumption of pollen rather than arthropod prey-is a defining feature of bees (Anthophila; the flower lovers). In virtually all bee species, larvae consume a diet composed of pollen mixed with nectar or floral oils. Bees arose from within a group of solitary, carnivorous, apoid wasps in the Early to Mid-Cretaceous, coincident with the rapid rise of flowering plants. It is assumed that the switch from carnivory to pollen-feeding was a key innovation that led to the rapid diversification of bees, but this has never been examined empirically. Here, we explore the hypothesis that pollinivory led to the increased diversification of bees. In contrast to common perception, we find that the switch to pollen-feeding per se does not explain their extensive diversification. Rather, our results indicate that pollinivory was a necessary but not sufficient condition for diversification, and that other complementary innovations, such as a broadening of host-plant diet, allowed the diversification of the major bee lineages. Our results have broad implications for understanding tempo and mode of bee diversification dynamics in light of their floral resources., (© 2018 The Authors.)