Foraging Activity Of Bees Research Articles

Predictive modelling of honey bee foraging activity using local weather conditions

We investigated the connection between foraging activity of honey bees (Apis mellifera) and local weather conditions. We measured bee egress rate along with temperature, solar radiation, atmospheric pressure, humidity, rainfall, wind direction and speed. Data was collected from two hives, over the periods June–September 2013 (hive 1) and July–September 2014 (hive 2). We fitted an ordinary-least-squares generalised linear model to the data, using weather to predict bee egress rate. We found that 78% of the observed variation in bee activity was explained by variation in temperature and solar radiation. We discuss the potential application of this approach for continuous, remote monitoring of honey bee colonies with possible implications for early detection and prevention of hive abandonment disorders.

Impact of different insecticides on the activity of bees on sunflower

This study examines the effect of different insecticides on the foraging activity of bees on sunflower (Helianthus annuus). The findings indicated that cypermethrin 10% EC and imidacloprid 17.8% SL sustained less bee visits up to two days. On third day, normal bee activity was restored in case of cypermethrin 10% EC and imidacloprid 17.8% SL treated plots. Fipronil 5% SC exhibited less bee visits only on the day of spraying. The reduction in the bee activity was observed for four days subsequent to application of indoxacarb 14.5% SC.

Mechanistic modeling of pesticide exposure: The missing keystone of honey bee toxicology.

The role of pesticides in recent honey bee losses is controversial, partly because field studies often fail to detect effects predicted by laboratory studies. This dissonance highlights a critical gap in the field of honey bee toxicology: there exists little mechanistic understanding of the patterns and processes of exposure that link honey bees to pesticides in their environment. The authors submit that 2 key processes underlie honey bee pesticide exposure: 1) the acquisition of pesticide by foraging bees, and 2) the in-hive distribution of pesticide returned by foragers. The acquisition of pesticide by foraging bees must be understood as the spatiotemporal intersection between environmental contamination and honey bee foraging activity. This implies that exposure is distributional, not discrete, and that a subset of foragers may acquire harmful doses of pesticide while the mean colony exposure would appear safe. The in-hive distribution of pesticide is a complex process driven principally by food transfer interactions between colony members, and this process differs importantly between pollen and nectar. High priority should be placed on applying the extensive literature on honey bee biology to the development of more rigorously mechanistic models of honey bee pesticide exposure. In combination with mechanistic effects modeling, mechanistic exposure modeling has the potential to integrate the field of honey bee toxicology, advancing both risk assessment and basic research. Environ Toxicol Chem 2017;36:871-881. © 2016 SETAC.

Effects of a neonicotinoid pesticide on thermoregulation of African honey bees (Apis mellifera scutellata)

Thiamethoxam is a widely used neonicotinoid pesticide that, as agonist of the nicotinic acetylcholine receptors, has been shown to elicit a variety of sublethal effects in honey bees. However, information concerning neonicotinoid effects on honey bee thermoregulation is lacking. Thermoregulation is an essential ability for the honey bee that guarantees the success of foraging and many in-hive tasks, especially brood rearing. We tested the effects of acute exposure to thiamethoxam (0.2, 1, 2ng/bee) on the thorax temperatures of foragers exposed to low (22°C) and high (33°C) temperature environments. Thiamethoxam significantly altered honey bee thorax temperature at all doses tested; the effects elicited varied depending on the environmental temperature and pesticide dose to which individuals were exposed. When bees were exposed to the high temperature environment, the high dose of thiamethoxam increased their thorax temperature 1–2h after exposure. When bees were exposed to the low temperature, the higher doses of the neonicotinoid reduced bee thorax temperatures 60–90min after treatment. In both experiments, the neonicotinoid decreased the temperature of bees the day following the exposure. After a cold shock (5min at 4°C), the two higher doses elicited a decrease of the thorax temperature, while the lower dose caused an increase, compared to the control. These alterations in thermoregulation caused by thiamethoxam may affect bee foraging activity and a variety of in-hive tasks, likely leading to negative consequences at the colony level. Our results shed light on sublethal effect of pesticides which our bees have to deal with.

Use of video surveillance to measure the influences of habitat management and landscape composition on pollinator visitation and pollen deposition in pumpkin (Cucurbita pepo) agroecosystems.

Pumpkin (Cucurbita pepo) production relies on insect-mediated pollination, which is provided by managed and wild pollinators. The goals of this study were to measure the visitation frequency, longevity and temporal activity patterns of pumpkin pollinators and to determine if local habitat management and landscape composition affected this pollination service. We used video surveillance to monitor bee acitivty within male and female pumpkin flowers in 2011 and 2012 across a pollination window of 0600–1200 h. We also quantified the amount of pollen deposited in female flowers across this time period. In 2011, A. mellifera made significantly more floral visits than other bees, and in 2012 Bombus spp. was the dominant pumpkin pollinator. We found variation in visitation among male and female pumpkin flowers, with A. mellifera visiting female flowers more often and spending longer per visit within them than male flowers in both 2011 and 2012. The squash bee P. pruinosa visited male flowers more frequently in 2012, but individuals spent equal time in both flower sexes. We did not find variation in the timing of flower visitation among species across the observed pollination window. In both 2011 and 2012 we found that the majority of pollen deposition occurred within the first two hours (0600–0800 h) of observation; there was no difference between the pollen deposited during this two-hour period and full pollination window (0600–1200 h). Local additions of sweet alyssum floral strips or a field buffer strip of native wildflowers did not have an effect on the foraging activity of bees or pollen deposition. However, semi-natural and urban habitats in the surrounding landscape were positively correlated with the frequency of flower visitation by wild pollinators and the amount of pollen deposited within female flowers.

<b>Effects of abiotic factors on the foraging activity of <i>Apis mellifera</i> Linnaeus, 1758 in inflorescences of <i>Vernonia polyanthes</i> Less (Asteraceae)

Knowledge on the foraging activity of Apis mellifera under the influence of abiotic factors has not been fully elucidated. Knowing the interactions between bees and plants with beekeeping relevance is fundamental to develop management strategies aimed at improving the beekeeping productivity. In this way, this study aimed to determine the foraging schedule of A. mellifera and to assess the influence of environmental factors on the foraging on inflorescences of Vernonia polyanthes. The study was conducted in the rural area of Valenca, Rio de Janeiro State. Visits of A. mellifera workers to V. polyanthes inflorescences occurred from 9 am to 4 pm, especially between 11 am and 3 pm. Among the abiotic variables, relative humidity (rs = -0.691; p < 0.0001) and temperature (rs = 0.531; p < 0.0001) were correlated with foraging activity. Increase in temperature and decrease in humidity resulted in increased frequency in bee foraging activity, accounting for 46.9% of the activity in A. mellifera. This study provides subsidies to the development of apiculture, emphasizing the importance of V. polyanthes as a food resource during winter, representing a good alternative to increase the productivity, especially in areas of grasslands or abandoned crops, where 'Assa-peixe' is abundant.

MIXED BREEDING SYSTEM AND ENTOMOPHILY IN Malachra capitata L. (MALVACEAE)

Malachra capitata is a small seasonal herb. Flowering occurs during September–October. It is hermaphroditic and self-compatible with a mixed breeding system. The conspicuous floral displays, non-tubular nature of the flower, and the small volume of nectar with high sugar concentration attract bees and butterflies with bees serving as the principal pollinator. The fruit set is 21% in open-pollination mode despite the hectic foraging activity of bees and butterflies. The observed fruit set rate is attributed to the high percentage of flower predation by beetles, and by the nature of soil nutrient/environment requirements. The fruit is a schizocarp with five 1-seeded indehiscent mericarps. New plants arise from seed during the rainy season mostly at parental sites and usually form pure stands; the plants complete their life cycle within six or seven months.

Observations on the urban ecology of the Neotropical stingless bee &lt;i&gt;Tetragonisca angustula&lt;/i&gt; (Hymenoptera: Apidae: Meliponini)

Tetragonisca angustula (Latreille) is a small, docile, cavity-nestingstingless bee that is widely distributed in the Neotropical region. This speciesis particularly abundant in disturbed environments, including humansettlements. Between August 2005 and March 2006, we located and followed duringeight months 59 nests of this species in Medellín, the second most populatedcity in Colombia. Herein, we document their foraging behavior, mortality, andincidence of predators and natural enemies. Also, to determine if higherambient temperature and light intensity in urban environments affect the dailyforaging activity of T. angustula, wecompared the daily foraging activity of bees from nests found in open areas in thecity and bees from nests from a nearby covered, forested area. Likewise, todetermine if urban nests of T. angustulaare largely undetected and undisturbed by people, we experimentally made themvisible by adding a ring color (white, red, or black) around the nest entrance tube.Our observations indicate that higher ambient temperature and light intensity inurban environments do not significantly affect the daily foraging activity of T. angustula. Nearly half of the markednests disappeared, thus suggesting that nests of T. angustula are often undetected by people in Medellín. We discussbriefly some features of the biology of T.angustula that might contribute to its success in urban environments.

An alarm pheromone modulates appetitive olfactory learning in the honeybee (apis mellifera).

In honeybees, associative learning is embedded in a social context as bees possess a highly complex social organization in which communication among individuals is mediated by dance behavior informing about food sources, and by a high variety of pheromones that maintain the social links between individuals of a hive. Proboscis extension response conditioning is a case of appetitive learning, in which harnessed bees learn to associate odor stimuli with sucrose reward in the laboratory. Despite its recurrent use as a tool for uncovering the behavioral, cellular, and molecular bases underlying associative learning, the question of whether social signals (pheromones) affect appetitive learning has not been addressed in this experimental framework. This situation contrasts with reports underlining that foraging activity of bees is modulated by alarm pheromones released in the presence of a potential danger. Here, we show that appetitive learning is impaired by the sting alarm pheromone (SAP) which, when released by guards, recruits foragers to defend the hive. This effect is mimicked by the main component of SAP, isopentyl acetate, is dose-dependent and lasts up to 24 h. Learning impairment is specific to alarm signal exposure and is independent of the odorant used for conditioning. Our results suggest that learning impairment may be a response to the biological significance of SAP as an alarm signal, which would detract bees from responding to any appetitive stimuli in a situation in which such responses would be of secondary importance.

A scientific note on honey bee foraging activity and airborne pollen flow

Several factors affect a honey bee colony’s collection of pollen. Most studies on this topic have focused on the colony’s response to stimuli located within the nest, principally the amount of brood and stored pollen (Hrassnigg and Crailsheim, 1998; Dreller et al., 1999; Fewell and Bertram, 1999; Rotjan et al., 2002; Vaughan and Calderone, 2002). One area that has not received adequate attention is the relationship between pollen collection and its availability in the natural environment. During the last few years, aerobiology studies demonstrated a link between airborne pollen concentration and the number of flowers in the area surrounding the sampler (Reddi and Reddi, 1985; Besselat and Cour, 1990; Cunha et al., 2003; Thibaudon and Lachasse, 2005). The aim of our work was to compare the total airborne pollen flow, collected with airborne samplers, with the total amount of pollen collected by honey bee colonies. Sampling was done in the northwest littoral of Portugal, in two rural areas, Cesar (40◦55’N, 8◦25’W, 300 m altitude) and Vairao (41◦20’N, 8◦40’W, 100 m), and one urban area, Porto (41◦11’N, 8◦39’W, 50 m). Airborne pollen flow and bee-collected pollen were studied in 2003 and 2004 at Cesar and Vairao, and in 2004 at Porto. At Cesar and Vairao, the airborne pollen content was sampled using two “Cour-type” samplers (Cour, 1974) placed at 12 m and 7 m, respectively, above ground level. The pollen was trapped in filters which were changed weekly. After acetolysis (Erdtman, 1960),

Evaluation of the Neotropical Stingless Bee &lt;I&gt;Melipona quadrifasciata&lt;/I&gt; (Hymenoptera: Apidae) as Pollinator of Greenhouse Tomatoes

The Neotropical stingless bee Melipona quadrifasciata Lepeletier was evaluated for pollinating tomatoes (variety Rodas; long-life hybrid) in greenhouses under plastic and with a hydroponic system and "organic concepts" in Minas Gerais State, Brazil. Flowers not pollinated did not set any fruit. Pollination by bees plus manual pollination did not differ from either bee or manual pollination. Maximum fruit diameter, fruit height, and roundness (quotient between maximum fruit diameter and fruit height) were not significantly different between treatments, but fruit visited by M. quadrifasciata had 10.8% less seeds (dry mass) than manual pollination. This apparently low efficiency of M. quadrifasciata pollination was attributed to the overlap of only 30 min between highest bee foraging activity and highest flower stigma receptivity. Thus, it was concluded that M. quadrifasciata is a feasible pollinator of greenhouse tomatoes because of 1) the observed increase in fruit quality with lower mechanical injury than traditional manual pollination, 2) no significant decrease in fruit size, and 3) high price of such product in the market. Some considerations for sustainable use of M. quadrifasciata as greenhouse pollinator are presented. Although techniques for keeping captive colonies of M. quadrifasciata are currently available, the sole current method for acquiring new colonies is removing them from the forest, and if demand was created for large numbers of colonies for commercial use, techniques for captive rearing must be developed to prevent serious declines in wild populations.

Trees, birds and bees in Mauritius: exploitative competition between introduced honey bees and endemic nectarivorous birds?

AimsTo investigate effects of introduced honey bees, Apis mellifera L., on the nectar‐feeding activity of two species of endemic nectarivorous birds, the Grey White‐eye, Zosterops borbonicus mauritianus Gmelin, and the Olive White‐eye, Z. chloronothos Viellot, on two endemic flowering trees, Sideroxylon cinereum Lam. and S. puberulum DC. (Sapotaceae), and to examine pollination efficiency of birds and honey bees.LocationAn upland heath area on the island of Mauritius, Indian Ocean.MethodsWe quantified visitation rates of endemic birds and introduced honey bees at two endemic species of flowering trees. Diurnal variation in nectar standing crop and nectar production was measured. Pollination efficiency of flower visitors was examined using bagging and caging experiments.ResultsWhite‐eyes were only nectar‐feeding at the two Sideroxylon species early in the morning, stopping when honey bee foraging activity rapidly lowered nectar standing crops. White‐eyes continued nectar‐feeding at other flowering plant species, exploited less by honey bees, throughout the day. Honey bees were less efficient pollinators of the two Sideroxylon species than white‐eyes.Main conclusionsOur results indicate that introduced honey bees could be interfering with endemic interactions between the two Sideroxylon species and the two white‐eye species. However, because of lack of a neutral control site without honey bees, we cannot exclude other explanations. We do recommend, although, that honey bees need to be taken into consideration in the future conservation management of Mauritian ecosystems. We suggest that island ecosystems are especially vulnerable to introduced honey bees.

Ventilation of greenhouses increases honey bee foraging activity on melon, Cucumis melo

SUMMARYMelons are grown in Israel in ‘walk-through’ tunnel greenhouses. We compared honey bee (Apis mellifera) foraging activity and melon nectar characteristics in well-ventilated and in closed greenhouses. Foraging activity in the open greenhouses was two- to five-fold greater than that in the closed greenhouses. This higher activity could be explained by higher flower attractivity due to a higher nectar sugar concentration both in hermaphroditic flowers and male flowers. The higher sugar concentration in the open, ventilated greenhouses was probably as a result of the relatively lower humidity there. The greater foraging activity in the open greenhouses also may have been due to lower air temperatures and better accessibility for the bees. It seems that greenhouse ventilation can improve honey bee pollination activity in melon and probably other greenhouse crops as well.

Alteration of the homing‐flight in the honey bee Apis mellifera L. Exposed to sublethal dose of deltamethrin

AbstractForaging activity of bees is currently disturbed by treatments with pyrethroid agrochemicals. To discover eventual troubles of spatial orientation of the foragers, we exposed bees to sublethal doses of deltamethrin sufficiently low to avoid motor incoordination or muscular troubles. In an insect‐proof tunnel, bees were trained to forage at a feeder 8 m from their nucleus. When temperature and global radiance conditions were optimal, some foragers were caught, exposed to a deltamethrin dose 27 times lower than its LD50, and released after 20 min of recovering. Among the contaminated bees, 54% took flight toward the sun and 81% did not come back to their nest within 30 s (which is 3 times longer than the mean time of control bees). Because pyrethroids are known to disturb learning and memory, we cannot conclude if this disorientation is due either to a trouble of information storage (wrong spatial perception or phototropism increase), or to a trouble of information retrieval (bad comparison of actual and memorized patterns). Routine chemical analysis of exposed bees does not detect residues of deltamethrin 3 h after bee sublethal exposure, although bees evidenced alteration in the flight.

Pollination Ecology in the Southwest

Comparisons of the pollination biology of members of a number of genera (Prosopis, Helianthus, Opuntia, and Krameria) widespread in the arid American Southwest are made between sites in the Sonoran Desert of southern Arizona and the dry oak-juniper grasslands of central Texas. As in the majority of cases studied to date in the dry regions of the Southwest, solitary bees are the dominant pollinators in all of the systems examined. Rich arrays of oligolectic bees are associated with Prosopis, Helianthus, and Opuntia, but none with Krameria which offers oils rather than pollen and nectar as the primary floral reward. Nevertheless, Krameria appears to have the most restricted pollination system as none of the other taxa are obligately dependent on their specialist bees. Reward production and bee foraging activity were examined in Opuntia and Helianthus. In Helianthus, bimodal pollen presentation, but near constant nectar production, results in different activity patterns of the specialist and generalist bees visiting the flowers. Reward production is unimodal in the Opuntia species studied, but diurnal phenological differences can result in apparent partitioning of floral resources by foraging bees.

Effect of Honey Bees on Yield of Three Soybean Cultivars1

The importance of insects in the pollination of soybeans [Glycine max (L.) Merr.] was studied over a year period by comparing the yields from plots caged with honey bees (Apis mellifera L.), plots without bees and without insects (insecticide treatment), and open plots. The pollinating activity of bees resulted in significantly greater yields from ‘Corsoy’ and ‘Hark’ cultivars but not from ‘Chippewa 64.’The foraging activity of bees on soybeans was dependent on the floral response of each cultivar to the environment. Hark had a high percentage of dissolved solids in the nectar and the highest quantity of nectar/floret.