Resource use and foraging patterns of honeybees, Apis mellifera, and native insects on flowers of Eucalyptus costata

Abstract

Introduced honeybees have become well established throughout Australia and concerns have been raised about their impact on the native flora and fauna. Such concerns include the possible depletion of nectar resources by honeybees to the detriment of native animals and the ability of honeybees to pollinate Australian plants. The foraging patterns and resource utilization of honeybees (Apis mellifera) and native insects on flowers of yellow Mallee (Eucalyptus costata) (Behr & F. Muell, ex F. Muell.) were studied in Wyperfeld National Park during spring 1994. Seventy‐four insect species visited the flowers with the most prevalent being honeybees, native bees (Lasioglossum and Hylaeus) and ants (Iridiomyrmex). Honeybees began foraging at lower temperatures than native bees and hence had initial access to the nectar supply that was primarily produced overnight by E. costata. However, the majority (90%) of early morning visits to flowers by honeybees involved the collection of pollen. Honeybees did not forage for nectar in substantial numbers until after native insects were active. Despite both consumption and evaporation, nectar supplies remained available at midday and at one site remained available for consumption at dusk. Honeybees regularly made contact with the receptive stigmata while foraging for pollen and hence had pollen loads consisting of numerous E. costata grains present on their body. These activities are indicative of the behaviour required by insects to facilitate pollination. Given the unique morphology of many native flowers and the contrasting findings from studies to date, it is critical that generalisations about the effect of honeybees in the Australian environment are not made from studies on a limited number of native plant species.

Impact of honeybee (Apis mellifera L.) density on wild bee foraging behaviour

“…Even though there was no statistically significant difference on the visit duration for each group, there was a slight trend of differentiation, probably because of the different bee body sizes. An increase in the number of honey bees in an area has been proven to depress the availability of nectar and pollen (Wills, Lyons & Bell, 1990;Horskins & Turner, 1999). This may explain why different sized wild bees react to this pressure.…”

“…Consequently the fecundity, abundance, and ultimately survival of the wild bees are thought to be affected. Some authors have shown a negative impact of honey bees on native bee foraging, reproduction, and populations (Pyke & Balzer, 1985;Sugden, Thorp & Buchmann, 1996;Kato et al, 1999;Goulson & Sparrow, 2009); whereas other researchers did not find such impacts (Butz Huryn, 1997;Horskins & Turner, 1999;Roubik & Wolda, 2001;Paini, Williams & Roberts, 2005). The various and contrasting results among the studies, or in some cases even among areas/seasons from the same study, may arise from multiple factors that may affect the relationship between honey bees and wild bees (i.e.…”

Gene flow estimation with microsatellites in a Malagasy seed orchard of Eucalyptus grandis

“…The presence of bees in the area also suggested that pollen could be carried several kilometres and be exchanged in the hive (B. Vaissiere, personal communication). Microsatellite markers helped to demonstrate that long-distance pollen-flow within populations is relatively common for wind-pollinated species (Dow and Ashley 1996;Streiff et al 1999) and insectpollinated species (Chase et al 1996;Horskins and Turner 1999;Konuma et al 2000).…”

Invasive Japanese beetles facilitate aggregation and injury by a native scarab pest of ripening fruits

“…A search of ecological journals from 1993 to 2004 nevertheless found 61 papers reporting evidence of such facilitation across a range of habitats (7). Mechanisms by which invasive species can directly benefit native populations (7) include trophic subsidy, i.e., serving as a food source or providing limiting nutrients to higher trophic levels (8,9), modification or creation of habitat exploited by native species (10), and pollination of native plants (11,12). Invasive species may indirectly benefit native ones by ameliorating predation or competition (7), or through plant stress-mediated interactions, e.g., increased colonization of defoliated oaks by wood borers after gypsy moth, Lymantria dispar (L.), outbreaks (13).…”