Conservation Evidence: Evidence Data

Collected Evidence: Collected Evidence: Translocate bumblebee colonies in nest boxesWe have captured three small trials in the 1950s and early 1960s testing the effect of translocating bumblebee colonies in nest boxes. Two trials in Canada provided evidence of queen death and one of these showed lower colony productivity following translocation. Just one, a UK trial, concluded that early bumblebee Bombus pratorum colonies adapt well to being moved. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F53https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F53Thu, 20 May 2010 01:34:59 +0100Collected Evidence: Collected Evidence: Reintroduce laboratory-reared bumblebee colonies to the wildSeven replicated trials have monitored the success of laboratory-reared colonies of bumblebees introduced to the environment. In four of the trials (three in the UK, one in Canada) colonies were left to develop until new queens were produced or the founding queen died. In two of these (both in the UK), the numbers of queens/colony were very low or zero. In two trials, good numbers of new queens were produced. Rates of social parasitism by cuckoo bees Bombus [Psithyrus] spp. in colonies released to the wild are variable. Two replicated trials in Canada and the UK found high rates (25-66% and 79% respectively). The UK trial showed that parasitism was reduced by placing colonies in landscapes with intermediate rather than very high nectar and pollen availability, late, rather than early in the season. Five other replicated trials reported no social parasites. We have not found evidence to compare rates of parasitism in artificial nest boxes with the rate in natural nests. Two replicated trials examined the effects of supplementary feeding for bumblebee colonies placed in the field. One, in Canada, found supplementary feeding improved the reproductive success of captive-reared colonies, but did not reduce their parasite load. The other trial, in the USA, found supplementary feeding did not increase colony productivity. One small scale trial in Norway showed that colonies of the buff-tailed bumblebee B. terrestris prefer to forage more than 100 m from their nest sites. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F52https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F52Thu, 20 May 2010 02:59:51 +0100Collected Evidence: Collected Evidence: Restore heathlandOne small trial of early-stage lowland heath restoration activity did not have an adverse effect on bumblebee diversity at one site in southeast England. Two replicated trials in Dorset indicated that long-term restoration of dry lowland heath can restore a bee community similar to that on ancient heaths. One of these studies showed that the community of conopid flies parasitizing bumblebees remained impoverished 15 years after heathland restoration began. We found no evidence on interventions to conserve bees on upland heath or moorland. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F9https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F9Thu, 20 May 2010 03:20:44 +0100Collected Evidence: Collected Evidence: Replace honey-hunting with apiculture One study reported that a programme to enhance take-up of stingless beekeeping in southern Mexico increased the number of managed colonies in the area. Five trials contributed to scientific improvement of stingless beekeeping methods. Two controlled trials showed that either brewer's yeast (one trial) or a mix with 25% pollen collected by honey bees Apis mellifera (one trial) can be used as a pollen substitute to feed Scaptotrigona postica in times of pollen scarcity. A study on the island of Tobago found a wooden hive design with separate, different-shaped honey and brood chambers allowed honey to be extracted without damaging the brood. One trial showed that 50 g of comb with mature pupae is enough to start a new daughter colony of S. mexicana. One trial found brood growth was higher in traditional log hives than in box hives with internal volumes exceeding 14 litres, and recommended smaller box hives. We have captured no clear evidence about whether these activities help conserve bees or enhance native bee populations. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F33https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F33Thu, 20 May 2010 06:29:24 +0100Collected Evidence: Collected Evidence: Restore species-rich grassland vegetationOne replicated controlled trial in Scotland showed that species-rich grassland managed under agri-environment schemes attracted more nest-searching queen bumblebees but fewer foraging queens in the spring than unmanaged grassland. Three small trials, two in the UK and one in Germany, found that restored species-rich grasslands had similar flower-visiting insect communities (dominated by bees and/or flies) to paired ancient species-rich grasslands. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F8https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F8Thu, 20 May 2010 07:08:34 +0100Collected Evidence: Collected Evidence: Sow uncropped arable field margins with a native wild flower seed mixFive replicated trials in the UK showed that uncropped field margins sown with wild flowers and subsequently mown support a higher abundance (and in three trials higher species richness) of foraging bumblebees than cropped field edges (all five trials), grassy margins (four trials) or naturally regenerated uncropped margins (three trials). One small trial recorded the same number of bee species on wildflower sown and naturally regenerated strips. Two trials demonstrated that perennial leguminous herbs in the seed mixtures are important forage sources for bumblebees, particularly for long-tongued species. One small replicated trial showed that common long-tongued bumblebee species (Bombus pascuorum and B. hortorum) strongly preferred plots of perennial wildflower seed mix over a mix of annual forage plants. We have captured no evidence on the effects of field margin management on solitary bees. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F19https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F19Thu, 20 May 2010 07:11:24 +0100Collected Evidence: Collected Evidence: Provide training to conservationists and land managers on bee ecology and conservation We have captured no evidence for the effects of providing training on bee ecology and conservation to conservationists and land managers. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F58https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F58Thu, 20 May 2010 09:03:14 +0100Collected Evidence: Collected Evidence: Reintroduce laboratory-reared bumblebee queens to the wild We have found no evidence for the effects of reintroducing bumblebee queens. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F51https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F51Thu, 20 May 2010 10:18:09 +0100Collected Evidence: Collected Evidence: Provide grass strips at field margins for beesThree replicated controlled trials in the UK have monitored wild bees on uncropped grassy field margins. Evidence of the effects on bees is mixed. One trial showed that 6 m wide grassy field margins enhanced the abundance, but not diversity, of wild bees at the field boundary. One trial showed that 6 m wide grassy field margins enhanced the abundance and diversity of bumblebees within the margin. A third, smaller scale trial showed neither abundance nor diversity of bumblebees was higher on sown grassy margins than on cropped margins. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F14https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F14Thu, 20 May 2010 10:42:47 +0100Collected Evidence: Collected Evidence: Provide nest boxes for stingless beesOne replicated trial tested nest boxes placed in trees for the stingless bee Melipona quadrifasciata in Brazil and found no uptake. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F49https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F49Thu, 20 May 2010 11:16:43 +0100Collected Evidence: Collected Evidence: Translocate solitary beesOne replicated trial in India showed that translocating carpenter bees Xylocopa fenestrata in immature stages can establish a population at a new site, but if adult bees are translocated a very small proportion remain at the new site. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F55https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F55Thu, 20 May 2010 11:18:56 +0100Collected Evidence: Collected Evidence: Retain dead wood in forest managementWe have found no evidence on the impact of retaining dead wood in forests or woodlands on wild bee communities or populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F36https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F36Thu, 20 May 2010 12:43:18 +0100Collected Evidence: Collected Evidence: Reduce grazing intensity on pasturesOne replicated trial has shown that reducing the intensity of summer cattle grazing can increase the abundance, but not the species richness of cavity-nesting bees and wasps. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F23https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F23Thu, 20 May 2010 12:44:56 +0100Collected Evidence: Collected Evidence: Raise awareness amongst the general public through campaigns and public information We have captured no evidence for the effects of campaigning or raising awareness about bees and their conservation. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F59https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F59Thu, 20 May 2010 16:10:10 +0100Collected Evidence: Collected Evidence: Restrict certain pesticidesOne site comparison study in Italy showed that a reduction in the number of solitary bee species in late summer associated with repeated applications of the insecticide fenitrothion can be avoided by not applying the insecticide. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F26https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F26Thu, 20 May 2010 17:07:09 +0100Collected Evidence: Collected Evidence: Reduce fertilizer run-off into marginsWe have captured no evidence on the effects of specific interventions to reduce fertilizer run off into field margins. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F28https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F28Thu, 20 May 2010 17:48:38 +0100Collected Evidence: Collected Evidence: Rear and manage populations of solitary beesSeveral species of solitary bee in the family Megachilidae are reared and managed commercially as pollinators, mostly for the forage crop alfalfa, or fruit trees. These species readily nest in drilled wooden blocks, or stacked grooved boards of wood or polystyrene. Parasites and pathogens can be problematic and a number of control methods have been developed. Rearing methods have been investigated for two other species not yet commercially managed and one replicated trial shows that temperature regimes are important to survival. If rearing for conservation purposes is to be attempted, we would recommend a systematic review of these methods. Three management trials with megachilids not commercially managed in the USA or Poland, and a review of studies of managed species, found that local populations can increase up to six-fold in one year under management if conditions are good and plentiful floral resources are provided. Two replicated trials have reared solitary bees on artificial diets. One found high larval mortality in Osmia cornuta reared on artificial pollen-based diets, including honey bee-collected pollen. The other found Megachile rotundata could be reared on an artificial diet based on honey bee-collected pollen, but bees reared on synthetic pollen substitutes either died or had low pre-pupal weight. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F54https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F54Thu, 20 May 2010 18:24:45 +0100Collected Evidence: Collected Evidence: Restore species-rich grassland on road vergesOne replicated controlled trial showed that road verges planted with native prairie vegetation in Kansas, USA supported a greater number and diversity of bees than frequently mown grassed verges. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F30https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F30Thu, 20 May 2010 18:38:51 +0100Collected Evidence: Collected Evidence: Re-plant native forest We have found no evidence on the impact of reforestation on wild bee communities or populations. 'No evidence' for an action means we have not yet found any studies that directly and quantitatively tested this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F35https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F35Thu, 20 May 2010 18:51:39 +0100Collected Evidence: Collected Evidence: Reduce pesticide or herbicide use generallyOne replicated trial in the USA showed that numbers of foraging bees on squash farms are not affected by the responsible use of pesticides. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F27https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F27Thu, 20 May 2010 19:22:20 +0100Collected Evidence: Collected Evidence: Reduce the intensity of farmland meadow managementFour replicated trials in Europe have compared farmland meadows managed extensively with conventionally farmed meadows or silage fields. Two found enhanced numbers and diversity of wild bees on meadows with a delayed first cut and little agrochemical use. Two found no difference in bee diversity or abundance between conventional meadows and meadows with reduced fertilizer use or cutting intensity. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F22https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F22Thu, 20 May 2010 19:27:37 +0100Collected Evidence: Collected Evidence: Reduce tillageEvidence on whether reduced tillage or no tillage benefits ground-nesting bees is mixed. Two replicated trials on squash Cucurbita spp. farms in the USA had contrasting results. One showed no difference in the abundance of bees between tilled and untilled farms, the other found three times more squash bees Peponapis pruinosa on no-till farms than on conventional farms. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F11https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F11Thu, 20 May 2010 19:41:46 +0100Collected Evidence: Collected Evidence: Rear declining bumblebees in captivityWe have captured 22 trials from 13 countries documenting captive rearing of bumblebee colonies by confining mated queens alone (eight trials), with one or more bumblebee workers (seven trials), honey bee workers (one trial), male bumblebee pupae (three trials) or following anaesthetisation with CO2 (four trials). One trial found that over four years of artificial rearing, Bombus terrestris queens gradually decreased in weight. Three trials have tried to rear North American bumblebees now declining or thought to be declining. Two induced spring queens of the half-black bumblebee B. vagans to rear adults in captivity, one trial induced queen yellow-banded bumblebees B. terricola (attempted in all three trials) and red-belted bumblebees B. rufocinctus (only attempted in one trial) to rear adults in captivity. All three trials tried to rear the yellow bumblebee B. fervidus and in all cases the queens laid eggs but the larvae died before becoming adults. One trial found the same pattern for the rusty-patched bumblebee and the American bumblebee B. pensylvanicus. One study reports rearing the large garden bumblebee B. ruderatus, a Biodiversity Action Plan species in the UK. Two trials have reported laboratory rearing of a pocket-making bumblebee, the Neotropical B. atratus. Three replicated trials demonstrated that the pollen diet of captively reared bumblebees influences reproductive success. In one trial, buff-tailed bumblebee B. terrestris colonies fed on freshly frozen pollen produced larger queens that survived better and produced larger colonies themselves than colonies fed on dried, frozen pollen. Two replicated trials demonstrated that B. terrestris workers can produce more offspring when fed types of pollen with a higher protein content. Two replicated experiments showed that an artificial light regime of eight hours light, 16 hours darkness, can reduce the time taken for artificially reared queen B. terrestris to lay eggs, relative to rearing in constant darkness. We have captured two replicated trials examining the effect of different artificial hibernation regimes in B. terrestris. One showed that hibernation of queens at 4-5°C for 45 days enhanced egg-laying and colony formation rates, but hibernated queens produced smaller colonies than non-hibernated queens. The second showed that queens should weigh more than 0.6 g (wet weight) and be hibernated for four months or less to have a good chance of surviving.Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F50https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F50Thu, 20 May 2010 20:22:36 +0100Collected Evidence: Collected Evidence: Sow uncropped arable field margins with an agricultural nectar and pollen mixFive replicated trials in Europe (three controlled) have documented bumblebees foraging on field margins sown with an agricultural nectar and pollen seed mix. Four replicated trials showed that field margins sown with perennial leguminous flowering plants attract significantly more foraging bumblebees than naturally regenerated (two trials), grassy (four trials) or cropped (three trials) field margins. Three replicated trials showed that a mix of agricultural forage plants including legumes (all annual plants in one trial) attracts greater numbers of bumblebees than a perennial wildflower mix, at least in the first year. Three trials in the UK found evidence that margins sown with agricultural legume plants degrade in their value to bumblebees and would need to be re-sown every few years. We have captured no evidence on the effects of field margin management on solitary bees. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F18https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F18Thu, 20 May 2010 20:59:45 +0100Collected Evidence: Collected Evidence: Provide set-aside areas in farmland Two replicated trials showed that species richness of bees nesting (one study) or foraging (one study), is higher on set-aside that is annually mown and left to naturally regenerate for two years or more, relative to other set-aside management regimes or, in the nesting study, to arable crop fields. Collected Evidencehttps%3A%2F%2Fwww.conservationevidence.com%2Factions%2F7https%3A%2F%2Fwww.conservationevidence.com%2Factions%2F7Thu, 20 May 2010 21:22:12 +0100