Posts Tagged ‘ pollination ’

Popular Pollinator Parts

Spare parts and accessories for the popular Brinkman Vibri Vario tomato pollinator are available in Australia from Roskam Young Plants.

The brochure picturing the accessories and numerous spare parts is available here.

Further inquiries can be made to Roskam Young Plants at info@roskam-youngplants.com

Issue 98: Greenhouse Production In Japan

January/February 2008
Authors: Mike Nichols & Bruce Christie

Although Japan has a large protected cropping industry, only a small proportion of growers use hydroponic systems, with an emerging trend towards plant factories. Report by Mike Nichols & Bruce Christie

In January 2007, we accepted an invitation to speak on organic hydroponics at the 24th SHITA conference in Tokyo, Japan. It was a very rushed visit, but we took the opportunity of looking at the progress being made in Japan in both plant factories and greenhouse crop production. This article will only look at greenhouse crop production, and plant factories will be the subject of a future article.

There are some 52,000 hectares of greenhouses in Japan, and a further 14,000 hectares of rain shelters. The bulk of the greenhouses are covered in plastic film, and less than 5% of the greenhouses are glass clad. Sixty-nine percent of the total greenhouse area is used for vegetable production, only 17% for flowers, and 14% for fruit tree production.

In such a high-tech country as Japan, it is somewhat surprising to find the area of greenhouses devoted to soilless culture is only 1,500 ha (which is comparable to only 3% of the total protected cultivation area). Although there are a range of hydroponic systems used, rockwool predominates followed by the deep flow technique (DFT), and three quarters of the crops grown hydroponically are vegetables. In Japan, melons, strawberries, and watermelon are all classified as vegetables and make up 30% of total greenhouse vegetable areas.

Our visit was in late January, the middle of the northern hemisphere winter, and our observations must clearly be tempered with this – coming from the middle of a New Zealand summer it is all too easy to be critical of production being undertaken in the most difficult part of the year.

In fact, it would be fair to say that with one exception we were very favourably impressed with what we were shown. We only had time to view a few properties in Chiba Province (just north of Tokyo), but learnt a great deal in just two days.

Chiba Province is at latitude 36°N, but has a far better winter climate than one might anticipate, as winter is the dry season, with very little cloud, and better levels of insulation than one might initially anticipate.

Presentation and freshness was paramount at this Farmers Market.

Our first visit was to a farmers’ market, housed in a specially planned building, and selling a very wide range of locally produced fruit and vegetables. Presentation and freshness was paramount, and the local farmers were clearly providing the local consumers with what they required with minimal ‘food miles’ and possibly a small carbon footprint! Of course, it is still possible that for out-of-season production the carbon footprint would still favour imported produce from a southern hemisphere country producing in the summer with lower production costs!

Our first visit was to a greenhouse strawberry producer. Producing ripe strawberries in the middle of the winter demands real attention to detail, and we were most impressed with the appearance of the crop. It was being grown in rockwool slabs on raised troughs, which were watered and fed using a recirculating hydroponic system. Surprisingly, both honeybees and bumblebees were being used for pollination with excellent results, and the price in the shop was even more impressive. We estimate that the price was between NZ$20-25 per tray, or around NZ$200/kg!

Honeybees and bumblebees are used for strawberry pollination.

In Japan, strawberries are classified as a vegetable crop.


This strawberry crop is grown in rockwool slabs on raised troughs.

The crop did not compare well with the greenhouse strawberry crops seen in Belgium (Nichols, 2006), but of course that was in the middle of the summer.

Perhaps the most interesting aspect of production was the area set aside for runner production – a key component of any out-of-season strawberry growing.

We use tip runners at Massey University (Nichols, 2002), but at this property runners were rooted into individual pots placed just below the rockwool slabs. It looked to be a more labour intensive and tedious system than tip runners.

Our next visit was to a greenhouse tomato producer. This was a little disappointing because the technology of greenhouse tomato production has developed tremendously over the past 20 years, and this was rather like visiting a time warp. High wires and layering are the keys to efficient production these days and yet this house still had low wires and layered so the fruit essentially sat on the floor.

Seedlings are grafted onto resistant rootstocks.

This house has low wires with the fruit sitting on the floor.

This operation is a small family business.

This was very much a family operation, which suggests inevitably that agribusiness will eventually take over greenhouse crop production, if only because it enables the manager to have sufficient time to keep up-to-date with new developments, and to re-invest in new technology.

Of course, it was not all bad; the next crop of seedlings had been grafted onto resistant rootstocks, the fruit quality looked excellent, and the small pack-house was simple but effective.

Deep flow hydroponic systems using floating rafts are something that we have little experience with in New Zealand. One of the main reasons for visiting Japan at this time was to get a feel for the potential of the system for leafy vegetables, particularly with reference to aquaponics. Not that Japan has developed any aquaponic systems to date, but they are well advanced with deep flow systems.

Soilless culture represents only 3% of the total protected cultivation area.

Our third visit was to a grower who produces about 250t per year of mitzudamo (also known as mizuna) from a 0.8ha greenhouse operation using a very sophisticated floating raft system. This is a continuous year-round operation, which starts with five or six seeds per cell being automatically sown on a block of polyethylene foam cells. Following germination in a controlled temperature room, the plants are grown on for a short time, before the individual cells are automatically transplanted by machine into holes in the expanded polystyrene floating rafts, then transferred to the deep flow system.

The initial rafts have their holes close together. When the plants have grown sufficiently they are again transplanted automatically by machine into floating rafts with holes at a wider spacing. The only difference between rafts is the number of holes per raft.

Seedlings are grown in small plant factories.

Mizuna seedlings with their roots suspended in solution.

Seedlings are automatically transplanted by machine into holes in the polystyrene floating rafts.

Typical DFT growing system.

Seedlings are automatically transplanted into rafts with wider hole spacings.

Harvesting rafts of leafy vegetables is still a manual process.


This small pack-house is simple but effective.

The final product ready for distribution.

A key component of successful transplanting is to ensure that the roots all hang down through the hole, and this is achieved by means of a water stream at transplanting.

The next visit was interesting because it involved the growing of spinach in a hybrid floating raft/NFT system. A similar propagation technology was used to the mitzudamo grower, but because spinach is very susceptible to root-borne diseases (e.g. Phytophthora), each planting was modularised with independent reservoirs.

High root temperatures can also increase disease risks so each reservoir incorporated a heat interchange coil, which could be used to cool the nutrient solution in the summer – between crops it could be used to pasteurize the nutrient solution by circulating hot (80°C) water through the heating coil, a novel way of reducing disease problems.

This spinach crop grown in a hybrid raft/NFT system.

Open view of the hybrid raft/NFT system.

A healthy crop of spinach.

Spinach can be susceptible to root disease problems.

Independent nutrient reservoirs prevent any disease spreading.

This grower had also started to use plant factories for some of his crop production, but in this case only for the propagation stage. We saw both tomato seedlings and lettuce seedlings grown in small plant factories, and there is little doubt in our minds that although the development of plant factories for many crops may be some years away, the use of plant factories for seedling production is here and now, if only to ensure the provision of good quality seedlings exactly when required, without reference to time of year or weather conditions. The speed with which quality seedlings can be produced on demand is outstanding.

The same cannot be said about the crop of lettuce being grown in the greenhouse from these seedlings, however. Botrytis was starting to appear, and could easily have been controlled with a single application of fungicide while the plants were small. This would have the effect of preventing Botrytis spores germinating on older leaves as they died due to old age. Initially, Botrytis normally only infects dead plant material – if the older leaves are protected by a suitable fungicide before they die, then Botrytis infection can be minimised.

An alternative strategy is to ensure that the humidity in the greenhouse is kept below 90%, but in practise this is difficult to achieve at the base of a lettuce crop. Botrytis spores require the presence of liquid water if they are to germinate and infect plants, and keeping the humidity down reduces this risk, as well as reducing the risk of tipburn on the leaves.

About the author

Drs Mike Nichols and Bruce Christie are horticultural research scientists at the College of Sciences, Massey University, Palmerston North, New Zealand. Email: m.nichols@massey.ac.nz or C.B.Christie@massey.ac.nz

References
• Nichols, M.A. (2002), Strawberry tip runners, Practical Hydroponics & Greenhouses, 64, 34-5.
• Nichols, M.A. (2006), Berry Fruit in Belgium, Practical Hydroponics & Greenhouses, 90, 41-46.

Issue 77: A Bee’s Eye View

July/August – 2004
Author: Steven Carruthers

The cases for and against the importation of bumblebees onto mainland Australia to pollinate crops

STEVEN CARRUTHERS analyses the cases for and against the application to introduce the bumblebee, B. terrestris, onto mainland Australia for crop pollination purposes. Should importation be allowed, he reports bumblebees will not dramatically change the status of the native and agricultural ecosystems, and there will be significant cost-savings for Australian growers as well as improved yields and fruit quality. He writes there will also be environmental benefits with a large reduction in the use of pesticides, that will also lead to improved worker and food safety.

The Australian Hydroponics & Greenhouse Association (AHGA) has taken the next step in applying to the Department of Environment and Heritage (DEH) to allow the import of bumblebees ( Bombus terrestris) onto mainland Australia to pollinate commercial greenhouse crops. The final three-step process began in April 2004 when the industry’s Draft Terms of Reference were posted on the DEH website for a period of 10 days to allow members of the public the opportunity to comment. The terms of reference outline the areas that interested parties believe should be examined prior to any determination on the application by the Federal Minister.

Step 2 requires the AHGA to write a detailed report that considers the points raised in the terms of reference, which will then be posted on the DEH website for 20 days to allow for further public comments.

Step 3 requires the AHGA to consider the public comments from Step 2, and produce a ‘final report’ for the Federal Minister for the Environment and Heritage. The Minister then consults with other Federal, State and Territory Ministers before deciding whether to add B. terrestris to the list of species suitable for import onto mainland Australia.

Greenhouse growers and other industry members will have their opportunity to have a say during Step 2 of the application process. At the time of going to press, the AHGA was still waiting to receive the public comments from Step 1.

In the meantime, the application to import bumblebees onto mainland Australia has provoked a strong response from conservationists opposed to it.

Bombus terrestris was accidentally introduced into Tasmania in 1992 where, in this most temperate of Australian climates, it has since spread to regions with good rainfall, mostly in urban areas where there is an abundant supply of nectar and pollen from preferred introduced plant species (Hergstrom et al. , 2002). Natural or accidental migration from Tasmania to the mainland cannot be ruled out (interceptions at two ports have been reported recently), but establishment has not so far occurred and is generally considered unlikely given unfavourable climate and lack of continuous food resources.

Broadly, those who oppose the application claim that, if allowed import onto the mainland, B. terrestris will invade a wide range of wilderness areas and compete with native bird and bee species for nectar and pollen, and possibly spread weeds through increasing seed set. Their case is primarily based on the study of bumblebees in Tasmania by Hingston (1999).

The case for the application
Why do Australian growers want bumblebee technology? Bombus terrestris is an effective pollinator of tomatoes because of its ability to extract pollen from the poricidal anthers by vibrating them at an appropriate frequency. Bumblebees are also effective pollinators of other important commercial crops including capsicum, eggplant and strawberry. While honeybees will also pollinate tomatoes, bumblebees are the preferred pollinators in greenhouses because they remain on the crop more than honeybees. Honeybees don’t like the conditions inside the greenhouse and usually escape.

Overseas, bumblebee technology has led to improved Integrated Pest Management (IPM) practices in greenhouses, resulting in adoption of biological control and a large reduction in the use of pesticides and other spray chemicals. These chemicals are not only expensive, but compromise food safety, worker health, and the environment.

In Australia, there have been some limited research trials using native bees to pollinate greenhouse tomatoes. The blue-banded bee (Amegilla spp.) has shown the most promise, but goes into dormancy when the weather cools. Tomato flowers do not produce nectar, so researchers also need to develop artificial feeders. Most greenhouse industry experts agree it will be many years before researchers are able to commercialise artificial hives for greenhouse applications, if at all.

Cost:benefit analysis
Currently, Australian greenhouse growers pollinate their crops using mechanical, hand-held vibrators, usually three times weekly at a high labour, equipment and maintenance (battery) cost. The AHGA estimates hand pollination will take 780 man hours per year for a 6,00osqm greenhouse growing two crops per year. On a casual rate of $16/hr, the total labour cost is $12,480/year or $2.08sqm. For a single tomato crop grown over a year, mechanical pollination will take 1,040 man hours at a cost of $16,640 or $2.77/sqm. Then there are the costs of vibrators and expensive batteries, and the secondment of trolleys for pollination duties when they can’t be used for other jobs.

By comparison, in Holland, the cost of bumblebee hives is around AU$117, and AU$140 in New Zealand. According to Dutch greenhouse data, a grower of tomatoes needs eight hives per hectare (8 hives/ha), and a grower of cherry tomatoes needs 12 hives/ha. A hive can have a life expectancy of anywhere between six weeks and three months, depending upon conditions. It’s usual to assume an average hive life of two months.

For cherry tomatoes, it will take seven hives to cover a 6,000sqm greenhouse area. The pollination period would be about 10 months (over two crops), so the grower would need 35 hives/year. Even at $160 per hive, this would be a total of $5, 600/year, or $0.93/sqm/year. This is a saving of $6,880/year compared to hand pollination, and $11,040 for one 12-month tomato crop. In both crop scenarios, there is more than a 50% saving to growers compared to mechanical pollination.

“The overseas experience has shown that bumblebee technology also improves yields and fruit quality and this, of course, is at no extra cost,” said Tasmanian greenhouse tomato grower, Mr Marcus Brandsema, who conducted the analysis on behalf of the AHGA.

Increased overseas competition
Overseas competition is also driving the case to import bumblebees onto mainland Australia. In 2002, Biosecurity Australia (BA) approved the import of greenhouse tomatoes from New Zealand. By December 2002, Australia had imported 330, 000kg of tomatoes worth $796,460. In December 2003, NZ tomato imports rose to 354,900kg worth over $1 million, a growth of 25% over the first year of imports, and the figures for 2004 are set to go even higher. In January, Australia imported 256,000kg of Kiwi tomatoes, valued at around $840,000.

There are apparent mitigating factors for this increase in tomato imports. The NZapplication to allow the import of Kiwi tomatoes was approved on the basis of meeting shortfalls in the Australian market as a result of drought in the Bowen and Bundaberg tomato-producing regions. However, in spite of the ongoing drought, Australia has managed to export five varieties of tomatoes worth more than $5 million a year to New Zealand.

Australian tomato growers will come under even more pressure with the arrival of the first Dutch greenhouse-grown tomatoes. In October 2003, Biosecurity Australia finalised the import conditions for truss tomatoes from the Netherlands to Australia. In the near future, Australian consumers will be introduced to high quality, greenhouse-grown Dutch tomatoes, elegantly packaged as tamper-resistant functional foods. If the marketeers follow European trends, then this packaging will include a symbol of the bumblebee, a consumer guarantee that these tomatoes are pesticide-free.

Both Dutch and New Zealand tomato growers use bumblebee technology to improve fruit yields and quality. In fact, Australia is about the only country with a large protected cropping industry that doesn’t use bumblebee technology. It’s to New Zealand’s credit that growers moved to state-of-the-art greenhouse technology several years ago. Today, all Kiwi tomatoes are grown in modern greenhouses, mostly glass, using automated nutrient management and climate control systems, as well as bumblebee technology to lower production costs compared to Australian growers.

The problem here is that the Australian greenhouse industry is underdeveloped compared to Holland and New Zealand, mainly because of a lack of investment in the industry. However, this is changing with significant greenhouse developments either on the drawing board or underway in Victoria, South Australia, and the Bundaberg region of Queensland.

Nonetheless, growers will still be disadvantaged because Australia has no commercial pollinator and no native species of bumblebee. Although researchers are trialing several native bee species as alternatives to bumblebees, this research is still in its infancy. Of those native bees being trialed, Amegilla shows the most promise as a pollinator of tomato crops however, commercial rearing and the development of artificial hives for greenhouse applications are still many years off. Finding a buzz pollinator that effectively pollinates tomatoes is one issue:rearing it in commercial quantities at an acceptable cost is quite a different proposition. A good reality check is to look at the 10 years of research that has gone into finding a natural enemy for control of western flower thrips in Australia. Many candidates ate thrips, but only one, the Queensland-originating predatory mite Typhlodromips montdorensis, lent itself to mass rearing.

Environmental ImpactStudy
The application to import B. terrestris for commercial use in greenhouses was actually first made in 1997. Concerns raised at the time resulted in a three-year Environmental Impact Study (EIS) on the impact of B. terrestris on Tasmania’s flora and fauna. The EIS was funded by Horticulture Australia and the AHGA, and the outcomes were reviewed in Practical Hydroponics & Greenhouses (Issue 69).

The AHGA also funded a climatology study using the CLIMEX model, (Hergstrom, 2003) to predict where B. terrestris is likely to spread should it be allowed importation to mainland Australia, or hitch a ride on strong winds across the Bass Strait.

Both the EIS and CLIMEX studies indicate bumblebees will not dramatically change the status of native and agricultural eco-systems. The CLIMEX study indicates the likelihood of only limited distribution of B. terrestris on mainland Australia should it arrive either by accident or design. The study predicts these areas will be restricted to the wetter areas of Victoria, the south-west corner of Western Australia, and a limited area of NSW across the northeastern border of Victoria, most likely in irrigated areas and urban gardens where there is an abundance of year-round nectar from preferred introduced plant species.

To ensure there are no or limited negative effects of bumblebees establishing in the wild, any importation would be tightly controlled, using ‘clean’ bees. These bees would form the nucleus of the commercial rearing unit. To provide further safeguards, modern commercial bumblebee hives are designed to prevent the escape of queens. It is also possible, but twice as expensive, to design and distribute worker-only nests at the greenhouse site (Griffiths, 2004).

The case against the application
Spearheading the case against the application to import bumblebees onto mainland Australia is the Australian Native Bee Research Centre (ANBRC), which claims bumblebees will invade a wide range of habitats and feed on a wide range of plants with negative impacts on native species. They frequently quote studies by Hingston (1999) as evidence of resource competition. However, industry experts and international scientists say this study is questionable science (see article this issue: ‘A Critical Study’).

The Hingston study on resource competition was conducted over only two days in two small adjacent quadrants, comparing bumblebees foraging with two unidentified native bee species of the Chalicodoma genus (recently renamed the Megachile genus).

However, weaknesses in the methodology make conclusions based on statistical analysis less than reliable. There are also serious omissions in the data on bumblebee activity during the study period.

A good example of the weaknesses in the Hingston experiment was demonstrated when Hergstrom et al. spent hundreds of hours monitoring exactly the same site, and came up with quite a different result.

Those opposed to the application have tried to implicate bumblebees as a potential threat to native bird species that share the same nectar and pollen resources. They particularly point to the endangered Swift Parrot (Lathamus discolor), which breeds only in the blue gum (Eucalyptus globulus) forests of Tasmania. The Swift Parrot migrates to the mainland every autumn to winter, and can be found mostly in the nectar-rich, box-ironbark forests and woodlands of Victoria and New South Wales. Recent sightings across southern Queensland suggest this species is also a regular visitor to that State.

The conservationists claim the Swift Parrot is largely dependent on nectar and pollen from E. globulus, and there is little breeding in the years when flowering of this tree is poor. They claim B. terrestris robs nectar and pollen from this tree, and point to the Hingston study of bumblebees observed on E. globulus over a four-month period as evidence. Two years later, Hergstrom studied B. terrestris over the same seasonal period, at 18 sites, and came to a completely different result. Hergstrom reports bumblebees only represented 2% of potential pollinators of E. globulus. Honeybees were by far the dominant pollinator (56%), followed by birds (25%). Native bees represented 4% of visitors.

In nature, competition for resources is the norm, not the exception. Even though it appears there will be less nectar available in flowers from each visitor, it’s stretching it to make assumptions on the long-term survival of native species utilising the same food resources, based on observations over a short time period and over a small sample area (1ha of suburban bushland). The fact that different species may feed on E. globulus nectar at some time, is not evidence of a negative impact.

The conservationists also fail to mention a key published paper on the Swift Parrot (McNally and Horrocks, 1999), that finds there were no relationships between measures of eucalypt flowering and densities of Swift Parrot in its winter range in central Victoria.

According to Birds Australia, a respected conservation group (www.birdsaustralia.com.au), the decline of the Swift Parrot is attributed to land clearing of more than 85% of their preferred wintering habitats, and continual clearing of 500-1,000 hectares of its breeding habitat for commercial wood-chipping every year. Many individuals also die after colliding with man-made structures, such as windows and tennis court fences.

Conservationists also compare bumblebees with honeybees (Apis mellifera) and their impact on Australian eco-systems, but they fail to mention a key study by Manning (1997), which criticises existing scientific studies relating to the impact of honeybees on Australian wildlife. Despite years of study, there is no consensus on the impact of the ubiquitous honeybee on Australian eco-systems.

Those opposed to the application claim bumblebees have invaded every corner of Israel, including the desert, since their introduction there more than a decade ago. They point to the Dafni (1998) study that predicts bumblebees will colonise the country. However, Israeli and international scientists have refuted the methodologies and predictions of this study.

According to Rivka Offenbach, a vegetable consultant in both greenhouse and open field vegetables in the Arava region, the use of bumblebees is widespread over Israel, including the desert areas, but only in greenhouses. “The bees are in closed structures isolated by nets,” she said. “Although the structures are not absolutely sealed, and some bees get out of the greenhouses, there is no spread of these bees in nature, and they are not able to reproduce. We did not find any damage to other insects in the desert,” she added.

According to Dr Shimon Steinberg, principal entomologist with Bio-Bee Biological Systems in Israel and a world-renowned expert on bumblebees, there is no evidence to support Dafni’s conclusions about widespread establishment of B terrestris in Israel (pers. corresp.).

“There is no evidence of feral establishment of B. terrestris in Israel outside its natural range, ” he said.

Apart from Dafni’s ‘research’ on the infamous single tree outside his office, he also co-authored on an area ravaged by fire. Dr Steinberg says this was just re-invasion of limited natural resources after the fire. Dafni admitted that B. terrestris has declined there over the past two years.

Bio-Bee also export B. terrestris to Japan where it was introduced a few years ago – this is significant because this would presumably be a warm temperature species. Japan has a number of native Bombus species, but attempts to commercially mass produce them failed because they were too expensive. Apart from intial opposition from a flawed study, Dr Steinberg reports he is not aware of any problems with B. terrestris in Japan. This is also supported by reports kept in Japan of feral bees.

These aren’t the only issues conservationists have with the application to import bumblebees onto mainland Australia, but they are the most significant. I don’t want to underplay the significance of these issues, especially as it relates to weed species, but space is a premium and the impact of bumblebees on weed species is dealt with in Dr Griffiths’ Critical Study (page 42).

Conclusion
The use of bumblebees to pollinate greenhouse crops will result in a significant increase in yields and fruit quality, as it has done in Europe, the USA, Japan, Israel and New Zealand. Australia is one of the few developed countries that doesn’t have access to bumblebee technology.

Bumblebee technology has also led to improved Integrated Pest Management practices, resulting in a large reduction in the use of pesticides and other spray chemicals. These chemicals are not only expensive, but can compromise food safety, worker safety and the environment.

There have been limited trials using the blue-banded native bee to buzz pollinate tomato flowers, but it will be many years before researchers are able to commercialise artificial hives for greenhouse applications, if at all, by which time bumblebees may have already migrated to the mainland. There has been an appalling lack of communication between native bee researchers and industry, which only recently became aware of the three-year trial to comercialise artificial hives for greenhouse applications. Nearing the end of its first year, the trial has yet to publish any milestone reports.

A cost:benefit analysis of using bumblebees to pollinate greenhouse tomatoes has found bumblebee technology will reduce pollination costs for a 6,000sqm greenhouse by more than 50%. The saving on pesticides is another significant cost saving for growers, and good news for consumers and the environment.

With the accidental introduction of B. terrestris in Tasmania, the industry funded an EIS and CLIMEX study to determine the likely impacts on Tasmania’s flora and fauna as a yardstick to predict likely outcomes on mainland Australia should it be allowed import, or migrates from the island State. Both the EIS and CLIMEX study indicate that bumblebees will not dramatically change the status of native and agricultural eco-systems on mainland Australia, and its distribution will be limited to the wetter regions of Victoria, southern NSW and south-west Western Australia, mainly in urban gardens.

A further safeguard if B. terrestris is approved for commercial release in Australia, is to only import a clean species sourced from a temperate region. This strain, being adapted to a colder climate, would be less likely to survive the hot summers experienced in most parts of mainland Australia, including all of those areas identified in the CLIMEX study as potentially capable of supporting B. terrestris. However, this wouldn’t be the best option for operating in hot greenhouses.

The case against the application has been based on conjecture and questionable science, using material that only supports that position and ignoring all information to the contrary. For example, opponents fail to mention that there have been several attempts to introduce Bombus species onto mainland Australia, including Victoria in the 1930’s and NSW in 1891 and 1912 (these early introductions from New Zealand were probably temperate species, which is why they didn’t establish on the mainland).

Nonetheless, the conservation lobby has been successful in getting B. terrestris listed as a ‘Key Threatening Process’ in Victoria and New South Wales. However, attempts to list the bumblebee as a Key Threatening Process at a Federal level failed when the Minister for the Environment and Heritage, Dr David Kemp, declined the application on the basis of insufficient evidence.

Under the Environment Protection and Biodiversity Conservation Act 1999 (EPBC Act), a ‘Key Threatening Process’ is defined as any process that threatens or may threaten the survival, abundance or evolutionary development of a native species or ecological community. For example, predation by the European Fox is a key threatening process. One suspects that the spectre of foxes and cane toads must have loomed large in government thinking. I have been unable to find any reliable literature where B. terrestris has been listed as a pest, including those countries where Bombus has been introduced for greenhouse pollination.

There are many cautions in biological literature about drawing inferences from short-term observations like those demonstrated in the Hingston studies. In the scale of time, the ‘Swift Parrot Recovery Plan’, an initiative of Birds Australia, reports there have been only three breeding seasons over a 10-year period (1985-95) when food supplies were abundant. This was based on gum honey production figures. Even the three-year Environmental Impact Study is a short study period to arrive at objective conclusions;but this and the CLIMEX study are the best science we have in which to make predictions about the potential establishment and distribution of B. terrestris on the mainland should it be allowed import, or arrive by accident or design.

As a result of claims made by the conservation lobby, the very real issues concerning the impact of bumblebees in Australia have become clouded by emotive statements designed to galvanise public opposition against the application. This makes it very difficult to conduct serious scientific studies that will provide a solid basis for objective decision-making. Questionable science is also the reason why there is no consensus on the impact of honeybees on the Australian biota – the debate will continue!

Greenhouse growers and industry members have an opportunity to show their support for the application during Stage 2 of the process, when the ‘detailed report’ is posted on the DEH website for 20 days.

In the meantime, the industry can only hope that good science prevails.

About the author
Steven Carruthers is the Managing Editor of Practical Hydroponics & Greenhouses magazine, and Vice-President of the Australian Hydroponic & Greenhouse Association.
Email: editor@hydroponics.com.au

References
Carruthers, S. L. , 2003.
Plight of the Bumblebee
Practical Hydroponics & Greenhouses, March/April 2003, p22-30.

Dafni, A. , 1998.
The threat of Bombus terrestris spread. Bee World 79, 113-4

Griffiths, D. , 2004.
A Critical Study on the Introduction onto mainland Australia of the bumblebee Bombus Terrestris for the commercial pollination of protected tomato and other crops.
Practical Hydroponics & Greenhouses, July/August 2004, p42-59.

Hergstrom K. et al. , 2002.
Environmental research on the impact of bumblebees in Australia and facilitation of national communication for/against further introductions. Horticulture Australia Ltd. Project No. VG99033.

Hergstrom, K. , 2003.
CLIMEX TM Model to predict where Bombus terrestris will establish in Australia. Australian Hydroponics & Greenhouse Association.

Hingston, A. B. , 1997.
The impact of the large earth bumblebee, Bombus terrestris on Tasmanian ecosystems. University of Tasmania. Honours Thesis.

Hingston, A. B. and McQuillan, P. B. , 1998.
Does the recently introduced bumblebee Bombus terrestris threaten Australian ecosystems? Australian Journal of Ecology 23, 539-549.

Hingston, A. B. and McQuillan, P. B. , 1999.
Displacement of Tasmanian native megachild bees by the recently introduced bumblebee Bombus terrestrisAustralian Journal of Zoology, 47, 59-65.

McNally, R. and Horrocks, G. , 1999.
Landscape-scale conservation of an endangered migrant: the Swift Parrot (Lathamus discolor) in its winter range. Biological Conservation 92, 335-343.

Manning, R., 1997.
The honey bee debate: a critique of scientific studies of honey bees, Apis mellifera, and their alleged impact on Australian wildlife. Victorian Naturalist 114 (1), 12-22.

Rees, S., 2003.
‘True blue’ bees with a buzz, Practical Hydroponics & Greenhouses, July/August 2003, p40-47.

Steinberg, S., 2004.
Bombus terrestris for natural pollination: 14 years of commercial application in Israel. Practical Hydroponics & Greenhouses, July/August 2004, p60-63.  Ω

PH&G July-August 2004 / Issue 77

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