Posts Tagged ‘ import ’

Issue 88: Bumblebees for Pollination of Greenhouse Tomato Crops in Australia

May/June – 2006
Author: Steven Carruthers

STEVEN CARRUTHERS provides an update on the Australian Hydroponic & Greenhouse Association’s application to import bumblebees (Bombus terrestris) onto the mainland to pollinate greenhouse tomato crops Crops in Australia.

Following a review period of 40 business days on the Department of Environment and Heritage (DEH) website to allow the public and industry stakeholders the opportunity to comment, the Australian Hydroponic & Greenhouse Association (AHGA) plans to proceed ahead with its application to allow the import of bumblebees (Bombus terrestris) on to the Australian mainland to pollinate greenhouse tomato crops.

The industry’s application to import bumblebees follows an eight-year investigation including a three-year Environmental Impact Study (EIS) following a national workshop to identify all the issues of concern to various groups, and an independent ‘Climex’ study to identify possible impacts on the Australian mainland. The AHGA engaged one of the world’s leading bumblebee experts, Dr Don Griffiths, from the United Kingdom, whose definitive study of all the key questions posed by both sides of the argument concludes with the following statement:

“If one considers all the facts given, then the case is clearly made to permit the commercial introduction of Bombus terrestris onto mainland Australia.”

Bumblebees were accidentally introduced into Tasmania in 1992. Although they have spread throughout the island State, studies have shown that they are mainly found in urban areas rich in imported floral species, the preferred plants of bumblebees. The EIS study found no adverse impacts to warrant their exclusion from the mainland to pollinate commercial greenhouse tomato crops.

“Bumblebee technology is available to almost every country on the planet except Australia.”

Currently, growers pollinate their tomato crops three times a week using mechanical hand-held vibrators touching each plant. The industry estimates that it costs Australian growers $25,000 to manually pollinate 1 hectare (10,000sqm) of tomatoes, against $7,000 for bumblebee pollination, a saving of $18,000 per hectare. This is a 72% saving or in excess of $8 million annually industry-wide, as well as improving tomato yields, quality and shelf life. Without bumblebee technology, Australian greenhouse tomato growers say they will be unable to compete with cheap tomato imports.

“Bumblebee technology is available to almost every country on the planet except Australia,” said AHGA President, Mr Graeme Smith.

“Pressure from NZ imports, with recent approval for importation of Dutch produce, and with Chinese imports on the horizon, means that if the industry hopes to match production standards with our international competitors, all of which use bumblebees, then access to this technology is mandatory.”

Mr Smith said: “The industry is not proposing to release bumblebees into the Australian environment. They will be confined to sealed greenhouses within hives specially fitted with a queen excluder device that allows only non-breeding worker bees into the crop. The technology is currently used in the USA and Canada to prevent the eastern bumblebee species, Bombus impatiens, from establishing in the west of that continent.

“On the basis of existing knowledge and climate restrictions, in the unlikely event of escape or accident, the AHGA predicts any chance of bumblebees establishing in Australia’s harsh environment to be very limited and transient,” said Mr Smith.

“Spurious claims that bumblebees are another cane toad or fox are clearly false.”

According to the industry’s research, bumblebees prefer exotic (introduced) plant species (90%), compared to native species (only 10%); therefore, there is little likelihood of any competition for floral resources.

Mr Smith added: “Spurious claims that bumblebees are another cane toad or fox are clearly false,” and he cited many positive examples of species imported into Australia such as the leafcutter bee, European honeybee, sheep, cattle, brown trout, and even the dung beetle without which inland Australia would be a mess. While Australia has its own native dung beetle, it simply can’t cope with the tonnes of dung expelled by imported animals on a daily basis. The dung beetle is also a friend in the cities of Australia, ridding parks of tonnes of dog droppings that occur every day.

Returning to bumblebees, the AHGA proposes to import only certified pathogen and parasite-free bumblebee stock from reputable producers. Mr Smith said that any parasite or pathogen that has been associated with Bombus terrestrisis unique to bumblebees and poses no risk to Australian honeybees or native bees.

“Despite the gloom and doom scenario painted by a few individuals, no adverse effects have been shown there.” (in Tasmania)

The industry’s detailed report points to previous releases of bumblebees on the Australian mainland in the 1800’s and 1900’s that failed to colonise. Although there were no studies conducted on these releases, Australia’s harsh climate and lack of all-year-round floral resources, are thought to be contributing factors why they didn’t colonise. In their native distribution range, bumblebees are only found between latitude 60°N and 30°N, which helps explain why they have established in New Zealand and Tasmania which enjoy similar climates. Ants are also thought to be a contributing factor for the failure of previous bumblebee releases on the mainland to colonise. Unlike honeybees that build their hives above the ground, bumblebees are ground nesters, usually in damp areas.

In the event that bumblebees do establish on the mainland, an AHGA-funded Climex study indicates that any distribution will be confined to the cooler, wetter areas and limited to Victoria, just over the NSW border, and the southwest corner of WA.

“First reported sightings of bumblebees in Tasmania, which has a much more suitable climate, were around 1992,” said Mr Smith. “Despite the gloom and doom scenario painted by a few individuals, no adverse effects have been shown there.

“Bumblebees have been present in New Zealand for over 100 years, and are popular with farmers and public alike. Over this time there have been no definitive examples of any negative effect on that country’s native flora and fauna, and reports of a negative impact in Israel and Japan are false, having been based on poor and limited research,” said Mr Smith.

“The threat to the survival of the Swift Parrot has everything to do with land clearing, wood chipping and habitat destruction.”

Mr Smith added that any threat to endangered Australian birds is pure speculation. While there has been some suggestion that bumblebees are a threat to the survival of the Swift Parrot, the EIS has shown a low bumblebee visitation rate (2%) to favoured blue gum flowers, compared to 56% for honeybees and 25% for birds.

“The threat to the survival of the Swift Parrot has everything to do with land clearing, wood chipping and habitat destruction,” he said.

Overseas experience has shown that bumblebees work long hours and have a high flower visitation rate, around 450 flowers/hr. They buzz pollinate, can tolerate the physical conditions existing within a commercial greenhouse, are housed in trouble-free hives suitable for delivery to growers, breed in sufficient numbers to provide the correct ratio of bees to open flowers (240,000 flowers/ha/week), and are available 52 weeks per year.

“Can they (blue-banded bees) be reared cost-effectively, 52 weeks a year?”

Mr Smith said that while native bee research is encouraged, the industry must be practical. Current research to develop a commercial solution using native blue-banded bees is now in its third year, and still a long way from developing economically viable commercial hives for pollination.

“Will this ever be accomplished, and if so, in what time frame 5, 10, 20 years,” questioned Mr Smith. “Can they ever hope to meet the requirements of a rapidly developing and expanding high technology industry? Can they be reared cost-effectively, 52 weeks a year? How much research money will be needed, with the possible result of no suitable alternatives at the end of it all?”

Although native bee researchers have been successful in breeding small numbers of blue-banded bees using clay and brick mortar nests in the greenhouse, it is not economical to ship mortar hives around the country. Researchers speculate that growers will maintain mortar hives within their greenhouse, which will be replenished regularly; however, the growers I have spoken to say they are simply replacing one labour cost for another and it is unlikely they will maintain permanent hives. By comparison, bumblebees are delivered in cardboard boxes which come with feeders for the life of the artificial hive – for bluebanded-bees, growers will be required to replenish feeders strategically located throughout the greenhouse. For bumblebees, all the grower is required to do is position the hive and open the cardboard entry/exit flap.

There is also a concern about the unusually large breeding area (5,000sqm) required to supply the entire hydroponic greenhouse tomato industry with fresh native bees on a monthly basis. The industry is currently going through expansion with at least another 24 ha of greenhouse production area due to come online during 2006. Presumably, this breeding area would need to expand to meet the future demand of the industry.

There are still many questions to be answered, and no certainty researchers will be able to deliver a commercially viable native bee alternative to bumblebee technology; if at all.

The AHGA believes it has a strong case for allowing the distribution of secure hives of B. terrestristo mainland greenhouses, and it hopes that the misinformation campaign against bumblebees will not prejudice the final outcome. To date, conservationists have been running a strong campaign against the application and they have succeeded in having the bumblebee listed as a ‘Key Threatening Process’ in Victoria and NSW; however, the Federal Government declined to support their application due to “insufficient evidence to support the claim”.

There have been public claims reporting that bumblebees are a pest in other countries, whereas a search of the scientific literature shows that the bumblebee is not regarded as a pest anywhere in the world. ABC Landlinealso incorrectly reported (12 February) that the Australian Quarantine InspectionService (AQIS) had already rejected an application to import bumblebees, when the application submitted by the AHGA is still with the DEH and has not yet been passed on to AQIS. These incorrect reports should be of real concern to industry for the success of its application.

Cost:benefit calculation
Bumblebees are very efficient pollinators. They can deliver up to a 28% increase in production in ideal conditions, at a cost of only 1% of production. If we assume even 10% improvement, then growers can make their own calculations:

Greenhouse size x Average Yield per m 2 x Average Gross Return per kg x 10% = improved yield by bumblebees.

Sample calculation for 4000sqm:
4,000 x 45kg/sqm x $3.00 x 10% = $54,000
Plus labour savings above – 4,000 x $1.80 = $7,200
Total saving = $61, 200

NOTE: These costings do not factor-in improved working conditions and worker safety that can flow on from the use of bumblebees.

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

PH&G May/June 2006 / Issue 88

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