APIS Volume 13, Number 7, July 1995
In this issue
- Widening the Pollination Perspective
- Pollination Information Resources
- Pheromonal Attractants
WIDENING THE POLLINATION PERSPECTIVE
Dr. Keith Delaplane at the recent Beekeepers Institute at Young Harris, Georgia discussed a variety of non-Apis bees that are potential pollinators. He urged those present to become actively involved in helping to conserve these so-called "pollen bees" (see April 1994 APIS). Allowing fields to fallow and fence rows to grow up in wild plants, Dr. Delaplane said, will help conserve the vegetation all insect pollinators, including honey bees, need for forage. In addition, these practices will help preserve the soil nesting sites required by many solitary bees. This message should be spread by beekeepers, Dr. Delaplane concluded, because few others are knowledgeable enough to do the job adequately.
For rabid honey beephiles, some of Dr. Delaplane's remarks might have raised a few eyebrows. Historically, many are concerned only with the welfare of Apis. Other bees have often been relegate to the sidelines because they produce no honey. However, it is becoming clear that concentrating on honey bees as either the only pollinators in the environment or the most efficient is no longer tenable (see June 1992 APIS). That said, Apis mellifera still remains the principal manageable resource agriculturalists can use to increase yields and crop quality.
And there is mounting evidence (see March 1993 and January 1994 APIS) that growers are finally receiving the message beekeepers have been trying to communicate for many years. Simply put, pollination is just as important an input as irrigation, fertilization and pesticide application. Pollination is difficult to measure, however, and honey bee colony performance may not always be up to par. According to Dr. Eric Mussen, writing in his May/June 1995 From the UC Apiaries, the latter is likely to be a contentious topic. Growers, he says, want to rent highly populous colonies that cannot fail to provide 100 percent pollination.
Few farmers or average citizens are aware, Dr. Mussen says, that darkness, rain, heavy fog and winds more than 12 miles an hour (conditions prevalent during a series of winter storms in California) not only kept honey bees inside their hives, but also caused pollen degradation and the spread of plant diseases. These conditions resulted in production losses, according to Dr. Mussen, practically ignored until California cherries became priced four times higher than normal this shipping season. In spite of efforts to communicate a different message, however, the simple perception spread by The Wall Street Journal and other media sources prevailed, according to Dr. Mussen. The honey bees, and by extension the beekeeper, didn't get the job done.
Thus, it's up to the beekeeper, Dr. Mussen concludes, to inform growers and others about the problems associated with keeping honey bees and using them as pollinators. Many do not realize how much expense is involved in managing colonies, nor what other factors might affect pollination success, including environmental conditions and the role of alternative pollinators.
Both Drs. Delaplane and Mussen seem to agree. The beekeeper is in the best position to consult with growers not just about honey bee rental, but pollination problems in general. Thus, the day may have finally dawned for pollination to become the growth industry many predicted (See November 1993 APIS). In order to remain credible, however, apiculturalists must widen their pollination perspective. Instead of simply focusing on the management of honey bee populations, they should become experts in all facets of the pollination process, including the role played by other pollinators.
POLLINATION INFORMATION RESOURCES
I listed some principal pollination resources beekeepers could use in the March 1995 APIS. That issue concentrated on commercial honey bee pollination and contained some pointed remarks by David Green, publisher of the Eastern Pollinator Newsletter, P.O. Box 1215, Hemingway, SC 29554. Since then, other resources have become available.
One mentioned by Dr. Mussen in his newsletter (cited above) is a videotape released by the A.I. Root Co, The Honey Bee--A Grower's Guide. This program sells for $49.95; its catalog number is XV219. To order, call 1-800/289-7668 Extension 3219. He quotes the producers as saying, "What this video does for you as a pollinator, is guarantee a grower he is getting his money's worth when hiring you."
A Guide to Managing Bees for Crop Pollination has just been released by the Canadian Association of Professional Apiculturists (CAPA). Although concentrating on honey bees, this publication also contains information on other factors affecting pollination. The 34-page booklet contains seven chapters: Pollination, Pollinating Agents, Primary Insect Pollinator - The Honey Bee, Management of Bee Colonies for Pollination, Management of Alternative Bee Pollinators, Pollination Requirements of Specific Crops, Pesticide Hazards and Bee Pollinators.
Two sections are of particular interest. One discusses other insect pollinators and another focuses on pollination aids. According to the publication, although honey bees are the most important pollinator, alternatives do exist. However, the management of these pollinators is as varied as the insects themselves. The technology to rear the leafcutting bee, Megachile rotundata, is well defined, as is that for the orchard bee (Osmia), cultivated in Japan for apple pollination.
The bumble bee (Bombus) is an important pollinator of native plants because it has a long tongue, forages during cold temperatures and buzz-pollinates (sonicates the anthers, causing pollen discharge). However, the rearing practices for bumble bees are not easily undertaken by the novice. The best advice, according to the publication, is to provide nesting habitat and a wide variety of food plants these insects need to complete their reproduction.
In his remarks at Young Harris College, Dr. Delaplane recounted some of what he has learned about rearing bumble bees. Calling them, the "hamsters of the bee world," he has designed a nest box and is trying to get these insects to complete their life cycle under controlled conditions. Most bumble bee rearing currently depends on capturing wild queens in early spring, letting the colony grow and abandoning it to its natural senescence in the fall. Because these rearing practices are time-consuming and complex, each insect in a bumble bee nest pollinating tomatoes in greenhouses may be worth as much as $1.25!
As a pollinating aid, the publication describes the concept of using a pollenizer, a plant variety providing a source of compatible pollen for cross-pollination. The use of pollen inserts that automatically apply pollen to bees a the hive's entrance is also explained, as are techniques that reduce competition from other plants that may be blooming at the same time. Finally, there is the possibility of directing or luring bees to crops.
The latter is controversial and requires a good deal more study. According to the publication, directing bees to target crops is difficult if the flowering plants have little or no pollen or nectar available, or if the crops provide less reward than nearby forage. The best attraction occurs when the target crop's odor is incorporated into the colony's food supply. Although spraying sugar syrup on plants may increase the number of visiting bees, the publication concludes, this seldom results in more yield. More research is needed to prove that pollen odors from extracts attract bees to plants requiring pollination.
Of the substances used to lure honey bees to plants, only those based on bee pheromones appear to hold much promise, according to the publication. The queen produces a five-component Queen Mandibular Pheromone (QMP) that has been synthesized and is sold under the name FruitBoost(R) in Canada. The publication states, "QMP is mixed with water and sprayed on crops slightly preceding peak bloom. Research on apples, pears, cherries, cranberries and blueberries indicate that QMP is effective in increasing the number of honey bees foraging on these crops under a wide range of environmental conditions, orchard management systems and geographical locations." Unfortunately, there is no information provided for Phero Tech, Inc., the manufacturer of FruitBoost(R). My latest communication from this company in 1992 stated the address to be 7572 Progress Way, Delta, BC, Canada V4G1E9, ph 604/940-9944, fax 604/940-9433.
The CAPA publication, along with the pollinator's bible, Agriculture Handbook 496 (see April 1995 APIS), is an indispensable tool for the pollination consultant. The handbook continues to be available from both the Tucson Bee Laboratory, 2000 E. Allen Rd., Tucson, AZ 85719 and the Weslaco Bee Laboratory, 2413 E. Hwy. 13, Weslaco, TX 78596. The CAPA booklet can be purchased from the American Association of Professional Apiculturists (AAPA) for $5.00 each ($3.50 each in units of 10 or more) plus shipping costs. For details on ordering, contact Dr. Marion Ellis, University of Nebraska, Department of Entomology, P.O. Box 83583-0816, Lincoln, NE 68583-0816, ph 402/472-8696, fax 402/472-4687. See http://ianrwww.unl.edu/ianr/entomol/beekpg/aapapubs.htm for more information.
PHEROMONAL ATTRACTANTS
Besides the FruitBoost(R) mentioned above, several other pheromonal attractants have been marketed (see February 1991 APIS), Bee Here(R) and Bee-Scent(R). The evidence for how valuable these products are as pollination aids has been mixed. Two specific studies I have in my possession deal with the product Bee-Scent(R), manufactured by Scentry, Inc., P.O. Box 426, Buckeye, AZ 85326- 0090, ph 602/386-6737.
The first is by G. Elmstron and D. Maynard at the University of Florida, 1990, "Attraction of Honey Bees to Watermelon with Bee Attractant," Proc. Fla. State Hort. Soc. 103:130-133. These investigators found signs of increased bee activity at one location and that the bee attractant may have been responsible for early fruit set in southwest Florida. However, results on fruit quality were inconclusive. The authors concluded the use of the product might be beneficial when bee populations are low, during periods of cold, windy or overcast weather and/or if nearby plants were competing for the bees' attention.
A more recent study was done in North Carolina, J. Ambrose and co-authors, 1995, "An Evaluation of Selected Commercial Bee Attractants in the Pollination of Cucumbers and Watermelons," American Bee Journal 134:267-272. The authors found no increase in bee activity nor yield for either crop using two attractants, BeeLine(R) and Bee-Scent(R). They do note, however, that other investigators, including those in the first study mentioned above, did have more positive results.
Part of the reason for mixed results in these studies, the authors from North Carolina state, is that different kinds of "attractants" have been used. They can be divided into three groups: feeding stimulants [BeeLine(R)], those based on worker pheromones [Bee-Scent(R)] and others based on queen pheromone [FruitBoost(R)]. They conclude: "There is always the consideration that under marginal pollination conditions (adverse weather), that one or more of the attractants may serve as an 'insurance policy' for adequate crop pollination. However, even under that scenario the grower should evaluate the cost of treating a crop with the bee attractant as opposed to renting additional colonies of honey bees."
The complexity involved in carrying out and analyzing studies on bee attractants was subsequently brought out in a letter to the editor of American Bee Journal, published in the July 1995 issue. Dr. T. Ferrari takes the North Carolina researchers to task, stating in no uncertain terms that their recommendation not to use bee attractants was unwarranted. He said that because no "pollination problem" had been identified, there was little possibility to evaluate improved foraging by bees on the crops in question. In addition, he suggested that "no matter how tedious," the amount of pheromone in tests before and after treatment should be measured. Sincerely,
Malcolm T. Sanford
Bldg 970, Box 110620
University of Florida
Gainesville, FL 32611-0620
Phone (904) 392-1801, Ext. 143 FAX: 904-392-0190
BITNET Address: MTS@IFASGNV
INTERNET Address:MTS@GNV.IFAS.UFL.EDU
APIS on the World Wide Web--
http://gnv.ifas.ufl.edu/~entweb/apis/apis.htm
Copyright (c) M.T. Sanford 1995 "All Rights Reserved"
