Linda Benedict | 3/6/2014 8:48:53 PM
Julie S. Leiby and John V. Westra
Varroa destructor, a mite that parasitizes honey bees, was accidentally introduced into the United States about 25 years ago. As it spread across the country, it killed honey bees, destroyed their colonies and created management challenges for beekeepers. Nearly the size of a pinhead, a female mite attaches herself to a honey bee and eventually enters the hive, where she finds a brood cell and lays multiple eggs on the pupae. The pupae soon develop with mites attached. The mites feed off of the bee’s hemolymph (similar to blood) until the pupae are weakened or dead. As more pupae and honey bees become infected, the colony is severely weakened and often dies. Evidence suggests this may be a contributing factor to colony collapse disorder. According to data from the U.S. Department of Agriculture’s National Agricultural Statistics Service, the number of honey bee colonies in the United States has declined substantially since 1986 – approximately the time Varroa destructor was discovered in the country.
Honey bees, which are not native to North America, were introduced by European colonists about 400 years ago. Today, honey bees produce about 147 million pounds of honey, with a production value of approximately $287 million annually. However, honey bees’ greater economic value to agriculture is in the pollination services they provide each year to a variety of crops. In addition to apples, melons, alfalfa seed, plums, avocados and blueberries, pollination by honey bees is an essential component of almond production. California almond growers are entirely dependent on honey bees pollinating almond blossoms each year to make an almond crop. If honey bees aren’t available at a critical, short period in the growing season, almond orchards cannot successfully produce.
Beekeepers have tried a variety of measures to prevent losses associated with the varroa mite. Some include nonchemical treatments, such as removing infected pupae, using screened floors and placing sticky traps on the bottom board of the hive to exclude or trap mites. Chemical treatments for killing mites, including fluvalinate and coumaphos, have limited future effectiveness, in large part because varroa mites appear to be developing resistance to these chemicals in certain areas of the country. Additionally, researchers have found that when colonies are treated with these chemicals, some honey bee queens suffer a high mortality rate or develop physical abnormalities and atypical behaviors. This is critical because each colony must have one queen to lay eggs that develop into bees. These bees carry half of the genetic traits of the queen and half of the genetic traits of the drone that fertilized the eggs.
Recent advances in bee breeding and methods for controlling varroa mites have contributed to a measured recovery of the beekeeping industry. One example of this work has been queens from a line of Varroa Sensitive Hygiene honey bees selected for hygienic behavior traits. Honey bees from queens with such traits, selected by researchers at the U.S. Department of Agriculture- Agricultural Research Service Honey Bee Breeding, Genetic and Physiology Laboratory in Baton Rouge, clean the hives, removing infected pupae and associated varroa mites. These VSH queens began to be released to commercial breeders and producers in 2001. VSH honey bees retain the commercial characteristics that beekeepers desire while also needing no chemicals for treating varroa mites.
For those beekeepers who have adopted this technology, varroa mite levels have decreased dramatically in their colonies. Since the release of VSH honey bees for beekeepers, however, the widespread adoption of this VSH technology has not occurred. This raises a question for researchers, Why haven’t more beekeepers adopted this technology? Part of the answer might be studying the reasons why some beekeepers have adopted this technology. If we know which characteristics or factors influence the decision to use this technology, we might be better able to develop outreach efforts tailored to increase adoption of this technology effective for managing varroa mites.
A survey was sent to commercial queen breeders across the country. These commercial queen breeders are firms that breed queens for honey bee production, which are then sold either directly to beekeepers (usually largerscale commercial operations) or to other firms that breed queens for resale to smaller, hobby beekeepers. Data from 108 respondents to the survey out of a sample of 228 queen breeders were gathered and analyzed. Of the 108 respondents, 50 reported using VSH technology.
A probit or limited dependent variable model was used to help identify factors that had a statistically significant influence on the adoption of the VSH queen technology. Among the many potential factors that might influence the adoption of VSH queens are risk preference, education level and household income. Results indicated that queen breeders who were risk averse or had a bachelor’s degree or higher were more likely to adopt VSH technology; these factors positively influenced the adoption decision. On the other hand, household income appeared to have a negative significant influence on the adoption decision, so that as income rose, commercial queen breeders were less likely to use VSH technology.
Specifically, with respect to the attitude of a queen breeder toward investment risk (risk averse), the odds of VSH adoption are 3.5 times higher for queen breeders who characterize themselves as risk averse regarding their investment decisions compared with queen breeders who are risk neutral or risk taking in their investment decisions.
Education was positively associated with VSH technology adoption. The findings indicated that for queen breeders with a bachelor’s degree or higher, the likelihood of VSH adoption is 3.6 times higher than for those queen breeders with only some college, technical school, high school or lower.
Counterintuitively, household income was negatively associated with VSH adoption by queen breeders. Substantial research in technology adoption tends to indicate that as income increases, the likelihood of an individual adopting an innovation increases. However, these research findings indicate that as household income increased, commercial breeders were slightly less likely to adopt VSH queens. Specifically, for an incremental increase of $30,000 in household income above the mean income level, the probability of adoption decreased by 26 percent.
These discoveries of the positive and negative factors associated with technology adoption will benefit the beekeeping industry because industry leaders can help better inform queen breeders and beekeepers about the benefits of VSH technology. Extension and outreach efforts can explain the potential effect of VSH on reducing the risk of colony collapse disorder and economic damages associated with varroa mites.
Julie S. Leiby is a graduate research assistant and John V. Westra is an associate professor in the Department of Agricultural Economics and Agribusiness
(This Article was published in the 2014 winter issue of Louisiana Agriculture Magazine.)