Milkweed in Bloom

Milkweed is an important bee plant that provides both nectar and pollen. It is also well known as being the sole source of larva food for the beautiful monarch butterfly. This common, climbing vine is attractive to a number of different species of insects. The plant that I encountered on the disturbed margin of a clover field was being visited by numerous monarchs as well as honey bees and native solitary bees. Click on the photo to see a foraging honey bee approaching a cluster of milkweed flowers. Pollination of milkweed is accomplished by insects, but the procedure is slightly different from that of most other flowering plants. Milkweed pollen is held in pollen sacs instead of individual grains. These are located in slits in the flower’s anthers. When an insect steps into a slit, a pair of pollen sacs is attached to the insect; and pollination occurs when the insect steps into the anther slit of another flower.

Milkweed is a plant of varied folk medicine and cultural uses. After being pollinated by an insect, the fertilized milkweed produces seed, covered in fine filaments and held in a pod. The seeds are distributed by the wind. The filaments provide greater insulation than down feathers. Native Americans collected milkweed nectar as a sweetener. The sticky, white sap of milkweed is used as a folk remedy for removal of warts. It is applied several times a day until the wart falls off. Milkweed sap is used in another folk remedy as an effective treatment of poison ivy rashes. The milkweed plant is toxic; animals eating one tenth their body weight in milkweed may die. Milkweed is an interesting plant that is often included in pollinator gardens. Many gardeners welcome milkweed to support the bees and the monarch butterflies.
--Richard

Small Hive Beetle Invasion

The small hive beetle probably entered the United States like many invasive species as a stow-away in a cargo ship. The unintentional migration of this honey bee pest from Africa occurred about a decade ago. The beetle entered the Arkansas Delta about 2004. As the beetle is virtually unchecked by any natural predators, it spread rapidly to almost all parts of the country. This invader is thought to be capable of flying for miles, and it is moved with migratory bee hives on trucks.

The small hive beetle is an opportunistic invader of bee hives. The adult beetle, about a third the size of a lady beetle, can live inside the bee hive, protected from the bees by a hard covering. The beetles often occupy a healthy hive and wait to move to a weakened, stressed, or queen-less hive. The small hive beetles are attracted to a stressed hive by the alarm pheromone given off by honey bees. Inside the stressed hive, the small hive beetles lay eggs. The beetles develop through a full four-stage metamorphosis like the honey bee. It is the second stage of the small hive beetle’s development that damages the honey bee hive. The small hive beetle larvae eat everything in the hive: comb, brood, pollen, and honey. They turn the hive into their waste, a wet, brown slime with the odor of fermenting oranges. The odor attracts small hive beetles from miles around and repels honey bees. Bees will abandon the slimed hive, often in a manner of a few days. Click on the photo of small hive beetles starting to take over a queen-less hive. The first sign of trouble that I detected was bubbles developing in the fermenting honey in the supers above the brood nest. Fermenting honey is in the cells to the upper left. Caught early, before the combs are slimed, the beetles may be killed by freezing the frames.
--Richard

Honey Bees are Survivors

Through the colony’s social structure, honey bees are highly adaptable. I am getting reports from across the Mid-South of bee colonies responding to the unseasonal cool and damp weather we encountered during this spring and summer. A number of beekeepers report honey production is far below that of past years. It appears that the honey bees are utilizing survival tactics as a result of the diminished nectar flow. I have observed some queens stopping their egg laying. The colony controls the queen’s egg laying by restricting the queen’s diet. I have also observed colonies killing off their drones earlier in the summer, an event that usually doesn’t occur until the frost of late November. Beekeeper Shirley Murphy reported robbing of her Tennessee River bees. She was able to control the robbing behavior by placing an entrance reducer in the hive. The reducer gives the colony’s guard bees the advantage over the robbers, because the guards have less area to defend. The colony that was being robbed also appears to have resorted to cannibalism of the drone brood. This behavior makes the colony more survivable by returning nutrients to the colony and reducing the feeding requirements for the brood. The honey bee’s social order is thus capable of adjusting the colony’s population and food requirements in response to the reduction in available food.

Today’s photo is of false indigo, a member of the important bee plant family, the legumes. If you click on the picture, you can see that it is being worked by one of the native pollinators, a bumblebee. Even though the false indigo grows in one of my bee yards, today I found it being worked by bumblebees and butterflies. Honey bees forage wherever there is an abundance of nectar and a concentration of sugars. They will choose to forage the strongest nectar sources or rob a weakened hive.
--Richard

Summer Hive Inspection

In the summertime, hive inspections are made less frequently. Because the honey supers are placed atop the hive bodies, it may mean moving hundreds of pounds of equipment just to get to the brood nest. By August, the hives have between two and six medium-size honey supers in place. Each super may weigh up to sixty pounds. The heat and humidity in the Delta are true limiting factors in the beekeeping task. Still, there are times when it is necessary to look into the brood nest and evaluate the hive. If there are dead bees on the ground in front of the hive or a lower than normal population of bees inside the hive, a thorough inspection hive is made. This year’s excessive number of rainy days made for some sporadic nectar flows. Some nectar producing plants just didn’t produce nectar during their bloom period simply because the cloud cover reduced photosynthesis. During these times of dearth, some bees, particularly those of Eastern European lineage, revert to survival instincts and stop brood production. These cool-climate races of bees survive during long winters and nectar dearth by stopping brood production, which consumes large amounts of food.

Click on the photo, taken in the brood nest of a hive showing a low population of bees in the honey supers. There are plenty of bees in the brood nest area. All three castes of bees can be found: workers, drones, and the queen. A drone is in the upper, right quadrant; the queen, marked in green, is to the left of center. Capped brood, holding pupae, is present; but there are no eggs or open larvae to be found. It appears that the queen has not been laying eggs for at least nine days. This colony should survive. With a strong nectar flow from fall wildflowers, or my supplemental feeding of sugar syrup, the queen should start laying eggs again and replenish the colony population. This year’s honey crop will be diminished, though.
--Richard

Grain Sorghum in the Delta

Grain sorghum, also called milo, is a cereal grain grown in the Arkansas Delta. In places, large tracts of the short, heavy-bodied plants grow. The plants are topped with large seed heads. Grain sorghum is used in the production of food, fodder, sorghum molasses, alcoholic beverages, and biofuels. Grain sorghum, like rice, wheat, and corn is a grass. The grasses are wind pollinated and don’t need insects like honey bees for pollination. They therefore don’t need to offer nectar or pollen to entice bees. The other two major crops of the Delta, soybeans and cotton, are flowering plants. They both offer the honey bees a reward of nectar and pollen to attract the insects for pollination, a necessary step for seed production and plant reproduction. Soybeans and cotton are major sources of nectar for honey production. The acreage planted in grain sorghum—or rice, wheat, or corn—is like a desert to the honey bee. A bee flying over a large grain sorghum field will find nothing to eat or bring back to the hive.

Farming in the Arkansas Delta is an example of modern industrial agriculture. It is highly efficient in producing large amounts of high value food and fiber crops. For the honey bees and other pollinators, the modern farm can be a harsh environment. Large tracts of a single plant offer little forage except during the short time that that particular crop is in bloom. If the crops are grasses, the crops offer no food to the pollinators. Modern farm fields are often designed without a weedy margin. The crops are planted to the very edge of the field and borders are maintained without weeds. This arrangement often results in a shortage of year-around food and habitat for the pollinators. Information on protecting the pollinators can be found on the National Academy of Sciences web site: http://dels.nas.edu/pollinators/.
--Richard

Evening Primrose in Bloom

The evening primrose is a nighttime blooming wildflower. While I have observed it being worked at dawn by honey bees foraging for pollen, it primarily attracts other pollinators. I have seen flies, moths, butterflies, and solitary bees working evening primrose early in the morning. Luna moths, the size of small birds, work the flowers at night. Click on the picture to see a blue orchard bee foraging for pollen in an evening primrose blossom. The fast flying and gentle blue orchard bee strikes the flower hard and then scrubs its body around inside of the blossom. Its active movement inside the flower makes the blue orchard bee an effective pollinator. The native blue orchard bee carries its load of pollen on hairs on the lower side of the bee’s abdomen.

The current research program that the USDA is funding to study bee health involves both honey bees and other pollinators. Bees that are not honey bees, called non-apis bees, are being established in managed arrangements at each of the seven bee yard locations in the nation-wide study. The purpose of this study of these non-apis bees is to determine if there are cross infections between the species. Bumble bees are being sampled to check for stress and, hopefully, increase efficiency of their use as pollinators. The investigators are also studying the effects of the neonicitinoid pesticides, like Imidacloprid, on the non-apis bees. They are looking into the sub-lethal effects of these pesticides and any effects caused by their residues. The non-apis bees, like the blue orchard bee, serve an important role in helping to pollinate flowering plants. They help the honey bee complete the pollination required to produce fruit and seeds for wildlife and humans.
--Richard

Bee Health Studies

Honey bees have been declining in numbers for the past three years. This year’s loss is slightly less than the previous two year’s losses of nearly a third of the nation’s bees each year. Yes, it’s been three years since the honey bees were first reported as leaving their hives in what is called Colony Collapse Disorder; and we still don’t have a known cause. The solution of the mystery has proven difficult, as there are numerous complex factors affecting honey bee health. The good news is that Colony Collapse Disorder brought enough attention that bee health is now receiving some long needed scrutiny. In the first year of a four year study headed by the University of Georgia, researchers have established seven apiaries across the country to study the genetics of the Varroa mite, honey bee viruses, Nosema parasites, miticides, and the effects of farm pesticides. They are also trying to encourage local production of queen bees to counter the effect of a lack of honey bee genetic diversity. The Environmental Protection Agency and the USDA have narrowed the potential causes of honey bee disease to six: new and re-emerging pathogens, pesticides, habitat loss, pests that infest bee hives, commercial bee management practices, and nutritional stress. Imidacloprid, a systemic insecticide in widespread use, has been suspected by beekeepers as being a possible cause of Colony Collapse Disorder. Its manufacturers claimed it was safe for bees. It may now be independently tested.

While examining my bee yard at the Memphis Botanic Garden, I walked over to the farmers market and ran into Marge and Joann. They come out each week, buy our honey, shop for fresh produce, and visit. They always ask about the bees. Hopefully, we will be able to start reporting some progress resulting from the studies in bee health. The University of Tennessee has placed extensive honey bee health information on the USDA web site eXtension.org. Follow the path: Resource Areas-Farm-Bee Health.
--Richard