DOVER-FOXCROFT, Maine — While bee populations are under stress from climate change, habitat loss, invasive species, pests and pathogens, there are actions farmers and gardeners can take to make their lands more bee-friendly.
In Maine, there are 276 species of bees, which are divided into six main families, said Jennifer Lund, Maine state apriarist for the Department of Agriculture, during a presentation at a pollinators event, held in mid-August on the Law Farm, owned by the Piscataquis County Soil and Water Conservation District. The six families are: Apidae, which include bumble, carpenter, cuckoo and honey bees; Megachilidae, include leafcutter and mason bees; Halicitade, which include halictids and sweat bees; Colletidae, which include plasterer, cellophane, polyester and yellow-faced bees; Adrenidae, which include miner and sand bees; and, Mellitidae, which include mellitids and oil collecting bees.
The Apidae bees represent some of best known bee species in the state, Lund explained. There are 17 species of bumblebees common to Maine. They are cavity nesters, which use old mouse burrows to form colonies of up to several hundred individuals and they are some of the first bees to begin foraging in the spring. Colonies only survive for one year.
There are 49 species of leafcutter and mason bees. They are tunnel nesters, which build nests from reeds and straw. Lund added that leafcutter and mason bees will eagerly occupy “artificial nesting blocks.” Mason bees emerge in the early spring and are important pollinators of fruit trees.
The Halictidae family of bees are solitary soil nesters. The prefer sandy soil on flat ground. Lund said the females are “generalist foragers and carry pollen on their hind legs or thorax.”
The Colletidae family are soil nesters, but will nest in artificial nesting blocks. They are also generalist feeders and collect pollen and nectar on their stomach, Lund said.
Miner and sand bees are also among the first bees to emerge in the spring, “right around the time that the trout lily comes up,” Lund said. They are soil nesters, and include both specialist and generalist foragers. They look like small honey bees at first glance.
The Mellitidae family include two general types in Maine, and represent a small, very uncommon bee family, Lund said. They collect loosestrife oil, which they use to line cells within their ground nests. They also feed the oil, mixed with pollen, to their young.
“One of the things that we can do is provide forage and nesting on our properties,” Lund said. “You don’t need a lot of property to do that. For forage, you can provide flowering plants. You should choose native flowering plants or non-invasive, non-native plants.”
Bees are attracted to flowers with bilateral symmetry, and prefer blue, purple, yellow and white blooms, Lund said. Since bees see colors in the ultraviolet spectrum, they cannot see red.
“You want to make sure when you plant your flower garden or your pollinator garden that you have a variety (of) plants blooming at any given moment,” Lund said. “You want at least three things blooming at any time, with different heights, because some of our bees are teeny-tiny, and you want to make sure that you have flowers that are down low and you also want high plants, like sunflowers.”
Lund said throughout the spring, summer and fall, pollinator gardens need to have something blooming. No blooms means no food, so bees will move on to find another food supply.
“The other thing that you can do is provide nesting resources,” Lund said. “About 30% of our bees are ground nesters. They need compact, sandy soil that’s relatively dry — places like gravel pits. So for our academy nesters, bumblebees and honey bees need a large area to establish colonies.”
About 70% of the bees are stem nesters. Plants, such as raspberry, have a “pithy center, and they will drill down into those,” Lund said. Bamboo, Japanese knotweed and sunflowers also attract stem-nesting bees. Habitats for stem-nesting bees can be made by simply drilling holes into 2-by-4 lumber or by using a bundle of paper straws.