Bees visit flowers for nectar or pollen and transfer pollen between plants. Bees play a key role in plant pollination.
Not all bees live in large colonies like honeybees. Most native bee species are solitary. Honey bees, brought to the American continent by Europeans, have been managed for honey production and crop pollination for hundreds of years. Of 20,000 native bee species in the world only six species produce honey. But some native bee species are being used for a much more important purpose – pollination services in farms and orchards. (Honeybee vs. native bee. Kathy Keatley Garvey, UC)
Female bees take pollen to their nests to make pollen balls or ‘bee bread’ for their developing young. Bees have complete metamorphosis with four developmental stages in their life cycle: egg – larva – pupa – adult. Bee Metamorphosis.jpg
Egg and larva on pollen balls (‘bee bread’) (Dennis Briggs)
Pupa in an underground brood cell (Robbin Thorp)
An adult mining bee feeding on an aster flower (John Ascher)
Bees work hard to collect pollen and nectar but they share the fruits of their labor with us. ~30% of fruit, vegetable and nut crops depend on bee pollination to set fruit. So, every third bite of food that we take can be traced back to bee pollination!
A balanced breakfast thanks to bees!
Our world without bees…
Bee flight ranges depend to some extent on their body size which depends on the species. Most bees forage for food in the day but some are active at night. Bees that can see in dim light are called crepuscular bees.
Bees see in the visible as well as the ultraviolet light spectrum while humans see only in the visible light spectrum.
Three tiny Ocelli on top of this sweat bee’s head complement two large compound.
(USGS Native Bee Inventory Monitoring Lab)
We may see a colorful flower while bees see nectar guides (patterned speckles) on petals!
These flowers are seen with visible (left) and UV light (right). (Wikipedia.org)
What other senses do bees use to find nectar?
They smell with their antennae like this long-horned bee! (Sam Droege)
Generalist bees visit many plant groups for their pollen. Bumble bees shake their abdomens to ‘buzz’ pollen from flowers by ‘sonication’.
Specialist bees obtain pollen from a narrow group of plants. Squash bees like pumpkin, cucumber, and zucchini; while cactus bees prefer prickly pear cactus flowers.
Bee plants http://Wildflower.org
All bees have the same body type with three segments: head, thorax, and abdomen. The thorax has three pairs of legs and two pairs of membranous wings (Hymenoptera).
Many bees are tiny so it’s hard to distinguish them from wasps or flies visiting flowers. Observe what they’re eating, their body shape and their wings. (Wikimedia)
Bee, Wasp or Fly?
- Bees are herbivores; they eat only nectar and pollen
- Wasps are carnivores that mostly eat insects but also nectar
- Flies are detrivores (eat decaying plants/animals) that can consume nectar
- Bees/wasps have 2 pairs of wings & long antennae; flies have 1 pair & stubby antennae
- Bees have rounded bodies; wasps have long narrow bodies
- Bees are hairier than wasps or flies; only bees have branched hairs (pile)
Native Bee Diversity
Since 2012 the Jha Lab has studied pollinators from 60+ sites in South, Central and Northern Texas. About 880 native bee species have been described in Texas.
Bees are as small as a rice grain or bigger than popcorn. Traits such as color and ‘hair’ location are used to identify bees.
Six Texas Bee Families
- Apidae: large & small carpenter bees, bumble, stingless, cactus, long-horned bees
- Miner bees like Diadasia (Andrenidae) dig tunnels with chimneys to build nests
- Some Colletidae bees make plaster by chewing leaves into spit balls to line their nests
- Tiny sweat bees in the Halictidae drink human perspiration for its salt (metal-green)
- Megachilidae leaf-cutters use mega mouth-parts to cut & drag leaves to their nest
- Some Melittidae bees such as Hesperapis collect plant oils in dry climates (marigold)