Leafcutter Ant

Lore & Background

The immediate ancestors of bees were stinging wasps in the family Ammoplanidae, which were predators of other insects. The switch from insect prey to pollen may have resulted from the consumption of prey insects which were flower visitors and were partially covered with pollen when they were fed to the wasp larvae. Based on phylogenetic analysis, bees are thought to have originated during the Early Cretaceous (about 124 million years ago) on the supercontinent of West Gondwana, just prior to its breakup into South America and Africa. Genomic analysis indicates that despite only appearing much later in the fossil record, all modern bee families had already diverged from one another by the end of the Cretaceous. The Melittidae, Apidae, and Megachilidae had already evolved on the supercontinent prior to its fragmentation. Further divergences were facilitated by West Gondwana's breakup around 100 million years ago, leading to a deep Africa-South America split within both the Apidae and Megachilidae, the isolation of the Melittidae in Africa, and the origins of the Colletidae, Andrenidae and Halictidae in South America. The rapid radiation of the South American bee families is thought to have followed the concurrent radiation of flowering plants within the same region. Later in the Cretaceous (80 million years ago), colletid bees colonized Australia from South America (with an offshoot lineage evolving into the Stenotritidae), and by the end of the Cretaceous, South American bees had also colonized North America. The North American fossil taxon Cretotrigona belongs to a group that is no longer found in North America, suggesting that many bee lineages went extinct during the Cretaceous–Paleogene extinction event. Following the K-Pg extinction, surviving bee lineages continued to spread into the Northern Hemisphere, colonizing Europe from Africa by the Paleocene, and then spreading east to Asia. By the Eocene (~45 mya) there was already considerable diversity among eusocial bee lineages. A second extinction event among bees is thought to have occurred due to rapid climatic cooling around the Eocene-Oligocene boundary, leading to the extinction of some bee lineages such as the tribe Melikertini. During the Paleogene and Neogene periods, bee lineages expanded worldwide.

In Their Own Story

The oldest non-compression bee fossil is Cretotrigona prisca, a corbiculate bee of Late Cretaceous age (~70 mya) found in New Jersey amber. A fossil from the early Cretaceous (~100 mya), Melittosphex burmensis, was initially considered 'an extinct lineage of pollen-collecting Apoidea sister to the modern bees', but subsequent research has rejected the claim that Melittosphex is a bee, or even a member of the superfamily Apoidea to which bees belong, instead treating the lineage as incertae sedis within the Aculeata. The Allodapini (within the Apidae) appeared around 53 Mya. The Colletidae appear as fossils only from the late Oligocene (~25 Mya) to early Miocene. The Melittidae are known from Palaeomacropis eocenicus in the Early Eocene. The Megachilidae are known from trace fossils (characteristic leaf cuttings) from the Middle Eocene. The Andrenidae are known from the Eocene-Oligocene boundary, around 34 Mya, of the Florissant shale. The Halictidae first appear in the Early Eocene with species found in amber. The Stenotritidae are known from fossil brood cells of Pleistocene age.

Reader's Guide

Bees are best known for their ecological roles as pollinators and, in the case of the best-known species, the western honey bee, for producing honey, a regurgitated and dehydrated viscous mixture of partially digested monosaccharides kept as food storage of the bee colony. Pollination management via bees is important both ecologically and agriculturally, and the decline in wild bee populations has increased the demand and value of domesticated pollination by commercially managed hives of honey bees. Human beekeeping or apiculture (meliponiculture for stingless bees) has been practiced as a discipline of animal husbandry for millennia, since at least the times of Ancient Egypt and Ancient Greece. Bees have appeared in mythology and folklore, through all phases of art and literature from ancient times to the present day, although primarily focused in the Northern Hemisphere where beekeeping is far more common. In Mesoamerica, the Maya have practiced large-scale intensive meliponiculture since pre-Columbian times. Bees have the following characteristics: a pair of large compound eyes which cover much of the surface of the head; between and above these are three small simple eyes (ocelli) which provide information on light intensity; the antennae usually have 13 segments in males and 12 in females, and are geniculate, having an elbow joint part way along; the mouthparts are adapted for both chewing and sucking by having both a pair of mandibles and a long proboscis for sucking up nectar; the thorax has three segments, each with a pair of robust legs, and a pair of membranous wings on the hind two segments; the abdomen has nine segments, the hindermost three being modified into the sting; many bees are brightly colored, displaying contrasting bands of yellow, orange, or red against black, which function as aposematic signals warning potential predators that the insect may sting or otherwise defend itself.

Did You Know?

• Over 90% of bee species are solitary, including mason bees, carpenter bees, leafcutter bees, and sweat bees.
• The largest species of bee is Wallace's giant bee Megachile pluto, whose females can attain a length of 39 millimeters.
• The smallest bee species may be dwarf stingless bees in the tribe Meliponini whose workers are less than 2 millimeters in length.
• Bees are thought to have originated during the Early Cretaceous (about 124 million years ago) on the supercontinent of West Gondwana.
• The oldest non-compression bee fossil is Cretotrigona prisca, a corbiculate bee of Late Cretaceous age (~70 mya) found in New Jersey amber.