Bees & Wasps & Flies – Discover-Nature

Bee An Early Pollinator

There are over 20,000 species of bees world-wide, and more species are found every year. Bees are important pollinators, especially in early springtime. Other pollinator species abound, and all are important to the life-cycle of flowers, but bees are thought to increase seed production by about 70%.

^{Dandelions on day 100 by Mike Deal, Apr 2010}

The bees we see in our gardens are all adults, emerging from their nests between early spring and late summer. The first to emerge are the bumblebees. They have wingbeats of about 200 strokes per minute and a metabolic rate that is double that of a hummingbird, allowing them to generate plenty of body heat to stay warm during cool spring weather. Orchard bees are the next out as soon as daily temperatures stay in the mid-50s. Native honeybees may also come out at about this time, but imported bees cannot fly in temperatures less than 60˚F. Early blooming flowers including dandelion, jewelweed, aster, goldenrod, and clover, are important sources for pollen and nectar in spring.

^{Honeybee covered in zucchini pollen by John Kimbler, Getty Images}

As crop plants start to flower, including fruit trees and vegetables, a large pollinator workforce is needed. Almost one-third of the food consumed by humans comes from plants requiring pollination. As pollen is collected by bees, the grains are spread over the bee’s body, allowing some of those grains to rub off and pollinate subsequent plants as the bee follows a route visiting various flowers. Adult bees feed mostly on nectar, eating very little of the pollen they collect. Pollen is brought to the nest to feed their young.

^{Bumblebee in flight with loaded corbicula by mirceax, Getty Images}

Honeybees and bumblebees have a bare spot on their back leg called a corbicula, surrounded by inward curving hairs. As pollen is collected from each flower, it is scraped into this holding area, which may amount to 20% of their body weight while in flight. After landing, a bee grips a flower tightly with its jaws and legs. Snuggling close to the anthers, the bee vibrates and dances to disrupt the pollen inside and let it fall onto their bodies. They proceed to groom all the pollen grains into the corbicula before moving onto the next blossom. When the corbicula full, the bee will fly straight to the nest, unload all of the pollen, and return immediately to where they left off to collect more.

^{Honeybee collecting pollen into scopa by baianliang, Getty Images Signature}

Other bees store pollen in scopa, tufts of hair on their legs and abdomens. As pollen covers the bee during its flower visits, the four front legs are used to scrape the pollen down past their abdomen where the two back legs pack it into the scopa. Some bees may carry the pollen dry, and others may mix in a little nectar to form a dough-like substance that easily sticks to their body hair.

Brown honeybee heading into narrow opening by Gregory Johnston

Buzz pollination video @ This Vibrating Bumblebee Unlocks a Flower’s Hidden Treasure | Deep Look

Pollen collection has resulted in the development of several adaptations found among many bee species. Electrostatically charged body hair attracts pollen. The charge is a result of air moving across the body while the bee is in flight. When plants are small enough that only the bee’s head fits inside, hooked hairs on faces and under chins allow easy pollen collection. Some plants keep pollen in anthers, long tubes that must be turned upside down and shaken to release the pollen. Many bee species use buzz pollination, hanging onto the anthers to tip them, then vibrating their wing muscles to loosen the pollen, allowing it to fall on themselves.

^{Red head bee, Pachyprosopis eucyrta, licking up nectar by Jean&Fred Hort, Mar 2014}

Nectar provides carbohydrates in the form of sugars and amino acids. Bees use their tongues to lick it or suck it up. Several species have longer tongues for use on deep-necked flowers. Honeybees collect nectar and bring it back to their hives to store it. Over time, some of the water content evaporates, forming honey. This is used as food over winter or at times when other food is scarce. Some bumblebees have been shown to also collect and return nectar to the hive, but don’t create true honey. This nectar is used as nourishment for the hive-bound queen only, not as a food source for the entire colony.

As we begin to see the many blossoms of spring and summer, remember that adult bees are only out in our gardens for a short period of their lives. We can assist their work as pollinators by allowing early spring flowers to finish their blooms before cutting them down.

^{Bumblebee on flower from skitterphoto, Pixabay}

^{Bumblebee collected pollen by vinkirill, Getty Images}

Common Milkweed Pollinators

Observe dozens of pollinator species on one plant

Butterfly weed, Asclepias incarnata, with bee, genus Andrena, by DonArnold 2020

Swamp milkweed, Asclepias incarnata, and monarch butterfly, Danaus plexippus by NatureNerd 2015

There are 15 species of milkweeds in the Chicago area. The genus name, Asclepias is named after the physician Aesculapius, the son of Apollo, who studied medicine under Chiron, a centaur in Greek mythology of great wisdom and knowledge of medicine. The common milkweed, Asclepias syriaca is found in several different habitats that all have plenty of sun and disturbed soils. These areas include old fields, pastures, remnant prairies, fens and along roadsides and railroads. This species and several other milkweed species are favorite plants in backyard gardens.

Common milkweed, Asclepias syriaca by DonArnold 2022

Common milkweed supports many insects and pollinator species. All parts of the plant are used for food including nectar, pollen, foliage and stems. Several species also breed on common milkweed, laying eggs in flowers where larva can feed on nectar and later move to feed on foliage.

Common milkweed foliage, Asclepias syriaca, by DonArnold 2022

Nectar provides food for 14 species of butterflies, four beetles, one weevil, six plant bugs, eight ants, 41 bees, six wasps, and six flies. The bees, wasps and flies also eat the pollen as do an additional ten beetles, three weevils and two ant species.

Black Swallowtail Butterfly, Eastern Tiger Swallowtail Butterfly, Monarch Butterfly, bees in the Andrena genus, and Hummingbird Moths are some of the more common insects that you can observe on milkweeds.

Eastern black swallowtail, Papilio polyxenes, by DonArnold 2020

Monarch butterfly,Danaus plexippus, by DonArnold 2020

All of the bees, wasps, and flies mentioned above plus ten beetle species, three weevils, and two ant species gather pollen from the flowers.

Bee, genus Andrena, on common milkweed by DonArnold 2022

Hummingbird moth, Hemaris thysbe, by DonArnold 2022

Milkweed foliage is food for three beetle species, one earwig, one leaf miner, and one weevil. The foliage also supports seven species of aphids and their symbiotic partners, ten ant species. The aphids feed on the common milkweed stem and leaves, then produce a sweet substance that the ants use for food. In return, the ants provide protection from predators for the aphids.

Ants & aphids on milkweed stem by Linda Tanner, 2012

Observing the many species of insects using this one plant throughout the day is fun and interesting. Many other milkweed species and insect groups are also found in our area. Take along a camera or hand lens on your next walk and watch closely to see all of the activity!

Milkweed beetle on common milkweed by DonArnold 2022

Honey bee, beetle and bumble bee on common milkweed by DonArnold 2022

Long-legged fly on common milkweed by DonArnold 2022

Bee Fascinated

There is a lot of snow on the ground around Chicago, and temperatures are in the deep freeze. But there are hundreds of bees in nests spread over our landscape that are all comfortably feeding on the honey they have stored away for the winter. How do bees create this great store of food?

Bees forage for nectar and pollen among the many flowers in our backyards. Nectar, a sugary fluid secreted by plants to attract bees and other pollinators, is sipped by worker bees for quick energy. It is also collected and brought back to the nest to be mixed with enzymes secreted by the bees to form honey. Pollen, a fine, powdery substance used in flower reproduction, is composed of amino acids, vitamins and fat that are all essential for bees. Together with honey, it can be stored for long periods in the nest to provide food for winter.

Bee with full pollen baskets by DonArnold

When visiting a flower for nectar, a bee collects pollen on the hair covering its body. They will brush the pollen from the hair into collection baskets on their legs. A bee will visit from 100 to 1000 flowers to get a full load of pollen before returning to the nest to deposit it. A single load takes 30-60 minutes to collect, and the bee will make an average of 10 trips a day. There are thousands of bees foraging every day, and as each bee enters a flower patch, she can be most efficient if she knows which flowers have a full load of nectar and pollen available.

Birds’ Foot Trefoil, *Lotus corniculatus* by Robert H Mohlenbrock

Borage, *Borago officinalis* by Scamperdale, 2009

Flowers are constantly refilling their nectar tubes during daylight hours. Different flowers produce nectar at different rates from two minutes for borage, Borago officinalis, to almost 24 hours for bird’s foot trefoil, Lotus corniculatus. The nectar is not visible, located in a long, slender tube at the base of the flower. A bee will crawl into the flower and drink from the tube using her long tongue. Foraging bees will not land on a flower that has recently been emptied of nectar, but how do they know which flowers to skip?

All insects are covered with an oil giving each species a particular scent. Studies show that after carefully washing the feet of several bees in a mild solution and painting this solution on flowers full of nectar, foraging bees avoid these flowers. The bees can smell the scent left by a previous visitor, can tell how old the scent is, and know how long that particular flower species takes to refill the nectar. Footprint odor has also been identified as an aid to the bees when they return to their nest. Landing close by the opening, bees walk the last short span, using scent to guide them to the exact spot of the nest opening.

IL Farm road with mowed edges, by R Boed

Bees require large numbers of flowers for nectar and pollen to feed their colony. They have thrived quite well up until the last hundred years when there has been a shift toward fewer flowers in both farmland and urban areas. In the agricultural areas, before mechanized plowing, many fields were bordered by flowering plant species. Since the automated plow, borders have been removed in favor of planting as much crop as possible. Along country roads, flowering edges are often mowed. In urban areas, the popular movement toward more lawn has also removed many flowering plants, especially in city parks and other recreation areas. These changes greatly reduce the amounts of pollen and nectar available to bees. You can make a difference in your own backyards by planting flower beds or areas of ground cover using flowering species.

Bee-ginning B’s

Bees are some of our most prolific pollinator species. In fact, there are over 4,000 species of bees in North America. Some of these can be observed in your own backyard. Bees have four wings, two long antennae, a thick-set body, eyes on the sides of their heads, and hair on the belly and rear legs for collecting pollen. Not all of the flying insects we see among the flowers are bees; some are wasps. They can be distinguished from bees by their skinny bodies with narrow waists, with no hair on their body or legs. Others are flies; they have two wings, short antennae, no pollen-collecting hairs on bodies or legs and eyes that are situated on top of their heads.

Bees typically live for only one year, although some species in our area, including honeybees and bumblebees may live longer. A majority of their lifetime is spent inside a hive or nest growing from an egg to a larva to a pupa to an adult. The bees that we observe in our gardens are the adult stage which typically lasts for several weeks.

Most bee species in North America are solitary: the females live alone, building their own nest, laying eggs, and providing food for their offspring’s development over the winter. The adults do not survive to see their offspring born. Other species, including honeybees and bumblebees, are social species. These bees live together in one nest and share all nest maintenance and parenting duties. In social colonies, especially those that are human managed, adult bees may live quite a bit longer.

*Panurginae* family Bumblebee with full pollen sacs by DonArnold

All bees collect pollen from flowers, and they have developed several unique adaptations for this process. Stiff hairs or hairs tipped with hooks on all parts of the body will collect the pollen when it is brushed against as the bee visits each flower. The bee will move the pollen into the hairs along the lower abdomen and hind legs for transport back to the nest. Bees also eat nectar from the flowers. Adults eat a lot of nectar and a little pollen, but they bring some of both back to the nest. A food packet consisting of a little nectar and a lot of pollen is placed with each egg to feed the developing offspring.

Brown-belted Bumblebee, *Bombus griseocollis* by Becky Donaldson

When a bee carrying pollen visits a flower looking for nectar and pollen, the bee must push past the stigma and through the anthers to get to the nectar found at the base of most flowers. The bee will collect more pollen from the anthers. But the stigma has sticky surfaces that will pull some of the pollen off the bee as it passes, and this will be used by the flower in its reproductive cycle.

Many fruits and vegetables we enjoy, as well as several beverages, all come from plants pollinated by bees. More than 70% of flowering plants are insect pollinated, and bees comprise a majority of those insects. Bees are struggling, though, and populations are in decline. Reasons include habitat fragmentation, an increased use of pesticides, and new diseases in bee populations. A majority of bees nest underground, and these habitats are becoming harder to find as we develop and pave over more places. Bees require many large groupings of flowers, a habitat also being lost to development. The latest farming practices often leave a monoculture of only one crop covering immense areas. Supporting backyard gardens and community development of both flower and food gardens will help to replace some of this lost habitat.