Monday, 26 March 2018

Gardening to attract native bees

A partnership post with local native bee enthusiast Alison Mellor
Native bees are some of the most rewarding insects to have in your garden. They come in many colours, shapes and sizes, from tiny black stingless bees to large orange Teddy Bear Bees and striking Blue Banded Bees. They appreciate a wide range of flowering plants for sourcing nectar or pollen, and will pollinate some plant species in return. Nectar is a high energy source which fuels busy adult bees, while pollen is a high protein food source important for growing bee larvae.

Bees interact with plants in a range of interesting ways besides collecting and consuming food. While there are more than 200 different species of native bees in the Illawarra, only one species, the stingless Tetragonula carbonaria, nests together in a hive, has queen bees, and produces honey (though in small amounts). Mature and dead trees can provide hollows for these colonies of ‘social’ bees, which live together in groups of around 10,000. 

The vast majority of native bee species are ‘solitary’ bees, meaning they live their lives independently, do not live in hives, and do not produce honey. Female solitary bees make their own individual nests where they lay their eggs. Many species make their nests in the ground by digging small tunnels into the soil. However some types of bees use plant stems, small holes in trees, or crevices under bark or fallen trees as nesting locations. Some bees, such as Resin bees, collect resin and use it to create and seal their nests, while Leafcutter bees exhibit the fascinating behavior of cutting and wrapping together soft leaves to form their nests.
A Leafcutter bee with a piece of Lilly Pilly leaf.
Male bees can often be seen roosting on twigs or plants stems. Sometimes a number of male bees roost tightly together in the same spot, jostling for what they see as prime position.
Male Lipotriches bees congregating
on a Basil stalk.
Most native bees are generalists, meaning they will forage from a wide range of plants, and do not rely on one particular kind of plant. Eucalypts are great at bringing in native bees, with their profuse flowering and plenteous nectar, but unfortunately most are too large for most suburban gardens. The smallest localeucalypt is the Swamp Mahogany (E. robusta), which reaches 8m to 10m in cultivation.Many otherlocal speciesof trees and shrubs appeal to native bees, including Lilly Pilly (Acmena smithii), Paperbarks (Melaleuca styphelioides), Banksia (Banksia integrifolia), Bottlebrush (Callistemon salignus), Tea Trees (e.g. Leptospermum laevigatum), Grevillea (Grevillea oleoides) and Grey Myrtle (Backhousia myrtifolia). If your garden is too small for a tree, maybe there’s room for one on the verge?
Lilly Pilly (Syzygium australe) is a great little
tree that also provides excellent bee habitat.
Image by Mithra Cox.
To attract native bees to your garden, it’s ideal to have a range of different plants that flower at different times throughout the year. It is also helpful to cluster plants of the same spices together, as a visit is more worthwhile if there are plenty of flowers present in one spot.Smaller plants with a long flowering period are ideal for this. Flax-lilies (Dianella species), Cockspur Flower (Plectranthus parvifolius), Guinea Flowers (Hibbertia species) and Fairy Fan Flower (Scaevola aemula) and are all good choices. Many native bees also like pea plants such as Pultenaeas, Golden Tip (Goodia lotifolia),Australian Indigo (Indigofera australis) and False Sarsaparilla (Hardenbergia violacea). Bees and other insects see more ultraviolet colours, and are strongly attracted to flowers that are blue, purple and white.
A well-designed 'bee hotel' can attract a range of bees
to your garden. Be careful though - these hotels may
also attract bee predator species such as Cuckoo wasps.
Meet some local bees  
There is an incredible diversity of native bees in Australia, with an estimated 2,000 different species. Only around 1,660 have been scientifically named, and, as with many insects, there is still much more to be learned about their fascinating lives.

It is estimated there are over 200 different species of native bees in the Illawarra, with representatives a number of different bee families and sub-families. The warmer months from September to April are the peak time for seeing adult bees flying around and visiting flowers, though a few species can be seen out foraging all year round. Over the cooler months from May to August, most solitary native bees are in nests, developing through the stages of egg, larva or pupa and preparing to emerge as adults in the warmer weather.

Below is a little more about just some of the many different types of native bees you can observe in bushland, parks, gardens and backyards in the Illawarra.

Stingless bees
Stingless bees that live together in a hive are often the first bees people think of when they think of native bees. There are 11 species of stingless bees in Australia, but only one species,Tetragonula carbonaria, is found in the Illawarra. If you know of anyone who has purchased a native bee hive for their garden in the Illawarra, they would be Tetragonula carbonaria bees.The south coast however is the southern limit of the range for these subtropical, honey-producing bees, and our marginal climate can be challenging for them. These small (3mm to 4mm) stingless bees can only forage about 500m from their hive, and they are active all year round, making them one of the few native bee species you will see in winter.
 
Tiny native stingless bees going about their business.
Blue Banded bees
Blue Banded bees are one of the most commonly observed native bees in the Illawarra, being large (1.5cm) and with quite distinctive coloured bands that range from bright blue to almost white. These noisy bees can perform a special kind of pollination – buzz pollination. Scientists have observed that during buzz pollination, Blue Banded bees bang their head against the flower a mind-blowing 350 times a second, releasing pollen held tightly within the flower. These ground-nesting solitary bees are quite fond of tomato flowers, and are often seen around veggie patches.
Blue Banded bees are some of the most recognisable,
and appealing, of the local bee species.
Teddy Bear bees
These gorgeous, noisy, furry-looking bees are quite large (1.5cm), and can be bright orange to paler golden/brown. They are sometimes confused with Bumblebees, but Bumblebees are not established on the Australian mainland (although they have been introduced to Tasmania). As a solitary bee, female Teddy Bear bees make their individual nests in the ground. Leaving some areas of bare soil (not mulched) in your garden can provide nesting opportunities for ground nesting bees.
A Teddy Bear bee on an Anise Hyssop plant.
Cuckoo Bees
It’s always special to be lucky enough to observe a cuckoo bee. They are fast fliers, and stop on flowers less regularly than other bees because they do not have to collect pollen for their young – just like cuckoo birds, these cheeky creatures sneak their eggs into the nests of other bees. The black and white Domino cuckoo bee predates Teddy Bear bee nests, while the striking Neon Cuckoo bee and beautiful Chequered Cuckoo bee predate Blue Banded bee nests.   
Chequered Cuckoo bee (Thyreus caeruleopunctatus).
Domino Cuckoo bee (Thyreus lububris) on a Zinnia flower.

Leafcutter bees
As their name suggests, Leafcutter bees are known for cutting bits of soft leaves, such as Lilly Pilly leaves, from plants to use in making their nests. They have a liking for young leaves on roses - if someone complains about perfectly shaped semi-circles taken from the edges of their rose leaves, tell them they don’t need to do anything and are very lucky to have these special native bees in their garden! These bees cut off bits of leaf with their strong jaws, and then carry them back to their selected nesting location, often tucked away in a crevice. The eggs are laid in ‘cells’ created with the pieces of leaf, and each cell is provisioned with a mix of pollen and nectar for the young larvae to consume. They will nest in hollow bamboo canes in native ‘bee hotels’ that are becoming popular for gardeners to make.
A Leafcutter bee resting on the
flowers of a Basil plant. 
Resin bees
Resin bees are so called because they like to collect resin from trees to use in creating their nests. They nest in old borer holes in trees, and will use artificial drilled holes in hardwood blocks that are a centimeter or less in diameter, and at least 10cm deep.
A Resin bee (Megachile punctata) using a bee hotel
installed at Wollongong Botanic Garden.
Masked bees
Masked bees can sometimes be confused with wasps, and they are generally black in colour with bright yellow or orange markings. Many Masked bees nest in the ground, but some nest in hollowed out plant stems, and some will use human-made native bee habitats such as bamboo canes and small holes drilled into hardwood.
A Masked Bee on dried Lilly Pilly leaves, showing
the distinctive brightly yellow markings.
Reed bees
Reed bees of the Exoneura species are one of the most abundant types of native bees in the Illawarra. Being small in size though (3-8mm), they often go unnoticed, or can be mistaken for small flies. These bees are interesting in that they do not live in a hive or have a queen, but are ‘semi-social’ with several female bees living in the same nest, helping to provide food for the young and guard the nest entrance. They make their nests by excavating the soft material out from pithy stems, such as in pruned stems of the local Small Leaved Bleeding Heart (Homalanthus stillingifolius). They also quite like lantana stems – if you notice a nest while you are removing these weedy plants, you can help the bees by pruning the stems with plenty of length, bundling them together with thin wire and securing them to a nearby tree. You can also make native bee habitats in your garden for Reed bees by bundling pruned stems 20cm to 30cm long from plants with a soft pithy centre like Bleeding Heart, lantana or even mulberries, grapes and Tibouchina, and hanging them from a branch, or placing them in a bee hotel. 
Reed bee feeding on a native daisy (Olearia species).
This shot shows a Reed bee nesting in the cut-off stem
of a Bleeding Heart (Homalanthus populifolius) plant.
There are many other native bee species around, but this should be enough to get you started exploring the bees that occur in your garden or local bushland reserve.

Safety
A word on safety – many people assume that native bees do not sting, but out of the 2,000 Australian native bees, only 11 species are stingless bees. That means 99.95% of Australian bee species can sting! However, only female bees possess a stinger, and they are not aggressive as they do not have a hive to defend like European honeybees. They will only sting if accidentally trodden on or picked up. The risk is so minimal, it has become popular for community gardens and schools to install ‘bee hotels’ that attract native solitary bees. However, especially if you have a known allergy to bee stings, it is important to be aware that most female bees do have the potential to sting.

Resources
The internet is full of resources on attracting native bees, including the following. Be careful though, - most are from other parts of Australia and may recommend plants not local to the Illawarra area:

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