CARPENTER BEES IN HONG KONG
Have you ever seen a big bumbly bee and assumed it was a Bumble Bee? Although there is a rarely seen species of Bumble Bee in Hong Kong, it will more likely be a Carpenter Bee.
There are several species in HK.
Their name is derived from their habit of boring into wood to make a nest – look out for perfect round holes in decaying wood or in bamboo stems.
A female will fabricate several cells within a cavity, either in bamboo or bored out in decaying wood, separated by thin partitions, and will fill each cell with a pollen mixture as food for her larvae.
They are Gentle Giants and quite harmless. They are not aggressive and are a wonderful addition to anyone’s garden where they are important pollinators.
However, should you inadvertently place your thumb over the entrance of a nesting female, you are likely to be stung as she will protectively use her abdomen to plug the hole.
This species as been consistently mis- identified locally – this is not a collaris but a dejeanii
This one is a male – hairier and paler than the female, with large green eyes
On a Petrea (Sandpaper Vine)
Males are harmless as they do not have a stinger.
A female on a Penta.
Females are darker than the males and mainly black
Only females have stingers. However, they are docile and do not attack.
Again, this has been misidentified in HK – it is not an X. collaris.
Xylocopa (Biluna) nasilis
The biggest and most common species in HK is the all-black bamboo carpenter bee.
This species had been identified as an Xylocopa iridipennis because of its beautiful irridescent wings.
However, X. iridipennis may not occur locally.
This may in fact be an Xylocopa (Biluna) near nasalis. Its ID is not yet completely confirmed.
This is a female.
She nests in bamboo stems.
Males are less black and generally smaller, and can be distinguished from females by the colour of their clypeus (face) which is generally lighter in males than in females.
Xylocopa (Alloxylocopa) phalothorax
A female on a Penta.
Nicola’s favourite –– they don’t come bumblier and more cuddly than this.
Easy to identify – it has a white pubescence on the thorax with a naked spot in the middle.
In other words, the thorax (the body part between the head and the abdomen) is covered in white, soft down; the black spot is actually a bald patch shining through.
Its wings are also iridescent in the sunlight.
Xylocopa dejeaniiXylocopa (Alloxylocopa) phalothorax
This may be a male Xylocopa phalothorax.
However, they are very similar to male X. dejeanii, save for a spot without hairs on the thorax.
The thorax is not visible in this photo, but the head is covered in so much soft hair, that this could well be a male Xylocopa phalothorax.
Carpenter bee hole in bamboo
If you see a perfectly round hole in bamboo, that will be a carpenter bee nest made by an Xylocopa near nasilis. Not all species nest in bamboo stems. X. phalothorax bores into decaying branches of trees.
Carpenter bees are traditionally considered solitary bees, though some species have simple social nests in which mothers and daughters may cohabit. However, even solitary species tend to be gregarious and often several nests will be near each other.
Be careful when handling bamboo – carpenter bees are not aggressive but you are likely to be stung should a female be in residence and you inadvertently put your thumb over the entrance to her nest. Unlike honey bees, she will not die after stinging.
Bamboo stems in Nicola’s garden
Nicola plants Pentas and Petreas (Sandpaper Vine) to attract bees and butterflies. When in flower, her Petreas are smothered in carpenter bees, the males pursuing the females. Nicola has placed bamboo stems against her walls to attract carpenter bees to nest in her garden. Not only are they a great source of joy to watch, carpenter bees provide a free pollination service.
Asian Honey Bees
Nicola also has a couple of bee hives in which wild bees take residence every year.
Although the honey is delicious, she doesn’t have the heart to take it from the bees after all the work they have put into making it!
A plea from Nicola – please do not use any herbicide or pesticide (such as Round-up) in your garden as this is deadly to bees. A bee can forage several kilometres from its nest, so any noxious chemical you use will have far-reaching effects.
If you find them nesting in the drainage holes of your walls, please do not try to remove them – they will not harm you as Asian bees are not aggressive. Please leave them be.
Bees are important pollinators – we need them.
Nicola has photographed in her garden all the confirmed species of Carpenter Bee known to be found in Hong Kong.
However, Asian fauna is poorly described for insects in general. There are probably 2-3 more species locally, pending identifications.
She is still looking for Hong Kong’s Bumble Bee, Bombus eximius, and hopes to find it in her garden one day. She has a wish-list of appropriate Bumble Bee food plants to plant.
With grateful thanks to Christophe Barthélemy, an Hymenoptera specialist (mostly social wasp species), for his expert carpenter bee identification advice.