Flowers wither as city bees stay away

a bee (apis cerana) visits the violet hued flowers of my purple basil

A bee (possibly apis mellifera) visits the violet-hued flowers of my purple basil

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The giant bee, apis dorsata, and a little dwarf bee, apis florea, come together for a drink of water

I used to take bees for granted, that is, till I started growing chilly peppers and tomatoes. In my mother’s suburban garden where gleaming, midnight-blue carpenter bees like to fly, eggplants, tomatoes, okra flower, then fruit, seasons turn, and all is as it should be.

But up here on the fifth floor in the middle of a busy city block, the nightshades I grew early on in the year did something strange. They flowered, but nothing happened after that. The flowers simply withered and fell from the parent plants stems and all. The issue was pollination, or the lack thereof. There were bees around, all kinds of bees, the little striped hive-making honey bees: apis florea (the dwarf honey bee pictured above), apis mellifera (the European honey bee) and the native apis cerana (the asiatic honey bee); the big ones: apis dorsata; and some solitary bees: nomia bees and resin bees. But soon I realised, they were just not the right kind, my little solanacea were after _ wild, native bees of the bumble, carpenter and halictid variety were absent from my terrace garden. Apparently, even a dulcet-toned breeze that shakes the self-fertile tomato flower could have done the job, but even these seemed to have gone wanting at the right time.

Dwarf honey bee (apis florea) visiting tamarind flower

Dwarf honey bee (apis florea) visiting tamarind flower

As I started reading up on this perplexing problem, it occurred to me that if I could not find the appropriate brightly-coloured almost-neon American halictid to do the job all the way here in India, I would have to depend upon sonicating or “buzz pollinating” local bees. Sensitive bumble bees stayed away from my garden as our apartment building stands in the middle of a densely-populated, traffic-filled area also crowded with mobile-phone towers. The next best buzz-pollinator was the blue-banded bee, which fortunately were plentiful here.

blue-banded bees

Local male blue-banded bees roosting on tamarind twig

I had found out that tomato and pepper flowers need to be sonically buzzed at opera style by bee-wing muscles and induced into spurting out their pollen, which is what certain bees like to collect in little white or yellow bundles on their legs. A portion of this released pollen sticks to the sticky stigmas of the same flowers causing self-fertilisation, and cross fertilisation takes place when bees rub their hairy pollen-covered bellies on the style tips. I found the best explanation here at the Old Drone blog.

sticky style tip of a tomato flower just showing from the centre of the anther cone.

Sticky style tip or stigma of a tomato flower just showing from the centre of the flower’s fused anther cone, which houses the locked-up pollen. The yellow petals have closed sightly as the picture was taken in the evening. I have buzzed at it with an electric toothbrush, and the tiny almost invisible white dots on the padded surface of the stigma are particles of pollen released from the anthers by the vibration.

Blue-banded bees with their dazzling turquoise colours do come to my garden from time to time. They, however, did not seem to be attracted to the yellow flowers of my tomato plant. They seemed instead to prefer the violet colours of a singular Buddleja specimen. In fact, the yellow tomato flowers and white chilly pepper flowers did not attract any of the bee visitors to my garden. And I hadn’t had a single tomato or pepper fruit yet, although the plants were all flowering profusely.

pollination in action: apis florea bee brushing past anthers of tamarind flower

Pollination in action: Apis florea bee (dwarf honey bee) brushing past anthers of tamarind flower. In this flower, the pollen just has to be brushed on to the bee’s hairy upper body. It is not locked inside the anthers, as in the case of the tomato flower.

apis cerana on mimosa flower

Wild apis cerana on mimosa flower

Male nomia bees roosting for the night

Male nomia bees roosting for the night high up in a tamarind branch. When the camera flashes at them, the white bands on their abdomens reflect rainbow colours. I have seen them referred to as rainbow bees.

At our local botanical garden, I had been witness to flowers of a nightshade brinjal being visited by other “apisian” guests. Sadly, being no expert, it was difficult to make an identification of the kind of bee. To me, it looked like a sweat bee, a halictid. A type of bee I have never seen in my fifth-floor terrace garden.

Flower of brinjal variety being visited by a possible sweat bee.

Flower of brinjal variety being visited by a possible sweat bee.

After some internet searches, I decided to resort to the old electric toothbrush technique. My first attempts at hand pollination were on a Thai chilly pepper growing on the kitchen window sill. I discarded the brush end of the toothbrush and touched its vibrating metal head to the flower’s anther cone, and voila, and pollen spurted out. I collected this flying pollen and used a cue tip to transfer pollen gently onto the stigma of the pepper flower.

Before: This is what the anthers look like before they were buzzed with the electric toothbrush

Before: This is what the anthers look like before they were buzzed with the electric toothbrush

After: After sonicating, the anthers have release their pollen

After: After sonicating, the anthers have released their pollen. (The above depict two different flowers on the same plant)

When the flowers were successfully pollinated and I got them to fruit, I began my toothbrush experiments on the tomato flowers.

Red Thai chilly pepper

Red Thai chilly pepper. The fruit is still wearing its withered flower as a little head skirt.

On the whole, it was a satisfactory experiment. Since the pollen-receptive stigmas of my tomato flowers lay just inside their anther cones (see picture above), my attempts at transferring pollen with a cue tip did not work. In this case, merely sonicating and gravity did the job of pollen transference. My little tomato plant produced a whole bunch of fruit before it finally gave into blight.

Tomato flowering

Tomato flowering

fruiting tomato

Fruiting tomato

Pollination by toothbrush

And finally, pollination by means of headless toothbrush

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