Winter had to be over by late May, the weather was getting cooler and warmest at noon. We had driven almost one and a half hours from San Mateo of San Francisco to Muir Woods, the only Red Wood Forest in Mill Valley. It is well known for the 1000 years Red Wood trees. We hope to spot some beetles in the forest, but we did not find them. We turned some rotten trunk and found multi-legged critters with dark green exoskeleton. We were however awed by the tall redwood trees that rose more than 80 meters into the gorgeous blue sky. The forest is well maintained in its natural form.
We were searching for one particular family of beetle, the Coccinellidae, commonly known as ladybirds, was particularly well received by the farmers in passing decades. They were once believed to be the saviors sent by Mary to answer the prayers of the framers to rid their crops of aphids and other pest, hence, the name ladybird, the bird of Mary.
Children nursery rhyme had been written about ladybirds which was sang to help them vacate from the plant after the farmers had harvested their crops and were about to burn the plant remains as fertilizer.
"Ladybug, ladybug, fly away home,Your house is on fire, your children do roam.Except little Nan, who sits in a pan,Weaving gold laces as fast as she can."
The next day we took off to the Golden Bridge Park, searched for hours in the park but we did not find any beetle too. San Francisco is home to many vineyards. A visit to the vineyard confirmed that no insects are welcome in the vineyard, as their squashed body during fermentation may degrade the quality of the wine. We did not find this beetle after a casual look around in the vineyard.
However, on our last day in San Francisco, we located one in the lawn of our resident. We were exhilarated and took many images of it. Though ladybird are inspirational for their form, colour and movement especially during their launch into flight, when their shield separated and the transparent wings fluttered gently lifting them angelically through space, they would secrete a yellow fluid with foul odor when felt threatened or squashed. This fluid can stain walls and draperies. Large aggregation of ladybirds also produces an undesirable smell. For some hypersensitive people they may trigger asthma in them. We had learned that the beetle can bite but we had not experienced it when handling ladybird. However, we could feel their claws scratching on the surface of our skin.
Asian ladybird, the Harlequin Ladybird, Harmonia axyridis, was introduced into America and European as a biological pest control against aphids and other pest in the early 1970s. Harlequin is a ferocious cannibalistic insect, which was seen as an alternative to insecticide and as an ecologically friendlier alternative.
Through industrialization and urbanization, vast farmland had been converted into a suburban dwelling area and the food for these Asian beetles had vanished. They invaded the gardens and tried to hibernate in houses during the winter months. They can be found in wall crevices, wooden furniture and bookshelves. For their lack of use, they are now nuisance to home dwellers and they endanger the local ladybird population both in America and United Kingdom. Somehow, we human had spoken so eloquently about bringing nature into our houses and living with nature, but we shrieked at the mere sight of them. We use insecticides to kill them and vacuum cleaners to suck them all out. Being with nature is easy said then done. There is a certain irony in this romanticism with nature.
In the United Kingdom, there was an organization set up to monitor ladybird, http://www.ladybird-survey.org/. In particular survey was carried out on Harlequin Ladybird, which the website http://www.harlequin-survey.org listed it as "the most invasive ladybird on earth". There were maps illustrating the spread of this ladybird, like a benign growth slowly engulfing from South-East towards the northeast. This mapping is a collaboration among various organizations. They are: the University of Cambridge, the Anglia Ruskin University and the Biological Records Centre. Till 2008, they had spread as far as north of Glasgow and reaching Durham. It was believed that they arrived in Essex from Netherlands, where they had been used as a biological pest control. However due to their voracious appetite they had out competed the locate ladybird on their staple food, aphids, reducing the local ladybird population significantly. They may in some instances eat up the local ladybird too. In the autumn of 2006, a swarm of ladybirds descended in the cloud on the Isle of Wight, covering crops, windows and even footpaths. Residents were horrified and Asian Ladybird reputation declined and they became a pest.
Dr Majerus,
"And there are lacewing, hoverfly larvae and even butterflies that are suffering because this thing is eating all the food, and it is also eating as secondary food butterfly eggs, and other ladybirds and lacewing larvae."
Harlequin Ladybird is identified by their various colours such as yellow-orange, orange-red, red or Black. They could be spotless or with up to 21 black or orange-red spots. They most commonly have 15-21 black spots in UK. They vary from 6-8mm in size.
Of course, some nurseries in America still sell ladybird to garden owners who are health conscious and detest the use of insecticide. These Ladybirds were kept in refrigerator and release to the garden when needed. Ladybird helps to rid aphids and other pest in their gardens. Ladybird starts to hibernate around October and November, through winter. They were harvested during the hibernating months where thousands migrated to certain valley and hid themselves beneath dead leaves and logs. For a good week these beetle harvesters could easily earned a thousand dollars each. However, the exact spots for harvesting them are kept secret among the harvesters and their territories are jealously guarded.
Ladybirds are well known for their promiscuity. Nine out of ten London Ladybird had STD, Sexually Transmitted Disease. They suffered a fungal STD, which is mild and benign. Another mite STD suffered by Eastern Europe Ladybird could render the female sterile. This mite could be a solution for the control of Harlequin Ladybird in America and UK. However, this should be well researched and controlled before another form of undesired effects breaks out. We Asian were quite puzzled about their population in Asia. We had not noticed their crime among our properties.
