I have been surveying Apis dorsata nestings in Ahmednagar (State Maharashtra), India since past four years. The rockbees have shown the tendency to migrate down to the plains around November every year and forage till the onset of summer i.e. till early weeks of March. There has been a steady decline in the A. dorsata population. However, this year i havent seen any nestings in the region. A few sites that are regularly utilised by bees for aggregations are absolutely empty. I am surprised and worried with the case. I want to know if this is only a local phenomenon or has it happened in other parts of the country as well?
Hello, Apis dorsata is naturally migratory, as you indicate. Thus, these bees are subject to environmental problems at the end points of their migrations and while migrating. In Malaysia a few years ago, smoke from forest fires was conjectured to interfere with migration and result in population decline. The use of pesticides in agriculture has been documented to kill A. dorsata, and I have witnessed direct applications of insecticides to A. dorsata nests in India to remove them from public buildings. Let's hope that what you describe is local and temporary.
In Europe also an acarian (Varroa destructor) is responsible for the killing most of the bees. And some scientists have an idea that the absence of bees may be correlated with the quantity of transgenic plants.
Apis dorsata lives in the same area as Varroa jacobsoni and V. destructor are native, so it is not likely to be a direct cause of decline for A. dorsata. A. dorsata also is afflicted by another mite, Tropilaelaps clarea (? spelling). The complex of pathogens and parasites that afflicts A. mellifera (at least in temperate regions of the world) may have parallels in tropical and subtropical Asia. We do not know.
The issue of transgenic plants is, as you say, and idea wihtout much evidence to support it.
When I was in China I noticed A. dorsata nest for the first time in Yunnan forest last year. I have the same case here in Egypt with A. mellifera many colonies completely declined due to several reasons like pests (Varroa, Nosema, ..etc), pathogens and lack of floral resources. In addition, urbanization and agriculture mechanization destroy a lot of natural bee nesting habitats like here in Egypt with members of the genus Megachile which nest in mud walls in some villages. I had a similar case with Andrena, some farmers used to fire the weeds around their flied so all bees completely sandpaper.
We hope that we will have a clear answer for colony collapse and decline of bees.
i thank you all... Peter Kevan, Ingo Schreiber and Mohamed Shebi. Frankly speaking, on a personal note, i am afraid to my guts with this total absence of Apis dorsata this season. Being the people related and concerned about nature, i hope you people can understand my feelings. Thanks again for your replies. Its a privilege to get a reply from you Peter Sir. I have been referring your work since some time. Really obliged. Good day to all...
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