The headlines last month were dire. "Plummeting insect numbers 'threaten collapse of nature'" warned The Guardian. "The rate of insect extinction is eight times faster than that of mammals, birds, and reptiles." That is such a definitive and frightening statement.
The analysis of 73 historical reports, published in the journal Biological Conservation, concludes that intensive agriculture is the main driver of the declines, particularly the heavy use of pesticides. They provide a few highlights of the exhaustive analysis:
Highlights
- Over 40% of insect species are threatened with extinction.
- Lepidoptera, Hymenoptera and dung beetles (Coleoptera) are the taxa most affected.
- Four aquatic taxa are imperiled and have already lost a large proportion of species.
- Habitat loss by conversion to intensive agriculture is the main driver of the declines.
- Agro-chemical pollutants, invasive species and climate change are additional causes.
I've already been hand pollinating the orchard, like they do in China, with a paintbrush. But now I immediately sought to learn what specifically pollinates vines. Lo and behold, I had forgotten that they are hermaphroditic. Hermaphroditic vines are preferred for cultivation because each vine is more likely to self-pollinate and produce fruit. Wind and insects play only a small role in aiding pollination, with the process being mostly self-contained within the vine. I found a chart of major crops on Wikipedia including this entry for Vitis spp. Pollinators have 0 influence on an increase in the yield of grape crops.
At least one factor is on our side.
| Grape | Vitis spp. | Honey bees, solitary bees, flies | fruit | 0-no increase | temperate |
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