The Smart Money: Perplexed pollinators and other buggy tales

Posted Tuesday, August 19, 2014 in Analysis

The Smart Money: Perplexed pollinators and other buggy tales

 Part two of a three part series on the cost of climate change


by Gina Hamilton


In southern Maine, some pear crops are in trouble. Pear flowers don’t attract their pollinators, mainly birds like the hummingbird, with pollen alone. They produce nectar that the birds sip, while collecting pollen on their feathers, before flying off to the next tree or flower. 

But over the last few years ... and this has happened really fast in climate terms ... the pear trees are blossoming earlier, before the hummingbirds and most other pollinators have returned for the spring. Many orchardists are hand-pollinating what they can, and hoping that the early bees will get the rest.

The disruption between plant and pollinator partners because of climate change is a very big deal. There is very little that we eat that is wind pollinated — mostly grain crops — and alone, they won’t make an adequate diet for anyone. Over time, the disruption may fade as the pollinators return earlier in the year, but such a thing is not predictable. 

Combined with the decline of honey bees, we are in the infant stages of a very serious problem, not just in Maine, but around the world.

Many fruit trees require pollination by other trees, so if apple or cherry trees are blossoming in April along the coast, but aren’t blooming yet inland, there is less of a chance that the trees will set fruit. Because of warming ocean waters, that’s pretty much what the pattern is. Blossoming early also means that the trees are subject to flower death during a cold snap. 

The news isn’t all bad. Maine is suddenly able to grow grapes and peaches and other warm-weather fruit, something that was very difficult to do in years past. But the same bit of pollinator perplexity holds true for the warmer weather fruits, too, as well as an additional menace. 

A certain species of fruitfly (actually, a vinegar fly), unheard of in Maine until now, is becoming common. It entered the country in 2009 at California, and has spread like wildfire since then. These flies feed on plums and blackberries, and other soft fruit. These flies can lay eggs not only in rotting fruit, but sound fruit. This year, the pest shut down the Connecticut raspberry harvest ... maggots and fly eggs are not good for business ... and Maine is next on its to-do list.

At a rate of loss of about 50 percent, this pest could do harm to Maine’s blueberry and brambleberry crops alone to the tune of $75 million per year. Peaches, tomatoes, plums, cherries, late strawberries, and other fruits  are at risk. Because the flies mature within the fruit, even non-organic farmers will be unable to kill it with pesticides once infested. 

The spotted-wing vinegar fly, an invasive species from Asia, is by no means alone. Some of the new pests and new pathogens carried by new pests are dangerous to humans and livestock, as well as plants. 

Changes to the rain pattern are causing problems that used to be occasional problems but now are becoming annual issues. Warmer, longer winters are leading to more stink bugs, that eat many summer garden crops. Late blight, the product of warm and wet seasons, are creating havoc in tomato and potato fields. In 2012, a warm winter led to apple trees budding out early, and when normal frosts occurred after full flowering, the blossoms dropped, leading to a year without many Maine apples. Maine broke a record that year — apple trees budded three weeks early. And fire blight, never a problem in Maine before, is attacking apple and pear trees because of increased variability in spring temperatures and weather patterns.

How much of this can be laid at climate change’s door is debatable, but taken as a whole, the cost of the changes to the climate are taking a toll on both human lives and crops. 

Sheila Pinette of the Maine CDC says that warming temperatures and more moist conditions are leading to earlier and more pervasive exposure to certain vector-borne illnesses, but that it is still very variable. This year, for instance, no mosquito pools have been found all summer containing Eastern Equine Encephalitis (EEE) or West Nile Virus (WNV). In 2012, Maine had one case of West Nile.

Other diseases, however, are being carried into Maine from warmer climates. There’s been a victim of Dengue fever, a case of malaria, and a few cases of chikungunya. All these diseases are transmitted by mosquito, as are EEE and WNV.  

We aren’t seeing large numbers of locally transmitted mosquito-borne disease — yet, although a species of mosquito — Anopheles barberi — was identified as living in Maine during a 2006 study. This is one of the species that can carry malaria, although it has never been seen to have malaria in the wild in Maine. 

Of greater concern to Maine residents who don’t travel to the Carribean, Oceania, and Africa, are tick-borne illnesses, which are also on the rise. Dr. Pinette said that part of the rise is probably owing to greater reporting and more accurate diagnoses, but the number of diseases associated with ticks and victims of each disease is on the rise. 

In addition to Lyme disease, which is carried by a bacterium and transmitted through the bite of an infected tick, two associated diseases that often occur with Lyme include Anaplasmosis and Babesiosis, which can be very severe. There has been one fatal case of Powassan, another tick-borne disease in the Mid-coast, but Pinette said that less severe forms of the disease are being seen and treated. 

The numbers are exploding. There were 595 cases of Lyme in Maine last year. So far this year, there have been 1,111 cases. The numbers are rising for Anaplasmosis and Babesiosis as well. The CDC recommends standard protection, using repellent, wearing light clothing, wearing pant legs inside socks, and checking for passengers when you get home. 

The cost to treat a patient who has later stage Lyme can be as much as $150,000. Early treatment is much less expensive.


Next week: Heating and cooling

blog comments powered by Disqus