The US Fish and Wildlife Service’s decision to add the rusty-patched bumblebee to the endangered species list (“Plight of the bumblebee,’’ Metro, Jan. 11) may seem like a minor postscript to President Obama’s environmental legacy. However, the near demise of this tiny insect can be traced to the overuse of pesticides (particularly neonicotinoids), combined with habitat loss and the effects of climate change, including drought, extreme temperatures, and storms.

As scientists and gardeners have noted for years, many flowering plants respond to a warming climate by blooming earlier in the spring. In the case of the rusty-patched bumblebee, the queen, who gives birth to a new hive each spring, may emerge too late to feed on the flowers that support her hive. When plant pollinators don’t show up in time, the crops that rely on them are in trouble, and so are we.

The rusty-patched bumblebee is highly important because it pollinates plants indiscriminately, using “buzz pollination,’’ where it shakes the pollen loose. This type of pollination is particularly important for cranberries, a quintessential Massachusetts crop.

As members of Congress question candidates for environmental posts in the new administration, they should remember that a changing climate disrupts some of the earth’s tiniest creatures, which, in turn, are essential to our food supply.

Liza Ketchum

Watertown