Everyone knows honey bees do all of the pollination for our pollination-dependent crops … right? Wrong.
I’m guessing most people who read this column probably know there are also other insects that pollinate our crops. Perhaps some people know there are ~20,000 species of bees in the world, and ~4,000 species in North America, many of which are crop pollinators. Perhaps some people also know that flies can be abundant and effective crop pollinators. And so can beetles and moths and other insects.
But just how much pollination is done by honey bees vs. other insects? This is a surprisingly difficult question to answer. There are a lot of crops in the world! And a lot of farms that grow those crops. And it’s not as straightforward as you might think to determine who did the pollination.
For this month’s column, we’re going to dig into this topic. What’s the relative contribution of honey bees vs. other insects to crop yields worldwide? Is the total number of flower visits by pollinators sufficient to predict crop yields, or is the diversity of pollinators also important? Are there rock-solid connections between pollinator visits, diversity, and yield with the current available science, or do we need more research to robustly answer these questions? These are the topics for the eightieth Notes from the Lab, where I summarize “Wild insects and honey bees are equally important to crop yields in a global analysis,” published in Global Ecology & Biogeography [2024] and written by James Reilly and colleagues at Rutgers University, with some help from co-authors in Spain and Argentina.
For their study, Reilly and colleagues did a deep dive into the literature on crop pollination. Specifically, they used the CropPol database (Allen-Perkins et al., 2022) to compile data from 93 studies of 35 crops. Their dataset represented a total of 129 study-years (i.e., some of the 93 studies spanned multiple years) and a total of 2,321 site-years (i.e., many of the 93 studies occurred at multiple sites). In other words, an impressive dataset.
Many of the 35 crops represented in the dataset will be familiar to readers from the USA, including apples (Malus domestica), blueberries (Vaccinium corymbosum), and pumpkins (Cucurbita pepo). But the dataset also included crops that may be more familiar to international readers, including Chinese okra (Luffa acutangula), the West Indian cherry (Malpighia emarginata) and a couple of my favorites: mangoes (Mangifera indica) and coffee (Coffea canephora and C. arabica) …
