Are native species inherently superior to non-native species?

The native plant movement is based on the fundamental assumption that native species of plants and animals are inherently superior to non-native species.  The basis of this assumption seems to vary.  Sometimes the explanation offered is as simple as “the non-native doesn’t belong here.”  It’s not clear what that statement means.  Putting it in the best light, it implies that there is some optimal ecology that is best represented by exclusively native species.  A less generous interpretation would be that non-native plant and animal species are the non-human equivalent of illegal immigrants

We will examine this claim of the superiority of native species in the context of bees to make the point that nature is complex and cannot be oversimplified by such a sweeping generalization.

Professor Gordon Frankie, our local expert on the bees of the Bay Area, says that native bees are superior pollinators to the European honeybee.  If that were true, we would consider that a legitimate basis for the judgment that, in this case, the native bee is superior to the non-native bee.  However, the evidence available to us suggests that a comparison of the native to the non-native bee is more complicated.

In considering this question, we will focus on agriculture rather than residential gardens, because agriculture is economically more important and for the same reason more is known about the role of bees in agriculture.

Why would native bees be superior pollinators than non-native bees?

We know of two specific examples of native bees that are more effective pollinators of agricultural crops.  Both cases illustrate the pros and cons of native bees as agricultural pollinators.

Bumblebee on Cotoneaster, Albany Bulb

There are some crops—tomatoes, cranberries, blueberries, eggplants, and kiwi fruits—that are effectively pollinated by native bumblebees (Bombus) because of their unique method of pollination.  This method is called “buzz-pollination” or “sonication” and it is described as “an intense vibration, like a tuning fork being struck, pollen gathered from other flowers literally exploded off Bombus.”(1)

Unfortunately, though its pollination technique is superior, other characteristics of the native bumblebee have limited its usefulness in agriculture.  The crops with which it is most effective produce only pollen.  Therefore, the bumblebee must be provided with an alternate source of nectar to fulfill its dietary needs.(2)  

The bumblebee, like most native bees, is solitary.  It does not live in hives like the social European honeybee.  Therefore, it cannot be transported where and when it is needed, as the honeybee can.  An attempt at a high-tech solution to this limitation ended in disaster:  “In the 1990s, a bumblebee species Bombus occidentalis, was made extinct when experimenting breeders mixed species in Europe and shipped queens back to America.  The queens carried with them an exotic disease that Bombus occidentalis has no immunity for.”   Growers of tomatoes are now “forced to resort to less efficient pollinators.”  (Schacker 2008). 

Another example of a native bee that is a superior pollinator of an agricultural crop is the alkali bee which is the most efficient pollinator of alfalfa, a crop that is essential to the dairy and beef industries.  “Alfalfa flowers…keep their sexual parts hidden, under tension like a spring.  Bees must trip the spring to get at the pollen, and in so doing, they are hit on the head—something honey bees are not particularly fond of.  The alkali bees…don’t mind getting hit on the noggin and will happily pollinate a field of alfalfa.”  (Schacker 2008). 

Native bee approaching nest in ground, Albany Bulb

Unfortunately, the alkali bee, like 85% of native bees in the US, nests in the ground, in particular the alkaline soils of the western US for which it is named.  As cropland in the west expanded, the alkali bee was virtually wiped out by plowing up the ground in which it nested.  A leafcutter bee was imported from Canada as a substitute, but a fungus is now infecting its larvae. (Schacker 2008)

These disadvantages of native bees can be compensated for by providing nesting and nectar sources adjacent to croplands.  These hedgerows must be large enough to provide sufficient nesting opportunities and nectar sources. 

However, such hedgerows do not solve all the potential problems of using native bees as pollinators.  Because the bees are resident year around and cannot be transported, they cannot be removed when the crops are sprayed with pesticides.  And the pesticides are very damaging to the bees.  Therefore, a commitment to providing hedgerows for a resident bee population is also a commitment to organic agriculture, i.e., without using pesticides. 

This is not to say that the honeybees aren’t being adversely affected by the use of pesticides in the crops they are pollinating.  The impact of pesticides on  honeybees would be exacerbated if they were resident when pesticides were applied to the crop.  As it is, the honeybee is being affected by the residues of the pesticides on the crops they pollinate.  This is considered one of the primary reasons for Colony Collapse Disorder of commercial honeybees which has been destroying about one-third of commercial honeybee hives in the past few years.

Unlike most native bees, the European honeybee does not hibernate.  It is therefore available year around to be transported where and when it is needed.  Most native bees hibernate, but not necessarily at the same time.  Different species of native bees hibernate at different times and are therefore available for pollination at different times. 

Most native bees are more selective in their pollination than the European honeybee which is an extreme generalist:  “honeybees have the greatest pollen dietary range…of any known pollinator.” Although there are “only a handful of well-documented cases in North America of truly monolectic bees [a bee that visits only one kind of flower]” (Buchmann 1996), the flower preferences of native bees are narrower than that of the European honeybee.  While some native bees may prefer native plants, honeybees are willing to pollinate both native and non-native plants.  This is important because virtually all of our agricultural crops are non-native.

Native bees are not inherently superior to non-native bees

Honeybee hives, USDA photo

In summary, the European honeybee has several important advantages over native bees as pollinators of agricultural crops:

  • Because the honeybee is a social bee that lives in hives, it can:
    • Be transported where and when it is needed
    • Be removed from the agricultural crop when it is sprayed with pesticides
    • Does not need to be provided with nesting space and an alternate food supply
  • The honeybee is available for pollination services year around because it does not hibernate.
  • The honeybee pollinates a wider range of flowers than most native bees.

While native bees may be more efficient pollinators of residential gardens, there are a number of disadvantages to using native bees for agricultural pollination.  Although many of these obstacles can be overcome with greater use of resources, we cannot agree with the assumption of native plant advocates that native bees are inherently superior to the non-native European honeybee.  As with all sweeping generalizations, the truth is usually more complicated because nature is complex and man’s understanding of it is limited.

(1) Schacker, Michael, A Spring without Bees, Lyons Press, Guilford, Conn, 2008.

(2) Buchmann, S, and Nabhan, G, The Forgotten Pollinators, Island Press, 1996

One thought on “Are native species inherently superior to non-native species?”

  1. No pollination expert would ever make a blanket statement such as “native bees are better than honey bees”. And certainly Gordon Frankie did not say that.

    Webmaster: Nor did we quote him as saying that. He said that native bees are superior pollinators and here is the link to the document in which he is quoted as saying that:

    SOME native bees are better than honey bees for SOME crops: blueberry bees, squash bees, bumble bees and other tomato pollinators, alfalfa bees (some of them non-native), mason bees (some of them also non-native).

    Webmaster: No doubt. That is precisely what we said in this article.

    Bumble bees are not solitary. They live in small colonies. In fact, bumble bee nest boxes are being used more and more.

    Webmaster: Here is what Dr. Frankie says on his website: “In contrast to the social honey bees, which make hives and live in colonies, more than 95% of our native bees are solitary in life style. That is, a single female bee mates with a male, and then goes about foraging and constructing a nest by herself to raise another generation of bees. There are no social structures or colonies associated with the solitary bees.”

    “The alkali bee was virtually wiped out by plowing”. Yes, but now they are alive and well. See this picture from 2008: They are very useful and their alkali nesting beds require minimal care.

    Webmaster: Thanks for that good news. The quote from this article is from a book that was published in 2008 and a citation was provided.

    Honey bees used in crop pollination do need food supplements, not only corn syrup but even bee bread with protein supplements.

    Tomato flowers don’t have nectar. That is a characteristic of the flower and not of the pollinator. We already established that honey bees cannot do it. Why do you say that this is a disadvantage of native pollinators?

    Webmaster: We didn’t say that

    Native bees are defenseless against pesticides. Shouldn’t we be changing our agricultural methods, rather than killing native wildlife?

    Webmaster: By all means.

    It is not an either/or issue: the use of honey bees vs. native bees in agriculture. Nobody is against the use of honey bees. But, native bees can be and are extremely useful in many instances; irreplaceable by honey bees in some cases.

    Webmaster: No doubt.

    But, most of all, nobody says that native organisms are “inherently superior to non-native species”.

    Webmaster: This is a sweeping generalization for which you would find many exceptions on this website when nativists are quoted in their publications and comments.

    However, communities of organisms that have co-evolved for eons are better integrated, function better and more efficiently, than those made of a mishmash of species introduced from a variety of different ecosystems. All those non-native species are just fine where they are native, where they are part of their own ecosystems. This has nothing to do with superiority or inferiority and nobody is saying that.

    Webmaster: The co-evolution argument is used more often than is justified. There are few mutually exclusive relationships in nature because they are a risky evolutionary strategy. Adaptation and evolution did not stop when Europeans arrived in America. There are many examples of rapid evolution reported by scientific studies that refute the perception of nativists that nature is immutable.

    You may want to read “I do not Hate Invasive Species”

    Webmaster: Thank you for this reference. We will definitely read it.

    We are not experts about bees. Therefore we have provided our readers with the quotes of experts and provided citations of the sources of every statement we have made in this article. Perhaps your argument is with them.

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