Status of Pollinators in North America (2007) / Chapter Skim
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2 Status of Pollinators
2 Status of Pollinators
Pages 34-74
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From page 34... ...
There are, however, numerous reports of declines of pollinating insects that have been documented according the strict criteria of federal or state law or regulations or by nongovernmental organizations. A case in point is the Massachusetts Endangered Species Act (MESA; 321 CMR 8:00)
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From page 35... ...
. POPULATION TRENDS Insect Pollinators Although more than 750,000 insect species have been described (Grimaldi and Engel, 2005)
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From page 36... ...
and wasps that represent a variety of families. Honey Bees (Apis mellifera)
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From page 37... ...
, it is useful in expansive monocultures where wild bees of other species with more limited foraging ranges are restricted to field margins. In addition, honey bees exhibit sophisticated communication, which increases foraging efficiency, and floral constancy; individuals repeatedly visit a single plant species during each foraging trip and can recruit nestmates to flowers of that species (von Frisch, 1967)
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From page 38... ...
Bumble bee species exhibit a primitively eusocial lifestyle. In advanced eusocial species, colonies are typically perennial and popu lations number in the thousands to even millions of individuals.
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From page 39... ...
Honey bees exhibit an advanced eusocial lifestyle. Several aspects of eusociality contribute to the value of the honey bee as a commercial pollinator: (1)
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From page 40... ...
Finally, because honey bees can be cared for and maintained by humans, they are buffered to some extent from declines in environmental quality. Honey bee populations have followed different trends in the three North American nations.
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. Statistics Canada collects data on honey bees kept for pollination and on those that produce honey (Statistics Canada, 2006)
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From page 42... ...
Few studies have examined the population status of feral honey bees over time. The USDA Carl Hayden Bee Research Center has data on the survival of feral honey bee colonies in southern Arizona that span 19 years (Loper et al., 2006)
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From page 43... ...
in the United States and Canada -- for which agricultural monitoring agencies often have long-term records of honey bee colonies (Figure 2-1) -- data on managed bumble bee colonies are not collected in the United States, Canada, or Mexico.
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From page 44... ...
Because there is no long-term monitoring or corresponding baseline data for bumble bees or other species of wild non-Apis bees in the United States, Canada, or Mexico, the population status of bumble bees cannot be determined definitively in North America. The United Kingdom, in contrast, has a long and well-established tradition of monitoring by scientists and naturalists.
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From page 45... ...
Thomas et al., 2004) , for bumble bees (Rasmont et al., 2006)
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From page 46... ...
presented information on the faunistic drift of Belgian bumble bee species; that report cites the first red list of threatened insects in the Belgian fauna. The 1988 report was updated and revised in 1993 (Rasmont et al., 1993)
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From page 47... ...
make a special case to discuss the plight of bumble bees in Europe. They reported a continental decline in abundance in several bumble bee species.
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. Mayan beekeepers have traditionally searched for stingless bee colonies in the low tropical forests of the Yucatán, traveling several kilometers from their villages to locate wild colonies of Melipona and Trigona.
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, orchid bees live in neotropical forests and can be found in Sonora and Sinaloa (Alamos region) and farther south, including the rainforests of Quintana Roo, Mexico.
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From page 50... ...
Sunflower bee Sunflower Eumegachile pugnata Other Bees Other than honey bees and bumble bees, more than 3,500 species of solitary bees pollinate crops and wild plants in North America. Examples of native bee pollinators include alkali bees, squash bees, and leafcutting bees (Table 2-2)
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From page 51... ...
. An excellent source of information on ant databases in general is http://antbase.org, a website maintained jointly by the American Museum of Natural History and the Ohio State University.
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From page 52... ...
Pseudomasarines are important to the ecology of these wildflowers, and they play ecosystem service roles in the southwestern United States and Mexico. Within the southwestern United States, several masarid species are restricted to highly localized habitats or have not been collected in decades (Richards, 1963, 1966)
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From page 53... ...
, and none in Canada. Unlike most flowering plants, which can be pollinated by a guild of pollinators and floral visitors, each Ficus species typically is primarily pollinated by one, or sometimes two, species of agaonid fig wasps (Weiblen, 2002)
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From page 54... ...
. The role of beetles as pollinators of temperate, North American flora differs by plant geography so that the role a beetle species plays in pollination of temperate, North American flora could change with the distribution of the plant species.
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From page 55... ...
STATUS OF POLLINATORS TABLE 2-4 An Illustrative List of Indigenous Beetle-Pollinated Plants of Canada and the United States (Common Names of Plants are in Parentheses) Other Plant Genus Taxa of Pollinating Beetles Pollinators References Asimina (paw Bombus, flies Kral, 1960; Norman Euphoria sepulchralis paws, 8)
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Leptaura propinqua Trichodes ornatus Total Plant Species 52 Total Pollinating Beetles Identified to Species 36
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From page 57... ...
Most higher flies are flower visitors and many have been documented as pollinators. All of the world's floristic provinces contain at least one plant species pollinated primarily or exclusively by flies, and fly pollination is regarded as second only to bee pollination in the evolution of flowering-plant diversity (reviewed by Larson et al., 2001)
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From page 58... ...
Although the few published monographs and revisions usually contain summary statements of material examined and, frequently, distribution maps, there are no publicly available databases of substantive specimen data. Similarly, there could be just one long-term program to collect population data for flies, using a Malaise trap at the Rocky Mountain Biological Laboratory in Crested Butte, Colorado.
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From page 59... ...
STATUS OF POLLINATORS TABLE 2-5 Total Number of Identified Diptera Species and the Estimated Number of Diptera Species That Are Pollinators Estimated Number of Canada, Level of Level of Number of Mexico, or U.S. Taxonomic Ecological Taxon Species Pollinators Knowledge Knowledge Syrphidae 5872 1001 Medium Medium Bombyliidae 5009 1095 Medium Low Culicidae 3517 289 High High Bibionidae 743 111 Medium Low Cecidomyiidae 5831 1250 Medium Medium Ceratopogonidae 5525 671 Medium Medium Psychodidae 2801 172 Low Low Chironomidae 6722 1126 Low Medium Tabanidae 4295 472 High High Rhagionidae 676 118 Medium Medium Athericidae 120 6 Medium Medium Stratiomyidae 2669 469 Medium Medium Asilidae 7166 1286 Medium Medium Apioceridae 165 89 High High Therevidae 1057 167 High High Mydidae 452 90 High High Acroceridae 395 68 High High Nemestrinidae 255 10 High High Empididae 4839 903 Medium Medium Dolichopodidae 6742 1459 Medium Medium Phoridae 3655 443 Low Low Drosophilidae 3863 321 High High Lauxaniidae 1844 172 Low Low Chloropidae 2841 320 Low Low Scathophagidae 291 153 Medium Medium Anthomyiidae 1887 709 High High Muscidae 4932 774 Medium Medium Fanniidae 295 119 High High Sarcophagidae 3015 484 Medium Medium Calliphoridae 1487 124 Medium Medium Tachinidae 9470 2005 Low Low Bolitophilidae 54 20 Medium Low Diadocidiidae 25 3 Medium Low Ditomyiidae 78 9 High Low Keroplatidae 837 88 Medium Low Lygistorrhinidae 27 1 High Low Mycetophilidae 3891 685 Medium Low Rangomaramidae 5 0 Sciaridae 2093 178 Medium Low NOTE: Documented population trends are not available for all taxa except for Syrphidae.
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From page 60... ...
. Numerous butterfly species are protected under the terms of the Endangered Species Act (Chapter 1)
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From page 61... ...
, the bay checkerspot was designated as threatened in 1987 and included on the Federal Endangered Species List. It was almost certainly more extensively distributed before the invasion of its habitat by Eurasian grasses (McLaughlin et al., 2002)
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Shapiro (University of California, Davis) , provide information about the variations in populations of 36 butterfly species in the Sacramento Valley.
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among other species. There are no data on population trends of moth species.
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1997) , North American thrips have not generally been the focus of concern about population decline; no thrips species is currently protected under the provisions of the Endangered Species Act (ESA)
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. There are at least 12 species of pollinating bats in North America, including southern Mexico (Baker et al., 2003; Ceballos et al., 1997; Medellín et al., 1997)
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From page 66... ...
. Few population data are available for pollinating bats in North America, given that populations are difficult to survey, few people are qualified to survey them, and few people study them.
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From page 67... ...
. No population estimates or trends have been obtained, but neither is considered to be facing conservation threats by the Mexican government and neither appears on the International Union for the Conservation of Nature and Natural Resources/The World Conservation Union Red List of threatened species (http://www.iucnredlist.org/)
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From page 68... ...
of these three species in the genus Leptonycteris are stable. However, taking those species off the threatened or endangered species list may be premature.
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Patuxent Wildlife Research Center. Bird banding data collected by individuals or at bird banding stations are compiled by the North American Bird Banding Laboratory, (http://www.pwrc.usgs.gov/bbl/)
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, in the states where the credibility index is high, the trend from 1966 to 2005 is mixed;
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(1983) reported that, over a 10-year period at the Rocky Mountain Biological Laboratory, the population of S
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. Some bird species of these genera are on the Mexican federal list of endangered species: six vireo species are under special protection, two species are threatened, and one is endangered.
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. At least two bumble bee species could face imminent extinction, and several other pollinators have declined significantly (honey bees and U.S.
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From page 74... ...
It should be noted that there is no evidence of population decline for some species merely because their populations have not been monitored over time. Overall, whether there is a "pollinator crisis" is difficult to ascertain inasmuch as there is no definition of "crisis" that is universally accepted; however, if "decline" is defined as a systematic decrease in population size over time, then there is evidence that some pollinators in North America representing a diversity of taxa are, in fact, in decline.
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