Access

You are not currently logged in.

Access your personal account or get JSTOR access through your library or other institution:

login

Log in to your personal account or through your institution.

If You Use a Screen Reader

This content is available through Read Online (Free) program, which relies on page scans. Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.

The Migratory Ambit of the Hop Aphid and its Significance in Aphid Population Dynamics

L. R. Taylor, I. P. Woiwod and R. A. J. Taylor
Journal of Animal Ecology
Vol. 48, No. 3 (Oct., 1979), pp. 955-972
DOI: 10.2307/4207
Stable URL: http://www.jstor.org/stable/4207
Page Count: 18
  • Read Online (Free)
  • Download ($18.00)
  • Subscribe ($19.50)
  • Cite this Item
Since scans are not currently available to screen readers, please contact JSTOR User Support for access. We'll provide a PDF copy for your screen reader.
The Migratory Ambit of the Hop Aphid and its Significance in Aphid Population Dynamics
Preview not available

Abstract

(1) Of about 320 species of aphids whose aerial distributions were examined, only sexual autumn migrants of the hop aphid (Phorodon humuli Schrank) originated from dense, isolated and persistent population `patches'. (2) These source patches were hop gardens maintained in two small areas in southern England. (3) Patterns of aerial distribution were the same for both sources and for both males and gynoparous females. (4) Parthenogenetic spring alates migrating from native host plants were more evenly distributed and patches could not be isolated because, like all other aphid species, migratory ambits overlapped. (5) As expected, migration was not random, but directional orientation was negligible. (6) Evidence suggests that boundary layer migration, stratiform drift and cumuliform high level migration (L. R. Taylor 1965), were all used on different occasions. (7) The gamma regression models (R. A. J. Taylor 1979a) described the mean density X distance profile; the median distance travelled was 15-20 km and the 95% limit was 100-150 km. The Delta -function probably has extreme parameter values. (8) The regression of log spatial variance on log mean density is identical for the autumn migration of males and gynoparous females; the summer migration of virginoparous females differs in intercept but not in slope.

Page Thumbnails

  • Thumbnail: Page 
955
    955
  • Thumbnail: Page 
956
    956
  • Thumbnail: Page 
957
    957
  • Thumbnail: Page 
958
    958
  • Thumbnail: Page 
959
    959
  • Thumbnail: Page 
960
    960
  • Thumbnail: Page 
961
    961
  • Thumbnail: Page 
962
    962
  • Thumbnail: Page 
963
    963
  • Thumbnail: Page 
964
    964
  • Thumbnail: Page 
965
    965
  • Thumbnail: Page 
966
    966
  • Thumbnail: Page 
967
    967
  • Thumbnail: Page 
968
    968
  • Thumbnail: Page 
969
    969
  • Thumbnail: Page 
970
    970
  • Thumbnail: Page 
971
    971
  • Thumbnail: Page 
972
    972