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The life history and population biology of an intertidal aphid, Pemphigus trehernei Foster
Author(s) -
FOSTER W. A.
Publication year - 1975
Publication title -
transactions of the royal entomological society of london
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.865
H-Index - 81
eISSN - 1365-2311
pISSN - 0035-8894
DOI - 10.1111/j.1365-2311.1975.tb00570.x
Subject(s) - aphid , alate , biology , halophyte , population , ecology , salt marsh , homoptera , botany , aphididae , pest analysis , demography , salinity , sociology
SUMMARY1 The fluctuations in the density and composition of populations of Pemphigus trehernei , an aphid that lives on the roots of the halophyte Aster tripolium , were followed on an area of saltmarsh on the north Norfolk coast between 1971 and 1973. 2 The aphid has a typical Pemphigus life‐cycle, but the emphasis is on the non‐sexual anholocycle. Many diapausing aphids overwinter on the marsh and relatively few alates fly to or from it. 3 The aphids are confined to the top 11 cm of soil and are highly aggregated: the dispersion of the population can be fitted to the negative binomial. The absolute density of the populations is relatively low, with a mean value of about 2000 aphids/m 2 of available marsh area. 4 Temperature, host‐plant growth and fungal attack are probably the most important factors affecting seasonal population fluctuations. Up to 50% of the populations may be infected with the fungus Metarrhizium anisopliae , which is widespread in the soil.