. The Biological bulletin. Biology; Zoology; Marine biology. 192 NELLIE M. PAYNE Table I Development of Ephestia k-iihniella Temperature Time required for fast strain Time required for slow strain Number of generations per annum of fast strain Number of generations per annum of slow strain °C. days days 32 35- 37 62- 65 30 41- 43 66- 68 27 43- 45 69- 72 25 50- 53 79- 81 20 63- 65 99-103 15 85- 90 135-157 10 140-175 205-243 8 cannot develop 250-270 — If w = z, or in other words, the reproductive powers of the host and parasite
. The Biological bulletin. Biology; Zoology; Marine biology. 192 NELLIE M. PAYNE Table I Development of Ephestia k-iihniella Temperature Time required for fast strain Time required for slow strain Number of generations per annum of fast strain Number of generations per annum of slow strain °C. days days 32 35- 37 62- 65 30 41- 43 66- 68 27 43- 45 69- 72 25 50- 53 79- 81 20 63- 65 99-103 15 85- 90 135-157 10 140-175 205-243 8 cannot develop 250-270 — If w = z, or in other words, the reproductive powers of the host and parasite are equal, then »-4. or the number of generations required by the parasite to equal the numbers of the host is equal to the quotient of the original number of hosts, divided by the original number of Fig. 1. Duration of development of host and parasite from the time the egg is laid until the emergence of the adult, plotted against temperature. Dotted line, parasite {Microbracon hebetor). Broken line, fast strain of host {Ephestia kuhniella). Solid line, slow strain of host {Ephestia kuhniella). However, Microbracon may lay as many as 22 eggs on a single host. The number of eggs laid on a caterpillar stung by the host varies from 0-22, with a mean value of 10. If a parasite lays 10 eggs on one host, it does not affect the host population as much as if it laid one egg on each of 10 hosts. The number of generations required. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Lillie, Frank Rattray, 1870-1947; Moore, Carl Richard, 1892-; Redfield, Alfred Clarence, 1890-; Marine Biological Laboratory (Woods Hole, Mass. ); Marine Biological Laboratory (Woods Hole, Mass. ). Annual report; HighWire Press. Lancaster, Pa. [etc. ] : Lancaster Press, inc. [etc. ]
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