The Company of Biologists

Table 1.

Development time, daily reproduction, fecundity and longevity of first instar nymph and newly moulted pre-reproductive adults

	Development time to adult (days)	Mean daily fecundity (nymphs per day)	Mean total fecundity (nymphs per adult)	Mean length of reproductive life (days)	Longevity (days)
Control nymphs	18.8±0.2^a	1.1±0.1^a	37.3±2.6^a	37.7±2.6^a	58.5±2.6^a
RCH nymphs	18.7±0.5^a	1.3±0.1^a	46.1±2.6^a	38.9±2.5^a	59.5±2.4^a
Exposed nymphs	18.1±0.4^a	1.6±0.1^b	50.7±2.6^b	35.7±2.5^a	56.3±2.5^a
Control adults	n/a	0.9±0.1^y	16.8±1.5^y	21.7±2.2^y	42.7±2.2^y
RCH adults	n/a	1.1±0.1^y	33.1±1.7^z	32.3±2.1^z	53.3±2.1^z
Exposed adults	n/a	1.1±0.1^y	34.6±2.7^z	33.2±2.7^z	54.2±2.7^z

	Development time to adult (days)	Mean daily fecundity (nymphs per day)	Mean total fecundity (nymphs per adult)	Mean length of reproductive life (days)	Longevity (days)
Control nymphs	18.8±0.2^a	1.1±0.1^a	37.3±2.6^a	37.7±2.6^a	58.5±2.6^a
RCH nymphs	18.7±0.5^a	1.3±0.1^a	46.1±2.6^a	38.9±2.5^a	59.5±2.4^a
Exposed nymphs	18.1±0.4^a	1.6±0.1^b	50.7±2.6^b	35.7±2.5^a	56.3±2.5^a
Control adults	n/a	0.9±0.1^y	16.8±1.5^y	21.7±2.2^y	42.7±2.2^y
RCH adults	n/a	1.1±0.1^y	33.1±1.7^z	32.3±2.1^z	53.3±2.1^z
Exposed adults	n/a	1.1±0.1^y	34.6±2.7^z	33.2±2.7^z	54.2±2.7^z

Control: aphids were maintained continuously at 10°C; RCH: aphids acclimated at 0°C for periods of time producing the highest survival at the discriminating temperature (2 h for nymphs and 30 min for adults) and then returned to 10°C. Exposed: aphids rapidly cold-hardened at 0°C for 2 h(nymphs) or 30 min (adults), prior to a 3 h exposure at the discriminating temperature (-11.5°C for nymphs and -12°C for adults).

n/a, not applicable.

Values are mean ± s.e.m. The letters in brackets indicate statistical significance; those with the same letter are not significantly different at P<0.05 (Tukey multiple comparison test). N=50.

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