The purpose of this study was to identify factors at various time points in life that are associated with surviving to age 90. Data from men enrolled in a cohort study since 1948 were considered in 12-year intervals. Logistic regression models were constructed with the outcome of surviving to age 90. Factors were: childhood illness, blood pressure (BP), body mass index (BMI), chronic diseases, and electrocardiogram (ECG) findings. After 1996, the Short Form-36 was added. A total of 3,976 men were born in 1928 or earlier, and hence by the end of our study window in 2018, each had the opportunity of surviving to age 90. Of these, 721 did live to beyond his 90th birthday.The factors in 1948 which predicted surviving were: lower diastolic BP, lower BMI, and not smoking. In 1960, these factors were: lower BP, lower BMI, not smoking, and no major ECG changes. In 1972, these factors were lower BP, not smoking, and fewer disease states. In 1984, these factors were lower systolic BP, not smoking, ECG changes, and fewer disease states. In 1996, the factors were fewer disease states and higher physical and mental health functioning. In 2008, only higher physical functioning predicted survival to the age of 90. In young adulthood, risk factors are important predictors of surviving to age 90; in mid-life, chronic illnesses emerge, and in later life, functional status becomes predominant.

Senescence is a time of decline; yet many seniors remain active and engaged into very old age. How and why do some seniors live long and keep well? We report the responses to this question from a representative sample of 2,783 Canadian seniors.

Overall, seniors placed primary responsibility for their long lives on their own individual practices, citing keeping active and maintaining good nutrition as the major themes. Physical illness was less significant than the will to adapt to illness and avoid further physical decline as long as possible. Francophone and anglophone respondents differed in the frequency with which they mentioned many of the themes. Francophones focused on life quality and family, while anglophones focused on the self. Systematic gender differences were also identified. Many responses validate existing theories of successful aging, and indicate that Canadian seniors are well-informed, insightful participants in the process of growing old.

Due to increasing life expectancy over time, persons who live into their nineties, known as nonagenarians, are an important and growing segment of the Canadian population. In 2001, there were 130,325 nonagenarians (compared to 3,795 centenarians), and it is estimated that they will top 400,000 by 2026. This paper provides a health profile and an exploratory analysis of selected social determinants of health for community-living nonagenarians, using the 2001 Canadian Community Health Survey (Statistics Canada, 2003). Perceived health, a selection of prevalent chronic illnesses, and several health behaviours are examined. One dominant pattern is the tendency for male nonagenarians to be in better health than their female counterparts. This finding is consistent with research on centenarians and is discussed in terms of a mortality selection effect. Other key findings include the strength of sense of belonging, income, and physical activity as potential social determinants of health, connected to particular dimensions of health status.

Introduction. Ricinodendron heudelotii Baill. est une essence forestière en voie de domestication au Cameroun où la plante est appréciée pour ses vertus alimentaires, écologiques et médicinales. Les dégâts causés par le psylle Diclidophlebia xuani Messi et al. aux jeunes plants, en pépinière ou après leur plantation, constituent l’une des principales contraintes à la domestication de l’espèce. La biologie de ce ravageur a donc été étudiée afin d’envisager son contrôle. Matériel et méthodes. Différents aspects de la biologie de D. xuani ont été abordés : processus d’accouplement, choix du site de ponte par la femelle, maturation sexuelle des imagos, fécondité des femelles, longévité des imagos, développement embryonnaire et larvaire, sex-ratio à l’émergence et spécificité alimentaire. Les expérimentations ont eu lieu dans la région de Yaoundé soit en champ, soit en milieu contrôlé durant les années 2001 et 2002. Résultats et discussion. Les mâles de D. xuani ont émergé avant les femelles et le rapprochement des sexes a eu lieu 15 min environ après la mue imaginale. La longévité des femelles a été de 29 jours en moyenne, celle des mâles, de 7 jours. La ponte a commencé 3 jours après l’émergence et s’est poursuivie jusqu’à la fin de la vie de la femelle. En période chaude (28 °C environ), une femelle a pondu en moyenne 532 œufs pendant toute sa vie ; en période de basses températures (24 °C à 26 °C environ), la fécondité moyenne a été de 758 œufs. Les œufs sont essentiellement déposés sur les étages foliaires les plus jeunes de R. heudelotii. Les développements embryonnaire et larvaire ont duré respectivement 7 jours et 22 jours environ. Le cycle de développement, d’œuf à œuf, a nécessité 32 jours en moyenne. Le sex-ratio a été proche de 1. Conclusion. D. xuani se développe entièrement et sans interruption sur R. heudelotii ; il n’a jamais été rencontré sur d’autres espèces de plantes. Il serait donc étroitement associé à cette plante.

The biological hypothesis that female parasitoids can adjust their fecundity schedule according to host availability, and tradeoff longevity with fecundity was tested in a thelytokous oophagous parasitoid, Trichogramma brasiliensis Ashmead (Trichogrammatidae: Hymenoptera) parasitising the rice moth, Corcyra cephalonica (Stainton) (Lepidoptera: Pyralidae). The tradeoff between early and late reproduction revealed that this wasp was able to exploit practically all available hosts during the first day or first few days of adult life. During spells of host unavailability, it was able to adjust its fecundity schedule accordingly. There was a negative relationship between survival and reproduction. Adult females survived shorter (10 days) when an unlimited supply of hosts was present, but longer (16 days) when no hosts were provided. These observations suggest the potential suitability of T. brasiliensis for inundative releases even in conditions of fluctuating host availability.

The developmental potential of the palm aphid Cerataphis palmae Ghesquière (Homoptera: Pemphigidae) on three dwarf coconut varieties—Malayan dwarf red (Mdr), Malayan dwarf green (Mdg) and Malayan dwarf yellow (Mdy)—was studied in a screenhouse using leaf clip-on cages. Under similar temperature (30°C ± 1.13) and relative humidity (69.8% ± 1.63) conditions, the aphid expressed significant differences in fecundity, longevity and developmental period on the coconut varieties. The total developmental period on Mdr lasted 12.17 ± 0.76 days while on Mdg and Mdy it was 14.84 ± 0.63 and 13.83 ± 1.05 days, respectively. Thus the aphid population increased on the dwarf red variety over a significantly shorter period than it did on the other two varieties. Furthermore, fecundity and longevity of C. palmae on Mdr were significantly higher than on the Mdg and Mdy varieties (P < 0.01). These results indicate that Mdr supports C. palmae development better than the other two palm varieties.

The biology of the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae), on four legumes (faba bean, field pea, lentil and grass pea) was studied in a greenhouse during the 1999/2000 seasons. There was no significant difference in length of nymphal period and number of moults (instars) among the crop species tested. The aphids generally took 9 to 11 days to reach the adult stage with a maximum of 3 moults. Lifespan was significantly longer on lentils than on other crops. Significantly more aphids survived beyond 15 days on lentil than on other crops. Similarly, the reproductive and post-reproductive period and adult longevity were longer on lentil. The pre-reproductive period was significantly higher on field pea than on the other crops. The net reproductive rate (R0) was highest on lentil (103.56 females /female) arid the intrinsic rate of increase (r) was highest on faba bean due to a short generation time (14.27 days). Generally, lifetime fecundity was higher on lentil (115.10/female) due to a higher daily reproduction rate (6.7 nymphs/female/day) on this crop. Nymphal production per aphid was strongly and positively correlated with lifespan, reproductive period and adult longevity but not of the nymphal period. Daily nymph production was significantly correlated with minimum temperature on lentil alone (F = 4.61, P < 0.05). Knowledge of the crop species and varieties susceptible to pea aphid is useful for identifying diets for the mass rearing of aphids for use in resistant variety selection and as diet for artificial natural enemy production. The present experiment indicates that lentil is suitable for both purposes.

Diet change in the cotton stainers, Dysdercus cardinalis and D.fasciatus, occasioned by their migration from Gossypium hirsutum (cotton) to alternate hosts Sterculia rhynchocarpa and Adansonia digitata, was overall beneficial to their bionomics. Only the host Abutilon mauritianum appeared to possess antibiotic effects against the fecundity, fertility and longevity of the stainers. The occurrence in tropical natural ecosystems of both suitable and unsuitable hosts appears to constitute a vital and a viable stainer population-regulatory mechanism. Overall, D. cardinalis exhibited superior reproductive parameters on a variety of diets than did D. fasciatus. The latter apparently suffered profound negative effects on its bionomics when feeding on certain hosts.

Haemocoelic injections of live Escherichia coli and oral administration of three tetracycline compounds, namely Reverin, Maxitet and Terramycin to female Glossina morsilans morsitans prior to their first larviposition, caused a decrease in fecundity, but had no effect on longevity. Trypanosoma brucei brucei and T. congolense administered by haemocoelic injections, however, caused no change in fecundity or longevity, but tsetse infected with T. b. brucei and T. congolense in their mouthparts had decreased fecundity and longevity as compared to controls.

Effects of temperature on female longevity, fecundity and fertility of the sorghum shootfly, Atherigona seccata Rondani, were investigated. The longevity, preoviposition and oviposition periods, eggs per female per day, mean eggs per female and fertility (per cent eggs hatched), for the shootflies maintained at constant temperatures of 20, 25 and 30°C and alternating temperatures of 30°C (photophase) and 20°C (scotophase) referred to as 20–30°C were determined. At lower temperature (20°C), the longevity, preoviposition and oviposition periods were prolonged considerably, while daily egg production, mean fecundity and fertility were decreased. Higher temperature (30°C) had the reverse effect on preoviposition and oviposition periods as well as daily egg production. There was a significant positive correlation between the pupal weight and the number of eggs laid by the fly at 20°C. Egg mortality increased with advance in maternal age. The rate of increase in egg mortality was faster at 30°C than at lower temperatures.

Studies on the effect of various diets on development, longevity and fecundity of Oxycarenus gossypinus were conducted in the laboratory at temperatures of 25–33°C. The mean periods of nymphal development when reared on seeds of okra, kenaf, roselle and cotton were 15.5, 15.7, 15.8 and 18.1 days, respectively.

Mated males lived longer and in decreasing order on okra (59.2 days), roselle (57.5 days) and kenaf (57.3 days) than on cotton (43.5 days). Mated females also lived longer on okra (41.4 days), kenaf (40.1 days) and roselle (39.3 days) than on cotton (32.5 days).

Mated females reared on okra seeds laid significantly the highest mean number of eggs per female per day (15.05 ± 0.87 eggs). But the mean number of eggs oviposited when fed on seeds of kenaf (12.9 ± 1.01 eggs) and roselle (10.9 ± 1.18 eggs) was not significant.

The biology of the aphid, Cerataphis variabilis H.R.L., on Raphia hookeri Mann & Wendl., was studied in the laboratory and the field using a ‘clip-on’ cage and a sleeve cage. The first instar lasted 5.1 days. The second and third instars each lasted 2.45 days, while the fourth instar lasted 2.4 days. The total developmental period of the nymphs was 11.3 days at 26.4 ± 1.43°C and r.h. 83 ± 1.46%; 11.6 days at 26.4 ± 1.63°C and r.h. 85 ± 1.19%; 12.9 days at 27.9 ± 1.04°C and r.h. 75.5 ± 1.64%; 12.95 days at 27.8 ± 0.33°C and r.h. 69 ± 1.23%; 15 days at 21.4 ± 0.58°C and r.h. 45 ± 1.77%. These periods were significantly different at 5% level (LSD = 0.59 days). The higher the temperature and relative humidity the shorter the developmental period (with temperature: r = −0.69, 20.8–28.9°C; r.h.: r = −0.97, 43.2–86.2%). The number of progeny per adult ranged from 54 to 60 in a period of 28–31 days. The longevity ranged from 31 to 34 days.