Published online by Cambridge University Press: 08 April 2017
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.
La biologie de l'aphis, Cerataphis variabilis (H.R.L.) sur Raphia hookeri (Mann & Wendl.) a été étudiée au laboratoire et aux champs en se servant de la cage ‘clip-on’ et d'une cage à manchon. Le premier ‘instar’ a duré 5,1 jours. Le deuxième et le troisième instars ont duré 2,45 jours respectivement tandis que le quatrième instar a duré 2,4 jours. La période totale de développement des nymphes était de 11,3 jours à 26,4 ± 1,43°C et r.h. 83 ± 1,46%; 11,6 jours à 26,4 ± 1,63°C et r.h. 85 ± 1,19%; 12,9 jours à 27,9±1,04°C et r.h. 75,5±1,64%; 12,95 jours à 27,8±0.33°C et r.h. 69±1,23%; 15 jours à 21,4±0.58°C et r.h. 45±1,77%. Ces périodes étaient différentes d'une manière significative au niveau de 5% (LSD = 0,59 jours). Plus la temperature et l'humidité relative montent, plus courte la période de développement (avec température: r = −0,69, 20,8–28,9°C; humidité relative: r = −0,97,43,2–86,2%). Le nombre de progéniture par adulte allait de 54–60 dans une période de 28–31 jours. La longévité allait de 31–34 jours.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.