ISSN:
1420-9098
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Description / Table of Contents:
Summary One of us has previously noted: On the one hand that the mean fecundity of females grouped in a breeding cage is reduced and that the eggs are deposited else here than on the branch of the potato plant; on the other hand that grouping diminishes the longevity and especially the food consumption of the insects. We also established a close correlation between the individual food consumption and the fecundity of the females. We resumed the experimental and stimultaneous study of these various factors with lots of 5 grouped females and 5 isolated females. The biometric analysis shows that the “regression” of longevity has a greater meaning than that of food consumption; but the difference between the lots of the isolated and those of the grouped is negligible in respect to longevity. On the contrary, the food consumption of the two binds of lots is markedly different; this explains in part the great difference in fecundity observed: the mean fecundity of the isolated females is 1.440 eggs, and that of the grouped ones 416 eggs. Taking into account the difference in fecundity due to the difference in food consumption, the first is reduced statistically from 1.023 to 677 eggs, the latter can be attributed in a significant manner to the effect of grouping. This phenomenon does not result from aneffet de masse, but presumably from the effect sensorial stimuli inhibiting certain physiological functions in a species that is typically solitary.
Notes:
Résumé Il est établi expérimentalement et analysé biométriquement que des femelles groupées deL. decemlineata présentent, par rapport à des femelles isolées: - une longévité un peu plus grande mais non significativement différente; - une consommation beaucoup plus faible; - une fécondité considérablement réduite. La différence de la fécondité n'est pas seulement due à la différence de consommation, mais vraisemblablement à des facteurs inhibiteurs intrinsèques.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF02225736
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