Variation in ovariole number within the Aphidoidea
Several different morphs from over 50 species of aphids were dissected and the number of ovarioles recorded for each. By using these results and published data, details of ovariole number in more than 125 species of aphid from seven families were analysed. Variation in ovariole number between generations was found in six of the seven families studied. Variation within a generation appeared to be restricted to certain subfamilies. Certain trends in variability of ovariole number appear to be linked with the morph of the aphid, migratory morphs (particularly within the Aphididae) having greater variability than non-migratory morphs. Heteroecious aphids tend to show greater variability than autoecious aphids which, in turn, show greater variability than anholocyclic aphids.