Showing papers on "Ant colony published in 1978"

Cherries, Ants and Tent Caterpillars: Timing of Nectar Production in Relation in Relation to Susceptibility of Catepillars to Ant Predation

Abstract: The North American black cherry, Prunus serotina Ehrh., has extrafloral nectaries which are most active during the first 3 wk after budbreak. These nectaries attract large numbers of the ant Formica obscuripes Forel, especially to trees within °20 m of an ant colony. The average number of ant visits per bud is highest just after budbreak, decreasing as the number of active extrafloral nectaries decreases. These ants are predacious on many species of insects found on P. serotina, including the eastern tent caterpillar, Malacosoma americanum Fabricus, the major defoliator of black cherry. Formica obscuripes is only able to prey upon M. americanuum within °3 wk of budbreak, after which time, tent caterpillar larvae are large enough that most escape ant predation. Tent caterpillar survivorship was found to be positively related to distance from colonies of F. obscuripes. It is suggested that the ant—cherry relationship is a faculative mutualism and that nectar production is timed so as to maximize the chance of successful ant predation on tent—caterpillar colonies.

Cherries, ants and tent caterpillars: timing of nectar production in relation to susceptibility of caterpillars to ant predation1

Abstract: The North American black cherry, Prunus serotina Ehrh., has extrafloral nectaries which are most active during the first 3 wk after budbreak. These nectaries attract large numbers of the ant Formica obscuripes Forel, especially to trees within ?20 m of an ant colony. The average number of ant visits per bud is highest just after budbreak, decreasing as the number of active extrafloral nectaries decreases. These ants are predacious on many species of insects found on P. serotina, including the eastern tent caterpillar, Malacosoma americanum Fabricius, the major defo- liator of black cherry. Formica obscuripes is only able to prey upon M. americanum within ~3 wk of budbreak, after which time, tent caterpillar larvae are large enough that most escape ant predation. Tent caterpillar survivorship was found to be positively related to distance from colonies of F. obscuripes. It is suggested that the ant-cherry relationship is a facultative mutualism and that nectar production is timed so as to maximize the chance of successful ant predation on tent-caterpillar colonies.

The numbers and distribution of subterranean aphids and their exploitation by the ant Lasius flavus (Fabr.)

Abstract: . 1. Subterranean aphids in old pasture were found to show extremely clumped distributions with about 3000 aphids (omitting first instars) per ant nest throughout the year. 2. They were generally distributed in and away from the nest mounds, but within the ant's foraging territories. 3. At summer temperatures, more than 3000 first instars are lost from the aphid population per ant nest per day and it is concluded that these are eaten by the ants in addition to some older aphids and the honeydew produced. 4. The aphids may therefore provide enough food to maintain the ants with very little extra needed in the form of other prey.