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The seasonal foraging sequence of the Camponatus sp. ant on the flowering buttons of the Neoraimondia arequipensis subsp. roseiflora (Werdermann & Backeberg) Ostolaza (Cactaceae) cactus was the subject of a study at Umarcata hills, lower Rio Chillon basin, Lima, Peru. Fifteen mature cacti plants were marked randomly and the number of total buttons, up to a maximum of 50 buttons, produced by each plant was registered monthly, during twelve months, and the observed total number of ants in each flowering button was simultaneously recorded. Observations were taken monthly from October 2003 to September 2004. Similarity matrices between these months, based on phenological and ant-related data, were compared by the Procrustes technique of rotational axis. A randomized test, Procrustes test or Protest with 1000 permutations, was used to analyze the significance of (non random) association between the configurations obtained by non parametric multidimensional acaling (NMDS) ordenation technique. Ants forage the nectar secreted over the flowering buttons, from the time they are covered by the areoles plush hair till they open as pink flowers. Ant visits show a peak during the months of March, April and May, reaching their maximum in April in response to the recurrent cactus phenophase, temperature and relative humidity. There is an association between the number of flower buttons produced and the number of visiting ants, which is intensified during April, July, October and November, and becomes weaker during the remaining months, which might respond to food offer and abiotic factors such as temperature and relative humidity. [ABSTRACT FROM AUTHOR]

Monitoring of the daily activity of the Camponotus sp. ant over the Neoraimondia arequipensis subsp. roseiflora (Werdermann & Backeberg) Ostolaza cactus was investigated at Umarcata hills, lower Chillon river basin, Lima, Peru. There were three visits to this site: on September 2003, January and August 2004. In each visit, hourly, for a 24-hour period, the number of working-ants on the button surface on the moment that the observer set his or her eyes on the floral button (n=7 buttons on each of 10 plants) was registered. Results show that the activity pattern of Camponotus sp. on these three visits was unimodal, with a maximum between 6 and 7 pm, and a minimum between 6 and 7 am. Similarly, Camponotus sp. presented greater dynamism during night hours. Ant daily activity is not related to temperature, nor relative humidity, but it might be related to photoperiod and the cactus-food offer, which might be reaching its highest nectar production peak during the night, similarly to many other nocturnal flowering cacti. [ABSTRACT FROM AUTHOR]

Ant nests were studied in three olive orchards under different agricultural managements located 20 km from Granada City. In each orchard, the area covered by 60 trees -six 10 trees contiguous rows- and five 100m long and 1m wide transects in the alleyways among the rows were monitored. In the ground under each tree crown and in the alleyways, the position of the nests were determined covering an area of 540 m² (9 m²/tree) and of 500 m² (100 m²/alley) respectively. Nest positions were assessed during May, July and September of 1997 and May of 1998. The distance between ant nests was mapped in the three 1997 months. Ant nests distribution was obtained with the distance to the nearest neighbour method. Results show regular nests distributions for the main ant species –Aphaenogaster senilis, Messor barbarus, Crematogaster auberti, Crematogaster sordidula, Solenopsis latro, Tetramorium semilaeve, Tapinoma nigerrima, Plagiolepis pygmaea, Cataglyphis rosenhaueri- and for all of the species in the orchards but it may turn into a random distribution when the nest density is decreased. The intra-annual nest permanence indeces were low (0.0 % to 57 %) and the inter-annual nests permanence indeces were 0%. The nest renovation indeces ranged from 0.0 % to 100 %. [ABSTRACT FROM AUTHOR]

Ant nests were studied in three olive orchards under different agricultural management located 20 km away from Granada City, Spain. In each orchard, It was monitored the area covered by 60 trees (six contiguous rows of 10 trees each) and five transects of 100 m long and 1 m wide on the alleyways among the tree rows. It was determined for each ant specie, the number of active nests in the ground under each tree crown -9 m²/tree- and in the alleyways -100 m²/alley- for a period of 15 min per tree and per transect between 09:00 and 14:00 hours, during May, July and September of 1997 and 1998. It was also determined the number of ant nests within the tree trunk through five-minute observation intervals. Results indicate that disturbances caused by cultural practices affect the number and abundance of ant nests in the ground under the trees and in the alleys. Olive orchards with an ecological management (Arenales) or abandoned (Colomera 2) showed significantly higher nest density in the ground below the tree than the orchard with pesticide application (Colomera 1). This orchard did not show any nest in the alleys. Cultural practices and pesticide applications done in the abandoned olive orchard resulted in the increase of subsidiary nests and their posterior decrease. Eighty-year old olive trees (Arenales) show nests in their trunks, while 25-year old trees do not show them. [ABSTRACT FROM AUTHOR]

A literature review on Neoraimondia arequipensis subsp. roseiflora (Werdermann & Backeberg) Ostolaza (1998), an endemic cactus in Peru, was performed. Previous researches show that there is a strong relation between the cactus and the ecosystem. This relation is manifested through interactions between this cactus and nurse plants, soil, pollination, seed dispersal, and surrounding enthomofauna, which reinforces the hypothesis that this cactus has a very important role in arid ecosystems and that it is the central axis in the trophic chain of a group of organisms. Finally, we outline future studies that could be carried out in order to understand the role played by this cactus as an axis of the interactions in arid ecosystems in Peru, as well as population's dynamics and community structure in the desert. [ABSTRACT FROM AUTHOR]

Observations were made in an arid ecosystem in the Chillón River Valley, in Lima -- Perú, on July 2003. The relation of the cacti community with the Camponotus sp. ant was determined in four 15 x 15 meters quadrants. The richness of the cacti species was S = 8 and it was found out that the ant forages only in the outside of the Neoraimondia arequipensis ssp. roseiflora bottom flowers. The results suggest that the ant acts as a bioindicator of the presence of external flower nectarines as the successful gaster pressure test conducted in the collected liquid content indicated. A highly significant correlation using the Pearson coefficient, between the number of bottom flowers in N. arequipensis and the foraging ants was obtained. These results on preliminary observations of the Lima's Cactaceae Sub Proyect are very important in this ecosystem with limited biotic elements and extreme abiotic variables. It is an interesting tool for gaining knowledge and for the comprehension of complex ecosystems. [ABSTRACT FROM AUTHOR]