umbis buscam a luz? Camponotus atriceps infectadas por Ophiocordyceps camponoti-atricipis morrem em locais mais iluminados na Amazônia Central Brasileira

Abstract

Specialized parasites can modify the behavior hosts to increase chances of reproduction. This behavior is considered an example of extension phenotype of the parasite. We study the relationship of the fungus Ophiocordyceps camponoti-atricips, a specialized parasite, with the carpenter ants Camponotus atriceps. Once infected by O. camponotiatricips, the ants dies in places with stable temperature and relative humidity. The reproduction of the parasite is locally increased on these areas. However, light is responsible for controlling the reproduction of several species of free-living fungi, and may play an important role in the terminal phase of parasitic fungal infection. On this work, we evaluate the effect of luminosity in selected sites of dead infected C. atriceps ants. In 10 graveyards (sites near of foraging trails with many infected dead ants), the luminosity was reduced 80% through shading screens in half of the plots area. We identified dead infected C. atriceps using colored marking ribbons over 6 months of fieldwork. The infected ants that died after establishment of the plots were monitored. We measured the number of fruiting bodies, height above ground and the orientation of infected ants in the field. The selected sites of infected C. atriceps shows strong influence by experimental light reduction. The shaded areas received 53 ants (32, 7%) in comparison to the adjacent control area, with 109 (67, 3%) ants. In addition, in the shaded areas only 15 dead ants produced fruiting bodies. In the control areas, 41 dead ants developed fruiting bodies. The infected C.atriceps also died at higher sites in the shaded areas (140 cm) in relation to the control areas (110 cm). Our findings suggest that light may have act in the place death of parasitized C.atriceps ants and therefore play an important role on reproductive cycle of the fungus O. camponoti-atricips.