Cooperative escape in ants and robots

The solution of complex problems by the collective action of simple agents in both biologically evolved and synthetically engineered systems involves cooperative action. Understanding the resulting emergent solutions requires integrating across the organismal behaviors of many individuals. Here we investigate an ecologically relevant collective task in black carpenter ants Camponotus pennsylvanicus: escape from a soft, erodible confining corral. Individual ants show a transition from individual exploratory excavation at random locations to spatially localized collective exploitative excavation and escape from the corral. A minimal continuum theory that coarse-grains over individual actions and considers their integrated influence on the environment leads to the emergence of an effective phase space of behaviors in terms of excavation strength and cooperation intensity. To test the theory over the range of predicted behaviors, we used custom-built robots (RAnts) that respond to stimuli and show the emergence (and failure) of cooperative excavation and escape. Overall, our approach shows how the cooperative completion of tasks can arise from relatively simple rules that involve the interaction of simple agents with a dynamically changing environment that serves as an enabler and modulator of behavior.

Keragaman Serangga Nokturnal dan Peranannya terhadap Agroekosistem di Kota Tasikmalaya

Keragaman serangga dinilai dapat memberikan kontribusi terhadap kehidupan manusia, termasuk peranan serangga dalam suatu agroekosistem. Serangga memiliki berbagai peranan dalam agroekosistem meliputi serangga hama, polinator, predator, parasitoid, dan dekomposer. Monitoring serangga merupakan langkah awal yang dapat dilaksanakan guna mengetahui keragaman dan keberadaan serangga dalam suatu agroekosistem. Informasi mengenai keragaman serangga serta peranannya terhadap agroekosistem di kota Tasikmalaya masih sangat terbatas sehingga dirasa perlu untuk melaksanakan monitoring keragaman serangga. Metode yang digunakan dalam penelitian ini adalah dengan pemasangan light trap pada 6 kecamatan berbeda di kota Tasikmalaya yaitu kecamatan Cihideung, Mangkubumi, Tawang, Tamansari, Kawalu, dan Cibeureum selama tiga hari. Serangga yang terperangkap kemudian diidentifikasi dan ditentukan peranannya terhadap agroekosistem. Berdasarkan hasil pemasangan perangkap dan identifikasi, didapatkan 15 spesies serangga berbeda. Sembilan spesies berperan sebagai hama: Drosophila spp., Oryctes rhinoceros, Lepidioma stigma, Leptocorisa acuta, Acanthocephala spp., Scirpophaga innotata, Helicoperva armigera, Spodoptera frugiperda, dan Spodoptera litura. Tiga spesies sebagai polinator: Anopheles spp., Musca domestica, dan Camponotus pennsylvanicus. Dua spesies sebagai predator: Paederus fuscipes dan Ortethrum sabina. Satu spesies sebagai dekomposer: Coptotermes curvignathus.

Ant colonies maintain social homeostasis in the face of decreased density

Interactions lie at the heart of social organization, particularly in ant societies. Interaction rates are presumed to increase with density, but there is little empirical evidence for this. We manipulated density within carpenter ant colonies of the species Camponotus pennsylvanicus by quadrupling nest space and by manually tracking 6.9 million ant locations and over 3200 interactions to study the relationship between density, spatial organization and interaction rates. Colonies divided into distinct spatial regions on the basis of their underlying spatial organization and changed their movement patterns accordingly. Despite a reduction in both overall and local density, we did not find the expected concomitant reduction in interaction rates across all colonies. Instead, we found divergent effects across colonies. Our results highlight the remarkable organizational resilience of ant colonies to changes in density, which allows them to sustain two key basic colony life functions, that is food and information exchange, during environmental change.

Biochemical compositions of black carpenter ant, Camponotus pennsylvanicus (Hymenoptedra : Formicidae)

not availableJahangirnagar University J. Biol. Sci. 6(1): 59-62, 2017 (June)

Biochemical Compositions of Black Carpenter Ant, Camponotus pennsylvanicus

Biochemical compositions of black carpenter ants (Camponotus pennsylvanicus) were analyzed using standard methods. The proximate composition (%) were as follows: crude protein (22.50), crude fibre (1.46), carbohydrate by difference (30.86) and energy (35.4Kcal). The predominant mineral was potassium and nickel was the least. The antinutritional properties (mgkg-1) ranged as follows: Oxalate (1.35), phytate (62.79), and tannins (0.72). The results suggested that the ant may be a good source of nutrition.