Learning walks in an Australian desert ant, Melophorus bagoti

The Central Australian ant Melophorus bagoti is the most thermophilic ant in Australia and forages solitarily in the summer months during the hottest period of the day. For successful navigation, desert ants of many species are known to integrate a path and learn landmark cues around the nest. Ants perform a series of exploratory walks around the nest before their first foraging trip, during which they are presumed to learn about their landmark panorama. Here, we studied 15 naïve M. bagoti ants transitioning from indoor work to foraging outside the nest. In three to four consecutive days, they performed 3 to 7 exploratory walks before heading off to forage. Naïve ants increased the area of exploration around the nest and the duration of trips over successive learning walks. In their first foraging walk, the majority of the ants followed a direction explored on their last learning walk. During learning walks, the ants stopped and performed stereotypical orientation behaviours called pirouettes. They performed complete body rotations with stopping phases as well as small circular walks without stops known as voltes. After just one learning walk, these desert ants could head in the home direction from locations 2 m from the nest, although not from locations 4 m from the nest. These results suggest gradual learning of the visual landmark panorama around the foragers’ nest. Our observations show that M. bagoti exhibit similar characteristics in their learning walks as other desert ants of the genera Ocymyrmex and Cataglyphis.

Keanekaragaman dan Distribusi Formicidae di Hutan Wisata Sesaot, Lombok Barat NTB

Hutan Wisata Sesaot merupakan kawasan wisata yang berbasis ekologi. Mempertahankan keberadaan sumberdaya hayati di kawasan perlu dilakukan supaya kegiatan wisata terjadi secara berkelanjutan. Salah satu sumberdaya hayati tersebut adalah formicidae. Tujuan penelitian ini untuk menganalisis keanekaragaman dan distribusi spesies formicidae. Data dikoleksi dari sampel yang diambil di 2 stasiun yaitu stasiun 1 berada di jalan masuk utama kawasan hutan wisata Sesaot dan stasiun 1 berada di sebelah utara stasiun 1. Pembatas antara stasiun 1 dan stasiun 2 adalah sungai yang di jadikan tempat pemandian untuk pariwisata. Analisis keanekaragaman menggunakan indeks Shanon-Wienner, dan distribusi spesies diukur menggunakan indeks Morisita. Hasil menunjukkan bahwa indeks keanekaragaman pada stasiun1 (H’= 1,57) dan stasiun 2 (H’= 1,55). Sedangkan nilai indeks Morisita semua spesies > 1. Selama pengamatan berhasil dikoleksi 1493 spesimen dari 5 jenis formicidae yaitu Oecophylla smaragdina, Odontomachus bauri, Monomorium minimum, Melophorus bagoti, dan Formica rufa. Spesies yang paling banyak ditemukan adalah Melophorus bagoti. dan yang paling sedikit adalah Formica rufa. Kesimpulan penelitian ini Indeks keanekaragaman formicidae lebih tinggi pada stasiun 1 dibandingkan dengan stasiun 2. Semua spesies formicidae memiliki pola distribusi mengelompok.

Sociogenetic Organization of the Red Honey Ant (Melophorus bagoti)

Kin selection and inclusive fitness are thought to be key factors explaining the reproductive altruism displayed by workers in eusocial insect species. However, when a colony’s queen has mated with <2 males, workers may increase their fitness by producing their own male offspring. Conversely, when the queen has mated with ≥2 males, workers are expected to increase their inclusive fitness by eschewing the production of their sons and preventing other workers from reproducing as well. Here, we investigated sociogenetic structure and worker reproduction in the red honey ant, Melophorus bagoti. Morphometric analyses revealed that workers belong to one of two distinct subcastes: they are either majors or minors. Using DNA microsatellite markers, we showed that all the colonies had a single, multiple-mated queen and that there was no relationship between worker patriline and worker subcaste. Furthermore, we found that workers were producing males in the presence of the queen, which contrasts with the predictions of inclusive fitness theory. Although our results are based on a small sample, they can serve as the foundation for future research examining worker reproduction in M. bagoti.