The Japanese pavement ant Tetramorium tsushimae Emery (Formicidae) is a species of seed-collecting ant found in Japan. However, its role in seed dispersal has not yet been satisfactorily documented. We investigated the seed-carrying behaviour of T. tsushimae both in the laboratory and in the field. In the laboratory, seeds of three common weeds [evening primrose Oenothera biennis (Onagraceae), purslane Portulaca oleracea (Portulacaceae), and dropseed Sporobolus fertilis (Poaceae)] were examined. More than 65% of each kind of seed was carried by the ants, but some were later discarded outside the nest. Among the three, S. fertilis seeds were collected most frequently. The germination rate of the seeds was higher than 80% for both discarded and stored O. biennis and S. fertilis seeds but lower than half for discarded P. oleracea seeds. In the field, the relationship between the ants and the growing locations of O. biennis or P. oleracea was investigated. The distribution of O. biennis plants considerably overlapped with the distribution of T. tsushimae nest holes at all survey sites. The distribution of P. oleracea also overlapped with that of ant nest holes at some sites. In areas where O. biennis and P. oleracea were absent, a high proportion (> 65%) of artificially placed seeds were carried by T. tsushimae. A few months later, O. biennis seedlings were observed near many ant nest holes. The mean distance between the seedlings and seed-set point was 7.2 m. Although P. oleracea seeds were observed near nest holes, their seedlings were not detected. The present results suggest that O. biennis plants benefit from seed dispersal by T. tsushimae and that the distribution of P. oleracea plants might also be influenced by ant foraging behaviour.

中文翻译：

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杂食性tsu虫金刚砂（Formicidae）在三种常见杂草物种中的种子传播

日本路面蚁Tetramorium tsushimae Emery（Formicidae）是一种在日本发现的采种蚂蚁。但是，其在种子传播中的作用尚未得到令人满意的证明。我们在实验室和野外调查了T. tsushimae的种子携带行为。在实验室中，检查了三种常见杂草的种子[月见草月见草月见草（Onagraceae），马齿Port马齿菜（Portulaca oleracea）（马齿ula科）和滴落的Sporobolus fertilis（Poaceae）。每种种子的65％以上都是由蚂蚁携带的，但有些种子后来被丢弃在巢外。在这三者中，S。fertilis种子收集最频繁。废弃和储存的O. biennis和S. fertilis种子的种子发芽率均高于80％，而废弃的P. oleracea种子的发芽率则低于一半。在该领域中，蚂蚁和不断增长的位置之间的关系O. biennis或马齿苋进行了研究。分布O. biennis植株的分布显着重叠T. tsushimae巢孔在所有调查点。油梨的分布在某些地方也与蚁巢孔的分布重叠。在O. biennis和P. oleracea的地区由于缺少，所以高比例（> 65％）的人工放置的种子由tsu虫（T. tsushimae）携带。几个月后，在许多蚂蚁巢穴附近观察到了O. biennis幼苗。幼苗与结实点之间的平均距离为7.2 m。尽管在巢穴附近观察到了油梨种子，但未检测到它们的幼苗。目前的结果表明，O。biennis植物受益于T. tsushimae的种子传播，而P. oleracea植物的分布也可能受到蚂蚁觅食行为的影响。