Johnson Robert A
Department of Biology, Arizona State University, Tempe, AZ, 85287-1501, USA.
Oecologia. 2002 Jun;132(1):60-67. doi: 10.1007/s00442-002-0960-2. Epub 2002 Jun 1.
The evolution of queens that rear their first brood solely using body reserves, i.e. fully claustral, is viewed as a major advance for higher ants because it eliminated the need for queens to leave the nest to forage. In an apparently unusual secondary modification, the seed-harvester ant Pogonomyrmex californicus displays obligate queen foraging, i.e. queens must forage to garner the resources necessary to survive and successfully rear their first brood. I examined the potential benefits of queen foraging by comparing ecological and physiological traits between P. californicus and several congeners in which the queen can rear brood using only body reserves. The primary advantage of foraging appears to lie in providing the queens of P. californicus with the energy to raise significantly more brood than possible by congeners that use only body reserves; the workers reared in the first brood were also heavier in mass than that predicted by their head width. Other correlates of queen foraging in P. californicus relative to tested congeners included a significantly lower total fat content for alate queens, a small queen body size, and a low queen to worker body mass ratio. Queens also forage in several other well-studied species of Pogonomyrmex, suggesting the possibility that queen foraging may be more common than previously thought in higher ants.
仅利用身体储备来抚育第一批幼虫的蚁后（即完全封闭巢居的蚁后）的进化，被视为高等蚂蚁的一项重大进步，因为这消除了蚁后离开巢穴觅食的需求。在一种明显不寻常的次生变异中，收获种子的加州收获蚁（Pogonomyrmex californicus）表现出强制性的蚁后觅食行为，即蚁后必须觅食以获取生存和成功抚育第一批幼虫所需的资源。我通过比较加州收获蚁与几种同属蚂蚁的生态和生理特征，研究了蚁后觅食的潜在益处，在这些同属蚂蚁中，蚁后仅利用身体储备就能抚育幼虫。觅食的主要优势似乎在于为加州收获蚁的蚁后提供能量，使其能够抚育比仅利用身体储备的同属蚂蚁多得多的幼虫；第一批幼虫中培育出的工蚁体重也比根据其头宽预测的要重。与经过测试的同属蚂蚁相比，加州收获蚁蚁后觅食的其他相关特征包括有翅蚁后的总脂肪含量显著较低、蚁后体型较小以及蚁后与工蚁的体重比低。在其他几种经过充分研究的收获蚁物种中，蚁后也会觅食，这表明蚁后觅食在高等蚂蚁中可能比以前认为的更为普遍。
