沙漠蝗虫平时喜欢单独生活，但有时也会成群结队地迁徙，形成遮天蔽日的蝗灾。
英国一项最新研究发现，成群结队的蝗虫与单独生活的蝗虫相比大脑要大出很多，这说明群体生活方式会对生物的脑结构产生显着影响。研究人员抓捕了一些群聚的蝗虫，将它们分开单独饲养并培育到第三代，然后对群聚和独居两种状态下蝗虫的大脑进行成像分析。结果显示，群聚蝗虫的大脑比独居蝗虫的大脑要大出30％。
分析还显示，虽然是同一物种，但两种状态下蝗虫大脑中不同功能部位的比例也发生了变化。独居蝗虫大脑中有关视觉和嗅觉部位的比例相对较大，这有利于它们探测环境信息；而群聚蝗虫的大脑中与学习和处理复杂信息相关的部位较大。
进行这项研究的奥特博士说，群聚状态下蝗虫大脑发生的显着变化与其生存环境有关，蝗虫通常在缺乏食物的情况下才成群结队地迁徙，其中的单个蝗虫处于高度竞争性的环境中，在抢占食物的同时还需要提防自己成为其他蝗虫的口中餐。他说，这种群体生活带来的挑战也许可以帮助解释为什么许多群居的脊椎动物都进化出特别大的大脑。
研究报告发表在新一期英国《皇家学会学报B》上。（生物谷Bioon.com）
生物谷推荐原文出处：
Proceedings of the Royal Society B:Biological Sciences doi: 10.1098/rspb.2010.0694
Gregarious desert locusts have substantially larger brains with altered proportions compared with the solitarious phase
Swidbert R. Ott* and Stephen M. Rogers
Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ, UK
The behavioural demands of group living and foraging have been implicated in both evolutionary and plastic changes in brain size. Desert locusts show extreme phenotypic plasticity, allowing brain morphology to be related to very different lifestyles in one species. At low population densities, locusts occur in a solitarious phase that avoids other locusts and is cryptic in appearance and behaviour. Crowding triggers the transformation into the highly active gregarious phase, which aggregates into dense migratory swarms. We found that the brains of gregarious locusts have very different proportions and are also 30 per cent larger overall than in solitarious locusts. To address whether brain proportions change with size through nonlinear scaling (allometry), we conducted the first comprehensive major axis regression analysis of scaling relations in an insect brain. This revealed that phase differences in brain proportions arise from a combination of allometric effects and deviations from the allometric expectation (grade shifts). In consequence, gregarious locusts had a larger midbrain∶optic lobe ratio, a larger central complex and a 50 per cent larger ratio of the olfactory primary calyx to the first olfactory neuropile. Solitarious locusts invest more in low-level sensory processing, having disproportionally larger primary visual and olfactory neuropiles, possibly to gain sensitivity. The larger brains of gregarious locusts prioritize higher integration, which may support the behavioural demands of generalist foraging and living in dense and highly mobile swarms dominated by intense intraspecific competition.
