Bembix rostrata (Hymenoptera: Crabronidae) is a conspicuous digger wasp, which is one of the most threatened species of bees and wasps in central Europe. Its distribution is restricted to sites with grey dunes or similar habitats, which B. rostrata needs for nesting. In the years 2012–2014, we have studied the ecological factors influencing the presence of this species in two localities in the Czech Republic, where this species is still relatively abundant. We found that B. rostrata needs continuity in the characteristics of the locality in time because B. rostrata avoids settling in newly emerging localities with the appropriate substrate. The decline in localities of B. rostrata in the Czech Republic correlated with habitat loss due to afforestation, incorrect conservational management, and isolation of the localities. The newly formed anthropogenic sites with fine-grained loose substrates, such as sandpits or fly ash deposits, were not colonised by B. rostrata. This is in sharp contrast with another species of the genus, Bembix tarsata, which is also endangered, but successfully settled in many bare sand patches on former lignite spoil heaps in the north-west of the country. We found that both species hunt Diptera as a prey for their larvae; both are generalists with a preference for species of the family Syrphidae. Unexpectedly, we found workers of the honeybee Apis mellifera captured as a prey for larvae of B. rostrata.

Implications for insect conservation Newly applied management tools, such as army vehicles use, manual sand scraping, or plant cover removal, have a positive effect on populations of B. rostrata, as well as on other species with similar ecological requirements.

Bembix rostrata（Hymenoptera：Crabronidae）是一种显眼的挖掘性黄蜂，它是中欧最受威胁的蜜蜂和黄蜂物种之一。它的分布仅限于罗氏沼虾需要筑巢的沙丘或类似栖息地的地点。在2012-2014年间，我们研究了在捷克共和国的两个地区影响该物种存在的生态因素，那里该物种仍然相对丰富。我们发现B. rostrata需要在时间特征上保持连续性，因为B. rostrata避免使用合适的基质在新兴的地方定居。B. rostrata的地区减少在捷克共和国，由于植树造林，不正确的养护管理和偏远地区而造成的栖息地丧失与之相关。刚形成的具有细粒疏松底物的人为场所，例如沙坑或粉煤灰沉积物，并未被罗氏沼虾所定殖。这与另一种濒危物种Bembix tarsata形成鲜明对比，但该种却成功地定居在该国西北部以前褐煤弃土堆上的许多裸露沙斑中。我们发现这两个物种都以捕食双翅目为其幼虫的猎物。两者都是通才，都喜欢鳞翅目科的物种。出乎意料的是，我们发现蜜蜂Apis mellifera的工人被捕捞为幼虫的猎物。B. rostrata。

对昆虫保护的意义新近使用的管理工具，例如军车使用，手动刮沙或去除植物覆盖物，对罗氏沼虾种群以及对具有相似生态要求的其他物种产生积极影响。