Schönrogge K, Gardner M G, Elmes G W, Napper E K V, Simcox D J, Wardlaw J C, Breen J, Barr B, Knapp J J, Pickett J A, Thomas J A
Centre for Ecology and Hydrology, CEH Dorset, Winfrith Technology Centre, Dorchester DT2 8XE, UK.
Ecol Lett. 2006 Sep;9(9):1032-40. doi: 10.1111/j.1461-0248.2006.00957.x.
The Red Data Book hoverfly species Microdon mutabilis is an extreme specialist that parasitises ant societies. The flies are locally adapted to a single host, Formica lemani, more intimately than was thought possible in host-parasite systems. Microdon egg survival plummeted in F. lemani colonies > 3 km away from the natal nest, from c. 96% to 0% to < 50%, depending on the hoverfly population. This is reflected in the life-time dispersal of females, measured at < 2 m, resulting in oviposition back into the same ant nests for generation after generation. To counter destabilizing effects on the host, Microdon manipulates the social dynamics of F. lemani by feeding selectively on ant eggs and small larvae, which causes surviving larvae to switch development into queens. Infested colonies rear double the number of new queens, thus propagating the vulnerable local genotype and compensating for damage to the host colonies. The consequences of such extreme host specificity for insect conservation are discussed.
《红色名录》中的食蚜蝇物种多变微食蚜蝇是一种极端特化的物种，它寄生于蚁群。这些苍蝇在当地适应了单一宿主——莱氏蚁，其亲密程度超出了宿主 - 寄生虫系统中原本认为可能的范围。在距离出生地巢穴超过3公里的莱氏蚁群落中，多变微食蚜蝇的卵存活率急剧下降，从约96%降至0%至低于50%，这取决于食蚜蝇的种群数量。这反映在雌性的终生扩散距离上，测量结果显示小于2米，导致一代又一代的雌蝇都在同一个蚁巢中产卵。为了应对对宿主的不稳定影响，多变微食蚜蝇通过有选择地取食蚁卵和小幼虫来操纵莱氏蚁的社会动态，这使得存活下来的幼虫转变为蚁后发育。受感染的蚁群培育出的新蚁后数量是原来的两倍，从而传播了脆弱的本地基因型，并弥补了对宿主蚁群的损害。文中讨论了这种极端宿主特异性对昆虫保护的影响。
