Systematics of Eucharitidae (Hymenoptera: Chalcidoidea)

真核蝇科是最多样化的寄生昆虫群体之一。所有真核幼虫都是蚂蚁蛹的特化寄生虫。雌性将卵产在植物组织中，活跃的一龄幼虫负责运输到蚁巢。它们在热带地区最常见，但也有少数种类出现在阿拉斯加和育空地区。对53个属的75个成虫形态特征进行系统发育分析的初步结果表明，Eucharitidae与蚂蚁宿主之间的关系具有很强的相关性：1)寄生Myrmicinae似乎与利用蓟马中间宿主进入蚂蚁窝有关，2)寄生Ponerinae与独立幼虫有关，3)寄生Formicinae与蚂蚁被卵团吸引有关。从28S rDNA的D2和D3扩展区收集的数据的初步结果显示，与基于形态学的分析结果有很强的一致性，但也存在需要解决的关键冲突区域。如果得到强有力的证实，分子分析将用于重新评估形态学特征状态编码，并暗示转化序列，以便仅基于形态学对所有属提出更明确的假设。初步分析认为，Gollumiella和Akapala是确定真核菌科行为变化极性的关键要素，今后将重点关注这两个属的新收集和生物学信息的获取。如果使用蓟马中间宿主被证明是Oraseminae和Eucharitinae的祖先模式，这将表明这种行为是该家族的原始行为，并可能表明最初的宿主如何向蚂蚁转移。在trigonalooidea和Elasmus （Chalcidoidea）中，寄主从鳞翅目寄主的超寄生祖先转变为鳞翅目寄主的膜翅目捕食者，从而适应了对社会性寄主的寄生。如果通过猎物对捕食者的适应对这些群体中的每一个都是正确的，那么这个一般假设可以应用于其他社会性昆虫的拟寄生虫。在自然或农业系统中，蠓科是控制昆虫种群数量的重要类群之一。在估计的40万种物种中，只有大约2万种被命名，已知的生物学知识要少得多，这是一个相对不为人知的群体。Eucharitidae在这个组合中是不寻常的，因为它们的属和种都是众所周知的，它们的生物学特征相对保守，与最初的关系分析相一致。此外，它们还显示出高度的地理地方性，与大约4000万到7000万年前南部大陆的分裂相对应。通过多种方法（分子、形态和行为）提供一个强有力的系统发育假说，我们可以更好地理解宿主转移的机制和相关的分类多样性增加。对真核蝗科的系统发育和行为进化的理解，将为今后对真核蝗科的比较研究提供一个模型系统。

Eucharitidae are one of the most diverse parasitic groups attacking eusocial insects. All eucharitid larvae are specialized parasites of ant pupae. Females deposit their eggs in plant tissue, and the active first-instar larvae are responsible for gaining transport to the ant nest. They are most common in tropical regions, but a few species occur as far north as Alaska and the Yukon. Initial results from a phylogenetic analysis of the 53 genera using 75 morphological features of adults indicate a strong correlation between the relationships of Eucharitidae and their ant hosts: 1) parasitism of Myrmicinae appears correlated with use of a thrips intermediate host to gain access to the ant brood, 2) parasitism of Ponerinae is correlated with independent larvae, and 3) parasitism of Formicinae is associated with the attraction of ants to the egg mass. Preliminary results from data collected for the D2 and D3 expansion regions of 28S rDNA show a strong correspondence with results from morphology-based analyses, but not without critical areas of conflict that need to be resolved. If strongly corroborated, molecular analyses will be used to reevaluate morphological character state coding and also to imply transformation series so that a more resolved hypothesis can be proposed for all genera based on morphology alone. Preliminary analyses suggest that Gollumiella and Akapala are key elements for establishing the polarity of behavioral changes in Eucharitidae, and emphasis will be made on obtaining new collections and biological information for these genera. If use of a thrips intermediate host is shown to be an ancestral mode for Oraseminae and Eucharitinae, this would suggest the behavior as primitive for the family and might indicate how the initial host shift to ants may have occurred. In Trigonalyoidea and Elasmus (Chalcidoidea), adaptation to parasitism of eusocial hosts may have been accomplished through a host shift from ancestors that were hyperparasitic in lepidopteran hosts to the hymenopteran predators of those Lepidoptera. If adaptation through a prey item to the predator is true for each of these groups, this general hypothesis could be applied to other parasitoids of eusocial insects.In natural or agricultural systems, Chalcidoidea are one of the most important groups controlling insect populations. With only about 20,000 of the estimated 400,000 thousand species named, and far fewer with known biology, this is a relatively unknown group. Eucharitidae are unusual within this assemblage because the genera and species are well known and they have a relatively conservative biology that corresponds with the initial analyses of relationships. As well, they show a high degree of geographic endemism that corresponds with the breakup of the southern continents approximately 40 to 70 million years ago. By providing a robust phylogenetic hypothesis using multiple methods (molecular, morphological and behavioral), we can better understand the mechanism of host shifts and the correlated increase in taxonomic diversity. A resolved phylogeny and understanding of behavioral evolution for Eucharitidae would form a model system for future comparative studies across the superfamily.