Bark and ambrosia beetles (Curculionidae, Scolytinae) display a conspicuous diversity of unusual genetic and ecological attributes and behaviors. Reconstructing the evolution of Scolytinae, particularly the large and ecologically significant tribe Cryphalini (pygmy borers), has long been problematic. These challenges have not adequately been addressed using morphological characters, and previous research has used only DNA sequence data from small numbers of genes.

Through a combination of anchored hybrid enrichment, low-coverage draft genomes, and transcriptomes, we addressed these challenges by amassing a large molecular phylogenetic dataset for bark and ambrosia beetles. The resulting DNA sequence data from 251 protein coding genes (114,276 bp of nucleotide sequence data) support inference of the first robust phylogeny of Scolytinae, with a special focus on the species rich tribe Cryphalini and its close relatives.

Key strategies, including inbreeding mating systems and fungus farming, evolved repeatedly across Scolytinae. We confirm 12 of 16 hypothesized origins of fungus farming, 6 of 8 origins of inbreeding polygyny and at least 11 independent origins of a super-generalist host range. These three innovations are statistically correlated, but their appearance within lineages was not necessarily simultaneous.

Additionally, the evolution of extreme host plant generalism often preceded, rather than succeeded, fungus farming. Of the high-diversity tribes of Scolytinae, only Xyleborini is monophyletic, Corthylini is paraphyletic and Cryphalini is highly polyphyletic. Cryphalini sensu stricto is part of a clade containing the genera Hypothenemus, Cryphalus and Trypophloeus, and the tribe Xyloterini. Stegomerus and Cryptocarenus (Cryphalini) are part of a clade otherwise containing all Corthylini. Several other genera, including Ernoporus and Scolytogenes (Cryphalini), make up a distantly related clade. Several of the genera of Cryphalini are also intermixed. For example, Cryphalus and Hypocryphalus are intermingled, as well as Ernoporicus, Ptilopodius and Scolytogenes.

Our data are consistent with widespread polyphyly and paraphyly across Scolytinae and within Cryphalini, and provides new insights into the evolution of inbreeding mating systems and fungus farming in the species rich and ecologically significant weevil subfamily Scolytinae.

树皮和沙棘甲虫（Curculionidae，Scolytinae）表现出明显的多样性，具有不寻常的遗传和生态特性及行为。长期以来，重建鞘翅目的进化，尤其是对具有重大生态意义的隐孢子虫（Cryphalini）（py虫）的进化。这些挑战尚未充分利用形态特征来解决，并且先前的研究仅使用了来自少数基因的DNA序列数据。

通过结合锚定的杂交富集，低覆盖范围的草图基因组和转录组，我们通过积累树皮和失窃甲虫的大分子系统发育数据集来应对这些挑战。来自251个蛋白质编码基因的最终DNA序列数据（核苷酸序列数据的114,276 bp）支持对鞘翅目的第一个稳健的系统发育的推断，特别关注物种丰富的隐孢子虫部落及其近亲。

关键的策略，包括近交交配系统和真菌种植，在整个鞘翅目中不断发展。我们确认了16种假想的真菌种植起源中的12种，近亲繁殖的8种起源中有6种起源，以及超绅士寄主范围的至少11种独立起源。这三个创新在统计上是相关的，但是它们在世系中的出现不一定是同时出现的。

此外，极端寄主植物普遍性的演变通常是在真菌种植之前而不是在成功之后进行的。在Scolytinae的高多样性部落中，只有Xyleborini是单系的，Corthylini是副系的，而Cryphalini是高度多系的。Cryphalini狭义是包含属进化枝的一部分Hypothenemus，梢小和Trypophloeus，与部落Xyloterini。Stegomerus和Cryptocarenus（Cryphalini）是进化枝的一部分，否则包含所有Corthylini。其他几个属，包括Ernoporus和Scolytogenes（Cryphalini），组成了一个遥远相关的分支。隐孢子虫属的几个属也被混合。例如，梢小和Hypocryphalus被混合，以及Ernoporicus，Ptilopodius和Scolytogenes。

我们的数据与Scolytinae和隐孢子虫内部广泛的多系和类系相一致，并为近交交配系统和真菌养殖在物种丰富和具有生态意义的象鼻虫亚科Scolytinae中的进化提供了新见解。