Chromosomes of two species of the tribe Aylacini (Cynipidae), Isocolus jaceae (Schenck, 1863) and I. scabiosae (Giraud, 1859) (both have 2n = 18) were studied for the first time. In addition, 2n = 20 is confirmed in a member of the same tribe, Aulacidea hieracii (Bouché, 1834). All chromosomes of these gall wasps are biarmed; however, they gradually decrease in size in the case of A. hieracii, whereas a pair of large metacentrics is characteristic of karyotypes of both Isocolus Förster, 1869 species. Chromosomes of the two latter gall wasps are either metacentric or submetacentric, but elements with lower centromeric indices prevail in the karyotype of A. hieracii. Chromomycin A3 (CMA3)/DAPI staining revealed single CMA3-positive bands on a particular pair of chromosomes of all species, and these bands apparently refer to the nucleolus organizing regions (NORs). However, localization of CMA3-positive bands differs substantially between the studied members of Isocolus and Aulacidea Ashmead, 1897. Together with normal haploid and diploid mitotic divisions, several metaphase plates with 2n = 17 containing a peculiar dicentric chromosome were found in a single male specimen of I. scabiosae; this appears to be the first report of an obvious dicentric in the order Hymenoptera in general. Certain aspects of the chromosome diversity and karyotype evolution within the family Cynipidae and the tribe Aylacini in particular are briefly discussed.

中文翻译：

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Aylacini部落（膜翅目，Cynipidae）的三只胆蜂的染色体

第一次研究了 Aylacini 部落（Cynipidae），Isocolus jaceae（Schenck，1863）和 I. scabiosae（Giraud，1859）（两者都有 2n = 18）的两个物种的染色体。此外，2n = 20 在同一部落 Aulacidea hieracii (Bouché, 1834) 的成员中得到证实。这些瘿蜂的所有染色体都是双臂的。然而，在 A. hieracii 的情况下，它们的大小逐渐减小，而一对大的中性着丝点是 Isocolus Förster, 1869 种的核型的特征。后两种瘿蜂的染色体是中着丝粒或亚中着丝粒，但着丝粒指数较低的元素在 A. hieracii 的核型中占优势。Chromomycin A3 (CMA3)/DAPI 染色显示所有物种的一对特定染色体上有单个 CMA3 阳性条带，这些条带显然是指核仁组织区 (NOR)。然而，CMA3 阳性条带的定位在所研究的 Isocolus 和 Aulacidea Ashmead 成员之间存在很大差异，1897 年。连同正常的单倍体和二倍体有丝分裂分裂，在单个男性标本中发现了几个具有 2n = 17 的中期板，其中包含一条特殊的双着丝粒染色体I. scabiosae; 这似乎是一般膜翅目中明显的双着丝粒的第一份报告。简要讨论了 Cynipidae 科和 Aylacini 部落内染色体多样性和核型进化的某些方面。连同正常的单倍体和二倍体有丝分裂，在 I. scabiosae 的单个雄性标本中发现了几个含有特殊双着丝粒染色体的 2n = 17 中期板；这似乎是一般膜翅目中明显的双着丝粒的第一份报告。简要讨论了 Cynipidae 科和 Aylacini 部落内染色体多样性和核型进化的某些方面。连同正常的单倍体和二倍体有丝分裂，在 I. scabiosae 的单个雄性标本中发现了几个含有特殊双着丝粒染色体的 2n = 17 中期板；这似乎是一般膜翅目中明显的双着丝粒的第一份报告。简要讨论了 Cynipidae 科和 Aylacini 部落内染色体多样性和核型进化的某些方面。