Department of Forest Protection and Entomology, Faculty of Forestry and Wood Sciences, Czech University of Life Sciences, Prague, Czech Republic.
Sci Rep. 2022 May 9;12(1):7573. doi: 10.1038/s41598-022-11630-w.
Although previous research has documented the occurrence of antagonists of bark beetles, the studies have only evaluated individual antagonists and have not assessed the overall effect of all antagonists on adult beetles. In this study, we determined which body-cavity antagonists were associated with a reduction in the fecundity and maternal gallery lengths of two important species of bark beetles: Ips typographus on Norway spruce and I. cembrae on European larch. We evaluated these relationships under natural conditions by collecting maternal females in galleries and examining their internal organs. The antagonists in the I. typographus hemolymph had significant negative associations with fecundity and gallery length. These antagonists were mainly nematodes and parasitoids in the hemocoel. In contrast, a positive association between gregarine presence and I. typographus fecundity was found. No antagonist that was likely to significantly alter I. cembrae fecundity or maternal gallery length was proven. Our study provides the first comprehensive assessment of antagonists that may have the potential impact on reduction the fecundity and thereby mass occurrence of these bark beetles.
虽然先前的研究已经记录了树皮甲虫的拮抗剂的发生，但这些研究仅评估了单个拮抗剂，并未评估所有拮抗剂对成虫的总体影响。在这项研究中，我们确定了哪些体腔拮抗剂与两种重要的树皮甲虫（挪威云杉上的 Ips typographus 和欧洲落叶松上的 I. cembrae）的产卵量和母体坑道长度减少有关。我们通过在坑道中收集母体雌性并检查其内部器官，在自然条件下评估了这些关系。I. typographus 血淋巴中的拮抗剂与产卵量和坑道长度呈显著负相关。这些拮抗剂主要是血腔中的线虫和寄生蜂。相比之下，发现了疟原虫的存在与 I. typographus 的产卵量呈正相关。没有证明哪种拮抗剂可能会显著改变 I. cembrae 的产卵量或母体坑道长度。我们的研究首次全面评估了可能对减少这些树皮甲虫的产卵量和从而大规模发生有潜在影响的拮抗剂。
