In 2008, a fungal pathogen causing severe necrotic leaf and stem lesions on Euphorbia paralias (commonly referred to as sea spurge) was collected in France. The fungus has recently been described as Venturia paralias and offers potential for the classical biological control of sea spurge in Australia, where the plant is invasive in dune and foredune ecosystems. To explore the host range of V. paralias, a series of experiments comprising 45 species from the Euphorbiaceae, Picrodendraceae and Phyllanthaceae families were performed. In addition, the development of V. paralias on leaves of sea spurge and the other species inoculated was examined microscopically. Results revealed that V. paralias is highly specific, only causing disease symptoms on sea spurge and Euphorbia segetalis, its most phylogenetically related species tested that is present in Australia. Microscopic observations showed that the infection process of V. paralias on its two susceptible hosts is similar to that of other Venturia species, with characteristic expanded hyphal networks within the subcuticular space of leaves. In contrast, V. paralias did not penetrate leaves of other species inoculated, except for three (Euphorbia myrsinites, Euphorbia helioscopia and Mercurialis annua) on which it penetrated the leaf cuticle and developed an initial infection hypha that did not expand any further. Results from this study support the conjecture that V. paralias will not pose a threat to valued non-target Euphorbiaceae species should the fungus be approved for introduction to Australia for the biological control of sea spurge.

2008年，在法国收集了一种真菌病原体，该真菌病原体在大戟（Euphorbia paralias）上引起了严重的坏死叶和茎损伤（通常称为海大戟）。这种真菌最近被描述为Paraturas paralias，并为澳大利亚对海浪的经典生物控制提供了潜力，在澳大利亚，该植物在沙丘和龟足的生态系统中具有入侵性。为了探索V. paralias的寄主范围，进行了一系列实验，其中包括大戟科，美人鱼科和毛兰科的45种。此外，在显微镜下检查了海大戟叶片和其他被接种物种上的V. paralias的发育。结果显示V. paralias它具有很高的特异性，只会在大戟和大戟（Euphorbia segetalis）上引起疾病症状，大戟和大戟（Euphorbia segetalis）是澳大利亚检测到的与系统发育最相关的物种。显微镜观察表明，寄生虫在其两个易感宿主上的感染过程与其他Venturia物种相似，并在叶片的表皮下空间内具有特征性的扩展菌丝网络。相反，V。paralias不能穿透其他已接种物种的叶子，除了三个（大戟myrsinites，大戟Helioscopia和Mercurialis annua），它穿透了叶的表皮并形成了最初的感染菌丝，并没有进一步扩大。这项研究的结果支持了V的猜想。如果该真菌被批准引入澳大利亚用于生物防治海潮，那么paralias不会对珍贵的非目标大戟科物种构成威胁。