美国夏威夷农业部门的官员希望利用昆虫学家在非洲东部发现的一种蜂来拯救夏威夷本地的刺桐树。这种“以蜂制蜂”的方法目前正处于实验室试验阶段。
据美联社3月6日报道,为了对抗刺桐瘿蜂(Erythrina gall wasp)对刺桐树的破坏,美国昆虫学家莫森·拉马丹花了两个月的时间在非洲坦桑尼亚寻求解决办法。最终,拉马丹发现了一种靠食用瘿蜂的幼虫和蛹为生的属于广肩小蜂属(Eurytoma)的胡蜂。在坦桑尼亚,这种广肩小蜂会对大约95%的瘿蜂发动攻击。
目前,夏威夷农业部官员已经在这种广肩小蜂身上进行了有关测试,以确保它除了只对瘿蜂起作用外,不会伤害其它任何物种。而测试全过程以及随后获得该州及联邦有关机构的正式批准需要大概1年的时间。上个星期,这种尚未被命名的广肩小蜂已经在实验室里产下了第一代小蜂。对此,拉马丹表示:“如果这个方法被证实是有特效作用的,”“那么它将拯救夏威夷的刺桐树。”
报道说,刺桐瘿蜂不仅对于夏威夷是个新鲜的物种,对整个世界也是一样。3年前,人们在中国台湾地区首次发现了该物种,2004年又在新加坡和毛里求斯等地发现了它的踪迹。自刺桐瘿蜂去年4月份在瓦胡岛被发现以来,就迅速蔓延至夏威夷各个主要岛屿。从那时起,夏威夷本地的刺桐树也因此遭到了严重破坏。刺桐树通常被用于美化景观,这种被称为“热带珊瑚”的树种也以“高刺桐”著称于世。
State officials are hoping to save Hawaii's native wiliwili tree with a bug found in eastern Africa.
Mohsen Ramadan, a state exploratory entomologist, spent two months in Tanzania looking for a natural solution to fight the wiliwili-destroying Erythrina gall wasp and found a wasp of the Eurytoma species.
The Eurytoma wasps feeds externally on gall wasp larvae and pupae. It attacks 95 percent of gall wasps in Tanzania.
The gall wasp found its way to all of the main Hawaiian islands after being discovered on Oahu in April. Since then, it began ravaging the wiliwili, which is regularly used for landscaping, and the "tropic coral," also known as "tall erythrina."
Hawaii agriculture officials have been conducting tests on the Eurytoma species and to ensure it doesn't pose threats to anything other than the gall wasp.
It could take up to a year for the testing to be completed and to obtain approval from state and federal agencies for permits to release the parasite.
State Department of Agriculture Plant Pest Control Branch biocontrol section officials are encouraged by what they've seen in lab tests of the Eurytoma wasp, which doesn't have a name. The parasitoid produced its first generation in their lab last week, at the expense of gall wasps.
"If this proves to be specific," Ramadan said, meaning there's no threat other than to gall wasps, "it will save the wiliwili."
The gall wasp is a new species, not only to Hawaii, but worldwide. Its presence was first documented three years ago in Taiwan, and in Singapore, Mauritius and Reunion in 2004, said state biocontrol section chief Kenneth Teramoto.
Teramoto said he thinks the pest may have arrived in Hawaii from Taiwan, which has a developing ornamental-plant industry.
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