打不死的小強：蟑螂耐藥性可快速增強4到6倍

家裏撒了蟑螂藥，但蟑螂依舊猖狂？最新研究發現，蟑螂對多種殺蟲劑產生了交叉耐藥性，而且這種耐藥性在一代之內提高到之前的6倍。

Cockroaches are stepping up their defenses against the poisons designed to kill them.

蟑螂對殺蟲劑的防禦機制正在加強。

A new study has found that German cockroaches, the Most common species of the insect in the world, are developing cross-resistance to numerous insecticides.

最新研究發現，全球最常見的蟑螂種類德國小蠊正對多種殺蟲劑產生交叉耐藥性。

cross-resistance：交互抗性

Not only were researchers in some cases unable to reduce cockroach numbers during a six-month study period, even when combining different insecticides, but they found the insects' resistance increased up to six-fold within one generation.

在某些情況下，研究人員不僅無法在爲期半年的研究期間殺滅部分蟑螂，甚至使用了多種殺蟲劑也是如此，而且他們發現，蟑螂的耐藥性在一代之內提高到之前的6倍。

'This is a previously unrealized challenge in cockroaches,' said Purdue University professor Michael Scharf.

普渡大學教授邁克爾·沙夫說：“我們之前在蟑螂身上從未遇到過的挑戰。”

'Cockroaches developing resistance to multiple classes of insecticides at once will make controlling these pests almost impossible with chemicals alone.'

他說：“蟑螂同時對多種殺蟲劑產生耐藥性將使單純利用化學物質控制它們變得幾乎不可能。”

The study published in the journal Scientific Reports focused on the species Blattella germanica L, which can be found all around the world.

這項研究發表在《科學報告》雜誌上，重點研究了德國小蠊這種遍佈全球的蟑螂種類。

The team tested different insecticides from different classes, and combinations of the bunch, in multi-unit buildings in Indiana and Illinois over a period of six months.

研究小組在半年時間內在印第安納州和伊利諾伊州的多單元建築物中測試了不同種類的殺蟲劑及其組合。

Exterminators often mix insecticides of different classes to ensure they're eliminating bugs that have developed resistance to one, the authors note.

研究報告的作者指出，滅蟲者通常會混合不同類別的殺蟲劑，以確保能夠殺滅對某一種殺蟲劑產生耐藥性的害蟲。

exterminator [ɪk'stɜːmɪneɪtə]：n.根除者；職業的消滅害蟲者

Roaches were captured from the sites before the lab to assess the best treatment for each scenario.

研究人員從實驗室前的多個地點捕捉蟑螂，以評估每種情況下的最佳方案。

'If you have the ability to test the roaches first and pick insecticide that has low resistance, that ups the odds,' Scharf said.

沙夫說：“如果能先測試蟑螂，然後挑選耐藥性弱的殺蟲劑，那就增加了殺滅機率。”

'But even then, we had trouble controlling populations.'

“但是即便如此，我們也很難控制蟑螂的數量。”

The team says it was able to keep the roach populations stable during the study period, but could not make a significant dent in their numbers.

研究小組稱，在研究期間蟑螂數量能夠維持穩定，但無法大幅減少。

With the two-insecticide mixture, the pests even appeared to thrive.

在使用了兩種殺蟲劑的混合物之後，蟑螂數量甚至增加了。

One of the single-insecticide experiments suggested the population was at first vulnerable to the method, and in that case they were able to mostly wipe them out. But, in another trial with 10 percent starting resistance, the population grew despite treatment.

其中一項單一殺蟲劑試驗表明，蟑螂起初對此很敏感，在這種情況下，大多數蟑螂基本上都被殺滅了。但是，在另一項耐藥性達到10%的試驗中，儘管使用了殺蟲劑，蟑螂數量還是增加了。

Surviving roaches then led to more resistant offspring.

倖存下來的蟑螂會生育出耐藥性更強的後代。

'We would see resistance increase four- or six-fold in just one generation,' Scharf said.

沙夫說：“我們發現，耐藥性在僅僅一代之內就增加了4到6倍。”

'We didn't have a clue that something like that could happen this fast.'

“我們此前不知道耐藥性會發展得如此之快。”

Female cockroaches can produce as many as 50 offspring during their three-month reproductive cycle.

雌性蟑螂可以在其三個月的繁殖週期內產下多達50個後代。

Even a small percentage of resistance and the potential for cross-resistance could mean a cockroach population just keeps coming back.

即便是很小的耐藥性比例和交叉耐藥性的可能性也意味着蟑螂會不斷繁衍。

'Some of these methods are more expensive than using only insecticides, but if those insecticides aren't going to control or eliminate a population, you're just throwing money away,' Scharf said.

沙夫說：“一些殺滅蟑螂方法的成本要高於僅使用殺蟲劑，但是如果這些殺蟲劑不能控制或殺滅蟑螂，那就是在浪費錢。”

'Combining several methods will be the most effective way to eliminate cockroaches.'

他說：“多種方法結合將是消滅蟑螂最有效的方法。”

爲什麼殺滅蟑螂這麼難？

The American cockroach (Periplaneta americana) is an omnivorous scavenger and one of the largest insect species that lives in close proximity to humans.

美國蟑螂（美洲大蠊）是一種雜食性食腐動物，是與人類生活在一起的最大的昆蟲之一。

omnivorous[ɒm'nɪv(ə)rəs]：adj.雜食的；無所不吃的

scavenger ['skævɪn(d)ʒə]：n.食腐動物

in close proximity to：與…靠得很近

It has one of the largest genomes known to exist among insects, second only to the common locust.

這種蟑螂的基因組在已知的昆蟲基因組中位於最大之列，僅次於常見的蝗蟲。

genome ['dʒiːnəʊm]：n.基因組；染色體組

In total, the species has 20,000 genes - which is the same number as a human.

美國蟑螂一共有2萬個基因，這與人類的基因數量相同。

Some genes control its internal detoxification system, which means the cockroach doesn't get ill if it eats toxic food.

一些基因控制着蟑螂體內的解毒系統，這意味着如果蟑螂吃了有毒食物不會有不適反應。

detoxification [di,tɑksɪfɪ'keʃən]：n.解毒

More genes help it combat infections, meaning it is resilient to living in filthy conditions.

更多的基因幫助它們對抗感染，這意味着蟑螂能在骯髒的環境中生存。

filthy ['fɪlθɪ]：adj.骯髒的

Cockroaches can also regrow limbs thank to its remarkable genetic sequence.

蟑螂還能重新長出四肢，這要感謝其非凡的基因序列。

Scientists have also found that female cockroaches are so resilient they don't need a male partner.

科學家還發現，雌性蟑螂的適應力很強，不需要雄性伴侶。