美國計劃繁殖數百萬隻蒼蠅，並將其從飛機上投放。原因如下 (2/2)

Recently Yahoo News on-line picked up the following:

The US has a plan to breed millions of flies and drop them from planes. Here’s why (2/2)

Kameryn Griesser, CNN

Thu, July 10, 2025 at 3:27 a.m. PDT·7 min read

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Fighting flies with flies: How it works

Just like a caterpillar goes into a cocoon before becoming a butterfly, the New World screwworm becomes a black, pill-sized pupa before emerging as an adult fly, Kaufman explained.

In a sterile fly production facility, the pupae are subjected to high-energy gamma rays that break down the DNA of the males, damaging their sex chromosomes, according to the USDA. The result: impotent adult flies that cause female mates to lay unfertilized eggs.

The amount of radiation the male flies are exposed to does not pose a danger to animals or humans, according to the USDA. But since the female flies only mate one time in their short, 20-day lifespan, once populations are exposed to sterile males, the populations die out over the course of months or years, depending on the size of the outbreak.

While it is unclear how dispersal would work in the US in the event of an outbreak, Kaufman said the adult flies are typically loaded into temperature-controlled containers and dropped from planes. However, there’s no need to panic about the fly drops coming to a suburb near you, he said — they usually target sparsely populated rural areas, since the flies have no interest in urban environments.

A pricey battle

At the COPEG facility, about 100 million sterilized flies are produced and dispersed aerially in affected regions each week.

Currently, the dispersal efforts have been focused in the southern regions of Mexico and throughout Central America, where cases of infestation have been reported, according to COPEG’s website.

The new US dispersal facility is expected to be located at the Moore Air Base in Hidalgo County, Texas, and to cost $8.5 million, per the release. The location and price tag of the production facility, or the “fly factory” itself, has not been revealed, but lawmakers estimate it could cost around $300 million.

In addition to the new sterile fly facilities, the USDA also announced $21 million plans to renovate an old fly factory in Mexico by late 2025.

While the plans are expensive, it’s a price worth paying to save the multibillion-dollar livestock industry, Diebel said.

‘When you offset the $300 million to the $10 billion of economic impact these flies would have, it’s an easy trade-off to understand,” Diebel said. “Having (a domestic production facility) here is super important … to control the distribution of those sterile flies more efficiently.”

Shortly after the June 18 announcement, the USDA shared plans to begin reopening livestock trading ports in Arizona, Texas and New Mexico that closed last year, citing “good progress” in surveillance and sterile fly dispersal efforts throughout Mexico.

COPEG did not immediately respond to request for comment on further details about the current progress of the US dispersal initiatives.

Translation

美國計劃繁殖數百萬隻蒼蠅，然後從飛機上投放。原因如下 (2/2)

（繼續）

以蠅治蠅：工作原理

Kaufman 解釋說，就像毛毛蟲在變成蝴蝶之前會先結繭一樣，新大陸螺旋蠅會先變成一個藥丸大小的黑色蛹，然後成熟為成年蒼蠅。

據美國農業部稱，在生產絕育蒼蠅設施中，蛹會受到高能量伽馬射線的照射，這種射線會破壞雄蠅的DNA，損傷其性染色體。結果是：成年蒼蠅喪失性能力，導致雌蠅產下未受精的卵子。

據美國農業部稱，雄蠅所受的輻射劑量不會對動物或人類構成危險。但由於雌蠅在其短短20天的生命週期中僅交配一次，一旦族群接觸到不孕雄蠅，族群就會在數月或數年內逐漸消亡，具體時間取決於疫情規模。

雖然目前尚不清楚美國在疫情爆發時將如何進行散播，但 Kaufman 表示，成年蠅通常會被裝入溫控容器中，然後從飛機上空投。不過，他表示，無需擔心這些散播蒼蠅會飛到你附近的城市以外的住宅區 - 它們通常以人口稀少的農村地區為目標，因為這些蒼蠅對城市環境不感興趣。

 

一場代價高昂的戰鬥

在 COPEG 的設施中，每週約有1億隻不孕蠅被生產並透過空中散播到受影響的地區。

目前，根據 COPEG 網站的訊息，散播工作主要集中在墨西哥南部地區和整個中美洲地區，這些地區已報告了感染病例。

據新聞稿稱，新的美國蒼蠅散播設施預計將位於德克薩斯州伊達爾戈縣的摩爾空軍基地，耗資850萬美元。生產設施, 或稱為「蒼蠅工廠」本身的地點和造價尚未公佈，但立法者估計其成本可能約為3億美元。

除了新的蒼蠅不育設施外，美國農業部還宣布了一項耗資2,100萬美元的計劃，將在2025年底前翻新墨西哥的一家舊蒼蠅工廠。

Diebel表示，雖然這些計劃耗資巨大，但為了拯救價值數十億美元的畜牧業，這筆代價是值得的。

Diebel說: 「如果用3億美元去抵消這些蒼蠅可能造成100億美元損失的經濟影響來看，那麼其中的利弊就很容易理解了」; 「在這裡建立（國內生產設施）至關重要……這樣才能更有效地控制這些不育蠅的散播」。

6月18日公告發布後不久，美國農業部宣布計劃重新開放亞利桑那州、德克薩斯州和新墨西哥州去年關閉的牲畜貿易點，並稱墨西哥全境的監測和不育蠅散播工作取得了「良好進展」。

COPEG尚未立即回應就美國散播計劃當前進展的更多細節置評的請求。

              So, an outbreak of New World screwworms has been spreading across Central America since early 2023 and hundreds of millions of flies dropping from planes in the sky could be the livestock industry’s best defense against a flesh-eating threat poised to invade the southwestern border of the United States. Apparently, flies dropping is an environmental-friendly way to deal with natural disasters comparing to using chemicals such as pesticides.