雅思阅读 126: Six-Legged Livestock（六条腿的牲畜）

改编自 PMC / Market Research Future（2026年）。雅思阅读 Section 3 难度，约 1050 词。 素材来源：https://pmc.ncbi.nlm.nih.gov/articles/PMC12965228/

Reading Passage

A. If the world is to feed nine billion people by 2050 without converting every remaining forest into pasture, the environmental cost of conventional livestock will have to fall. Cattle alone contribute roughly 14.5 per cent of global greenhouse-gas emissions, demand vast tracts of land and water, and convert only a small fraction of the feed they eat into edible meat. Into this pressure cooker has stepped a solution that makes many Western diners uneasy: insects. Insects have been eaten for millennia across much of Africa, Asia and Latin America, but only in the last decade have they been farmed at industrial scale and marketed as a serious alternative protein. The economic case is striking. For every kilogram of edible protein produced, modern insect farms use about 75 per cent less land and 50 per cent less water than beef operations, while emitting a fraction of the greenhouse gases. The global edible-insect market was valued at around 1.6 billion dollars in 2024 and is forecast to approach 6.2 billion by the early 2030s — growth that reflects both regulatory approval and rising investor confidence. The United Nations Food and Agriculture Organization has actively promoted insects as both human food and animal feed since a landmark 2013 report, and that endorsement has given the sector a credibility it lacked a decade ago.

B. The arithmetic of feed conversion is where insects genuinely outperform conventional animals. A kilogram of edible crickets requires only about 1.7 kilograms of feed, compared with roughly 2.5 for chickens, five for pigs and twelve for cattle. That ratio means insects convert a far larger share of what they eat into body mass, and they need far less land per unit of protein. Crickets are also cold-blooded, so they waste metabolic energy maintaining body temperature the way mammals and birds do. They reach harvest weight in six to seven weeks under controlled warmth and humidity, and they reproduce quickly. The species now farmed commercially — house crickets, yellow mealworms, black soldier fly larvae and a handful of others — are chosen less for novelty than for hardiness: they thrive on a wide range of organic side-streams, including spent grains from breweries, vegetable waste and food-processing by-products. In effect, they are bioconversion machines that turn what would otherwise be landfill into high-quality protein meal suitable for animal feed and, increasingly, for human food.

C. The regulatory path for insects as human food has opened unevenly. The European Union approved dried yellow mealworms as a novel food in 2021, followed by migratory locusts, house crickets and lesser mealworms in subsequent years, each approval requiring dossiers on allergenicity, nutritional composition and processing hygiene. The United States Food and Drug Administration has generally recognised house crickets and yellow mealworms as safe when produced under good manufacturing practice, but individual states maintain their own labelling rules. In much of sub-Saharan Africa and Southeast Asia, insects have never required novel-food approval because they are part of the traditional diet; the challenge there is scaling artisanal harvesting into consistent, food-safe supply chains. Religious authorities have also weighed in: Islamic scholars have generally ruled grasshoppers permissible, and Jewish dietary law permits certain locust species, opening halal and kosher market segments that were once assumed closed to insect protein. These regulatory openings matter because, until a few years ago, most insect product was legally restricted to pet food and animal feed.

D. Consumer acceptance remains the sector's hardest problem. Surveys across Europe and North America consistently show that the majority of adults would try a cricket-based snack but would not replace familiar meat products with whole insects on a regular basis. The "yuck factor" is real, and it has pushed most Western producers toward an invisible strategy: grind the insects into powder and bake them into protein bars, pasta, crackers or fortified flour, where the consumer never sees a leg. This works for protein supplementation but limits the product to a health-and-wellness niche rather than displacing supermarket beef. Food safety adds a second layer of caution. Insects can accumulate heavy metals and mycotoxins from their feed, so producers must tightly control diet and test batches; allergen risk — people allergic to crustaceans often react to insects — requires clear labelling. None of these issues is fatal, but they raise production costs above what the market will currently bear for a mass-market meat substitute, even after the environmental savings are counted. Producers are betting that a generation raised on plant-based burgers will be more receptive to insect-derived protein than their parents were, and that the environmental argument will eventually overcome the initial disgust response through repeated exposure in supermarkets and restaurants.

E. The most likely near-term market for insects is not human food at all, but aquaculture and pet food. Fish farms already rely heavily on fishmeal, a finite and increasingly expensive commodity, and insect meal is a nutritionally comparable alternative that can be produced in enclosed facilities near coastal processing plants. Black soldier fly larvae, in particular, are efficient converters of food-waste streams into protein meal, and several European and North American plants now process municipal organic waste into larval biomass that is then fed to salmon, shrimp and poultry. The UN Food and Agriculture Organization has long argued that insects should be promoted both as human food and as feed, precisely because the feed market is larger, less squeamish and better aligned with industrial supply chains. Whether Western palates eventually embrace six-legged protein as a staple — or whether insects remain a supplement and a feed ingredient — will depend less on the environmental argument, which is settled, than on whether producers can deliver a product that consumers actually want to eat at a price they are willing to pay.

Questions 1-4

Choose the correct heading for paragraphs B, C, D and E from the list of headings below.

List of Headings i. Why insects outperform conventional livestock on feed conversion ii. The history of cricket consumption in ancient Rome iii. Regulatory approval — and where it still blocks the market iv. The consumer acceptance obstacle v. The most likely near-term market: aquaculture and pet food vi. How to breed mealworms in a garden vii. The price of fishmeal in 2024

1. Paragraph B: ____
2. Paragraph C: ____
3. Paragraph D: ____
4. Paragraph E: ____

Questions 5-8

Choose the correct letter, A, B, C or D.

5. Approximately how much less land does insect farming use per kilogram of protein compared with beef? A. 25 per cent. B. 50 per cent. C. 75 per cent. D. 90 per cent.

6. How long do house crickets typically take to reach harvest weight? A. Six to seven weeks. B. Three months. C. Six months. D. One year.

7. What is the main strategy Western producers use to overcome the "yuck factor"? A. Selling whole roasted insects in supermarkets. B. Grinding insects into powder for use in protein bars and flour. C. Advertising on television. D. Giving away free samples.

8. Why is aquaculture considered the most likely near-term market? A. Fish prefer insect food. B. It is larger, less squeamish and aligned with industrial supply chains. C. Insects grow faster in the sea. D. It requires no regulation.

Questions 9-13

Do the following statements agree with the claims of the writer?

Write:

• TRUE if the statement agrees with the information
• FALSE if the statement contradicts the information
• NOT GIVEN if there is no information on this

9. Cattle contribute around 14.5 per cent of global greenhouse-gas emissions.
10. Insects convert a smaller share of feed into body mass than pigs.
11. The European Union approved dried yellow mealworms as a novel food in 2021.
12. Most North American consumers now regularly eat whole insects as a meat replacement.
13. Black soldier fly larvae can process food waste into protein meal.

Questions 14-15

Complete the summary below using NO MORE THAN TWO WORDS from the passage.

Insects outperform conventional livestock on feed conversion because they are cold-blooded and need less energy for (14) __________ maintenance. While human-food adoption faces a consumer acceptance barrier, the more immediate market is insect meal for (15) __________ and pet food.

答案与解析

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