This isn't the first time I've mentioned Parasitic Wasps. They're a rude sort of parasite, laying their eggs inside unwitting hosts to grow up and eat them from the inside out. While it sounds gross and, frankly, a little evil, it makes them also really good at one thing: biocontrol.
When Sarah Palin made her off-putting remark about research on fruit flies, everyone assumed she meant the bio model Drosophila. But she was actually referring to research on the Olive Fruit Fly, Bactrocera oleae. The pest infiltrated Californian olive groves in the late 1990s, and has been wreaking havoc ever since. Olives are the second largest cash crop in Napa County, below, of course, grapes. The impact of the fly has reduced olive yields by at least 30% - and, in some coastal areas, as high as 100% losses. A 2004 USDA report said it simply: "The recent establishment of the olive fruit fly ... in California has threatened to destroy the U.S. olive industry."
Pesticides and traps are expensive and hurt other wildlife. So, instead, Californians are trying out a new control method: Parasitic Wasps.
It turns out that a wasp from Africa, Psyttalia concolor, happens to deposit its eggs in the maggots of fruit flies. It was introduced to Italy and other Mediterranean areas to control the same pest that plagues California's olive industry. Now scientists from the USDA's Agricultural Research Service are working on understanding the interaction between the wasp and its host to use it as a biological control measure in California's olive groves. Their initial data is promising (PDF). They're discovering exactly how and when the parasite lays its eggs in its host, and how well it parasitizes populations when released into the wild. It's picky about its host, too - thankfully, it doesn't infect beneficial flies native to the area. Studies like this one get us step by step closer to using natural means to keep our crops safe from pests.
So what's so sci-fi about a wasp? How about the fact that it's convinced us to single-handedly increase its habitat from Africa to Europe and the Americas. Talk about an increase in range! It may not use mind control or voo-doo to manipulate us, but we sure are doing it a lot of favors. Imagine a world where we team up with all kinds of parasites... It's a Sci-Fi Utopia! Until, like all Sci-Fi scenarios, something goes terribly wrong... *suspenseful music*
Cited: Victoria Y. Yokoyama, Pedro A. Rendón, John Sivinski (2008). Psyttalia cf. concolor (Hymenoptera: Braconidae) for Biological Control of Olive Fruit Fly (Diptera: Tephritidae) in California Environmental Entomology, 37 (3), 764-773 DOI: 10.1603/0046-225X(2008)37[764:PCCHBF]2.0.CO;2
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