The asian citrus psylid has been spotted in California and while the bug itself is not a bit threat, a disease it can carry could spell disaster for California citrus growers.

From the Homegrown Evolution blog:

When I spotted state agriculture agents on our street I knew something was wrong. It turns out that a specimen of the dreaded Asian citrus psylid showed up in our neighborhood. The Asian citrus psylid is not a problem in itself, but carries an incurable bacterial disease called huanglongbing (HLB). HLB, first reported in Asia in 1919, renders citrus fruit inedible and eventually kills the tree. Parts of Africa, Asia and South America are infected with HLB and in some regions of Brazil the disease is so bad that they've given up growing citrus altogether. HLB is in Florida and is adding to a nightmarish collection of other diseases afflicting citrus in the Sunshine State. Now California growers are panicking with the appearance of the psylid.

So far the psylids found in California do not carry HLB. However, according to an article in the Journal of Plant Pathology (pdf), HLB inevitably follows the citrus psylid within a few years. In several ways HLB resembles Pierce's disease which has killed most of my grape vines and basically made growing table or wine grapes in Southern California impossible without copious pesticide application. Both diseases are bacterial and both are spread by phloem sucking insects. The pesticides used to control the Asian Citrus Psyllid and the Glassy Winged Sharpshooter (the insect that spreads Pierce's disease) are also the same, and include a ground application of imidacloprid, marketed under the brand name Merit and manufactured by Bayer Environmental Science. State agricultural officials that I spoke with at an informational meeting on Wednesday in Echo Park hope that applications of imidacloprid and pyrethroids will slow the progress of the psylid and, "buy some time", as they put it, to come up with a strategy to deal with the possible appearance of HLB. California agriculture officials hope that their proactive approach combined with lessons learned from missteps in psylid control in Florida and the rest of the world will slow the progress of the insect and minimize the damage of an emergence of HLB in California.

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Read the full blog post (with relevant links) here.

Invasive species can wreak havok on isolates ecosystems. Take Australia for example. And the heinous zebra mussels that threaten many freshwater bodies here in North America. The latest harbingers of death are likely suspects: mosquitoes. And with increased tourism, the Galapagos doesn't seem to stand a chance.

From the Times Online article:

Mosquitoes introduced to the Galápagos on chartered flights and tourist boats could put the islands’ unique species at risk of extinction, scientists will warn today.

According to a study published in the Royal Society journal Proceedings B, aircraft are routinely introducing mosquitoes into the islands' ecosystem.

Many of these will carry diseases such as avian malaria or West Nile fever, with potentially devastating consequences for the native species, including Galápagos tortoises, marine iguanas, sea lions and Darwin’s finches.

“The animals have evolved in the absence of these diseases so they have virtually no resistance,” Simon Goodman, a geneticist from the University of Leeds who led the research, said.

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Read the full article here.