Tag Archives: disease

Engorged mosquitoes

Some photographs of me donating blood. The first is, I think, an Asian rock pool mosquito (Ochlerotatus japonicus japonicus; formerly known as Aedes japonicus japonicus). The second is an Asian tiger mosquito (Aedes albopictus). Introduced to New Jersey in 1998 and Texas in 1985, respectively. Both photographs were taken in Pennsylvania. 

Colin Purrington Photography: Insects &emdash; Asian rock pool mosquito (Ochlerotatus japonicus) with blood meal

Colin Purrington Photography: Insects &emdash; Asian tiger mosquito (Aedes albopictus) drinking blood

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Mutant milkweeds

Below are some photographs of strange growths on a patch of Asclepias syriaca I visited several weeks ago. From the few publications I’ve found, enations can be caused by viruses (Geminiviridae, Luteoviridae, etc.), and thus could be transmitted to nearby individuals via insect vectors or by the connected roots (milkweeds are clonal). Could be a genetic mutation, too, I suppose — could be spread by seed or via clonal growth. Anyone seen this before?

Colin Purrington Photography: Plants &emdash; Developmental aberrations on milkweed leaves

Colin Purrington Photography: Plants &emdash; Developmental aberrations on milkweed leaves

Colin Purrington Photography: Plants &emdash; Developmental aberrations on milkweed leaves

Photographed at Hildacy Farm Preserve in Media, PA.

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Using mosquitoes’ sweet tooth to control Zika transmission

Now that everyone wants to kill mosquitoes that transmit Zika virus, can somebody please make a transgenic plant that expresses mosquitocidal Bti (Bacillus thuringiensis subsp. israelensis) toxins? Just stick the Bti gene behind a phloem-specific promoter so that the protein gets pumped into the nectar. Then when males and female mosquitoes drink (and almost all do), they die. You could then plant acres of the modified plant nearby towns to protect people from Zika (and anything else transmitted by mosquitoes). The beauty of this method is that you could reduce populations of mosquitoes from an area without spraying, and do so for generations if you modified nectar-producing perennials. I know it’s trendy to dislike GMOs (like vaccines), but I think many people would support them under these circumstances.

And yes, apparently Bti toxins can kill adult mosquitoes (including Aedes aegypti), not just larvae. Klowden and Bulla 1984 demonstrated it, for example. And yes, Aedes aegypti drinks nectar (and probably fruit juice).

Of course, even if somebody had the incentive to make such a plant, it could take a decade to wade through the red tape involved in getting non-regulated status from governments. So if you want to do something today, leave out containers of sugar water (10%) that is laced with Bti (e.g., Mosquito Dunks, which you can buy online or at hardware stores). Maybe add something floral to attract them, too. (A review of olfactory cues suggests that imitation cherry and apple can work. If you don’t have those sitting around, I’d wager a few drops of jasmine flavoring or rose water would work, and those are easily found at local stores.) Even if the Bti doesn’t immediately kill the adult, adults sucking up a big sugar meal can transfer the bacteria to water where they lay eggs, and thus eventually cause the death of any larvae that develop. Note that bees and ants might get interested in your sugar water, but the Bti is completely harmless to them.

And if you don’t want to use Bti, there are plenty of articles on using sugar baits laced with insecticides (e.g., Qualis et al. 2013, Junilla et al. 2015). They really can work: mosquitoes absolutely love sugar and will drink up poisons in the process. These are great if you don’t want to use crop dusters to destroy all insects in the area.

If you have kids and want to entertain them, add food dyes to the sugar bait and then challenge them to find mosquitoes with bellies full of sugar water. For older kids that might be amused by actual science, use two dyes to test attractiveness of two different volatiles (or different sugars). It’s probably rare to recapture one right after a nectar meal, but when distended they reveal gut contents nicely.

Colin Purrington Photography: Insects &emdash; White-footed woods mosquito (Psorophora ferox) nectaring on goldenrod

FYI, the photograph above is a white-footed woods mosquito (Psorophora ferox), not Aedes aegypti. It doesn’t transmit Zika, but illustrates to the unbelieving that mosquitoes drink nectar. 

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Graphic images from the antibiotic resistance movement

If you need an image for a talk on antibiotics, please help yourself to anything on my Pinterest board, “Antibiotic Resistance Movement.”

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Shopping list for anti-infectives

Although Darryl is supposedly illiterate, the rest of characters on The Walking Dead, even those with higher degrees, seem to be science illiterates*.  Details in my earlier post/rant (“The Walking Dead need antivirals, not antibiotics“), if you care. But you probably just want the image, so I won’t be hurt if you just download and go.  It’s low quality because I used a camera to take a photograph of my television screen.  Please use it to spice up your upcoming lecture during Antibiotic Awareness Week.

Darryl holding shopping list on The Walking Dead

* Thanks, though, to Chris Hardwick for apologizing during The Talking Dead for all the antibiotic gaffes.

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