Stupid nematodes

Sometimes working with animals, no matter how relatively simple their husbandry, can be a real trial, or reveal some completely unforeseeable problem. The plan for the last few months was to collect 40-60 female Drosophila melanogaster to kick-start a population to work with for a selection experiment. The recipe: catch flies, separate out females, keep the right species. Here's how I went:

Round 1, late April: Early AM, day 1. Collected 200-250 flies. Am confident most, if not all, are the right species based on a previous tip-off for the collection site.
Early PM, day 1. Most flies are not right species, but still have 67 "potentials".
Day 10. Only 27 are the right species. It is now too cold to catch more flies, but will try anyway. Time to start again.

Round 2, early May: Early AM, day 1. About 20 flies in total caught. Am not confident of species. Will leave traps out and return 2 hours before sundown.
2 hours before sundown, day 1. Catch 600 or more flies. Considered a successful trip. Return to lab to sort flies.
Day 10. Of 250, only 82 are the right species. That's ok, have more than enough females to start up a population.
Day 20. What's that strange stuff on the side of the population bottles? Looks like moisture, whatever.
Day 21. Did I see a small drop wriggle? I'm seeing things.
Day 24. Oh?! A nematode. Well, I don't want the spread of a pathogen, so I'll segregate this bottle from all the others.
Day 26. Oh wow, all the bottles have a few nematodes. I wonder if they are bad?
Day 26, 10 mins after previous observation. Oh wow, these nematodes are bad. Huh? Some nematodes use fruit flies as a vector, the target: human eyes!?! I don't think I've touched my eyes after contacting the bottles.... and I'm sure there is some research that has a way to kill off the nematodes but not the flies....

It turns out that nematode infestations in laboratory Drosophila cultures is quite rare, and there is no readily found preventative or killer of nematodes that doesn't affect their hosts. Unless I get rid of these swarming nematodes, I can kiss my populations (and a PhD chapter) goodbye, and I am limited in how much time I can spend on solving this problem as I only have about 9 months left of my PhD (in theory anyway). Oh, and my own health is a concern too. I'm seeing an optometrist to check my (and my partner's eyes) for nematode infection tomorrow. It's sad when I realise my health is my second, not my first, thought after reading about nematodes and how they like peoples' eyes. My first thought was "Oh no! My poor flies are living with nematodes, and it is going to screw up my experiment!". I'm going to call this the third symptom of PhD-induced insanity: "PhD comes before personal health". The first two symptoms is (1) The feeling that you are the unwelcome outlier, and, (2) I would rather eat a piece of poo than write that document.

In most cultures there exists tales of a trickster deity or spirit that is responsible for sowing discord in the universe as it is known. The Norse have Loki, a famously malicious and unconventional trickster god, the Japanese have Kappa, apparently responsible for both kidnapping and drowning people, the Greeks have Eris, Africans have Ekwensu, and the Irish, leprechauns. If my lab has a malicious trickster spirit that is distributing nematodes and screwing with our experiments, I would just like to say, "I don't like you" (that is re-phrased politely from what I would actually like to say). I am considering acknowledging that each lab may have a special little sprite that just wants to cause trouble when not doing something tedious, like, I don't know, cleaning the receiver on antique radios. In my lab's case, probably cleaning the insides of tygon tubing or computer screens. If you can relate to this, or have any suggestions on killing nematodes but not fruit flies, please post your comments!