A few weeks ago Andrew from Zooillogix suggested that we jointly interview entomologist Justin O. Schmidt, creator of the infamous ‘Schmidt Pain Index.’ Both Andrew and I had found the index fascinating since it cataloged in (literally) excruciating detail the subjective feeling of being stung by a bevy of venomous insects, rating them on a scale from 0 to 4. We were finally able to track Dr. Schmidt down and send him a few quick questions to pick his brain about venoms, pain, his work at the Carl Hayden Bee Research Center in Tucson. Thanks very much to Dr. Schmidt for being such a great sport!
Q. Why are some insect stings more painful than others? Is it a result of gross tissue/cell damage or are they specifically evolved to interact with pain neurons?
A. We don’t know for sure. My hunch is that gross tissue/cell damage is a minor part in most situations, and that the venom components directly interact with tissues or receptors involved with pain signaling.
Q. What do you think is the most interesting insect venom, and why?
A. Three come to mind. Bullet ant because it causes such intense pain and, especially, that it lasts so long and is not “diluted” out of the pain-inducing concentration in the local sting area. Second is the tarantula hawk because its pain-inducing component(s) cause such immediate pain, yet the pain is gone within a couple of minutes, either by the component(s) being degraded or diluted. Third is the harvester ant venom because it seems to directly affect the neuromuscular junction and other cholinergic receptors (unique among insect venoms) and is so incredibly toxic.
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Q. Was there a point that you regretted letting a particular insect sting you?
A. I never directly “let myself be stung” by anything particularly painful. Those that are really painful are quite good at stinging one without help. The worst stinging I received was probably by some black wasps (Polybia simillima) in Costa Rica. It was the only time I have ever seen that species, was ill-equipped at the time to collect the large nest, did not realize how good they were at penetrating bees suits and other barriers, and I absolutely needed that nest. The result was lots of nasty burning stings and a few irate colleagues who were nearby. Incidentally, most of my nasty stinging events are similar – they were serendipitous discoveries of a wonderful species that I needed and had no choice: grasp the moment, or lose it.
Q. What are common chemical components in invertebrate venom?
A. Peptides, enzymes, biogenic amines.
Q. While your Sting Pain Index makes for an infinitely better drinking story, could their ever be a lab-based chemistry based approach to ranking Hymenopteran stings, like the Scoville Scale for chili peppers?
A. Yes, if we could develop a good assay technique to connect electrodes directly to pain transmitting nerves and relate the voltage values recorded to our sensation of pain level.
Q. It’s been awhile since you revisited your Pain Index. Would there be anything you would add or change since you initially designed it? Any new bites to rank?
A. Yes, I need to add to it; that is, update the list. Nothing entirely earth shakingly extreme, just much-needed fleshing out. This will take some time and is a project on the list for writing next year.
Q. Is there a difference between venoms that are meant to defend the insect and venoms that are meant to kill prey?
A. Definitely. For maximal effect, venoms to defend need a component to induce pain, with or without a toxic component. To simply kill prey (makes handling easier), the ideal venom would be non-painful, yet very quickly toxic.
Q. Is there a correlation between the potency of a sting and the aggressiveness of an insect?
A. Definitely, yes. The more aggressive species, almost without exception, have the most toxic and lethal venoms.
Q. Is there anything to this honeybee venom therapy for arthritis? If so, what would be the possible mechanism?
A. The literature suggests the answer is clearly yes. No one knows the exact mechanism at play, and that is part of the problem. The scientific community tends not to accept results for which we have no mechanistic answers; that is, how does it work? My own opinion is that it stimulates the immune system via the effronteries of the venom components, and in so doing, helps tune the immune system to function properly. A properly tuned immune system does not attack “self”.
Q. During the 1990s, I feared two animals, Jaws and Africanized honey bees (‘killer bees’). Was the concern among entomologists as serious as it was on A Current Affair?
A. Don’t know, but most entomologist viewed the story on killer bees more as a soap opera than a meaningful and serious risk to human life.
Q. Anything else you would like to share with ScienceBlogs readers?
A. Science should help to solve the mysteries of the universe, improve society, and be fun.