Reef Central Online Community - View Single Post - Use of Ivermectin to Control Red Bugs (Tegastes acroporanus)

ousnakebyte · 01/25/2011, 08:01 PM

Hi everyone -

I saw the other thread about finding new medications for control of the red bug copepods, so I thought I would post this here - I didn't want to hijack the other thread, which sounds like it might be promising as well. Plus, dahenley (the Red Raider... missing Leach?) reminded me that I should post my results since I have been testing Ivermectin.

About 5 years ago, our staff vets and I treated three separate Acropora valida colonies for Tegastes acroporanus, the red bug copepod parasites. One colony was treated using the "industry standard" milbemycin oxime (Interceptor), and the other two were treated using two different concentrations of Ivermectin - 2mg/L and 4/mg/L. Treatments were done outside of the display aquarium in 2.5 gallon tanks, and after three separate treatments at 6-hrs each, all a week apart, all three colonies were alive and free of the red bugs. Since this was such a small experiment with no replicates, it was not big enough for a paper. But, we did present our results at a poster session that year at the Regional Aquatics Workshop in Pittsburgh.

Then, I got busy with other projects at work and forgot about ever repeating the experiment. Then, recently, I was treating some acros at home that had the red bugs, and I did the standard Interceptor treatment, leaving the coral in the bath for over 8 hours. But, the red bugs were still alive. Thinking that perhaps my pill was expired, I tried another treatment and still these few bugs did not die. I even tried a whole-tank treatment with red bugs visibly making it through the treatment, despite leaving the Interceptor in the whole tank for two days.

So, I got concerned with milbemycin oxime-resistant red bugs, which made me reopen my old experiment. I couldn't remember the old dosages or find my notes, so I referenced the CoralZoo conference papers here: Coral Zoo Conference

One thing that is nice, is that some often have difficulty obtaining Interceptor unless you have an understanding vet. I don't even have a dog or a cat, but Ivermectin is easily purchased without a prescription as Ivomec on 1800petmeds, seen here: Ivomec

Over the past week, I have treated two different acroporids, A. loisettae, and another indiscriminate bushy/staghorn growth formation acropora at a concentration of 2 mg/L of 1% Ivomec, which equates to approximately 2 mL per 10L (~2.6 gallons) - so basically, I have been using a 2.5 gallon tank with 2 mL of Ivomec (I% Ivermectin solution).

The results have been promising. Of the first two A. loisettae frags, one did indeed perish - HOWEVER, this very small frag was from the end of a colony already not doing very well. And, I was an idiot and placed it higher up in the tank at the end of the treatment instead of back next to the mother colony - but I didn't want a reinfestation over night. The second frag did well and is still alive today.

Just today, I treated the second acropora colony (don't know species ID), that I broke into four fragments. All four fragments had a confirmed red bug sighting. After 6-hrs in the bath with gentle aeration, all four fragments look good, but I will know tomorrow if they have perished or not. This colony looked healthier than the A. loisettae, so I anticipate they will pull through.

I used this visor here to search for red bugs still on the corals: Optivisor I have both the 5x and 10x versions. I did find two red bugs still clinging to one colony, so I used a needle to gently remove the bug. It was definitely dead - or close to it - b/c it did not move at all. If you have seen red bugs in action, you know they can move very quickly. This one, and a second I found still clinging, were mot moving at all and were easily removed to a small vial of clean saltwater for later inspection. However, the corals do produce a bit of mucus/slime during the bath which seems to all cling together, and the vast majority of the red bugs were caught up in this mucosal discharge, albeit dead - a convenient side effect it seems.

I did do one other experimental treatment after rinsing the four fragments of this Acropora sp. in clean saltwater. I took two of the frags and soaked them in an aerated Revive Coral Cleaner bath for 15 minutes (I meant to do ten, but I got busy multi-tasking and forgot about them... ). My thinking was that if any bugs were still clinging to life after a 6-hr Ivermectin bath and were then hit with Revive, they wouldn't stand a chance.

I will look first thing tomorrow morning to see if all four have made it through the treatment(s).

Important notes/summary:

1) These treatments are done OUTSIDE of the main display. Throughout the Ivermectin treatments, not only the do the red bugs die but so do mini brittle stars (echinoderms) and chitons (molluscs). I have not yet tested a whole tank treatment, but given the die-off of other organisms, I don't yet think this can be a replacement to a whole tank Interceptor treatment.

2)This is meant to be a prophylactic treatment for incoming acroporids. If you read the Coral Zoo papers, you'll see that Ivermectin has been used to treat flatworms. I cannot stress enough the importance of quarantine in addition to broad-spectrum treatments. THIS IS NOT MEANT TO REPLACE QUARANTINE!!!

3) As I mentioned above, Ivermectin is easily obtained without a prescription. It is also liquid, and anyone who knows how poorly Interceptor pills dissolve in water will know that it is already easier. However, this means you will need a 1mL syringe with needle to extract it from the bottle. In short, you get to play doctor.

4) Life evolves via natural selection. If we are starting to see Interceptor-resistant red bugs, then this will hopefully help in that ever-continuing evolutionary arms race.

Cheers
Mike

01/25/2011, 08:01 PM	#1
ousnakebyte Registered Member Join Date: Feb 2003 Location: Washington, D.C. Posts: 595	Use of Ivermectin to Control Red Bugs (Tegastes acroporanus) Hi everyone - I saw the other thread about finding new medications for control of the red bug copepods, so I thought I would post this here - I didn't want to hijack the other thread, which sounds like it might be promising as well. Plus, dahenley (the Red Raider... missing Leach?) reminded me that I should post my results since I have been testing Ivermectin. About 5 years ago, our staff vets and I treated three separate Acropora valida colonies for Tegastes acroporanus, the red bug copepod parasites. One colony was treated using the "industry standard" milbemycin oxime (Interceptor), and the other two were treated using two different concentrations of Ivermectin - 2mg/L and 4/mg/L. Treatments were done outside of the display aquarium in 2.5 gallon tanks, and after three separate treatments at 6-hrs each, all a week apart, all three colonies were alive and free of the red bugs. Since this was such a small experiment with no replicates, it was not big enough for a paper. But, we did present our results at a poster session that year at the Regional Aquatics Workshop in Pittsburgh. Then, I got busy with other projects at work and forgot about ever repeating the experiment. Then, recently, I was treating some acros at home that had the red bugs, and I did the standard Interceptor treatment, leaving the coral in the bath for over 8 hours. But, the red bugs were still alive. Thinking that perhaps my pill was expired, I tried another treatment and still these few bugs did not die. I even tried a whole-tank treatment with red bugs visibly making it through the treatment, despite leaving the Interceptor in the whole tank for two days. So, I got concerned with milbemycin oxime-resistant red bugs, which made me reopen my old experiment. I couldn't remember the old dosages or find my notes, so I referenced the CoralZoo conference papers here: Coral Zoo Conference One thing that is nice, is that some often have difficulty obtaining Interceptor unless you have an understanding vet. I don't even have a dog or a cat, but Ivermectin is easily purchased without a prescription as Ivomec on 1800petmeds, seen here: Ivomec Over the past week, I have treated two different acroporids, A. loisettae, and another indiscriminate bushy/staghorn growth formation acropora at a concentration of 2 mg/L of 1% Ivomec, which equates to approximately 2 mL per 10L (~2.6 gallons) - so basically, I have been using a 2.5 gallon tank with 2 mL of Ivomec (I% Ivermectin solution). The results have been promising. Of the first two A. loisettae frags, one did indeed perish - HOWEVER, this very small frag was from the end of a colony already not doing very well. And, I was an idiot and placed it higher up in the tank at the end of the treatment instead of back next to the mother colony - but I didn't want a reinfestation over night. The second frag did well and is still alive today. Just today, I treated the second acropora colony (don't know species ID), that I broke into four fragments. All four fragments had a confirmed red bug sighting. After 6-hrs in the bath with gentle aeration, all four fragments look good, but I will know tomorrow if they have perished or not. This colony looked healthier than the A. loisettae, so I anticipate they will pull through. I used this visor here to search for red bugs still on the corals: Optivisor I have both the 5x and 10x versions. I did find two red bugs still clinging to one colony, so I used a needle to gently remove the bug. It was definitely dead - or close to it - b/c it did not move at all. If you have seen red bugs in action, you know they can move very quickly. This one, and a second I found still clinging, were mot moving at all and were easily removed to a small vial of clean saltwater for later inspection. However, the corals do produce a bit of mucus/slime during the bath which seems to all cling together, and the vast majority of the red bugs were caught up in this mucosal discharge, albeit dead - a convenient side effect it seems. I did do one other experimental treatment after rinsing the four fragments of this Acropora sp. in clean saltwater. I took two of the frags and soaked them in an aerated Revive Coral Cleaner bath for 15 minutes (I meant to do ten, but I got busy multi-tasking and forgot about them... ). My thinking was that if any bugs were still clinging to life after a 6-hr Ivermectin bath and were then hit with Revive, they wouldn't stand a chance. I will look first thing tomorrow morning to see if all four have made it through the treatment(s). Important notes/summary: 1) These treatments are done OUTSIDE of the main display. Throughout the Ivermectin treatments, not only the do the red bugs die but so do mini brittle stars (echinoderms) and chitons (molluscs). I have not yet tested a whole tank treatment, but given the die-off of other organisms, I don't yet think this can be a replacement to a whole tank Interceptor treatment. 2)This is meant to be a prophylactic treatment for incoming acroporids. If you read the Coral Zoo papers, you'll see that Ivermectin has been used to treat flatworms. I cannot stress enough the importance of quarantine in addition to broad-spectrum treatments. THIS IS NOT MEANT TO REPLACE QUARANTINE!!! 3) As I mentioned above, Ivermectin is easily obtained without a prescription. It is also liquid, and anyone who knows how poorly Interceptor pills dissolve in water will know that it is already easier. However, this means you will need a 1mL syringe with needle to extract it from the bottle. In short, you get to play doctor. 4) Life evolves via natural selection. If we are starting to see Interceptor-resistant red bugs, then this will hopefully help in that ever-continuing evolutionary arms race. Cheers Mike __________________ Living is easy with eyes closed, misunderstanding all you see - John Lennon Last edited by ousnakebyte; 01/25/2011 at 08:08 PM.