I assume you meant to hope they are not semp eaters.
Well, sorry to disappoint you but these look like weevils to me. There are a lot of bugs that can dine on semps, but usually they do not do a great deal of damage and can be tolerable. I am not an expert on semp insect problems. However, I do know that some species of weevils will lay eggs around the base of the plant, which hatch into maggots. The maggots can eat the roots of the semp but typically will be found near the ground level munching on the tender leaves there.
Here's a pic of some root maggots that I found infesting one of my semps this spring. It was a single plant and I never did see the weevils. From what I've read,
infestation is typically opportunistic and will generally not do a lot of damage. However, in this case, I lost the plant because the maggots had done too much damage before I spotted them,
Always watch your plants daily for signs of poor health. If you see a rapid decline in health of a plant, then dig it up and give it a close examination. Maggots move and are generally easy to spot.
How to treat infected plants:
1) Dig, wash, (examine) and dry.
2) Spray with appropriate insecticide if found and be sure to discard soil and wash water in a way that won't spread infection.
3) Remove dead and dying leaves from plant stalk.
4) Wash and spray a second time a day later.
5) Examine carefully and if found pest free, plant in new soil and isolate.
6) Keep the plant quarantined until you are comfortable it is clean of problems.
Our gardens are always full of many different kinds of bugs, that usually do not cause any problems until the plants get stressed. The best defense is usually to grow the healthiest plants possible. This has definitely been a stressful year for many due to the weather, so it is not unreasonable to expect to see some problems. Seeing a few weevils is not a time to panic and probably doesn't mean anything. However if the plants start to show signs of problems, then action is needed.
If you do have a problem with insects damaging your plants, then you can spray them with the insecticide of your choice. I have not heard of any particular sensitivity issues with semps and jovis.. Always test on a few first, when working with any new chemical or pesticide, just to be sure. I have used Sevin, Insecticidal Soap, Neem and pyrethrins and not seen any problems with the plants not tolerating the application.
