Keeping and Culturing Bean Beetles/Weevils - Cheat sheet
***Warning the beetles & larvae are considered agricultural pests so please be careful if you intend to use these as a feeder insect and do not release these outside your house***
Bean beetles are easy to culture. Their larger size and prolific production make them a great alternative to D. Hydei as well as a valuable supplemental feeder insect. They are pretty much a must have in our hobby.
1) When you receive your new beetles, either make an additional culture using one half of the contents of your newly acquired culture or at least add fresh beans as soon as you can. Place approx 2 inches of black eyed beans (cheaply and easily found in any local grocery store) in the bottom of a clean, clear plastic deli cup – the kind we commonly use in the hobby for fruit fly culturing. Your culture may contain a wadded up paper towel for packing support and if it does, carefully remove any beetles from it and discard – as it is not needed.
2) Add approx 30 beetles from your main culture to the new culture including beans and any detritus that is in the bottom of the culture – not a problem. No need to try to make a “sterile” culture. Include all the debris and frass – discarded beans, dead beetles ect. Not a problem.
3) Keep the cultures high on your frog racks and try for a steady 80F temperature. Make sure you use ploy-fil or other ventilated lids as moisture and high humidity inside the container will rot the beans and cause harmful fungus.
• No water or food (other than the beans) is needed. Adult beetles live for about 10 -14 days post emergence, have no mouthparts and cannot chew or eat at all. Add a small, approx 1 inch layer of fresh, new beans every 3-4 weeks – right on top of the old layer(s).
• Beetles will lay their eggs on the beans. Once eggs hatch, larva will bore through beans and emerge as adults in approx 1.5 months. Beans can host multiple beetle larvae.
• Use a section of cardboard like an unused egg carton portion and place in the deli cup for the beetles to climb on. This cardboard feature will have added ability to act as an easy collection point from which to shake off the beetles into another dusting cup for feeding out. Beetles hold superfine powdered really well, also.
You may be tempted to discard a culture that you have not seen any activity from in weeks but you should not do this as there is always a delay – sometimes more than 5 weeks, depending on temperature and seasonal variances that will make it appear that the culture is dead when in fact, it may not be.
If and when you truly want to dispose of the culture, make sure you freeze it inside a regular refrigerator freezer for 3 days, before discarding.