Cicindelid Breeding

[Mecynorrhina]

Hi everyone, 

I haven't been on this forum since the first few months after I joined it. Thought I should make a new introduction, but I guess it's better to just get into talking about stuff right? I am highly interested in breeding tiger beetles in captivity, and I had some success recently from some specimens I collected last year. Last year I tried breeding Cicindela scutellaris lecontei, and Cicindela sexguttata. I got larvae from both species, but had a very low survival rate. Over the past few weeks I've had pupation occur in C.sexguttata and recently I have had my first two C.sexguttata emerge as adults! I want to learn as much as I can about breeding cicindelids in captivity and I'm curious, has anyone else had any success?

 

[Hisserdude]

This one of those groups I've always wanted to see people breed more, but adults can apparently be picky about what substrates they'll oviposit into, (needs to mimic the soil they were collected at pretty well), and larvae obviously need very stable substrate to construct their burrows in.

Low larval survival rates in Carabidae seems to be the norm unfortunately, in your case are you sure you were feeding them enough? In my experience, Carabidae larvae starve pretty quickly... 

One thing I think you may have to take into consideration is a winter diapause, it's quite possible larvae of species in your area will never pupate or just halt their growth completely and die without a cool period from mid fall through winter... You might get a few stragglers to mature without a diapause, but if I had to guess, I'd think that's where your bottle neck would be in terms of getting more adults to mature than what you started with. 

 

[Mecynorrhina]

I definitely agree about substrate types being a major factor for oviposition. I messed around with a few different substrate compositions ( half sand/half clay, silt, soil/sand mixtures) and while C.sexguttata definitely seems to be more of a generalist, C.s.lecontei prefers substrates that are 70% or more sand. Kinda curious if they prefer specific types of sand or if any kind will work (for lecontei I collected sand from the habitat). I believe it was a combination of improper feeding and poor humidity balances for them. Switching foods seems to be extremely important for them for each stage. I'm testing this again this year, but last year for C.sexguttata I found these diets worked best for each stage: L1-early L2: D.melanogaster. L2: Tribolium sp. larvae. L3: Tribolium sp. and small mealworms. About diapause, I definitely think it could be a factor for preparing adults for breeding, as I've read temperate species tend to overwinter in order develop their ovaries, but I'm not sure about rearing larvae. I had the most deaths when I was trying to figure out how to provide humidity well for larvae. I have some more larvae hatching right now so that could definitely be something to test this year. 

 

[Hisserdude]

I definitely agree about substrate types being a major factor for oviposition. I messed around with a few different substrate compositions ( half sand/half clay, silt, soil/sand mixtures) and while C.sexguttata definitely seems to be more of a generalist, C.s.lecontei prefers substrates that are 70% or more sand. Kinda curious if they prefer specific types of sand or if any kind will work (for lecontei I collected sand from the habitat). I believe it was a combination of improper feeding and poor humidity balances for them. Switching foods seems to be extremely important for them for each stage. I'm testing this again this year, but last year for C.sexguttata I found these diets worked best for each stage: L1-early L2: D.melanogaster. L2: Tribolium sp. larvae. L3: Tribolium sp. and small mealworms. About diapause, I definitely think it could be a factor for preparing adults for breeding, as I've read temperate species tend to overwinter in order develop their ovaries, but I'm not sure about rearing larvae. I had the most deaths when I was trying to figure out how to provide humidity well for larvae. I have some more larvae hatching right now so that could definitely be something to test this year. 

Yeah some species aren't too picky about the exact substrate composition for oviposition, others are incredibly picky though, all depends on the species. 

Ah OK, yeah those two factors may have contributed most towards the larvae dying off then, hopefully more consistent humidity and better prey items will get them growing better for you in the future.

See I didn't know exactly when they are supposed to pupate, if they do so earlier in the fall and overwinter as adults, then of course a diapause will play little role in rearing the larvae up to adulthood, but like you suggested it may be neccesary to get CB adults to breed, as Carabidae in general seem to rely heavily on seasonal cues to induce actual oviposition.