Rearing Cryptocephalus sanguinicollis (Coleoptera: Chrysomelidae)

Long story short: larvae generalist detritivore/herbivore (specimens do eat/climb not only rotten leaves but fresh living vegetation, the latter including grocery lettuce leaves and Rosa/Hibiscus petals, although their climbing ability is poor and it's unclear whether they'd be able to feed on the more chemically well-defended flora present in their natural habitat) and were reared via standard "rear Cryptocephalinae" protocols; adult observed eating live Salvia apiana in situ, but unlike the larva the adult appears to have weird psychological requirements and behaves unnaturally in cages (in cage, flies or walks to ceiling and leaves the host, paces + tries to chew through cage mesh constantly and displays poor appetite). F0 adults were released after a few days in captivity as they appeared too stressed to oviposit more than a few eggs and may have died from exhaustion if they had not been put back outdoors.

Larvae also go dormant when dehydrated and can survive at least a week (probably months) in this state. Lid is sealed only by the head at first but is plugged with frass for longer droughts, intensive rehydration causes the plug to be removed. Short mistings do not seem to induce loss of dormancy. Sometimes prone to pseudo-cannibalism, larvae eat each other's cases (this seems to happen primarily when wet) which can result in indirect fatalities from dehydration.

Contributed by C on 10 June, 2024 - 1:42am
Last updated 12 June, 2025 - 12:06am

Update 6/10/2024

The life cycle takes one year in culture although I cannot rule out the possibility it may take more in harsher conditions. Of the 4 out of eight larvae that survived to maturity, 1 has successfully molted into a normal adult as of this writing,

and another has been damaged during an incident but succeeded in pupating (I have not checked the status of the other two larvae yet). Of note is that this success occurred despite non-rotten rose petals forming the primary diet, and that all mortalities so far have occurred due to either larvae damaging each other's cases or to my accidentally misplacing specimens during food changes. Perhaps I should have provided more rotten matter in the diet to discourage the case-eating behavior. But then again, the rose-based diet did not seem to stunt/slow growth or cause direct mortality.

As I had hypothesized, tricking my F1 adult into thinking there was no cage ceiling stopped it from behaving abnormally in captivity. Long story short I got one of those giant mesh pop-up cages, put a hostplant (Rubus) in in a way that the leaves weren't touching the walls/ceiling, and put the beetle on the plant. It usually flew away in alarm from being handled (and, being too attracted to light, was psychologically unable to fly/walk back to the host once on the cage walls/ceiling), but sometimes would get hungry enough to start eating as it was climbing up to the top to prepare for its escape flight and forget to flee, and (more rarely) it would initiate the escape flight and bounce off the wall in just the right way to end up back on the host by accident (however escape flights that were only a cm or two long did not placate it when they ended on a leaf, probably because they were not long enough to count as a "successful escape" to its instincts. In both of these cases it would calm down and remain on the host as long as there were non-excessive* levels of direct sunlight to bask in. It is notable that similar methods for preventing climbing-induced starvation have been used by others to rear Phyllium.

*I'm not sure how much direct sunlight is fatal, but have observed wild specimens making no attempt to seek shade at temperatures physically painful to myself (and I'm pretty heat-tolerant).

Foliage I have observed the adult to eat include that of domesticated Rubus and Salix lasiolepis.

… C, 10 June, 2025 - 3:27pm

Update 2

Rearing project discontinued, as I was still unable to get the adult to behave normally all of the time (alarmed by visual proximity to me?)

… C, 16 June, 2025 - 2:52pm

Disclaimer: Dedicated naturalists volunteer their time and resources here to provide this service. We strive to provide accurate information, but we are mostly just amateurs attempting to make sense of a diverse natural world. If you need expert professional advice, contact your local extension office.

Contributors own the copyright to and are solely responsible for contributed content.
Click the contributor's name for licensing and usage information.
Everything else copyright © 2003-2025 Iowa State University, unless otherwise noted.

Bugguide is hosted by:

Printer Friendly Version