Bean weevils

[Warren Beattie]

Just for the sake of curiosity and idle chat. Bean weevils, or rather cowpea beetles, Callosobruchus maculatus: anyone tried them? Any opinions?

I recieved a tester culture from Virginia Cheeseman over the weekend. Just a tester, because I'd heard that invertebrates don't like them much; but after a couple of false starts my smaller arachnids took them with few complaints.
Personally, with their relatively quick breeding cycle and larval diet of dry beans, I hope these can be a useful alternative to fruitflies (although used alongside other livefood). Despite my efforts and precautions, fruitfly medium tends to generate a lot more mites and mould than flies for me.

[Daniel Carpenter]

Havent relly tried them myself ...they sound good, i might have a look into them , cheers.
Dan.

[Colin D Wilson]

This was drilled into me when i was training as a chef way back when.....
Many types of beans contain toxins called lectins, i think the highest concentrations are found in kidney beans, this is why we have to soak them for about five hours and boil them to make them ready to eat, even a few raw beans can cause severe sickness and nausea. (tinned beans are already processed so are edible)
Not sure about feeding these weevils to other inverts as i'm not sure (without doing further research) if the toxins are absorbed by the weevil and can be passed on, and / or if they're harmfull to tarantulas. (maybe this is the reason why you've heard they're not liked much by inverts)
I think i would aire on the side of caution myself.
will have a shufty around on the net and see if i can contact some of my laboratory friends in the know.

[Daniel Carpenter]

Thanks you colin that has stoped me suddenly buying them, and maybe doing harm...i wondered why i had not heard fo them.
Dan.

[Warren Beattie]

Colin: true, true. My own caution is why I mentioned I'd use them as a supplemental livefood. Though I guess that would be a good idea anyway.

Although, from what I've read on other forums, they're popular among dart frog keepers; and seem to be readily taken by other amphibians (and there's one group of animals that's vulnerable to toxins...) as well as some lizards. I haven't heard any worries from those quarters yet.

Also, it seems the beetles are only, or can only be, raised on black-eyed beans (a.k.a. cowpeas) and possibly mung beans (I'll have to check). It jogged one of my own culinary memories, and a quick internet search shows that black-eyed and mung beans don't have to be soaked before cooking. How does that relate to any lectins in them? I don't know.

[Colin D Wilson]

Yes warren, i think you're right on the beans, some have little or next to no lectins, mainly black eyed and harrocate (think i've spelt that right, they're the ones used for baked beans). i wonder if they only choose the black eyed beans because of the toxic nature of the others.
One thing about amphibians though, although susseptable to toxicity, it's mainly toxins taken in through the skin that cause problems and not injestation. i.e. some frogs that are in an area populated by millipedes will fall ill when in contact with the irritant fluid ejected by the millipedes but will eat them when food is scarse with no ill effects,

[Warren Beattie]

Ah. My bad.

Haricot beans. One of the reasons I say they ignore other beans is because of a photo of a culture that showed black-eyed, mung, and 'garden' beans together. The white 'garden' beans looked a lot like haricot beans, or black-eyed beans without the black eye. Eggs were laid on all three, but the beetles only emerged from the black-eyed and mung beans.

A little more info on the beetles here.

[Colin D Wilson]

VERY interesting.......
brought back memories of writing endless waffle for my degree

Dont for the life of me know what an adzuki bean is though !!!

Looks like you've got an alternative food source then mate

[Robert Farmer]

I myself tried bean weevils from Virginia, looked good at first but none of my slings (1-3cm) could kill them!

Even the 2cm P Murinus couldn't kill one and damn it tried!

Only thing that could take'em was the Praying Mantis, and even that was with a struggle.

They're like the Rocky of the insect world!

[Warren Beattie]

Colin: Ah, but I thought I'd bring it up partly in case anyone else was interested in an alternative food source.

Very community-minded, I am.

Robert: Heh! They seem to be a little tough, and probably take some getting used to because of that. I watched my little Selenotholus sp. wrestle with one yesterday; almost thought it was going to give in, but it overpowered the beetle after a few seconds.
For others in my collection I left the beetles in overnight. Since the adults are nectar feeders I figured they wouldn't do as much potential damage as a cricket or mealworm. That seemed to do the trick.

[Jimmy Dale]

Though i'd revive this thread as i've just acquired a culture of bean weevils. I've had tried some grown on Cyriocosmus leetzi slings on them with mixed responses. I've offered them these about 4 times each now and have one which seems to have no problem with eating them while the other 2 remain unsure. Is anyone else using bean weevils as a food for slings?

[James Box]

i also got a test culture from Virginia Cheeseman. they are neat little bugs...not sure about how much the spiders like them, though i believe my irminia (1cm) destroyed them, as there was no sign. the H macs of the same size ignored them, from what i can tell.
now i was told bean weevils have a high shell to meat ratio, but i would expect with their diet to be quite nutritious.
i will be trying them more often, as i now have a few smaller true spiders as well as some small slings.
one problem though is that they tend to boil over the side of the deli cup they're in with great speed, and can fly! i thought crickets were bad but their climbing ability is limited so STILL a food source i have to refrigerate before dealing with lol
i will post on this site about how the animals i try them with like them.
i will probably use them as a supplement to crickets, maggots and mealworms, rather than a full replacement.