Dealing with Hibiscus Weevils in seeds.

Everyone--especially Dr. O...

This may run a bit long--as I have been putting up with this every year
for a long time.
I have two perennial Hibiscus--the tall ones. Red and white.
I collect seeds from both Hibiscus every year. I lay them out on a plate to dry
and then bag them up in a Zip-baggie.

There is nothing unusual at this time--and NO visible signs of any of the weevils.
The seeds are absolutely intact.
Then--maybe in December or January--as I start to divvy up my seeds
in the small baggies for swapping--there they are--groggily crawling around in the bag.
I shake and rattle the whole bag--and now they all come creeping out.
HUNDREDS and HUNDREDS of them!
Oddly--they will survive for months in a small, sealed, plastic bag--so no oxygen seems
to be needed.

Somehow, at some time in the bloom/seed development, they seem to be already inside the seeds.
After a couple months--they are full grown and have eaten out the germ, leaving a hole in the seed--
at one end--like in a small bead. At least 70% of the seeds are affected by these Weevils.
These seeds will never germinate--as there is no gem left.

I have tried all kinds of things over the years---mostly putting all the seeds on a
plastic styrofoam plate, spraying all the seeds heavily with an insecticide, and then
covering it tightly with plastic wrap...for days! NOT a pretty sight!
I shake up the plate--and they all start crawling around--endlessly.

They are hard-shelled--lie any weevil--almost black and about 2mm-3mm in size.
Many of them die--but many do not--as they are still inside the seeds.
and so this "process" drags on and on until they are all dead.

Before packing them up for Swaps--I have to wash and dry all the seeds--
as I could never offer them to anyone after this treatment.
I have to also write a note to anyone I give them to not to plant the ones with the holes.
I DO NOT have time to sort through the seeds--and now it is left up to the receiver.

HERE IS WHAT PUZZLES ME THE MOST:
--At what stage of the bloom /bud development do they make their way into the developing
flower or seed pod??? WHO lays the eggs or how do they get in them???

--Seems they develop already inside the seed, as there is NO signs of them when I am
removing the seeds from the pods. These seeds are small, round balls ~~3mm.
There are a few little bugs crawling around the inside of the dried up seed pod,
but I am assuming this is normal. The seeds are all intact looking...
One bug that seemed to be in many of the pods was a small beetle, about the size of a
lady Bug--but more elongated. Longer legs and antennae. Maybe 2/8"--3/8" in size.
Dark brownish/maroon body with tiny, blue markings on them. Took a pic--very fuzzy!

Dr. O--or anyone--can you enlighten me on this?????

I have just finished removing all the seeds from many,many pods. Need to do something
before these Weevils grow up and eat out the germs.

***DO YOU THINK FREEZING THE SEEDS WOULD KILL THEM???*** How long?
Not knowing what "stage" they are in at this time (if any)--not sure it would work.

Here are some pictures of this fiasco: PLEASE HELP!!!!

1--This is the Hibiscus--it grows about 5' tall. Very pretty!
2--This is what the seed pods look like--ready to pick. Lots of room in them for bugs...
3--This is the small beetle that was inside many of the pods. Any importance???
Sorry--This was as macro as I could get...
4--Plastic covered plate after they all were sprayed with insecticide.
5--A close-up of the rim --you can make out all the weevils. These are from 2008!

DISGUSTING!!!! Gita

That is some spooky! I have a beautiful pink/red center hardy Hibiscus- I certainly hope I don't get those critters! I don't think mine is even going to make seeds- I will have to root cuttings, I think.

Those are definetly weevils and they lay their eggs in the seeds at flowering or thereafter as the flowers dries down. 72 hours in the freezer at 0 degrees should work. If you freezer isnt that cold keep them in there for a week. Hopfully the seed wont be damaged from the cold...that may happen. But make sure the seed is completely dry before you stick them in the freezer to minimize damage to the seed.

Next year at flowering spray insecticide like Sevin regularly to control weevils and prevent them from laying eggs.

Could also try mothballs in with the seeds in the bags, but think freezing is best bet.


This message was edited Sep 7, 2013 6:17 PM

Dear John---(This is Marsha.....:o) ) Haa..haaa...

Me thinks you were on vacation for a while. Yes? Did not see you posting...
Been looking--as I knew you would have some good suggestions....

However--all your info. just lead me to a bunch of more new questions...
Inquiring minds want to know..............need more answers.

--Where do these weevils materialize from? The plant dies back to the ground
every winter--I pick off all the seed heads where the adult weevils are in--
SOOO--where do they come from? Are they dormant in the soil?
Should I treat the soil before the Hibiscus breaks dormancy? With what??

--You say the Weevils lay their eggs in the seeds during bloom time.
ARE there seeds already formed as the plant blooms? Where are they?
How many hundreds of seeds can the weevil lay in a short time?
Last year I cut off all the seed heads in frustration and discarded them.
Did not want to deal with all this crap again.
This year--I wanted to 'refresh" my seeds...WHY??? I have thousands!

--Spraying with Sevin regularly to prevent the weevils from laying eggs.....
What part of the plant should i spray? All of it? Just the blooming branch tips?
Should i spray right INTO the blooms?

--Re the freezing---IF they are already developing in the seeds (as yet unseen)
and I freeze the seeds--kill the weevils--how much damage could already
been done to the germ? Even if they have started chewing on it--would that
not already affected the germination of this seed?

--More on the actual freezing.
NO! I cannot turn my freezer on "0"--Need to check on my freezer thermometer
what it actually is now. Have NO idea....

--Should I freeze them in a paper envelope? A zip baggie? In a container?
How could i tell if the seed has been damaged by the freezing?
NOT gonna plant the seeds here again! But--if i share them with someone--
how would they know?

You know what--"Dear John"......I think I should just cut off all the dry seed-heads
and toss them every year from now on. WHY bother!!!!
The days of lots of people asking me for these seeds are long gone-ONLY
because I have not "advertised" them.
All I have to do is post a beautiful picture--and tell "them" I have seeds--
and the requests will start rolling in. NOT doing it!!!

I have 100's and 100's of seeds from Daturas and 4 O'Clocks...these Hibiscus,
a million (?) seeds from Northern Sea Oats--and the Wintersweet Shrub. and others....
WHY bother gathering new ones???? I know--my disease/compulsion...
A cosmic question.....

Thanks for reading and caring.....and your great answers.
Will miss you at the swap tomorrow.....Lets hope you can make one next year.

Gita

yes I went to upsate NY to look at grapes and apples for work. Lots of downy mildew and Botrytis as well as apple scab and summer diseases.

The weevil adults can lay their eggs in the seeds and seed heads at anytime from flowering to seed formation up until you harvest the seed heads. Most flowers when they bloom already have small immature seeds forming already.

In season applications of Sevin could be made to the flowers every 7-10 days from flowering until harvesting the seed heads. The weevils come from other plants and overwinter in the seeds of other plants as well. I dont think it will help to treat the soil.

Yes if you wait too long to freeze it is possible too much damage to the seed may be done...so the Sevin or even a systemic insecticide like imidacloprid makes even more sense.

I'd freeze them in an envelope. Its worth at least trying.

Good luck!

Seems to me that if one were to spray from Flowering till harvest, there would be no pollination, hence, no harvest, not to mention a lot of dead pollinators.

these are actually Hibiscus Beetles. here is some good info on them and their amazing life cycle: http://www.trop-hibiscus.com/CNBugs/chew3.htm

I don't agree that they are hibiscus beetles. And yes Sevin or carbaryl applied in a liquid form can cause flowers to abort in some plants. I would use the dust to avoid reduce the chances or a product like bifenthrin.

trackin...

I just read all through the link you posted. Nowhere was it mentioned the small
weevils entering the seeds and feeding on the gem as it grows--or I assume they
feed on the germ. Don't know...but they DO make the holes in the ends of seeds.

The seeds that I have--all have the hole only at one end of the seed--so I have
always assumed that they eat out the germ. Might just be the seed matter???

Also--almost all the hibiscus pictured in the link are the Tropical Hibiscus--judging by
the leaves and photos. Perhaps it does not matter--but mine is a perennial,
tall (5' x 3') upright "shrub" which sends up tall stems from the ground each year. .

In the picture of the 3 different adult beetles/weevils, the first one looks like
the ones I found in good numbers in the seed pods when shelling the seeds.
Upon squishing these--there was a red stain, tinted with a bit of green.
I remember these had a snout. The picture I took (above) is too blurry.
I had my camera on macro--but I may need a super macro.

In the end--I question whether we are, actually, talking about the same insect???
If you look again at the closer shot of all the weevils on the edge of the plate
you can see how tiny they are--as they all just crawled out of the ends of the seeds.
See pictures below.

I will bookmark this site--though. Lots of good information.
Thank you, Gita

John--we cross-posted.....Gita

we can agree to disagree. your pictures do not look like weevils to me but beetles. i would love to see a clear, close up shot to get a good look at the snout.

To be correct weevils are actually beetles. So no need to disagree. Most belong to the family Curculionidae. I beleive Gita has granary weevils based on their life cycle and what she has observed.

http://www.pestproducts.com/weevils.htm

well that would make sense. the only time i have seen small weevils in such abundance were in stored bags of grain.

i found a great up close and personal picture: http://en.wikipedia.org/wiki/Granary_weevil

This message was edited Sep 8, 2013 10:08 PM

trackin--

If you go back to the picture I just posted--the 2 weevils on the plate--
and enlarge it--you will see there is NO cinched waist on my weevils
as you showed in the Wikipedia link.

To enlarge type or a picture--press "shift" and then the "+" mark.
Each time you press these--what is on the screen will enlarge. Go as bog as you want.

Then--look at my weevils again. Their upper body is all one--NO cinch at the waist.
To get back to normal size--press "shift" and the "-" (minus) mark.
I cannot provide you a better picture--as all my seed pods are empty and discarded.
My seeds are drying on a plate--and, soon, i will put them all in an envelope
and put it in the freezer for 4 days- a week.

John--
the link you posted had no picture attached. So--I cannot compare.
I have NO pantry of grain infestations in my house. I hardly ever use rice or other grains.
I do feed birds outside--NOT in the summer--so there may be a source for this.
However--I NEVER keep bird seed in the house. Just in my shed.
I just keep sealed, unopened bags in my Shop now and then.

SO? Are we back at stage #1??? Thanks again---Gita

Gita,

There are a number of different weevils and I'm not sure which one you have. But based on the life cycle you explained it is some type of weevil. I would need to have a better picture to really know for sure. But regardless the treatment would be the same.

I included the link knowing there wasnt a picture but because it talked about the heat and cold treatments as a method of control.

John

Thanks John--You ROCK!!!! can't wait to meet you....

I can "allow" a few of the seeds to go through the usual process
and then mail you a small baggie with the seeds AND the weevils in it.
That way you can see them all in action.

Gita

Anyone know how to "Bookmark" a whole Thread??????
I would like to save this Thread to refer back to.
Thanks.

gita, that is why i thought they were a Hibiscus Beetle and not a Weevil in my original post. i know that weevils and beetles are in the same Order (general family) but while a weevil is technically a beetle, all beetles are not weevils. does that make sense? LOL

the Hibiscus Beetle that i referred to likes any large flower with lots of pollen but because your insects are in the actual seeds, it would seem that they are not HB's but a different weevil or beetle.

i would get a really good close up shot of the insect in question and post it on the Insect ID forum. flapdoodle is excellent, as are a few others on that forum, when it comes to nailing down a positive identification.

in the mean time, the suspense builds!

track--

I cannot get a better picture--as there are NO weevils at this time.
These weevils will nor show up until a couple months later.

I DO plan to freeze all the seeds--BUT--for the sake of ID'ing--
I will allow some some of the seeds to just "veg" and then, as these weevils
start crawling out--I can get a better picture.
Deal? G.

DEAL! lol

I was able to get a decent picture of the BEETLE that I saw many of
while shelling the seeds. The same I tried to post a picture of--but it was all fuzzy.

There was one seed pod left on the white Hibiscus--and these were crawling inside.
By the time I got it positioned so i could see one--most of them were gone.
All the rest of the 'stuff" you see in there were dried up body partss of the same.
A bit of canibalism?????

So--this COULD be the one of the Hibiscus BEETLES you were referencing to???
G.

the HB's are small and black. this picture looks more like the nymph of a true bug to me but please post this picture on the insect id forum. there are SO many insects out there....

I have the same beetles, which just appeared within the last couple of days. They hide from the sun on a shaded leaf during the day. At night they migrate into the dried bud.

those are stink bug nymphs

Mine too, John???? Stinkbug nymphs??? Verrrrry interesting............
It sure looked like a complete Beetle to me!

They must have eaten a lot of other bugs-unless the litter below the live one
is the skins/shells/pupas they came out of....????

My camera does not go to super macro--just regular macro--
so i cannot take any really close up shots. It is a Nikon--should have this function.

Maybe I should take a look at the CD that came with it. Never have yet--
it is now over a year.....i HATE reading manuals.....

G.

after looking at jujy's pic, i agree with drobarr, stink bug (a true bug) nymph. whether they are predaceous stink bugs or are eating the plant material, i cannot say. i do not think they are related to the little black insects in your original post.

I grow hardy Hibiscus but have never had trouble with weevils. Looked it up in my trusty bug encyclopedia and here is what it states.

"They are really beetles and belonging to two types. Those that attack stored seeds and those that attack growing plants. There are many varieties of weevils, one type for just about every plant. The adult female lays an egg in the flower in the Fall. The young larvae eat into the flesh of immature and soft seeds. It eats the seed from the inside then after 2 or 3 weeks eats an escape hole and fall to the ground and burrows in the soil where it pupate and in a month emerging as an adult beetle.

Because of their habit of feigning death when disturbed and falling to the ground, they can be controlled by what is known as the "jarring method". Place a sheet around the plant and hit it with a wooden or cloth-covered mallet. The insect will fall onto the sheet to be destroyed. Jarring the plant each morning for 6 weeks after blossoming has been recommended. Also pick up any dropped blossoms and destroy them.

Malathion will also kill the beetles.

Blomma--

What is described above cannot be the Hibiscus weevil. As it stated-
there are all kinds of weevils. This is not the one I was describing.
My Hibiscus are the tall variety--like 5' tall--NOT the bushy, short, perennial kind.
There is NOTHING left in the fall to lay eggs in. The plant completely dies back.
The stems are cut down and that's that until new growth emerges in late spring.

Gita

Since this is not an edible crop I would treat the whole plant with systemic insecticide through the soil. Also, a soil drench to kill overwintering pests.

I'm wondering if anyone has tried using something less toxic than malathion, sevin, or imidacloprid (which is a neonicotinoid, a class of pesticides now thought to be instrumental in the decline of bee populations), for weevils. I checked whether neem might be effective against weevils, and there is claim of that. Of course, neem is now said to be a magic bullet for lots of stuff, including fungi and a variety of diseases, and it is always my tendency to be skeptical of such enthusiasms.

But to tell the truth - for me, it works; has worked for everything except adult Japanese beetles. And I can't get it to do anything about slugs and grubs.

The stuff I have now is a bit old, so I think it needs to be replaced. It's important to have a fairly fresh bottle and to use it according to recommendations. I'd sure give it a try before going to any of the more known-toxic options. I've used it to keep aphids off my hibiscus, and it seemed to discourage spider mites as well. And, what was far, FAR more destructive: a rabbit! ;D

Another idea:
Treat the seeds to CO2 long enough to kill the pests.
You will have to research the method, but I understand it involves dry ice in a nearly sealed container such as a mason jar. 'Nearly' sealed until the dry ice is all gas, then seal the container.

i don't know about this particular weevil but the ones i deal with are all root weevils. they spend their adult life on the plant, then lay eggs. the larvae hatch and fall to the ground where they spend their juvenile span gnawing on roots. in spring they come up through the ground as adults and it starts all over again.

if you only have the problem on a few plants, you could try raking away all the mulch and then putting down a fine grade nylon screen from close to the trunk/stem out to the width of the plant. the screen won't degrade and it will let enough moisture in as long as it isn't clogged over with more mulch. the adults won't be able to get up and the larvae may not be able to bury in. the important thing is to break the cycle before summer starts again. you can use hairpin type plant markers to hold the screen in place. if you could leave it down from spring through to the next year's summer, i think you'd pretty much get rid of them....IF they have this particular life cycle.

All good advice--almost too much....

I have 3 perennial Hibiscus. The tall red--the tall white ("Luna")
and the Kopper King Hibiscus. They are all perennials.

This past summer was the 1st time the KK Hibiscus. made ANY seeds.
Of course--they too had the weevils. All are in different locations.
Seems the Weevil bugs seeks out Hibiscus and does their thing on them.
I believe these bugs are actually called the "Hibiscus Weevil".

It seems inevitable that seeds from the red and white will have weevils. NOT on all!
I have had it-- and now just cut off the seed heads and do not collect any seeds.
I have enough to share--w/o holes in them. Considering that one bloom
will produce a seed pod with about 100+ seeds in it, I have plenty.

Bonide Systemic Granules are all but unavailable any more. hard to find.
I still have a big jug--but to buy a new one would run about $30.
I still use it on all my plants I bring in for the winter--which is a zillion!
And--I have NEVER had any bugs on my plants because of it.

I am to the point in my gardening, in general, to just "laise fair"....Let it be!
I do not wish to go to any great lengths to do this and that. All my plants do OK--
all on their own. I am pushing 78--and don't feel like too much fussing...

I DO have some mite issues on my Brugmansias. I try to treat those with spraying.

At the Home Depot--there is a liquid and granular Systemic by Beyer for sale.
Maybe $15 each container.

Does anyone have a preference between liquid or granular Systemic?
Seems the liquid would work faster....

Thanks--Gita

This is just part of all the plants I bring in for the winter, They are ALL over--in every room.
They all do well and have always survived the winter and then I just put them all back outside.



Gita

Gita, you have a wonderful collection of plants!
Yes, at 78 you sure can pick and choose what you want to do!

Beautiful!

You have one true green thumb!

Love the Christmas cacti. You even have plants on your bed!

John

Dr---

All those Holiday Cactus grew bigger and then they all bloomed.
I have many different colors--thanks to JB and mescrounging racks
at Lowes when they are out of bloom for broken off sections.

I also, endlessly, propagate these. Got to stop it!
I have taken pretty pictures of all my CC's in bloom. The whole plant--
and a macro of their blooms.
These pics are on a separate memory card. I have not uploaded them yet.

I can show you some pics that are in my Nov. and dec, Folders, though.

1--The same rack as above--but now all blooming
2--Peaches and Cream--from JB
3--The "Small fry under my task light on my kitchen counter.
4--This is a TRUE Christmas cactus. Smaaller, smooth-edged leaves
with a drooping habit. Blooms hang straight down. "Birder" sent me small
cuttings about 3 years ago. Will transplant this when it is done flowering.
5--Macro if the fuschia blooms. Lovely!

Need to up;load that nes Folder--so i can show you the rest.
Will show JB als well--on the "Other Site"

Gita

OK! I can go back to last November and show you some pictures from
my CC's last year. same blooms--maybe just a smaller plant.

1--White Christmas
2-- Bright pink
3--Salmon--one of my favorites
4--Common Fuschis and white
5--Yellow

The bright pink is my favorite...not just the color but the form.

More--from last year....

1--White Christmas and a red one
2--My favorite pink
3--White Christmas and my "Pretty Pink" (the name I gave it).
4--Salmon--whole plant
5--This is my red Easter cactus. Note--also smooth leaf edges.

Thanks, Doc!

Here is my Easter cactus--it also has smooth leaf edges and blooms
sometime around....mid summer. Whenever it decides.

This is from JUne, 2011

Gitagal All I can say it WOW, just beautiful. Reminds me of years ago when I used to have 41 different houseplants when I owned an old house with large window. I now have only 3 since I have 2 large windows and the rest are small. The roof have an overhang so this house isn't good for growing many plants.

I do have Daylily seedlings under fluorescent lights, to be planted out May 31. .