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Post by admin on May 23, 2015 14:45:23 GMT -8
Here's my scenario: I'm in southern California. I have passion vine growing in my yard. Every year the gulf fritillaries come around and lay their eggs. I wait a while, then harvest the caterpillars and rear them out in a cage with cuttings. Three years ago I began to notice that there were less and less caterpillars to be found on my vine even though the butterflies continued to lay their eggs. I thought it was maybe because of wasp attacks. There are a lot of potter type wasps in my neighborhood. But after a while I could not find any caterpillars on my vine at all. So I adopted a new strategy. I started just catching the female butterflies and putting them in a cage with potted passionvine. They laid a ton of eggs each time and I just reared the resultant larvae in the cage. Then the ### hit the fan... The larvae would munch happily on the passion vine until they got about to 4th or 5th instar. Then they would crawl to the top of the cage and sit still for a few days. Then they would turn to MUSH!. This has been happening to me for 3 consecutive years! I have not been able to get even one caterpillar to make it to pupae stage. Here are some pictures I took today:   No visible parasites are ever found in the corpses (such as parasitic fly pupae, etc.) I heard somewhere there is a gulf virus going around, but there is a problem: My friends who live in Los Angeles are not having this problem. So, is this a regional thing? I know I am supposed to wash & disinfect my cages and stuff. I'll admit maybe I haven't been diligent enough about that. I know this is even more important for monarch rearing because of the accumulation of the OE parasite. But for gulfs too? This is my third consecutive year with this problem. If the cause is because of dirty cages then why am I not finding any more full grown larvae on my plant outside? Could it be that the vine itself has become toxic to the caterpillars because of the fertilizer I use? It doesn't look that healthy, to be honest. I alternate between rose food and fish emulsion. So, I'm looking for answers. Thanks. |
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Post by oehlkew on May 23, 2015 16:48:10 GMT -8
Clark,
Just a thought. Perhaps the plants have become toxic to larvae because of your constant picking of leaves. I have read that when trees become defoliated due to insect infestations, that they sometimes produce a toxin that kills the insects as a defense mechanism, or perhaps there is a virus present on foliage whether inside or out. Fertilizer may also be the culprit.
Best of luck. I would change the fertilizer and give the plants a rest for one year.
Bill Oehlke
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Post by admin on May 23, 2015 16:55:06 GMT -8
Clark, Just a thought. Perhaps the plants have become toxic to larvae because of your constant picking of leaves. I have read that when trees become defoliated due to insect infestations, that they sometimes produce a toxin that kills the insects as a defense mechanism, or perhaps there is a virus present on foliage whether inside or out. Fertilizer may also be the culprit. Best of luck. I would change the fertilizer and give the plants a rest for one year. Bill Oehlke There are plenty of leaves on my vine. It is robust. I don't think it will miss any. I did give the plant a rest for a long while and it started turning yellow. When I added fish emulsion it perked back up and became more green. The vine is very old. Soil is not good beneath it. I'm thinking just to cut it off at the base and let it regrow. |
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Post by compsulyx on May 23, 2015 23:57:33 GMT -8
Hi Clark,
I think it's a virus. You should try to get a new strain from another region and try again. If you met a similar situation, then it comes from your environmental area / equipment / hostplant....
Concerning passion vines, they like a healthy ground with lots of life in it. Best is to mulch the soil and give organic fertilizers instead of chemical fertilizers, which tend to saturate the soil and make it inert. If you maintain a good mulch on top ground, life will come again and your passion vine will be healthy !
Then for all the passion vines, they have a normal cycle of 4-5 years maximum, then needs to be replaced with new ones. If not, they will give less flowers and less fruits, and will get more and more growth issues. So I totally agree with you, you need to replace your passion vines.
Hope this helps...
Thierry
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leptraps
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Post by leptraps on May 24, 2015 1:56:00 GMT -8
I lived in south Florida for many years and suffered some of these problems. I tried several things, spraying the vines with a bleach water solution, anti fungul stuff used on orchids, I even peed around the vines. Nothing worked. I finally switched to potted plants.
Passion vines grow every where in South Florida.Vacant lots always had vines. I carried a shovel and black plastic pots used at garden centers in my truck. When I return home with plants, I repotted them in large 5 gallon or larger pots. I kept the potted plants in our screened patio enclosure. No parasitc wasp or flies.
I never had problems with Aristalochia vines. I grew them on a 10' X 10' wire rack on a well of our home. I had several speices. The flowers are stunning but smell like feces which attract filth flies to polinate them. I reared Battus polydamus several times. However, I left the rack up and maintained the plants. Lepidopterist visitors to our home always went home with mature larva or pupa of Betty's polydamus.
My yard in South Florida was full of native plants and a few non-natives. I was always raising something. I had several
Sennea bushes. Pheobus philea and P. sennea were always present, year round.
After I finished rearing, I always washed the pots and cages with bleach water to kill bacteria. Even then I would suffer a bacteria attack. I would put the pot, plant and larva in a plastic trash bag at throw it in the trash.
There was a native garden center in Homestead, Fl.I could purchase Passion Vines, Aristalochia Vines and many other plants to feed to hungry catapillars.
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Post by jshuey on May 24, 2015 5:38:39 GMT -8
All the symptoms point to a NPV outbreak. (Nuclear polyhedra virus)
j
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Post by admin on May 24, 2015 7:43:09 GMT -8
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leptraps
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Post by leptraps on May 24, 2015 8:06:11 GMT -8
While I was working in the Entomology Dept. of the University of Kentucky there was student working on a project with these biological control virus/bacteria on Sugar Cane and Sorgum. His lab had restricted access and was bio-secured.
In 2011 Leptraps sold 30+ light traps to a corn seed grower in Indiana who used the traps to monitor the corn plants for corn pest. When the first moth was collected in a light trap they began to apply this virus/bacteria to control the corn borers.
I would guess it would kill anything that used corn as a larval host. Maybe Monarchs in near by fields on Milkweeds?
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Post by mikelock34 on May 24, 2015 11:36:58 GMT -8
Had the same problem several times rearing Saturnids. Once the virus was in the aquariums I was using each time, even bleach did not help. Had to throw out the aquariums and begin with fresh ones to use for rearing.
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Post by jshuey on May 24, 2015 11:59:53 GMT -8
NPV's are usually pretty specific as to what they kill. The one for gypsy moths also kills about a half dozen other species that are closely related here in the Midwest. They are generally touted as the most "biologically friendly" agents you can use. They are expensive - because you have to grow the virus in larvae. .
j
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Post by lepman1256 on May 24, 2015 13:15:55 GMT -8
To solve this problem here in Florida, I would isolate each caterpillar in a 12 oz. clear cup with lid. It would work for about two broods before I tossed them out. Even bleach did not solve the problem. My passionvines were many, many years old, so I feel the problem is a virus that tended to manifest itself in the more humid Summer months. A circular piece of paper toweling in each cup helped cut down moisture issues. I've been able to rear 200 to 300 fritillaries each year using this method.
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Post by 58chevy on May 24, 2015 13:31:35 GMT -8
A vanillae is usually the most common butterfly in my area (Houston, TX), but I haven't seen any of them this spring. Maybe it's the virus.
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Post by irisscientist on May 24, 2015 15:17:18 GMT -8
Hi Just a quick comment that I wish to raise. The NPV Wiki link clearly says "The virus is unable to affect humans in the way it affects insects: human cells are acid-based, while this virus requires an alkaline-based cell in order to replicate".
You all comment that bleach (an alkaline) is not helping to decontaminate your boxes/cages. No sh*t Sherlock. Any alkaline based solutions will surely only exacerbate the problem? In order to kill/prevent the virus from spreading, perhaps try using an acid based cleaning agent? Even vinegar (weak acetic acid) and/or lemon juice (citric acid) should have more beneficial effects against NPV than applying solutions which ultimately only help the virus to replicate.
Mark
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Post by mikelock34 on May 24, 2015 16:49:10 GMT -8
Hi Just a quick comment that I wish to raise. The NPV Wiki link clearly says "The virus is unable to affect humans in the way it affects insects: human cells are acid-based, while this virus requires an alkaline-based cell in order to replicate". You all comment that bleach (an alkaline) is not helping to decontaminate your boxes/cages. No sh*t Sherlock. Any alkaline based solutions will surely only exacerbate the problem? In order to kill/prevent the virus from spreading, perhaps try using an acid based cleaning agent? Even vinegar (weak acetic acid) and/or lemon juice (citric acid) should have more beneficial effects against NPV than applying solutions which ultimately only help the virus to replicate. Mark There you go. |
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Post by africaone on May 25, 2015 0:23:44 GMT -8
Hi Just a quick comment that I wish to raise. The NPV Wiki link clearly says "The virus is unable to affect humans in the way it affects insects: human cells are acid-based, while this virus requires an alkaline-based cell in order to replicate". You all comment that bleach (an alkaline) is not helping to decontaminate your boxes/cages. No sh*t Sherlock. Any alkaline based solutions will surely only exacerbate the problem? In order to kill/prevent the virus from spreading, perhaps try using an acid based cleaning agent? Even vinegar (weak acetic acid) and/or lemon juice (citric acid) should have more beneficial effects against NPV than applying solutions which ultimately only help the virus to replicate. Mark is this rule for all the vriruses or only some kinds ? |
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