squash vine borers - hand picking eggs

16 years ago

I have squash vine borers laying eggs on my pumpkin vines.

I know that row covers would have kept them off - but, well, these were not planned-for pumpkin vines; they volunteered in my year-old finished compost bin, and I have a soft heart and am fascinated by their growth, and would like to keep them alive.

I did an image search on SVB eggs, and think I've identified them - bronze colored disk shaped eggs, laid in ones or twos on stems and flowers. I've handpicked 31 of them this morning, and I'm sure I looked at only about 10 or 20% of the vine surfaces.

I've been tossing the picked-off eggs onto the sidewalk, assuming there's no danger of a hatchling having the wherewithall to get from the sidewalk to the vines; anyone have experience that makes that seem unwise of me?

The adult insect (what do you call it? I presume only the grubs are called squash vine borers?) is kindof pretty, and VERY very fast. I have had no success in swatting it into the cup of soapy water I brought out for that purpose. I am wondering if a soapy squirtgun might help!

While hand picking eggs, I found some shiny black eggs (more oblong in shape) on the underside of a leaf. On the theory that anything laying eggs on the pumpkin vine is planning to eat it, I handpicked those as well. In retrospect, I realize that predators would also lay eggs on my pumpkins. Anyone have a guess as to what the black eggs were? Ladybug eggs are pale / yellowish, I think, and laid in clusters. These three black eggs were all under one leaf, but not in a cluster. (I'm pretty sure I saw a ladybug nymph wandering the vines; off to google that to see if I am recalling their appearance right!)

Thanks,

Lisa

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Comments (4)

lcpw_gw
Original Author
16 years ago
I'm fairly astonished to say, things are still going well with the pumpkin vines. Some days I pick 70 to 80 eggs off of the vines; other days I only pick off a few.

I can say with authority that they do NOT lay exclusively on the vines - I find plenty on leaf stalks, flower stalks, the flowers themselves, and even the little fine-diameter tentacle-like thingies they send out to grab ahold of any and everything to support them. It does seem like they favor undersides and shady bits, but really the eggs have been all over.

What surprises me is that I haven't found any evidence of a hatched egg - no caterpillars within a stalk, no wilting that I can't attribute to simple breakage of a leaf stalk. I still imagine it will come (those eggs can't all be unfertilized, can they?).

I made a solution of a very little bit of dish soap in a lot of water, and put it into a plant mister, and turned the dial to the "squirt" direction to make a giant squirtgun to zap the adult laying the eggs. Gosh she is FAST!! I am not certain the soapy water bothered her at all - it isn't clear whether I was getting rid of some squash vine borers that were then replaced by others, or if the same females were coming back again and again.

The vines are 7 or 8 feet tall at this point, and still very entertaining. If anything else interesting or unusual or edifying happens, I'll post again to share, in case anyone finds it interesting.

- Lisa
anney
16 years ago
Lisa

I do!

Here are some interesting controls of the SVB, though they don't involve your detailed handpicking of the eggs!
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gabo
16 years ago
If you treated the area prior to infestation with neem oil and neem cake you would be fine. If you are treating after the fact and have issues, more than likely eggs have been laid and the borer is inside the plant which means you haven't got a whole lot of time. If you get liquid BT and inject it into infested vines the larvae will eat it and die without affecting the plant. IF the infestation is too far along inject 2" or so above the area where the eggs were laid. IF you have significant infestation continue to spray every other day, broadcast neem cake then diatomaceous earth at the root zone. Continue to spray neem (make sure you get under leaves) every two - 5 days and spread more DE if it rains.
Bottom line, neem is great stuff but nothing works after the fact. It may stop further infestation but it will not address what is already inside the hollow stem and thoroughly protected.
Christian
14 years ago
I have about 7 acorn squash plants, and 2 hill of young pumpkin plants. Everyday I go out and pick eggs.

I had just become knowledgeable about the infestation of SVBs since I had an earlier set of plants die with the borers after only a few squash.... So I got a late start trying to defend my second batch of acorn squash and have seen some SVB damage, but I injected them with BT and have sprayed NEEM and also let some soak into the ground. (I've read that NEEM acts systemically, and the plant absorbs it, hope its true!).
My Acorn plants are doing well and starting to put out male flowers. I pick about 20-30 eggs off each day. Like Lisa said, I find them everywhere but a pattern I notice is this:
- they seem to prefer the outermost plants, especially 2 that are more isolated from the other. (the others are close together)
- the definitely like under leaf stems, and close to the main vine.
- NEEM oil doesn't seem to deter them from laying... Still see same number of eggs as before I started spraying with it.
- One more thing, having a hand mirror REALLY HELPS. I've been able to use the mirror to see the plant from different angles and have found many eggs I would have not seen otherwise.

I know this could all be frustrating, but I've began to think if this as a game, a challenge, and see if I can outpick the SVBs egg-laying.

Hopefully the BT injections have killed the worms inside. I really didn't want to slice the vines open. So far 1 week after injecting, the plants look real healthy, and I have not seen any more new frass... there is some stem cracking, but after more injections of BT, I have also tried to cover a lot of the stem with dirt and watered it well, so it can heal up.

Now regarding the pumpkins, I've picked eggs off of them but haven't found nearly as many eggs on it compared to the Acorn squash. The plants are still pretty young though, just beginning to send runners. I notice the pumpkin stems are a lot hairier and spike-ier than the Acorn squash... wonder if that somewhat discourages the SVB?

Keeping my fingers crossed and praying I can beat these beasts. If and when the pumpkin vines get real big it will be challenging to keep them egg free.
Being in North Texas, I think we have multiple generations of SVB, so it wont probably be until late Sept that I dont have to worry about them anymore :(