Unidentified Pest! Need Help Identifying so I can Stop it!

10 years ago

Hi Everyone,

I've read posts on the forum for a while but recently joined because I need help. I live in San Diego, so I have a great climate to grow lettuce year around in my backyard (never gets below 40 and I have enough sunlight for lettuce all the time). I just started this year and had great success with lettuce from Jan-May until I moved onto summer crops.

I went back to lettuce a month and a half ago and my seedlings started to sprout and then disappeared quickly. I figured out quickly it was a pest eating them. I figured it was birds, have heard they like seedlings and we live by several large trees and have a large bird population and I have caught them eating my tomatoes before so I figured that was the culprit.

As a response to that suspicion I covered my raised bed with a double layer of bird netting and re-seeded. At first all seemed well, my seedlings werent disappearing, but it has started again! To describe my setup I have a raised bed which is enclosed by redwood 2x10's. The 2x10's have fencing attached to them to keep my dog out. And at the end of the bird netting I put a row of rocks on top of the netting so it was flush with the ground that I had hoped would keep mice out if they were the culprit.

The little leaves of the seedlings are being eaten and the small stem remains. I didnt find any traces of disturbance in the netting or disturbance in the dirt (though I doubt mice are heavy enough to leave footprints in most dirt). I cant imagine something making it through my netting setup without leaving some sort of trace and I have a dog which should be deterring pests like mice!

At this point the only thing I could think of would be mice/rats or slugs???

Any chance sombody else has experienced a similar problem and found out what is causing it? Or have an idea of what it might be based on the eating pattern?

Thanks for any help I can get!

Sort by:Oldest

Comments (6)

morz8 - Washington Coast
10 years ago
Go out at night with a flashlight and look. Begin about dusk and make additional trips until you find something. I suppose mice might be a possibility but I suspect you will find something other than 4 legged/footed pests. Let us know what you find and we can suggest a control.
jjoey388
Original Author
10 years ago
Did some more reading and considering caterpillars as a possibility. Have seen them several times before and seems like an eating pattern they might have.

But I am continuing my detective work. Thanks for your thoughts!
Related Professionals
Barrington Hills Landscape Architects & Landscape Designers · Cottonwood Landscape Architects & Landscape Designers · San Juan Landscape Architects & Landscape Designers · Manchester Landscape Contractors · Williamsburg Landscape Contractors · Burlington Landscape Contractors · Del Aire Landscape Contractors · Golden Gate Landscape Contractors · Hicksville Landscape Contractors · Louisville Landscape Contractors · Mahwah Landscape Contractors · Middle River Landscape Contractors · San Pedro Landscape Contractors · South Portland Landscape Contractors · Goldenrod Landscape Contractors
Kimmsr
10 years ago
If the plants arte totally disappearing overnight you have a mammal problem, not an insect problem. Slugs and snails seldom devour a plant completely in one night and caterpillars would be observable on the plants.
morz8 - Washington Coast
10 years ago
Diurnal caterpillars are active during daylight (where they might be 'observable')and nocturnal caterpillars, some of which have voracious appetites, are active during the night - and finding those requires flashlight, looking at night.
rhizo_1 (North AL) zone 7
10 years ago
Cutworms are a common example of caterpillars that hide in mulch or loose soil during the day. They are perfectly capable of plowing through seedlings. I'd also look for sowbugs, another critter well known to mow down seedlings at night.
jjoey388
Original Author
10 years ago
Thanks everybody. I did some searching for common repelants for lettuce feasting insects and came up with garlic and pepper as commonly being effective. I may also look into using BT, though I'd prefer to stick with stuff I have around my house while I can. I do think it's some sort of insect, I still havent been able to observe anything though. I feel like if it were some sort of rodent there would be some kind of trace left behind, a whole or disturbance in my netting, footprints, trampled seedlings, something, none of which I've observed.

It's not the whole plant that's being eaten, just the two leaves of the seedling with the stalk left there still standing, which quickly dies with no photosynthetic surface.

I'm going to keep applying a garlic and pepper spray every 3-5 days and see how that works. Since I applied it Saturday I havent noticed a significant decline in the # of seedlings, so perhaps it's having some effect.