HOME > Chowhound > Gardening >
Are you making a specialty food? Get great advice
TELL US

Is this yellow bug harmful?

c
CocoaNut May 14, 2009 01:43 PM

Ok - my 2 tomato plants now have about 7 tomatoes of varying sizes between them. They're all still green, but I've been noticing that the leaves on the lower limbs are beginning to look unhealthy - not really wilted, but certainly not firm like the newer upper leaves. Some are also turning a splotchy, anemic looking light greenish/yellow beginning in the centermost part of the leaf. Each plant is about 3-1/2'.

Just now, I've seen a very busy small vividly colored small bug that's yellow-gold with multiple black spots. Except for the color, it resembles a small lady bug. And it's very busy, running back and forth across the top surface of the leaf. So far, I've only seen one.

A quick Google search rendered no specific info. Can someone tell me if this bug is friend or foe? Would it be causing the deteriorization of the lower leaves?

  1. choco_lab38 May 14, 2009 01:59 PM

    If it indeed looks like a ladybug except for the color, it IS a ladybug. They aren't limited to red. She's helping you out, so don't hurt her :)

    The discoloration could be a result of many things. Check out this website and click on Leaves. You'll see a number of pictures of different leaf problems and if you click on one that looks like what you're experiencing, it tells you possible causes.

    http://aggie-horticulture.tamu.edu/pu...

    6 Replies
    1. re: choco_lab38
      j
      jumpingmonk May 14, 2009 02:43 PM

      I don't know what they're called but I see them a lot too, itsty bitsy (about sesame seed sized) thing with taxicab yellow shells and a complicated series of elongated and connected spots (does the pattern on its back look a bit like an anchor or cartoon dog head to you, if so we're talking about the same bug) I think they're harmless. P.S. its been a fairly cold spring so dont be surpised if you also see a lot of backwards two spottd ladybugs (black ones with red spots) also the maroon ones they import from Japan and the odd grey lady bug.

      1. re: choco_lab38
        c
        CocoaNut May 14, 2009 02:44 PM

        Thank you much. Googling ladybug, I can see images that closely resemble what she looked like. For now, she's flown the coop - hopefully, she'll return later with friends.

        That web site is great. I've come across it on a different search and have the results bookmarked. But based on the picture link, I believe the leaf problem is Spotted Wilt, for which there appears to be no remedy. I have an organic nursery close by, so I'll go by there and see what they have to say. Bummer! I have NO idea where thrips would have come from. While I'm in somewhat of a rural area surrounded by a lot of undeveloped land, I am in a suburb between Dallas and Ft Worth and there are certainly no grain or other large farms around.

        1. re: CocoaNut
          h
          harrie May 14, 2009 03:15 PM

          You might also want to google images for "spotted cucumber beetle," just to take a look. If it's on your tomatoes, it might just be confused, but it's probably not all that helpful (like a ladybug would be).

          If there's a possibility the markings could be stripes, not dots, you might also want to google images of "potato beetle.: They are definitely not friends of your tomatoes and should be dealt with.

          1. re: harrie
            c
            CocoaNut May 14, 2009 03:25 PM

            Arrrggg - definitely, without doubt, spotted cucumber beetle - more elongated than a ladybug, and smaller. I'll have to figure out what to do with that little buddy. Hopefully, he'll find his own way to his proper "feeding ground" and leave my tomatos alone. He sure was busy scurrying around though. Harrie, thanks for your "hint".

            In past years, I've had such health, though non-productive plants. This year, just the opposite. Very frustrating!

            1. re: CocoaNut
              h
              harrie May 14, 2009 04:49 PM

              In that case, this is from Dave'sGarden.com:

              <<One of the most destructive insects in my area is the Spotted Cucumber Beetle, Diabrotica undecimpunctata howardi. Many gardeners have no idea how harmful this insect is, and simply think it is a green Ladybug. This benign looking little creature can lay waste to a nicely tended vegetable garden, even if there are no cucumbers planted. It carries a virus called Bacterial Wilt that attacks many types of vining vegetables. Once your plants are weakened by it, the harvest is in jeopardy, or the plants might die. Your plants are most susceptible when they are very young. Adult Cucumber Beetles chew the leaves and stems. Larvae chew the roots. In my area, the physical damage caused by actual chewing is minimal. The virus that is introduced into the plants will cause the entire plant to wilt and die. After a plant is infected, there is no cure. Row covers are an effective organic control, while applying an approved pesticide for your area in the evening will control them chemically.>>

              Here's a link to the page, which is very useful and has some good links:
              http://davesgarden.com/guides/articles/view/1341/

              And on the bottom of this page is a long list of ways to deal with them:
              http://www.ghorganics.com/CucumberBee...

              1. re: CocoaNut
                meadandale May 17, 2009 09:59 AM

                Spotted cucumber beetles are definitely not your 'little buddy' and you should kill them on sight. They are a major garden pest.

        2. t
          toastnjam May 19, 2009 12:04 PM

          The lower leaves of a tomatoe plant will turn yellow, wilt and drop off as the plant ages. Entirely normal and nothing to be worried about. You can cut them off about an inch out from the main stem. If you are concerned that it is a disease (fungus/virus) then check out this site to see whether anything matches. It is a great site (with pictures!!!) for diagnosing tomatoe problems.

          http://aggie-horticulture.tamu.edu/pu...

          1 Reply
          1. re: toastnjam
            c
            CocoaNut May 19, 2009 03:24 PM

            Thanks tnj - Harrie had passed along this very helpful website earlier. Based on the picutres alone, I think I have Spotted Wilt, however, the 12 or so tomatoes that have popped out (at different sizes) are anything but malformed. Though they are still green, I guess I'll just have to wait to see if their color becomes mottled whenever that time comes for them to redden. And it seem to be taking forever for them to "ripen" into a red color. (How long does that generally take? Is 3 weeks an exceptionally long time or is this another patience issue? ;) )

            What has me concerned over and above the normal leaf drop of lower leaves that you describe is that the upper, very healthy leaves are taking on a yellow spotty appearance that eventually turns brown with the leave dying (See Spotted Wilt). Since there are only my 2 plants in the whole of my neighborhood (and one seems much stronger), I plan to let it play out to find out EXACTLY what it is when the fruit ripen. But thanks for your input.

            By the by - I haven't seen the flying nuicance again that began this thread.

          Show Hidden Posts