There have been two sets of calls coming in recently to the gardening hotline. One involves those pesky stinkbugs and leafhoppers on tomatoes; the other is about blossom and fruit drop on citrus.
Let’s start with the citrus issue. As with most plants, about 90% of what happens to them is environmental; it’s only when plants are stressed that bugs and diseases find their opportunities. So consider the weather patterns we have had in the past couple of years. Way below normal rain patterns have been followed by gully-washers; we had an unusually cold winter, and it stayed cool much longer than usual. Citrus trees aren’t really tempermental, but they certainly like their tops and bottoms to operate in the same temperature zone, and they haven’t had that much lately.
The most important thing to a fruit-bearing plant is to survive well enough to put out progeny. The fruit or nuts, while a bonus for us omnivores, can’t compete against the need to save one’s skin, as far as the plant is concerned. So protection of the roots, the trunk, and the branches must come first. The younger the tree is, the more important this is; until a tree is at least 7 years old, it can’t be considered “established,” and our funky weather in the past few years can set that back, unless you, the home gardener, help even out the odds.
So local gardeners, if they were lucky after the cold spell, reported lots of blossoms on their citrus. This was followed by very small fruit, which then dropped. Some of this is normal; here’s what Texas A&M (i.e., Aggie Horticulture) has to say: “ Typical citrus trees go through three distinct periods of fruit drop. First is the drop of about 70 to 80 percent of the flowers during and immediately following bloom. The second drop occurs a couple of weeks later, involving small fruit of pea-size to marble-size. The third drop occurs in late May, involving larger fruit, almost golf ball in size. Navels will drop again in mid-summer and in late summer. A few fruit on all citrus will continue to drop through final harvest, but that is normal and cannot be prevented.”
If you lost all your fruit, blame the climate. You can help by protecting your younger trees in the early years, by regular watering (1 inch a week), and fertilization of the citrus after the first two years. And pray for regular weather patterns.
Now, about those bugs: whether they are leaf-footed bugs or green or brown stinkbugs, they are the despair of vegetable gardeners everywhere. Dr. William Johnson, Agri-Life Extension Agent-Horticulture, of Galveston County, has this to say: “The rough sandpaper-like texture that you have seen is evidence of an insect known as the leaf-footed bug. While many area gardeners also call them stinkbugs (because they produce a foul odor when handled), leaf-footed bug is the preferred name.
The immature stages (known as nymphs) of this insect are spindly, soft-bodied and bright orange-red in color. Very young nymphs stay tightly clustered as a family unit. The adult stage of the leaf-footed bug is brown, oblong and nearly an inch long. The species most common to this area has a distinctive white band extending across the front wings. The hind legs have a leaf-like shaped area from which the insect’s name is derived.
There are other species of stinkbugs that feed on tomato fruit including the green and brown stinkbugs. However, the green and brown stinkbugs are minor insect pests in our growing area.
Leaf-footed bugs have a needle-like, piercing-sucking mouthpart through which they suck plant juices. The puncture made is what caused the spot and the deformation that you have observed. While making the puncture, a toxin is injected into the fruit. If you peel back the skin, you will see that this discolored area is more than superficial. The tissue below the skin is a somewhat corky or spongy mass of silvery white cells.
This damage is serious for commercial fresh market tomatoes and whole pack processing tomatoes because it renders the fruit unmarketable. However, if the fruit was of high quality prior to damage, the processor might cut out the spots and use the remaining tomato as canned pieces. The undamaged portion of the tomato in a home garden certainly can be consumed, if desired.
Leaf-footed bugs are also serious pests of other crops including beans, cowpeas, eggplants, okra, citrus, and pecans. Adult leaf-footed bugs migrate from weedy areas into tomato plants, particularly when the fruit has started to ripen. This is why you typically do did not see damage early in the season but you did see damage later in the harvest season.
Leaf-footed bugs are difficult to control. Weedy areas, such as fence rows and ditch banks, serve as shelters for these insects during the winter season, and when tomatoes and other host plants are not available. Therefore, to eliminate such areas near your garden or to keep weedy areas closely mowed would be beneficial.
Insecticides such as permethrin (such as Spectracide’s Bug Stop Multi-purpose Insect Killer or Bonide’s Total Pest Control Concentrate Outdoor Formula) or cyfluthrin (such as Bayer’s Advanced Garden Lawn & Garden Multi-Insect Killer) or esfenvalerate (such as Ortho’s Bug-B-Gon Multi-purpose Insect Killer Concentrate or Bonide’s Bug Beater Concentrate) are effective in controlling leaf footed bugs as well as stink bugs, aphids, fruit worms and hornworms. Do not use permethrin on varieties with fruit less than one inch diameter. Be sure to observe the days-to-harvest period indicated on the pesticide label. Be certain to wash the fruit before using.
It is important to observe your garden on a daily basis. Should you spot leaf-footed bugs, you might handpick the bugs, especially early in the season and when the very young nymphs are tightly clustered. You should use gloves because of the odor they will emit when handled and you should drop them into a can of soapy water.”
Release date: June 19, 2014
Contact: A. Lynette Parsons, 409-550-3065
– Be kinder than necessary, for everyone you meet is fighting some kind of battle.