Problems in the Garden this Week

It continues to be another busy week for our bug and disease infected mouth foaming Buggy Joe Boggs (OSU extension).  This week, BJB is reporting tomatoes that were ‘on hold’ are finally starting to ripen (although Joe has thoroughly enjoyed a summer filled with fried green tomatoes), tomato and tobacco hornworms devouring bean leaf beetles chomping on – it’s early, you can guess it – green bean foliage and bean pods, yellow leaves dropping from a weeping cherry (no insects or damages – could have been cherry leaf spot, but is too late to spray), common and giant ragweed starting to rear their ugly heads above other weeds (getting ready for major hay fever ’sneason’ late summer and fall), multiple calls on yellow jacket and other ground nesting hornets, boxwood still showing winter injury, Phytophtora root and stem rot on petunias, “Ling Chih” conk (mushroom) found on red oak which causes root and butt rot (say what?), powdery mildew on pumpkin leaves, organically grown tomatoes diagnosed with late blight, second generations of Fall Webworm (can affect over 120 species of trees) and Mimosa webworm (usually only on honey locust), ailanthus webworms on – can you guess it? – Ailanthus, or commonly known as the Tree of Heaven, grasshoppers feeding on ornamental grasses (would that make them ornamental grasshoppers?) (By the way, did you know that grasshoppers have been known to eat not only plant foliage, fruits, grains, etc, but also eat paper, paint, window screens, window caulking, fence posts, and hoe handles?  I’m not making this up!), acorn plum galls dropping from – yes – red oaks, magnolia scale crawlers crawling, obscure scale crawlers on oak are now crawling, Japanese beetles pretty much down to nothing as this stage (heavy damages in NE Ohio), bedbugs showing up in homes after the homeowners had stayed in a motel/hotel (at  least that’s their story where they stayed), powdery mildew on many other landscape plants and veggie plants, dog vomit slime mold having a great time this summer slimming around, and last but not least, purple greasy looking grass which is actually caused by a  slime mold growing on the grass blades.  Purple greasy looking grass?  Give me a break. 

-Catch The Buggy Joe Boggs Report every Saturday at 8:42am on 55KRC The Talk Station. 

 SOCIAL BEES & WASPS A FRIGHTENING EXPERIENCE!  This time of the year, yellow jackets and hornet nests become an issue.  So here’s some great information from our good friend Dr. Dave Shetlar, The Bug Doc.

I am always a bit amused when I hear of the encounters that homeowners have with social wasps! Just last week, a person called in to report that he had “suddenly” discovered a football-sized bald-faced hornet’s nest just outside his front door. This nest has obviously been building in size since May, yet the homeowner hadn’t noticed it! This just reinforces entomologist’s contentions that most of the social wasps are quite benign, and in fact, beneficial (mainly insect predators).

HOWEVER, now is the time that these social wasps, especially yellow jacket species, bald-faced hornets, and our European paper wasp, become more aggressive in seeking sugary foods. This is the time that people-wasp interactions are most likely to occur. In short, up to now these wasps have been feeding on other insects, primarily caterpillars, sawflies and flies. The wasp workers capture these insects, chew them up and take the “bug burger” back to the nest to feed the helpless maggots (their larvae) that are growing within the individual cells located with each nest. Until now, the queen wasp has been laying eggs that produce only sterile female workers. However, now the queen begins to lay eggs that will develop into new queens and drones. These new queens will have fully developed reproductive organs, but they won’t produce eggs until next spring. New queens and drones don’t forage for food like the workers do, but usually hang around the nest begging the workers for food. In this case, these reproductives prefer high carbohydrate foods rather than the high protein food needed by the larvae.

The workers pick up on the begging and begin to switch their foraging behavior to find foods with high sugar and yeast content. Of course, this means that they become real nuisances around parks, outdoor eating establishments and other places where people like to have sugary drinks, fruits and even beer. And these wasps have a memory! They remember where they were successful in finding high sugar foods and they will return again and again, often after recruiting fellow workers.

This is why outdoor feeding establishments and amusement parks have to be diligent at maintaining self-closing trash cans regularly picking up or washing down food and drink spills and practicing similar sanitary procedures.

The German yellow jacket, eastern yellow jacket, yellow hornet and bald-faced hornet are the most common species of social nuisance wasps found in Ohio urban and suburban areas. Most entomologists claim that these wasps are generally “non-aggressive” except if you get near their nests. This is usually misunderstood by the average person. What we’re talking about is their tendency to sting, not their persistent behavior to pursue food! These wasps can be very “aggressive” in pursuit of their food, but unless you physically restrain them (trap them under clothing, step on them, or get them caught in a soda can), or strike them while flaying your arms in an attempt to shoo them away, they won’t sting.

In fact, I’ve forced myself to be very unafraid of wasps buzzing around me or even landing on my arm or clothing. In most cases, they are simply inspecting me to determine if I’m food or not! On the other hand, if one strikes me or persists in buzzing loudly in front of me, I must assume that I may be close to a nest and this worker is giving me a warning to move away. Honey bees, bumble bees and many wasps do give “warnings” if you are willing to listen! Stinging is really the last resort and the behavior can be very risky for the bee or wasp. Honey bees actually die after stinging because their barbed stinger gets stuck and pulls off the tip of the abdomen when the bee departs.

My general recommendation about social bees and wasps is to try and avoid getting near their nests. They’ll be gone after the first hard frost. However, if you happen to find a nest that has been built under the mulch in a flower bed, a hole in the lawn, or other place where you may regularly need to perform maintenance, control may be necessary. There are all kinds of wasp and hornet aerosol sprays on the market, but these are generally inadequate for control of bees and wasps that nest in the ground or in wall voids. Only the umbrella wasps, Polistes, can be easily hit with these sprays. If you can locate, during the day, where the yellow jackets or bumble bees are entering their nests, try to determine where the wasps or bees land before crawling into the nest chamber. Make a mental note of this. Your strategy will be to dust this area with an insecticide, AT NIGHT, when the bees and wasps are unlikely to fly or be disturbed. My favorite insecticide to use is Sevin garden dust, but you can find other garden dusts with pyrethroids. Thoroughly dust the landing spot with the dust so that the next day most of the bees or wasps will walk through the material. Once they walk through the insecticide dust, the insects will carry the material into the nest. There, the bees and wasps will groom themselves and each other, distributing the insecticide throughout the colony. I’ve been pretty successful at knocking out a colony with one application, but sometimes a rain or irrigation can wash away the insecticide dust, so another application may be necessary in a few days.   -Dr. Dave Shetlar