Landscape and nursery
§ Japanese beetles are out and they are hungry
§ European chafer and Japanese beetle in Nurseries
§ Oak wilt beginning to show up in Michigan red oak stands
§ Heat and water stress equal poor weed control
Turfgrass
§ July is the best time to treat for European chafer and Japanese beetle grubs
§ Start watching for chinch bug and billbug damage in lawns
Christmas trees and forestry
§ Pine tortoise scale
§ Pine needle scale
Around the home
§ News from Diagnostic Services: Brown recluse
§ Deer flies on the attack
§ Larder beetles
Other news
§ 2005 Summer Field Day
§ Kent MSU Extension “Stuck on Gardening” tour July 16-17
§ Heat and dryness continue
Japanese beetles are beginning to defoliate some trees and flowers in southern Michigan. They feed on most flower blooms and a wide range of deciduous trees and shrubs especially roses, linden, sassafras, sycamore, pin oak, Norway maple, birch, elm and flowering fruit trees. Japanese beetles are usually a pest for about six to eight weeks. After feeding on leaves and flowers the beetles mate and lay eggs in turfgrass where they become the white grubs that can damage home lawns.
In order to protect susceptible types of trees, shrubs and flowers from Japanese beetle, spray them with Sevin (carbaryl) or Bayer Multi-Insect Killer (cyfluthrin) as soon as they start stripping leaves. Spray again every two weeks, until late August, if necessary. The Japanese beetle traps are a great way to find out if you have Japanese beetle, but do little to prevent plant damage.
Discus and Flagship are labeled for grub control in nurseries. These products work best for grubs when applied in June or July. They are not effective after August 15. If applied as a soil-directed spray, covering the soil surface with soil after application may improve control. Unfortunately, this also disturbs any kind of herbicide barrier put down for weed control. Rain or irrigation is needed to move the insecticide down to where the grubs are.
Oak wilt is caused by the fungus Ceratocystis fagacearum and is considered an invasive species to Michigan forests, having originated outside the state, although the pathogen is thought to be of North American origin. Because of that, it is recognized as an invasive species and the Michigan Department of Agriculture is charged with managing the disease and certifying that oaks cut for lumber and slated for export are harvested from counties free of the disease. This is a demanding and ominous chore as the disease spreads rapidly through forests and woodlots and is unpredictable in its occurrence. Housing developments near or in woodlots often increase the spread of oak wilt as oak trees are damaged during development attracting insects carrying the spores of the fungal pathogen. The Michigan Department of Natural Resources has attempted to control the disease when close to campgrounds, recreation sites and environmentally sensitive areas, but in home landscapes it is difficult to manage.
Long-distance transmission of the fungus is dependent on insect vectors (sap-beetles or nitidulids), and is the means by which new infection centers are established. Insects are attracted to the fruity smelling mycelial mats that the fungus produces between the cambium and the bark. The mats contain copious spores that adhere to the insects' bodies and if the beetle enters a fresh wound on a healthy oak, the fungus is effectively vectored to the new tree.
The current recommendation is not to prune oak between April and June and the longer pruning can be put off toward November, the less risk of insects spreading the disease to wounds on the trees. Local dispersal of oak wilt from infected trees to non-infected trees primarily occurs in the soil through root grafts. Root grafts form between compatible oaks when their roots come into contact; thus, providing a way for the fungus to enter and infect new trees. Transmission through root grafts may take between one and three years after a new infection center is established.
Once oak wilt has infected a susceptible oak, it spreads throughout the current year's xylem. Initial wilt symptoms on mature trees develop about six weeks after infection, and the tree may die shortly after that.
Control of oak wilt has largely relied on trenching to break root grafts between infected and non-infected trees. However, trenching is often difficult, messy, and costly. Systemic fungicides have also been used with varying degrees of success – white oaks seem to respond well to fungicide injections, while red oaks rarely recover even with the injections.
Management protocols may be discussed with extension personal and researchers at the MSU Agricultural Experiment Station.
It’s really tough to control weeds this time of year. High temperatures combined with water stress causes weeds to increase the thickness of the leaf cuticle and also reduces the plant’s metabolism so that any herbicides that get through the thick wax layer aren’t as effective.
Using the highest application rates on the label may increase control marginally but greater material costs will hit your bottom line. The best solution is to educate your customers so they understand the best time to control weeds is in September and October and why an application now won’t work.
European chafer beetles are almost done flying and laying eggs in southern Michigan now. Some lawns were hit hard by European chafer grubs last fall and this spring. These areas can be treated now to prevent grub damage this coming fall and next spring. Lawn care professionals and golf course superintendents can apply Merit, Arena, or Mach 2 any time in the next three weeks. Granular formulations remain the most stable until a rain washes the insecticide into the soil, but sprayable formulations should also work.
Homeowners can use GrubEx or Season-Long Grub Control, containing imidacloprid. Follow instructions on the label with the exception of timing. Make sure it is applied before August 1 to get the best results.
Chinch bugs are starting to cause damage to home lawns. Check sunny areas of low maintenance lawns (no irrigation) for patches of brown turf that look like drought stress. Examine the edges of the brown patches of turf for chinch bug by parting the turf and examining the soil surface for the tiny (1/16 to 1/8 inch-long) black and white bugs. If you find more than 20 chinch bugs in two minutes of searching, there are enough there to cause turf injury. Spot treat the damaged areas and a 10-foot swath around the damaged areas with a turf insecticide.
Also check for billbug damage. Billbug damage will peak in late July and early August. Damage is mostly in Kentucky bluegrass lawns but can be in other turf types as well. To check for billbugs, pinch a clump of damaged turf and pull it up. Examine the broken turf stems. If they are hollowed-out and packed with sawdust like frass, the damage was caused by the ¼- to 3/8-inch long white larva of the bluegrass billbug. Spot treat infested areas now with Sevin or Dylox and water with a half-inch of irrigation. All of the turf insect problems discussed today – grubs, billbugs and chinch bugs – can be minimized by growing a healthy lawn with frequent irrigation.
Growers are still finding scale crawlers hatching. This scale feeds on sap on the woody shoots of pine trees. It is known as black scale because it secretes a huge amount of sticky, sugary honeydew. Black sooty mold then grows on the honeydew, turning affected shoots and foliage black.
We have
found that crawlers can continue to hatch over a month. You should be scouting
your trees now, looking for crawlers. The crawlers are bright pink or red, and
you will be able to see them moving about on the twigs and needles. In areas
where you have a heavy population, you may need to apply a second spray.
Remember good spray coverage is essential.
In most years, the summer generation eggs
continue to hatch over a relatively long time period of two to four weeks. This
extended period of hatching probably occurs because the spring generation
scales develop at different rates during May and June. Some scales develop
relatively quickly because they are exposed to more sun and warmer temperatures
than scales that feed in shaded locations on the tree. The newly hatched
crawlers move onto the expanding shoots and feed primarily on the current-year
needles. These scales mature and lay eggs late in the summer, then die. Their
eggs overwinter under the white armor until the following spring.
Recent research at MSU indicates that the
summer generation eggs can begin hatching at roughly 1,280 GDD50 (usually early
to mid-July). Hatching may continue over two to three weeks. The ideal window
for applying insecticides to control the summer generation eggs generally
occurs at around 1,500 GDD50. Spraying after nearly all eggs have hatched and
most crawlers are in the hyaline stage should achieve good control. Applying an
insecticide after scales have produced the hard, white armor will not be effective
because scales and even scale eggs are well protected by the white armor.
Note: Growers will want to use caution or avoid
applying pesticides with the current hot, humid and dry weather conditions
because of the increased potential for phytotoxicity. Make sure to read the
pesticide label for any precautions.
The sample arrived without fanfare, just another bug in alcohol. Without even putting the spider under the scope I knew we had just received something unusual: my first brown recluse spider. The spider was sent to us by a woman who lives in the Grand Rapids area. She found it in her bathtub. Yikes!
I thought to myself, “Don’t this just beat all!” Just two weeks ago I told a reporter from the Ludington Daily News that none of the 1,000 or so spiders suspected to be recluse spiders that were sent to me over the past 15 years turned out to be a brown recluse spider. I told the reporter that I didn’t think the spider was native to Michigan. And now this; I prefer a little onion in my crow pie, thank you. I’m still not convinced that Michigan has a naturally occurring population of brown recluse spiders. The spider has been found in Michigan before but the origin was traced back to a shipment of goods that came from where the spider commonly occurs. I’m thinking (and hoping) these Grand Rapids recluse spiders originated elsewhere. But I have been wrong before – just ask my wife.
The brown recluse is famous for its “necrotizing” bites. Medically, necrotizing means causing the death of a specific area of tissue. I find it interesting and somewhat ironic that human bites are reported to frequently cause necrotizing infections too.
Before general panic spreads throughout west Michigan, I’d like to share an excerpt from an article written by an entomologist in California who has authored a number of scientific articles about the brown recluse.
More can be read at: http://spiders.ucr.edu/hyperbole2003.html.
Of interest should be the following excerpt that this guy wrote about the numerous, sometimes horrific, photographs of brown recluse bites.
“However, the main effect that this set of images will have is to cause paranoia in the non-arachnological public, bring out all the "hell, yeah" stories of people who have some alleged brown recluse story and will proliferate once again the hyperbolic message about recluses. One of the forms of this series that I saw was a statement something like, ‘warn people – save a life.’ Once again – hyperbole. I have recently added a web page web site lifting quotes from an article by Phillip Anderson, a Missouri dermatologist who specialized on brown recluse bites for over 30 years. Basically here is a summary from his article and several since then by other authors.
§ Almost all brown recluse bites heal very nicely without medical intervention.
§ Only three percent of brown recluse bites require skin grafts.
§ Despite the fact that lots of people believe that brown recluses are deadly, there are only about eight reported deaths from possible brown recluse bites in the medical literature. Philip Anderson states that there is still not one verified death from a brown recluse bite and none of the alleged fatal cases are convincing.”
An Ohio State University web site offers more detail on the spider’s biology. See
http://ohioline.osu.edu/hyg-fact/2000/2061.html.
I may have mentioned in past articles that I live on the edge of a large cattail marsh. And boy, do we get bugs. Lots of ‘em. It’s an entomological dream come true if one happens to be a bug geek. My wife is not. For her it can be a nightmare. Our present nightmare is all about deer flies. We have a swarm that waits for us to walk from the door to our vehicles, then they dive bomb us. Clouds of them follow my truck and bounce off the side mirrors as I drive through the marsh down the lane to the house I’ve been building for the past fours years (Another nightmare that my wife lives with daily, but that’s another story).
For the past three years the deer flies around my swamp haven’t been too bad. But this year, oh my word! They are back big-time this year and they’re a bloodthirsty lot.
Deer flies and related horse flies belong to the family Tabanidae. There are about 350 species of tabanids in the United States and Canada. They apparently have their place in America history: Ross Arnett author of American Insects, A Handbook of the Insects of America North of Mexico, reports the following. “It is said the Declaration of Independence was signed by July 4, 1776 instead of a later date that would have permitted further discussion because the horse flies in Philadelphia were biting so fiercely at the time that the delegates decided to adjourn just to get away from them.”
My family enjoys at least 15 species of tabanids throughout the summer. The smaller species attack us in the early summer. Generally these guys start to show up around Memorial Day week. The different species get bigger as the summer progresses with the giant black horse fly appearing in late August, sort of like the grand finale.
Others who are plagued by deer flies have probably noticed that mosquito repellents don’t seem to work against deer flies. The main reason for this failure is that tabanids do not use scent to find their hosts. They use their keen vision and key in on anything that moves. They are among the fastest fliers in the insect world so somebody who is walking in their yard or jogging down the road, or running full speed for that matter is really no match for a swarm of hungry and determined deer flies. Wearing a hat helps, they seem to be attracted to hair.
If you live in a deer fly kinda world and wish do to something about it then traps and sticky patches are your only hope. I found a couple of suppliers of small 3X6 inch patches with sticky goopage on one side attached to the back of your baseball cap. When flies zoom in, they get stuck in the goopage, and it’s all over for that fly. Somebody down in Florida did some research on the effectiveness of these patches and found them to work pretty well. More on this research can be reviewed at: http://www.fcla.edu/FlaEnt/fe83p476.html
If you’re interested in trying them, these patches can be purchased through the following web sites:
http://www.gemplers.com/a/shop/product.asp?T1=RDF4&src=21SM001
http://www.tucker-usa.com/users/stieg/deerfly.htm
Another approach to controlling deer flies is to catch them in a trap that uses something other than us for bait. There are commercially available deer fly traps that use motion to attract the flies. One such trap is called The HORSE PAL® fly trap. The following is from the manufacturer. “The HORSE PAL® biting fly trap is constantly on duty, attracting the biting flies in the area and capturing them. The trap is environmentally sound. It requires no smelly or messy baits. The only care required is occasionally removing the capture bottle and dumping out dead flies.”
Dumping out bottles filled with dead deer flies must be pretty satisfying if the thing works.
You can read about these traps at: http://bitingflies.com/. If you decide to buy one, let me know how it works.
More general information on tabanids can be read at the Ohio State University web site at:
http://ohioline.osu.edu/hyg-fact/2000/2115.html
There is a seeming increase in the number of larder beetle samples that I have received this summer. This bug is a nice one to follow the other articles because they don’t bite or necrotize anything. The larder beetle, Dermestes lardarius (Coleoptera: Dermestidae), was once considered by many to be primarily a pest of hides and other animal products including dried meats, cheese, feathers, hair, horns and skin and other foods with a high protein content especially dog or cat food. This beetle is also found in bird nests, animal remains and bee and wasp nests. But lately I’ve come to think of this bug as a general protein scavenger, just like its close but smaller relatives, the carpet beetles. It is likely that every house over two years old has a population of both larder and carpet beetles living harmoniously (and probably gratefully) with the human occupants of the house.
An adult larder beetle is just under 3/8 of an inch long and dark colored with a pale yellow band across the center of the beetle. The grub or larva is dark brown and very hairy in appearance with two curved dorsal spines on the tail end. In Michigan, there is one generation per year with the eggs being laid in the spring and early summer. The larvae are known to burrow into wood to construct chambers in which to pupate. We have some reports of structural damage to kitchen cabinets and hen houses because of this behavior. The first step in larder beetle control is to locate and dispose of all infested material. This may be difficult or next to impossible if the beetles are feeding on dead insects in wall voids and other hidden sites. Insecticides are always an option, but don’t expect to totally eliminate them from your house. They are just too darn good.
A Summer Field Day will be held on July 29 at Calvin College in Grand Rapids, Michigan.
Registration will begin at 7:45 AM, with orientation and morning workshops to follow. A complementary lunch will be available with afternoon workshops held from 1:00 PM to 3:00 PM. Registration for The Association of Grand Rapids Landscape Professionals (AGRLP) members is $20 and $30 for non-members.
Morning workshops include:
§ Pesticide Safety and PPE;
§ Top Five in 2005, discussions of pest, weather-related and cultural problems in turfgrass;
§ Perplexed by Perennials;
§ Strategies for a Healthy Sports Turf;
§ Plant Right the First Time; and
§ Identifying and Caring for Shrubs in the Landscape.
Afternoon workshops include either a session on ornamentals or a session on turf, and both will take visitors through the campus of Calvin College.
For more information on the Summer Field Day or on how to become a member of AGRLP, please call (616) 531-1370 or visit www.agrlp.org.
The day is planned by AGRLP in conjunction with the Kent MSU Extension and Michigan Certified Nurserymen (MCN).
Garden enthusiasts will be delighted this July while visiting ten exceptional Master Gardener gardens in Kent County. The garden tour is designed to be educational for those who participate, young or old. Kent MSUE Master Gardeners will be on hand at every site to answer your gardening questions on Saturday, July 16 from 10:00 AM to 5:00 PM and Sunday, July 17 from 12:00 noon to 6:00 PM.
Garden visitors can expect to see a wide variety of site conditions and design styles including lush shade gardens, hot and sunny mixed borders, a small urban garden, water gardens, garden art, pool landscaping, herbs and a natural garden in a suburban setting.
Proceeds from the garden tour benefit the Kent MSU Extension Junior Master Gardener Program. This volunteer program equips young gardeners with current, research-based gardening knowledge so that they can volunteer in their home communities.
Kent MSU Extension
775 Ball Ave., NE, Grand Rapids, MI 49503
(616) 336-3265
Monday – Friday, 8:30 AM – 4:00 PM
Tickets can also be purchased at any site on the days of the Tour. A list of addresses can be obtained at the Kent MSU Extension web site at www.msue.msu.edu/kent then click on Jr. Master Gardener or www.stuckongardening.com or by calling (616) 336-3265.
Ticket Prices: $10.00 Adult (no charge for children 15 & under)
For more information about the tour, please contact Rebecca Finneran, Horticulture Educator, or Judy Sink, Junior Master Gardener Coordinator. Both can be reached at: Kent MSU Extension, 775 Ball Ave., NE, Grand Rapids, MI 49503, Telephone: (616) 336-3265.
Upper air ridging and surface high pressure has persisted for much of the past several weeks across the Great Lakes region, leading to abnormally hot and dry weather. Unfortunately for those areas in need of rain, this pattern is expected to continue for at least part of the next week. Seasonal precipitation deficits (since April 1) currently range from about two inches in east central sections of the state to more than eight inches in some spots across southwestern Lower Michigan. Normal rainfall for this time frame is generally in the 9.5- to 11.5-inch range from east to west across the state.
In the short-term forecast, the remnants of Hurricane Dennis will remain almost stationary across the Ohio Valley through early Saturday before finally moving eastward out of the region by late Sunday. As has been the case for much of the past few days, this ex-tropical system will continue to set off scattered showers and thunderstorms across sections of the state each through early Sunday with best chances for rainfall during the afternoon and early evening hours and geographically across the southern few tiers of counties in Lower Michigan. Due to the upper air center of Dennis remnants passing close to the southern border of Michigan during the next 24 to 36 hours, precipitation probabilities late Friday into Saturday (July 15-16) will be somewhat greater than they have been during the past several days, with up to 50/50 odds of precipitation along the Michigan/Indiana/Ohio border. Rainfall totals will still likely remain below 0.25 inches, although some 0.50- to 1.00-inch totals are possible in a few (very lucky) locations. Hot and dry weather is expected again over most areas of the state Sunday.
A cool front will approach from the west in the late Sunday-early Tuesday time frame, bringing the next best chance for significant rainfall. Temperatures will remain at above normal levels for the next several days with daytime highs ranging from the upper 70s in northern lakeshore areas to mid to upper 80s elsewhere. Low temperatures will range from the upper 50s north to the upper 60s to near 70 south.
The NOAA Climate Prediction Center 6-10 day (for July 20-24) and 8-14 day (covering July 22-28) outlooks both call for broad upper air ridging across western sections of the country with weak troughing across the east with a continuation of above normal temperatures during both forecast periods. More importantly, precipitation totals during the both time frames are forecast to increase to a range from near normal levels across the Lower Peninsula to above normal totals across the Upper Peninsula.