Kansas State University


K-State Turf and Landscape Blog

Month: September 2015

Not so mysterious “Itching” (Oak Leaf Itch Mite)

(By Dr. Bob Bauernfeind: KSU Entomology)

Whereas scratching an itch sometimes provides satisfying (almost pleasurable) relief, at other times scratching an itch can be painful and distressing.  The latter situation is attributable to the mite, Pyemotes herfsi (Oudeman).

Unlike chiggers which have been long-recognized for producing annoying but fleeting bouts of itchiness, mysterious “bites” causing raised quarter-sized reddened areas each with a centralized pinhead-size blister were of widespread occurrence in 2004 in various Midwestern states.



Through investigative studies, the aforementioned Pyemotes herfsi mites were identified as being responsible for the mysterious bites.  Although the existence of these mites had been well known for multiple decades, the correlation between them and reported widespread occurrences of human discomfort was unknown.  The severity of the 2004 outbreaks resulted in cooperative efforts between K-State and the University of Nebraska entomologists, the resultant being the identification of Pyemotes herfsi as responsible for the stressful skin disorders.

Pyemotes herfsi were recovered from marginal fold galls on (primarily) pin oak leaves.  Marginal galls are associated with the larvae/maggots of tiny midges.  That is, Pyemotes herfsi prey upon the midge larvae.  The following side-by-side close-up images show an intact marginal gall, and a dissected gall revealing female Pyemotes herfsi.  Despite their small size, they become readily visible due to their bulbous abdomens which can contain up to 200 offspring.



Due to their minuscule size compared to that of midge larvae, Pyemotes herfsipossess a potent neurotoxin used to paralyze their maggot hosts.  This toxin is that which is responsible for initiating the skin irritations which cause discomfort in individuals upon which Pyemotes herfsi happen to come in contact with.  Because Pyemotes herfsi are associated with the midge larvae responsible for marginal galls on oak leaves, Pyemotes herfsi have been given the common name, Oak Leaf Itch Mite.  It is believed that oak leaf itch mites also prey upon the larvae of another closely related midge species responsible for the formation of vein pocket galls on the undersides of oak leaves.  A full description of the oak leaf itch mite life cycle is available online by accessing Kansas State University Extension Publication MF2806.

The good news is that oak leaf itch mite populations may be extremely low or absent for years-on-end —— people can enjoy the outdoors without having to contend with oak leaf itch mite encounters.  The bad news is that the reappearance/resurgence of oak leaf itch mite populations is unpredictable. There are various unknown factors as to the whys-and-where their populations are and when they will surge.  Undoubtedly there are ever-present reservoir populations of oak leaf itch mites, but, where are they?  Possibly a major factor for population explosions is contingent on fluctuating populations of the appropriate gall midges responsible for the formation of  marginal galls and/or vein pocket galls.  An intriguing question then would be, “How do the tiny mites detect and move to the galls up in tree canopies?”

More bad news:  Each female oak leaf itch mite produces many progeny.  And the developmental cycle is reported to be just 7 days.  The resultant is the production of uncountable numbers of oak leaf itch mites which ultimately leave the confines of leaf galls. Passive dispersal via air currents is the bane to people, especially those in neighborhoods where pin oaks constitute the main trees species.

The bad news continues: There is a wide time frame during which encounters with oak leaf itch mite might occur.  It is not only the initial late summer encounters, but the presence of oak leaf itch mites extending well into the fall when people are raking leaves and kids having fun playing in leaf piles.

And if this is not enough negativity regarding oak leaf itch mites, there is little to be done (well, actually nothing to be done) in treating and reducing/eliminating their populations.  THEY WILL HAVE THEIR WAY!

 The people who are most likely to encounter oak leaf itch mites will be those in living in areas/neighborhoods where oaks (again, especially pin oaks) are the dominant tree species.  When oak leaf itch mite populations are excessive, restricting outdoor activities is one method of reducing the risk of exposure.  While the use of repellents may work against annoying insect species which actively seek a host, repellents have little effect against oak leaf itch mites which are passively dispersed, and lack the ability to alter their course/direction.  It has been suggested that susceptible individuals (yes, some people do not have negative reactions to oak leaf itch mite bites) spend as little outdoor time as possible.  And showers immediately upon returning indoors might eliminate/wash off mites before they bite and cause reactions.

Individuals experiencing oak leaf itch mite encounters might utilize medications and lotions so designed to provide relief from itching discomfort as well as secondary infections of excoriated areas.  Seek advice and recommendations from appropriate personnel.

New Fine-Textured, Cold-Hardy Zoysiagrass on the Horizon

‘Meyer’ zoysiagrass was released in 1952, and is still widely used in the transition zone due, in large part, to its excellent cold hardiness. However, as good as Meyer is, it has limitations, including a medium coarse leaf texture and inferior density compared to Zoysia matrella-type cultivars. In 2004, researchers at K-State and Texas A&M AgriLife Research-Dallas began working together to develop dense, fine-textured zoysiagrasses that are as cold hardy as Meyer. Eleven years later, the first zoysiagrass from this effort, KSUZ 0802 (a formal name is forthcoming), has been approved for release by K-State, and is expected to be approved for release by Texas A&M this autumn.

KSUZ 0802 is a fine-textured, cold-tolerant zoysiagrass hybrid co-developed by Texas A&M AgriLife Research, Dallas, TX and the Kansas Agricultural Experiment Station, Manhattan, KS. KSUZ 0802 is a F1 interspecific hybrid developed in 2001 from a cross between Z. matrella (L). Merr. cv. ‘Cavalier’ and an ecotype of Z. japonica Steud. named ‘Anderson 1’, a derivative of ‘Chinese Common’ which was collected from rough areas at Alvamar Golf Course in Lawrence, KS. Cavalier is a high quality Z. matrella cultivar, but lacks the hardiness to be used in the upper transition zone. By crossing it with Chinese Common, which is cold hardy, we have created a cultivar that has Z. matrella-like quality, but with good cold hardiness. KSUZ 0802 must be propagated vegetatively.

fig1 zoysia

Initially, over 800 individual, genetically different hybrids were developed at Texas A&M AgriLife Research – Dallas in 2001. Grasses were planted in Manhattan, KS in 2004 and evaluated for quality and winter survival between 2004 and 2006. KSUZ 0802 was one of 31 hybrids selected for further evaluation at Manhattan in 2007 and 2008 under golf course conditions. These 31 were later narrowed to 7 hybrids, including KSUZ 0802, which were evaluated at nine locations in the transition zone under typical lawn or golf course fairway management conditions from 2009 to 2012. These locations were Wichita and Manhattan, KS; Columbia, MO; Fletcher and Jackson Springs, NC; Stillwater, OK; Knoxville, TN; Virginia Beach, and Blacksburg, VA; and Dallas, TX.

KSUZ 0802 has repeatedly demonstrated cold hardiness equivalent to Meyer in replicated field plot research (Fig. 1). Following a severe winter in 2013 in Manhattan, KS, KSUZ 0802 and Meyer had >99% survival; conversely, ‘Empire’ (Z. japonica) had 78% survival, ‘Zeon’ (Z. matrella) had 72% survival, and a large number of experimental Z. matrella selections had <50% survival (Thompson et al. 2013). Freezing tolerance studies conducted under controlled conditions at K-State showed that KSUZ 0802 had an LT50 (lethal temperature that kills 50% of the tillers) that was statistically similar to Meyer in two consecutive winters (Okeyo et al., 2011). Observed LT50 ranged from – 8.4 to – 10.3º C (17 to 14 º F) for KSUZ 0802 and from – 10.7 to – 12.0º C (13 to 10 º F) for Meyer. Based upon the results from research, KSUZ 0802 can be used as far north as zone 6a on the USDA Plant Hardiness Zone Map (http://planthardiness.ars.usda.gov/PHZMWeb/).


In general, KSUZ 0802 has a finer leaf texture and better density relative to Meyer, which results in better overall turf quality (Fig. 2 and 3). Average turf quality of KSUZ 0802 (average rating of 6.1 on a 1 to 9 scale) was higher than Meyer (average rating of 5.5) maintained at lawn height in Wichita, Kansas; Jackson Springs, NC; Stillwater, OK; Dallas, TX; and Blacksburg, VA. At fairway height, quality of KSUZ 0802 (average of 6.9) was superior to Meyer (average of 5.6) at the two locations it was evaluated – Manhattan, KS and Stillwater, OK.

fig 3

To summarize aforementioned results, and other research that has been with KSUZ 0802, its freezing tolerance, spring green-up and fall color retention are equivalent to Meyer, but it has a finer leaf texture than Meyer. KSUZ 0802 is also superior to Meyer for turfgrass quality and resistance to bluegrass billbug (Sphenophorus parvulus) damage. KSUZ 0802 is well suited for use on golf course fairways and tees, home lawns, and other recreational areas in the transition zone. It is currently under evaluation by sod growers in Kansas, Oklahoma, Texas, Illinois, Indiana and North Carolina. If you have questions about KSUZ 0802, or interest in producing it, contact either Jack Fry (jfry@ksu.edu) or Ambika Chandra (a-chandra@tamu.edu).


Funding tosupport the development of KSUZ 0802 came from a number of sources, including the Kansas Agricultural Experiment Station, Texas A&M AgriLife Research, the Kansas Turfgrass Foundation, the Heart of America Golf Course Superintendents Association, the Kansas Golf Course Superintendents Association, and the Kansas Golf Association. also acknowledge others who contributed to this research: Genovesi, Meghyn Meeks, and Milt Engelke, Texas A&M AgriLife Research; Qi Zhang,Okeyo, Jason Griffin, and Linda Parsons,-State; Justin Moss, Oklahoma State Univ.; Erik Ervin, Virginia Tech; Xi Xiong, Univ. of Missouri; Susana Milla-Lewis, North Carolina State Univ.; andBrosnan, Univ. of Tennessee. you!

(Jack Fry and Ambika Chandra)

Be an Exhibitor at the Annual Turfgrass Conference


We have a lot of opportunities for you to increase your companies visibility at the Annual Turfgrass Conference!

Here is a list of ways to support the Annual Conference and promote your company

  1. Become a birdie, eagle, or albatross Sponser.
  2. Purchase and exhibitor booth.
  3. Raffle Donations.
  4. Exhibitor Bingo Card.

For more all the registration information, see the link below.



Meet the Featured Speakers at the Kansas Turfgrass Conference

We have a great lineup of speakers this year for the 65th Annual Turfgrass Conference.  Here is a little bit more about the speakers.  Hope to see everyone at the conference.





horvath_headshotDr. Brandon Horvath is the Turf Pathologist in the Plant Science Department at the University of Tennessee, Knoxville.  His research interests include epidemiology of turfgrass pathogens and development of strategies based upon epidemiological research to manage turfgrass diseases.



leah_tallDr. Leah Brilman is the Director of Research & Technical Services for Seed Research of Oregon, a division of Pickseed. She serves as a turfgrass breeder and agronomist for the company. She has been responsible for the development and release of over 70 commercial varieties. As more and more golf courses switch to effluent water, Leah’s work focuses on increasing the tolerance for salt stress in the company’s species.





Kreuser_Bill_210x315Dr. Bill Kreuser is an assistant professor in the Agronomy & Horticulture Department at the University of Nebraska-Lincoln. His research focuses on turfgrass soil, water and nutrient management. He is interested in the relationship between turf crown moisture and temperature stress tolerance. This has implications for turfgrass survival during summer and winter droughts and can result in desiccation of injury and plant death. Other interests include sustainable lawn management, use of nitrogen sensing technology to increase fertilizer application precision, and the cause and management of impermeable iron-oxide layers in sand-based putting greens.

jay_mccurdyDr. Jay McCurdy is the Extension Turfgrass Specialist in the Department of Plant & Soil Science at Mississippi State University. His emphasis is on turfgrass weed control, herbicide resistance and low maintenance, and biologically diverse turf systems.

New This Year at the Kansas Turfgass Conference

If you attend the Kansas Turf Conference this year December 1-3 in Topeka, you will notice several new features.

First of all, the Kansas Nursery & Landscape Association will be joining up with us for our conference this year, offering additional sessions in Basic and Advanced Nursery & Landscape, as well as having more vendors at the trade show in this area. We are excited for the possibilities this can bring to the dynamics of our conference.

Exhibitor Bingo 

Each attendee will receive a KTF Exhibitor Bingo card in their registration packet. Join the fun by visiting participating exhibitor booths each day during the trade show hours and turning in your completed card at the KTF booth. A raffle drawing will be held both Tuesday and Wednesday for a great prize. You must be present to win.

Trade Show Educational Events

Each afternoon the trade show will “kick-off” with a 15-minute presentation. On December 1, Dr. Brandon Horvath, one of our featured out-of-state speakers from the University of Tennessee, will talk on “The History and Development of Mowing Technology.   On December 2, Chery Boyer and Jared Hoyle will talk on “How to Use Social Media in the Green Industry.”   You won’t want to miss these talks!

There will be an interactive exhibit on turf and landscape weeds, diseases and insects. You can complete the activity once (either Tues. or Wed.) to earn 0.5 hr of credit in 3A & 3B. Be sure to stop by that booth!


Building a Pitcher’s Mound

The Sports Turf Management session on Dec. 2 at the Kansas Turf Conference will be presented by Ewing Irrigation Products. It is part of an initiative to educate coaches, sports turf managers and volunteers on how to maintain the safest, most playable baseball fields possible. At this event, you will have the opportunity to network and learn tips from two former top NFL/MLB groundskeepers. The breakout will be focusing on the proper construction (material selection, preparation tips, etc.) of building a pitching mound from the ground up.

Troy Smith is Ewing Irrigation’s National Sports Field Product manager based out of Phoenix, AZ. Prior to joining Ewing Troy maintained both cool-season and warm-season turf at the highest levels for organizations such as the Milwaukee Brewers, Denver Broncos and the Arizona Cardinals. Troy earned his B.S. in Landscape Horticulture/Turfgrass Management from Colorado State University, and was president of the Sport Turf Managers Association (STMA) in 1999.

Luke Yoder is a member of Ewing’s national sport field team and is currently based out of Southern California. Luke comes from a very decorated sports field management career acting as a head groundskeeper in both major and minor league baseball. For the past 12 MLB seasons, Luke has been the head groundskeeper as well as director of field and landscape maintenance for the San Diego Padres. In addition to his responsibilities as head groundskeeper at Petco Park, Luke also worked with all of the team’s minor league affiliates as well as the team.

We have a great educational program lined up this year, along with an improved layout for our trade show. Pesticide recertification credits will be available, as well as educations credits fo GCSAA and International Society of Arboriculture.





Mark the dates to attend—December 1, 2 & 3. You should receive your conference program in the mail soon.



Kansas Turfgrass Conference In Conjunction with KNLA in 2015

IMG_2802This year the Kansas Turfgrass Conference will be held in conjunction with the Kansas Nursery & Landscape Association at the Kansas Expo Centre in Topeka on December 1, 2 & 3. By partnering with KNLA, we hope to have a larger audience and trade show, as well as offering more sessions for attendees.

The conference is an excellent way to learn about turf and landscape management, visit with old friends, network with new ones, and see all the latest and greatest equipment and supplies from local and national vendors.

Sessions include Basic Turfgrass; Disease, Insect & Weed Management; Golf Turf Management; Sports Turf; Lawn Care; Basic Nursery & Landscape and Advanced Nursery & Landscape (sponsored by NurseryWorks).

On December 2, Ewing Irrigation is sponsoring the Sports Turf session which is part of anIMG_2811 initiative to educate coaches, sports turf managers and volunteers on how to maintain the safest, most playable baseball fields possible. At this event, you will have the opportunity to network and learn tips from two former top NFL/MLB groundskeepers., Troy Smith and Luke Yoder.   The focus will be on the proper construction of a pitching mound from the ground up by actually building a pitcher’s mound in the trade show area.

You can register online for the conference HERE! 

The conference has been approved for the following :

State Pesticide Applicator Recertification Credit Hours:

1 Core Hour             3A—9.5 hours                           3B—9.5 hours

GCSAA Education Points

December 1 workshops—.55                   December 2 & 3 conference—.75

International Society of Arboriculture

CEUs available for Certified Arborists

You will receive a conference program in the mail with a ballot for board of directors of KTF. Please take the time to vote for 3 board of directors and mail or fax it in. See you in December!

2015 KTF sechedule_Page_1 2015 KTF sechedule_Page_2 2015 KTF sechedule_Page_3 2015 KTF sechedule_Page_4 2015 KTF sechedule_Page_5 2015 KTF sechedule_Page_6 2015 KTF sechedule_Page_7 2015 KTF sechedule_Page_8

anthracnose in putting greens

(Megan Kennelly, KSU Plant Pathology)


I just heard from a superintendent in South Central KS who is experiencing some anthracnose, and Dr. Lee Miller recently reported anthracnose activity in Missouri as well. We commonly see anthracnose during summer stress but it can definitely occur all season long.

Over the past few years, Rutgers University has led a multi-university research program to investigate the impact of cultural practices and fungicides on turfgrass anthracnose, including fertility (it’s really important!), mowing height (even a small increase can help!), and more.

We have some more information about anthracnose HERE.

The BMP’s from Rutgers are outlined HERE.

If you just can’t get enough, details from Rutgers are available HERE (you can click through a 54 page pdf with lots of images and data)

Drum roll please …. “Top Ten Tree Planting Mistakes”

(Megan Kennelly, KSU Plant Pathology)

Boy oh boy, have I seen a lot of tree problems that originated with improper planting. My colleagues Tim McDonnell and Eric Berg from the Kansas Forest Service have just put together a handy new 2-page guide about the Top Ten Tree Planting Mistakes. Below is the summary – You can read the details by clicking HERE.

  1. Poor tree selection
  2. Inadequate root system
  3. Poor planting site
  4. Pot bound or girdling root
  5. Planting hole is too small
  6. Planted too deep
  7. The tree is improperly mulched or not mulched at all
  8. Tree is not staked
  9. Improper watering
  10. Failure to monitor


Spring dead spot in bermudagrass

(Megan Kennelly)

(Photos courtesy Jacob Weber, KSU Extension)

SDS jake weber 3 SDS jake weber 2

Spring dead spot is a severe root disease of bermudagrass. We see symptoms in the spring, as the turf is greening up. Affected areas remain brown, and the turf collapses leaving a sunken area that is prone to weed invasion. It can take a big chunk of the summer for recovery.

In the past, fungicide treatments in Kansas have had inconsistent results. Applications in September have sometimes had good results, but sometimes they have not worked at all.

There is some info about fungicide sprays for spring dead spot HERE (check page 20). Also, Dr. Lee Miller next door in Missouri reports that he has recently seen good results from Velista applied twice (mid September + mid October). Click HERE for Dr. Miller’s comments, paying particular attention to the fact that this usage involves a Section 2(ee) recommendation, not the main label.

Who has oak itch mite bites? I do! :(

(Megan Kennelly)


Why am I making a sand-and-grumpy face? I have two itch mite bites on my neck that are driving me bonkers.

As we move into more fall weather, with raking around the corner, here’s one more reminder to be careful about those itch mites, in case you missed Jared’s recent article (https://blogs.k-state.edu/turf/hot-holiday-weekend-didnt-slow-down-the-oak-leak-itch-mite/)

They itch and sting, and are highly annoying, and I think the worst case scenario would be little kids getting into them. Little kids don’t know how to resist scratching, and if they scratch until they break skin they can get secondary infections. Last year around this time we were at the pediatrician with our own son for his checkup, and the doc said he had seen lots of kids with mystery itchy bites. He didn’t know about itch mites, so I gave him some info.

Despite trying to stay away from our pin oak, I’ve got some bites on me from this weekend. I mean, it’s impossible to totally avoid an entire part of our yard, and it’s not practical to change my clothes and shower 3x a day when we are out trying to enjoy the weather. Plus, there are lots of pin oaks in our neighborhood and so on windy days I’m sure they are blowing all over, no matter where we go.

Last year, before we knew what was going on with the itch mites, my poor husband did some raking and playing in the pin oak leaves and ended up with EIGHTY bites. Luckily my son was NOT involved in that process, and he escaped unscathed. We kept him away from pin oak leaves all fall. We raked those spots when he was napping and wasn’t around to “help.”

Here’s one in the crook of my elbow – they often (but not always) have a raised pimply/blister appearance like you see here. On me, the bites last much longer than mosquito bites do.


You don’t want itch mites. You don’t want to be making grumpy faces. Be careful around those pin oaks!

Disclaimer – I’m not a dermatologist! If you have a mystery rash that is causing problems, you should get it checked out. This post is just a reminder that itch mites are active.

Here’s a reminder of the symptom on the tree:


A little midge does the leaf rolling, and the mite feeds on the midge. But, sometimes the mites fall/blow out of the tree onto US.

If it’s any consolation – we are a “dead end host” and they won’t spread further once they’ve been on us.