Utah Pests News Spring 2009

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Africanized honey bees found in southern utah
Utah Dept. of Agriculture and Food (UDAF) recently detected Africanized honey bees in monitored traps and in honey bee hives in Washington and Kane counties. UDAF, USU, and agricultural stakeholders will work together to develop tools and educational materials for beekeepers and citizens. This bee has been present in southern and southwestern U.S. since the early 1990s. The new fact sheet,
Africanized Honey Bees, provides more details.


Diane Alston 
Entomology Specialist  

Ryan Davis
Insect Diagnostician 

Kent Evans (No longer at USU)
Plant Pathology Specialist 

Erin Frank (No longer at USU)
Plant Disease Diagnostician 

Erin Hodgson (No longer at USU)
Entomology Specialist 

Marion Murray
IPM Project Leader 
Editor, Utah Pests News

Utah Plant Pest Diagnostic Lab
BNR Room 203
Utah State University
5305 Old Main Hill
Logan, UT 84322

Utah Pests News is published quarterly by the UTAH PESTS staff. 





Additional articles in this issue:

Imidacloprid for Insect Control

Utah Pests Holds In-Service Training

Turf Problems to Watch for This Spring

Getting Nit-Picky About Head Lice

Surge in Black Pineleaf Scale

Spotlight: Transitioning to Organic Agriculture

News, Publications, Web sites

Sabbatical Research Experience with the NW Michigan Cherry Industry

My family and I had a fun and productive sabbatical experience in northwestern Michigan during the spring and summer of 2008.  Michigan produces 75% of U.S. tart cherries and is one of four major producers of sweet cherries.  I collaborated with Michigan State University entomologists on research projects on plum curculio biological control and cherry fruit fly ecology and management.   Drs. Nikki Rothwell, Mark Whalon, Larry Gut, and others were generous with their time and expertise and helped me jump right into research opportunities with the Michigan fruit industry.

First, I conducted a survey of 37 fruit orchards and vineyards for the presence of entomopathogens (nematodes, fungi, and bacteria that kill insects).  A goal was to assess whether the sandy soils of NW Michigan are conducive to entomopathogens and microbial activity.  By targeting soil-dwelling life stages of insects, such as the summer generation of plum curculio and cherry fruit fly larvae, growers can take advantage of additional timings to suppress pest populations.

Waxworm larvae were used to “bait” soils for native entomopathogens.  Entomopathogen-induced insect mortality ranged from 5-95% per site, and was 50% or greater in 22 of the 37 sites.  Soils of organically managed sites had greater entomopathogen activity than transitional organic, sustainable, and conventional orchard soils.  Entomopathogens were more common in grape and tart cherry sites than in sweet cherry, and apple sites were intermediate.  These results support that the presence of mulches and ground covers, and lower toxicity or shorter-lived pest control products used in organic production may encourage biologically active soils that can suppress soil-dwelling insects.  Additionally, results suggest that the sandy soils of NW Michigan are conducive to entomopathogens, and as long as adequate soil moisture is maintained, may be good sites for application of entomopathogen products, such as nematodes and fungi.

  Diane used a new trick for hanging traps: attaching the trap to a bamboo pole and hooking it over a limb as high as 12 feet in the tree.
Second, I contributed to a statewide effort to develop a predictive model of plum curculio (PC) phenology in fruit.  Such a model would allow growers to better time controls for the summer generation, such as insect growth regulators that reduce egg hatch, entomopathogens to kill larvae in the soil, or post-harvest foliar sprays for adults.   Results showed that PC phenology was more advanced in tart and sweet cherry than in apple, and more advanced in fruit on the ground than fruit in the tree.  At 450-500 DD50, the majority of PC in fruit on trees were eggs and 1st instars, while in fruit on the ground the majority were 1st to 4th instars.   At 650-700 DD50, most PC in cherry fruits on trees were 3rd to 4th instars while in fruit on the ground most were 4th instars or had already exited (except not from apple).  These data suggest that applications of entomopathogens to target 4th instars burrowing into soil would need to be applied beginning at about 500 DD50 and continue past 700 DD50.  This study is on-going and more data will be collected in subsequent years.

Third, I participated in a study on cherry fruit fly (CFF) reproductive maturity and behavior in sweet and tart cherry orchards as compared to a native host, black cherry.   The goal was to build upon data collected by Dr. Luis Teixeira of MSU suggesting that peak egg-laying of CFF in cherry orchards occurs during and just after cherry harvest when fruits are at peak ripeness, but that CFF trapped in nearby black cherry trees don’t have mature eggs until later in August when black cherry fruits become ripe.   My results support these findings.  Observations of CFF behavior in tart cherry trees found that flies didn’t begin to spend time on fruits until they were fully red in color.  Most of the flies collected from fruits were males, suggesting that males sit and wait to mate with females.  Results from this study will be contributed to research and Extension publications.

In addition to the exciting research opportunities, my family and I found many diversions.  We took advantage of the abundance of places to kayak, fish, swim, and hike. Sleeping Bear Dunes National Lakeshore is a real treasure and we hiked on many of the park’s trails.  We take with us fond memories of the region and people in the “Cherry Capital of the World.”

-Diane Alston, Extension Entomologist


Featured Picture of the Quarter

Grape phylloxera (Daktulosphaira vitifoliae) is an aphid-like pest of grapes, native to eastern U.S. Two forms exist, one that feeds on root galls and one that feeds on leaf galls.  Native grapes tolerate feeding, while European rootstocks are highly susceptible.  This pest almost destroyed the wine industry in France in the late 1800s.

The foliar-feeding form produces galls on the leaves, inside which nymphs feed.   Adults emerge and lay eggs (shown at left) via asexual reproduction (parthenogenesis).  Up to seven generations can occur.

-Photo by Diane Alston