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Full-Text Articles in Life Sciences

Tof-Sims Analysis Of Plant Seed Interactions With Plant Growth-Promoting Bacteria, Tammy Pheuphong, Rachel Komorek, Xiao-Ying Yu Aug 2018

Tof-Sims Analysis Of Plant Seed Interactions With Plant Growth-Promoting Bacteria, Tammy Pheuphong, Rachel Komorek, Xiao-Ying Yu

STAR (STEM Teacher and Researcher) Presentations

The use of time-of-flight secondary ion mass spectrometry (ToF-SIMS) in plant biology is a relatively unexplored and quickly developing field. The majority of research in plant SIMS involves the application of ToF-SIMS to study dried wood tissues, and only a handful of studies apply SIMS on plant stems, roots, and/or seeds. Our project provides a brief description and review of previous work using SIMS on plant stems, roots, and/or seeds, along with an emphasis on the sample preparation in each study. Additionally, the use of Brachypodium distachyon (Brachypodium) as a model system for research on grasses has also ...


Understanding Soil Moisture Levels On Soledad Ridge, Santa Rosa Island, California During The Summer Months, Dulce M. Lopez, Stephen Bednar, Kathryn Mceachern Jan 2018

Understanding Soil Moisture Levels On Soledad Ridge, Santa Rosa Island, California During The Summer Months, Dulce M. Lopez, Stephen Bednar, Kathryn Mceachern

STAR (STEM Teacher and Researcher) Presentations

Santa Rosa Island located off the coast of Santa Barbara County was grazed by non-native ungulates leaving the island stripped of vegetation topsoil layer. With the removal of ungulates, the National Park Service began restoring the Cloud Forest on Soledad Ridge. Soledad Ridge is said to have once been covered by large stands of island oaks (Quercus tometella) and other endemic and native plants. The unique leaf and structural morphology of such vegetation collects water from wind derived fog which serves as the main source of water for this unique ecosystem. In an effort to jump-start ecosystem vegetation recovery, a ...


Ecological And Organic Life Safety Concerns Of Hfo-1234yf, Alberni V. Ruiz Aug 2017

Ecological And Organic Life Safety Concerns Of Hfo-1234yf, Alberni V. Ruiz

STAR (STEM Teacher and Researcher) Presentations

While at NOAA my research was directed by the inquiry of whether or not HFO-1234yf, a new compound being introduced into coolant system and replacing greenhouse gases HFC, is harmful to organic life. Using the computer program Matlab I was able to develop figures that represented the concentration of HFO-1234yf (HFO) in 12 different tower locations throughout the country. Comparing and contrasting concentrations of this HFO compound at each site led me to the question the possible harmful side effects this compound could bring to organic life due to the fact that concentration levels are increasing, with one factor being ...


Ultramafic Geoecology Of South And Southeast Asia, M.L. Galey, A. Van Der Ent, M.C.M. Iqbal, N. Rajakaruna Apr 2017

Ultramafic Geoecology Of South And Southeast Asia, M.L. Galey, A. Van Der Ent, M.C.M. Iqbal, N. Rajakaruna

Biological Sciences

Globally, ultramafic outcrops are renowned for hosting foras with high levels of endemism, including plants with specialised adaptations such as nickel or manganese hyperaccumulation. Soils derived from ultramafic regoliths are generally nutrient-deficient, have major cation imbalances, and have concomitant high concentrations of potentially phytotoxic trace elements, especially nickel. The South and Southeast Asian region has the largest surface occurrences of ultramafic regoliths in the world, but the geoecology of these outcrops is still poorly studied despite severe conservation threats. Due to the paucity of systematic plant collections in many areas and the lack of georeferenced herbarium records and databased information ...


Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen Jan 2017

Effects Of Habitat Restoration On Soil Retention On Santa Rosa Island, Michael Perez, Kathryn Mceachern, Ken Niessen

STAR (STEM Teacher and Researcher) Presentations

Ranching began on Santa Rosa Island in the 1840’s, consequently introducing nonnative megafauna that put novel selective grazing pressures on endemic plant species. Their movement patterns also altered substrate integrity as the land became denuded of any stabilizing vegetation. Dense groves of island oak (Q. tomentella) are known to aid in sediment deposition and retention. The groves also function to collect water during periods of intense fog common to the island. This experiment sought to determine whether sediment is being lost or deposited on a ridge in the middle of the island containing a grove of Q. tomentella. The ...


Testing Predictions Used To Build An Agrivoltaics Installation On A Small-Scale Educational Model, Katie Kinney, Rebecca Minor, Greg Barron-Gafford Oct 2016

Testing Predictions Used To Build An Agrivoltaics Installation On A Small-Scale Educational Model, Katie Kinney, Rebecca Minor, Greg Barron-Gafford

STAR (STEM Teacher and Researcher) Presentations

Models are valuable tools for explaining and testing systems. Small-scale models can be especially useful for educational purposes. For models to be useful, they have to accurately depict the larger system that they are describing. A novel man-made system, known as an agrivoltaic structure, is being constructed at Biosphere 2 near Oracle, Arizona. The word agrivoltaic is a combination of agriculture and photovoltaics, or solar farming. My research involved creating a small-scale version of this system for educational purposes. The model of this system tested two predictions: that plants will grow better in the shade of a panel and that ...


Studying The Effects Of Serpentine Soil On Adapted And Non-Adapted Species Using Arduino Technology, Kiana Saniee, Edward Himelblau, Brian Paavo Oct 2016

Studying The Effects Of Serpentine Soil On Adapted And Non-Adapted Species Using Arduino Technology, Kiana Saniee, Edward Himelblau, Brian Paavo

STAR (STEM Teacher and Researcher) Presentations

Abstract: Serpentine soils are formed from ultramafic rocks and are represent an extreme environment for plants. Serpentine soils are unique in that they carry high concentrations of heavy metals, are nutrient deficient, particularly in calcium, and have poor water retention capabilities. Although these soils constitute harsh conditions for plant growth, there are a number of species that are adapted and even endemic to serpentine soil. Water retention by commercial potting mix was compared with serpentine soil. Also, serpentine adapted and non-adapted species were grown in both soil treatments and physiological data were collected. We used the Arduino electronic platform to ...


Impacts Of Fog Drip On Survivorship And Growth Of Native Herb And Shrub Seedlings On Santa Rosa Island, Julianne Bradbury, Ken Niessen, Kathryn Mceachern Sep 2016

Impacts Of Fog Drip On Survivorship And Growth Of Native Herb And Shrub Seedlings On Santa Rosa Island, Julianne Bradbury, Ken Niessen, Kathryn Mceachern

STAR (STEM Teacher and Researcher) Presentations

Overgrazing on Santa Rosa Island led to loss of topsoil in ridgeline groves of endemic island oaks (Quercus tomentella). Restoration specialists attempting to mitigate the impacts of wind and water erosion must determine efficient methods of reestablishing native vegetation. Planting pillows, burlap sacks filled with planting mix and attached to the bedrock substrate, may nurture seedlings long enough for their roots to penetrate the underlying sandstone. Since the island’s ridgeline habitat is often inaccessible during the rainy season, restoration efforts are largely confined to the dry summer months, during which condensed fog is an important source of moisture for ...


Effects Of Soil Erosion Barriers On Percent Cover And Sediment Size, Michael Perez Aug 2016

Effects Of Soil Erosion Barriers On Percent Cover And Sediment Size, Michael Perez

STAR (STEM Teacher and Researcher) Presentations

Ranching began on Santa Rosa Island in the 1840’s, introducing nonnative megafauna that put selective grazing pressures on endemic species. Dense groves of island oak (Q. tomentella) are aid in sediment deposition and retention. A current restoration effort, involved installing soil erosion barriers, known as wattles, to prevent sediment from being lost upslope and recruit plant growth whose root systems could further stabilize the slope. This experiment was designed to compare percent cover of vegetation growth in areas with and without soil erosion barriers. This was done using the line intercept method (n=42) on three meter transects, measuring ...


Citizen Science Sensor Development - Smap | Soil Moisture Active Passive, Hagop Hovhannesian Aug 2016

Citizen Science Sensor Development - Smap | Soil Moisture Active Passive, Hagop Hovhannesian

STAR (STEM Teacher and Researcher) Presentations

“Detailed monitoring of soil moisture provides a view of how our whole Earth system works.”

The Soil Moisture Active Passive (SMAP) satellite mission was launched in January 2015; its main purpose is to acquire global measurements of soil moisture. SMAP partnered with the GLOBE program (Global Learning and Observations to Benefit the Environment), which is an international program where students collect environmental variables in a scientifically methodical way. SMAP readings and maps have various uses in various fields, which include monitoring drought, predicting floods, assisting in crop productivity, and linking water, energy and carbon cycles. The goal of this project ...


A Comparative Study Of The Flora And Soils Of Great Duck And Little Duck Islands, Maine, Usa, Luka Negoita, Matthew Dickinson, Glen H. Mittlehauser, N. Rajakaruna Apr 2016

A Comparative Study Of The Flora And Soils Of Great Duck And Little Duck Islands, Maine, Usa, Luka Negoita, Matthew Dickinson, Glen H. Mittlehauser, N. Rajakaruna

Biological Sciences

Strong environmental gradients and varied land-use practices have generated a mosaic of habitats harboring distinct plant communities on islands on the coast of Maine. Botanical studies of Maine’s islands, however, are generally limited in number and scope. Baseline studies of Maine’s islands are necessary for assessing vegetation dynamics and changes in habitat conditions in relation to environmental impacts imposed by climate change, rising sea levels, invasive species, pests and pathogens, introduced herbivores, and human disturbance. We conducted a survey of the vascular plants and soils of forest, field, and ocean-side communities of Great Duck and Little Duck Islands ...


Designing A Remote Aerial System To Image And Analyze The Health Of Grape Crops At Cal Poly San Luis Obispo, Alexander D. Vice, Dylan Benton, Adipratnia Asmady, Andrew Mercier, Andrew Meyer, Eric Belfield, Aaron Drake Aug 2015

Designing A Remote Aerial System To Image And Analyze The Health Of Grape Crops At Cal Poly San Luis Obispo, Alexander D. Vice, Dylan Benton, Adipratnia Asmady, Andrew Mercier, Andrew Meyer, Eric Belfield, Aaron Drake

STAR (STEM Teacher and Researcher) Presentations

In the last decade the prevalence of unmanned aerial vehicles (UAVs) has exploded; however, the presence of UAVs in research situations is still a relatively new and untested field. The autonomous flight lab (AFL) at Cal Poly San Luis Obispo is a new lab site that is dedicated to using UAVs to benefit research for all backgrounds. Before AFL was able to fly missions we first needed to actually receive our vehicles, create a lab space that would provide all of the necessary resources and equipment necessary to fly, and to be granted permission by the Federal Aviation Administration (FAA ...


Chemical Oxygen Demand Reduction Using The Algae Dunaliella Primolecta And Chlorella Vulgaris, Angeles L. Mora, Alejandro Hernandez, Alejandro Calderón-Urrea Aug 2015

Chemical Oxygen Demand Reduction Using The Algae Dunaliella Primolecta And Chlorella Vulgaris, Angeles L. Mora, Alejandro Hernandez, Alejandro Calderón-Urrea

STAR (STEM Teacher and Researcher) Presentations

Farm industry wastewater is characterized by high organic materials and by high chemical oxygen demand (COD). Farms with large livestock and poultry operations can be a major source of wastewater thus a major concern for effective environmental and industrial management. Effective environmental and industrial management are high in cost therefor biofuels produced from plants have a potential of replacing a portion of fossil fuel consumption with a renewable efficient alternative. Due to California’s water crisis in the recent years, it is questioned if a biological treatment system that uses algal growth to create renewable energy in the form of ...


The Pioneer Of Santa Rosa Island, Andrea Martinez, Michael Perez, Kathryn Mceachern, Sarah Chaney, Ken Niessen Jul 2015

The Pioneer Of Santa Rosa Island, Andrea Martinez, Michael Perez, Kathryn Mceachern, Sarah Chaney, Ken Niessen

STAR (STEM Teacher and Researcher) Presentations

Santa Rosa Island which is part of the Channel Islands in California has a ranching history that goes as far back as the year 1843. While rich in history, the island is no longer “rich” in native plant populations due to the sheep, cattle and other livestock that once occupied the island. As a result of these grazers that the ranchers livelihood depended on, a great disturbance in the native plant population took place. It is up to plants such as Baccharis pilularis, commonly known as Coyote brush, to assist these endangered and threatened plants to once again flourish on ...


Bacterial Expression Of Plant Pyruvate Kinase, Kristina Fuller Jan 2015

Bacterial Expression Of Plant Pyruvate Kinase, Kristina Fuller

STAR (STEM Teacher and Researcher) Presentations

Pyruvate kinases serve an important role in regulating glycolysis pathways. Different pyruvate kinase isozymes can dictate which of several different products will be formed during the final step of glycolysis. Being able to reliably copy active pyruvate kinases (PK) would allow study of the different isozymes, with the goal of eventually creating plants that are more nutritionally beneficial for humans. This study focused on improving the protocol for replicating each of two isolated PK isozymes from the model plant Arabidopsis thaliana. Previous attempts had resulted in the PK denaturing and consequently precipitating out of solution and so we manipulated the ...


Evaluation Of Fungicides For Control Of Dollar Spot And Brown Patch Of Greens Height Creeping Bentgrass In Kansas, 2013, C. Thompson, R. Braun, M. Kennelly Aug 2014

Evaluation Of Fungicides For Control Of Dollar Spot And Brown Patch Of Greens Height Creeping Bentgrass In Kansas, 2013, C. Thompson, R. Braun, M. Kennelly

Horticulture and Crop Science

No abstract provided.


Xrf Analyses Of Prehanford Orchards, Komal Rana Aug 2014

Xrf Analyses Of Prehanford Orchards, Komal Rana

STAR (STEM Teacher and Researcher) Presentations

Subsequent to 1943, the use of Lead Arsenic was banned from the Orchards standing on the Hanford site. This use of Lead Arsenate pesticide was popular among the orchard owners and was dispersed over the site in a myriad of ways. The presence of the traces of lead and arsenic are found today, more than half a century later. Using a portable X-ray florescence analyzer (XRF), the values of lead and arsenic are evaluated while determining the efficiency of the equipment itself. Samples from different decision sites were collected, with lead arsenic values in the low, high and medium range ...


Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea Aug 2014

Growing Conditions For Algae, Angeles Mora, Tamar Melkonian, Alejandro Calderon-Urrea

STAR (STEM Teacher and Researcher) Presentations

With the growing demands of water in California and the increasing cost of fossil fuels to operate water-cleaning equipment, Algae was cultivated in different concentrations of Nitrogen, Phosphorus, and Potassium (NPK) during different trails to identify the best growing conditions for the removal water contaminates. Before testing algae in waste water, the Algae: Dunaliella Primolecta, Chlorella Vulgaris, and Scenedesmus Dimorphus were cultivated in four different media containing distilled water and plant vitamins. The different mediums used include: Orchid Grow More (20-20-20), Miracle Grow (30-10-10), Murashige & Skoog, and Orchid Bloom Boster (11-35-15). As a result of the investigation, the algae, Scenedesmus ...


A Preliminary Study Of The Role Of Nickel In Enhancing Flowering Of The Nickel Hyperaccumulating Plant Alyssum Inflatum Nyár. (Brassicaceae), R. Ghasemi, Z. Zare Chavoshi, R.S. Boyd, Nishanta Rajakaruna Mar 2014

A Preliminary Study Of The Role Of Nickel In Enhancing Flowering Of The Nickel Hyperaccumulating Plant Alyssum Inflatum Nyár. (Brassicaceae), R. Ghasemi, Z. Zare Chavoshi, R.S. Boyd, Nishanta Rajakaruna

Biological Sciences

Alyssum inflatum is a native of serpentine soils and is able to hyperaccumulate nickel (Ni), but the importance of Ni to reproduction in the species is unknown. We investigated if reproductive fitness is enhanced by Ni in the growth medium, and included a treatment involving a relatively high level of Mg to provide a comparison with elevated levels of another metal. Seedlings were grown in a modified Hoagland solution culture in an inert medium of Perlite and were treated with Ni (100 μM), a high concentration of Mg (5 mM), or under control conditions (solution culture without Ni or the ...


Additional Lichen Records And Mineralogical Data From Metal-Contaminated Sites In Maine, Ian D. Medeiros, Alan M. Fryday, N. Rajakaruna Jan 2014

Additional Lichen Records And Mineralogical Data From Metal-Contaminated Sites In Maine, Ian D. Medeiros, Alan M. Fryday, N. Rajakaruna

Biological Sciences

Geochemistry and mineralogy of rocks play important roles in the occurrence of individual lichen species and assembly of lichen communities. Whereas lichens of metal-enriched settings have been a focus of study for many decades, only a few such lichen inventories exist for North America. We reexamined the lichen biota of Pine Hill, a serpentine outcrop on Little Deer Isle, Maine and Callahan Mine, a copper-and zinc-enriched Superfund site in Brooksville, Maine by conducting additional field surveys and reexamining unidentified taxa from previous collections. To better characterize the substrates upon which the lichens were found, we conducted elemental analyses via x-ray ...


Evaluation Of Fungicides For Control Of Dollar Spot Of Fairway Height Creeping Bentgrass In Kansas, 2012, C Thompson, Z Raundenbush, Megan Kennelly Aug 2013

Evaluation Of Fungicides For Control Of Dollar Spot Of Fairway Height Creeping Bentgrass In Kansas, 2012, C Thompson, Z Raundenbush, Megan Kennelly

Horticulture and Crop Science

No abstract provided.


Evaluation Of Granular Fungicides For Control Of Brown Patch Of Lawn Height Tall Fescue In Kansas, 2012, Cole Thompson, M. Kennelly Aug 2013

Evaluation Of Granular Fungicides For Control Of Brown Patch Of Lawn Height Tall Fescue In Kansas, 2012, Cole Thompson, M. Kennelly

Horticulture and Crop Science

No abstract provided.


Identifying Molecular Markers Associated With Salt And Boron Tolerance In Poplar Trees, Darshanpreet Gill, Nathan Follen, Davis W. Cheng, Kyan Salehi, Gary Banuelos, James P. Prince Aug 2013

Identifying Molecular Markers Associated With Salt And Boron Tolerance In Poplar Trees, Darshanpreet Gill, Nathan Follen, Davis W. Cheng, Kyan Salehi, Gary Banuelos, James P. Prince

STAR (STEM Teacher and Researcher) Presentations

Standard irrigation practices promote salt and boron accumulation in soils on the Westside of Central California. The build-up of these inorganic salts leads to the degradation of arable land and reduction of crop production. Different clones of poplar trees have been shown to grow in salt- and boron-contaminated soils, and in doing so, gradually remove significant amounts of these inorganic salts from the soil. In an effort to identify molecular markers linked with salt and boron tolerance in poplars, 31 PCR primer pairs have been designed based on candidate genes identified from the literature, and an additional 31 PCR primer ...


Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan Jan 2013

Using Stable Isotope Analysis Of Zooplankton To Document Trophic And Biogeochemical Changes In The San Francisco Estuary, Steven C. Westbrook, Julien Moderan

STAR (STEM Teacher and Researcher) Presentations

Zooplankton represent a vital link between phytoplankton and fish, like the endangered Delta Smelt. Human interferences (nitrates from waste water, flow alteration, invasive species introduction…) have altered the structure of the San Francisco Estuary (SFE) ecosystem. We use stable isotope analysis to improve our knowledge of the planktonic food web in the SFE and gain insights into its evolution over the past decades. We use the ratios of certain isotopes (Nitrogen, Carbon, Sulfur, etc.) in different species of zooplankton to tell us what it is feeding on as well as the trophic level it feeds in. My research focused on ...


Evaluation Of Headway G For Control Of Brown Patch Of Lawn Height Tall Fescue In Kansas, 2011, C Thompson, M Kennelly Aug 2012

Evaluation Of Headway G For Control Of Brown Patch Of Lawn Height Tall Fescue In Kansas, 2011, C Thompson, M Kennelly

Horticulture and Crop Science

No abstract provided.


Edaphic Adaptation Maintains The Coexistence Of Two Cryptic Species On Serpentine Soils, Jenn M. Yost, Teri Barry, Kathleen M. Kay, Nishanta Rajakaruna Apr 2012

Edaphic Adaptation Maintains The Coexistence Of Two Cryptic Species On Serpentine Soils, Jenn M. Yost, Teri Barry, Kathleen M. Kay, Nishanta Rajakaruna

Biological Sciences

Premise of the study: Divergent edaphic adaptation can contribute to reproductive isolation and coexistence between closely related species, yet we know little about how small-scale continuous edaphic gradients contribute to this phenomenon. We investigated edaphic adaptation between two cryptic species of California wildflower, Lasthenia californica and L. gracilis (Asteraceae), which grow in close parapatry on serpentine soil.

Methods: We reciprocally transplanted both species into the center of each species’ habitat and the transition zone between species. We quantified multiple components of fitness and used aster models to predict fitness based on environmental variables. We sampled soil across the ridge throughout ...


Response Of Evergreen Perennial Tree Crops To Gibberellic Acid Is Crop Load-Dependent: Ii. Ga3 Increases Yield And Fruit Size Of ‘Hass’ Avocado Only In The On-Crop Year Of An Alternate Bearing Orchard, Lauren C. Garner, Grant Klein, Yusheng Zheng, Toan Khuong, Carol J. Lovatt Oct 2011

Response Of Evergreen Perennial Tree Crops To Gibberellic Acid Is Crop Load-Dependent: Ii. Ga3 Increases Yield And Fruit Size Of ‘Hass’ Avocado Only In The On-Crop Year Of An Alternate Bearing Orchard, Lauren C. Garner, Grant Klein, Yusheng Zheng, Toan Khuong, Carol J. Lovatt

Horticulture and Crop Science

Despite problems of low fruit set, small fruit size and alternate bearing, the Hass cultivar dominates commercial avocado production worldwide. To increase yield and fruit size, gibberellic acid (GA3) (25 mg L−1) was applied at different stages of ‘Hass’ avocado tree phenology: (i) mid–late April (flower abscission), end of June–beginning of July (fruit abscission and beginning of the exponential phase of fruit growth), and mid-January (beginning of pre-harvest fruit drop); (ii) end of June–beginning of July; and (iii) mid-September (near the end of the major fruit abscission period; period of exponential fruit growth). In both ...


Evaluation Of Fungicides And Fungicide Programs For Control Of Dollar Spot Creeping Bentgrass In Kansas, 2010, M Kennelly, C Thompson, Z Raudenbush Aug 2011

Evaluation Of Fungicides And Fungicide Programs For Control Of Dollar Spot Creeping Bentgrass In Kansas, 2010, M Kennelly, C Thompson, Z Raudenbush

Horticulture and Crop Science

No abstract provided.


Preventative Fungicide Application For Control Of Dollar Spot On Creeping Bentgrass In Kansas, 2010, M Kennelly, Z Raudenbush, Cole Thompson Aug 2011

Preventative Fungicide Application For Control Of Dollar Spot On Creeping Bentgrass In Kansas, 2010, M Kennelly, Z Raudenbush, Cole Thompson

Horticulture and Crop Science

No abstract provided.


Temperature Thresholds And Degree-Day Model For Marmara Gulosa (Lepidoptera: Gracillariidae), M. J. O'Neal, David H. Headrick, Gregory H. Montez, E.E. Grafton-Cardwell Aug 2011

Temperature Thresholds And Degree-Day Model For Marmara Gulosa (Lepidoptera: Gracillariidae), M. J. O'Neal, David H. Headrick, Gregory H. Montez, E.E. Grafton-Cardwell

Horticulture and Crop Science

The developmental thresholds for Marmara gulosa Guillen & Davis (Lepidoptera: Gracillariidae) were investigated in the laboratory by using 17, 21, 25, 29, and 33°C. The lowest mortality occurred in cohorts exposed to 25 and 29°C. Other temperatures caused >10% mortality primarily in egg and Þrst and second instar sap-feeding larvae. Linear regression analysis approximated the lower developmental threshold at 12.2°C. High mortality and slow developmental rate at 33°C indicate the upper developmental threshold is near this temperature. The degree-day (DD) model indicated that a generation requires an accumulation of 322 DD for development from egg to adult emergence. Average daily temperatures in the San Joaquin Valley could produce up to seven generations of M. gulosa per year. Field studies documented two, Þve, and three overlapping generations of M. gulosa in walnuts (Juglans regia L.; Juglandaceae), pummelos (Citrus maxima (Burm.) Merr.; Rutaceae), and oranges (Citrus sinensis (L.) Osbeck; Rutaceae), for a total of seven observed peelminer generations. Degree-day units between generations averaged 375 DD for larvae infesting walnut twigs; however, availability of green wood probably affected timing of infestations. Degree-day units between larval generations averaged 322 for pummelos and 309 for oranges, conÞrming the laboratory estimation. First infestation of citrus occurred in June in pummelo fruit and August in orange fruit when fruit neared 60 mm in diameter. Fruit size and degree-day units could be used as management ...