Research and Extension Programs:
(1) Sterile insect technique for navel orangeworm: Navel orangeworm (Pyralidae: Amyelois transitella) (NOW) is a key pest of tree nuts in California. There are 3-5 generations per year, adults oviposit onto nuts and larval feeding reduces nut yield, quality and can introduce aflatoxin, which is strictly regulated in key export markets. The CA pistachio industry and USDA recently invested in sterile insect technology (SIT) for NOW, but it is unclear how to most effectively use this technique in California tree nuts. I’m a member of the Technical Advisory Committee for this program and my lab is carrying out much of the initial research to evaluate the quality of irradiated NOW, including mating competition, dispersal capacity, and determining appropriate overflooding ratios. This work is in collaboration with Dr. Charles Burks (USDA-ARS, Parlier) and Dr. Gregory Simmons (USDA-APHIS, Salinas).
(2) Pheromone and related attractants for leaffooted bugs: Leaffooted bugs (Coreidae: Leptoglossus zonatus, L. clypealis) (LFB) are key pests of almonds, pistachios and pomegranates. There are 2-4 generations per year, adults lay eggs on tree branches and feeding of nymphs/adults can lead to nut abortion, necrosis and transmission of pathogens. IPM of LFB is weak due to the lack of an effective monitoring program, and so growers apply insecticides at will. My lab works with Dr. Jocelyn Millar (UCR) and Dr. John Beck (USDA-ARS) to develop the use of pheromones (Millar) and host-plant volatiles (Beck) for trapping LFB. The first goal of this program was to identify an effective LFB trap – which my lab successfully did in fall 2017 – and we are now conducting further studies to refine trap efficacy and evaluate candidate LFB lures under field conditions.
(3) Overwintering biology and cultural controls for walnut husk fly: Walnut husk fly (Tephritidae: Rhagoletis completa) (WHF) is a key pest of walnuts. This univoltine fly overwinters as a pupa in the soil. Adults emerge in the summer, oviposit into walnut husks and larval feeding reduces crop quality and yield. In the fall, larvae drop from the nuts and pupate in the soil. My lab is leading a project to identify key factors that lead to increased mortality of WHF larvae and overwintering pupae, with the goal of developing practices to reduce overwintering success. This is a collaborative project that involves Area IPM Advisors Rijal (North San Joaquin Valley) and Symmes (Sac. Valley).
(4) Mating disruption of navel orangeworm in figs: CA fig production is mostly for the dried market but recently growers have begun to expand into the organic, fresh market. With this comes lower tolerance for crop damage and restrictions on insecticide. As such, growers are interested in the use of mating disruption for NOW control. My lab is evaluating the only mating disruption product registered for use in organic production. We are also evaluating novel PPO traps for monitoring NOW in orchards under mating disruption. My lab is also working with the CA Dried Fruit Association to improve postharvest evaluation of insect damage to figs. These projects are in collaboration with UC Area Orchard Advisor Phoebe Gordon (Madera-Merced Counties).
(5) Aggregation pheromones to monitor driedfruit beetle in figs: Driedfruit beetle (Nitidulidae: Carpophilus hemipterus) (DFB) is a primary pest of figs. This polyphagous beetle has 10-12 generations per year. Feeding causes direct damage to figs and can introduce bacteria and fungi that spoil fruit. My lab is evaluating the efficacy of experimental DFB aggregation pheromones to improve monitoring and possibly develop an attract-and-kill program.
(6) Trap crops to control large plant bugs in pistachio: A pistachio grower with significant organic acreage expressed interest in the use of trap crops to monitor and control large plant bugs, such as LFB and various pentatomids (Thyanta pallidovirens, Chinavia uhleri, Chlorochroa hilare). These pests are all known to feed on various weedy vegetation that in some cases may be more attractive than pistachios, and my lab is currently evaluating the ability of a mustard, radish and alfalfa trap crop to reduce large bug populations and crop damage. This is in collaboration with Dr. Kent Daane (UCB, Kearney Ag. Center) and is part of the dissertation for my PhD student Robert Straser.
(7) Influence of orchard habitat diversification on navel orangeworm in almonds: Multiple labs at UCD (Williams, Gaudin) and UCR (Ponisio) are exploring the influence of cover crops and hedgerows on pollinators in almond orchards. The role of my lab in these projects is to evaluate the effects of these practices on NOW (Williams, Gaudin) or provide support with collaborating growers (Ponisio).
(8) Cannabis IPM survey: As a “new” commodity in the CA agricultural landscape, cannabis production will become subject to the same regulatory pressures as other specialty crops like almonds, grapes and citrus. Improper pesticide use, amongst other production practices, is likely leading to negative environmental impacts. As such, the development of IPM programs and non-chemical strategies will be a research priority. My lab recently led an effort to survey cannabis growers across the state to characterize production practices in CA. This research will soon be featured in a special edition of California Agriculture. This project is a collaboration that I organized with UCB faculty (Butsic, Grantham, Getz, Daane) and The Nature Conservancy (Carah).
(9) Vineyard IPM: I remain involved in research and extension efforts to improve biological control of the invasive Virginia creeper leafhopper (Cicadellidae: Erythroneura ziczac) as well as evaluate the ecology and transmission efficiency of insect vectors of grape vine red blotch-associated virus (GRBaV).