Pest control efforts disrupt navel orangewormmating
vest, minimizing damage from other sources and year-round mummy man- agement help. There are biological con- trols with parasitoids and predators and insecticide options. Symmes said it is important to watch mower height and speed when dealing withmummies. She said it is also import- ant tominimize damage to trees from in- sects and disease and to follow practices thatminimizemummiesand“stick-tights,” or almonds that don’t release fromthe tree when shaken. Symmes said practicing sanitation not only combats NOW, it reduces patho- gen inoculum from brown rot, bacterial spot and anthracnose. And commingling mummy nuts with the current harvest adds to the reject percentage. Proper use of irrigation and nutrients affects disease incidence. Other insect damage can come from hull gummosis with leaffooted bugs, stinkbugs and other plant bugs. As for insecticides, using softer chemis- tries requires precise timing and excellent coverage. Growers also must be aware of nontarget beneficials and pollinators and environmental impact considerations. Organophosphate use in almonds has dropped dramatically. Use of pyre- throids, diamide and methoxyfenozide has risen. Hexadecadienal (phero-
mone use) has risen dramatically. Symmes explainedhowmating disrup- tionworks.NOWfemales produceand re- lease small concentrations of pheromone, which attractsmales. Natural pheromone molecules are fragile and plumes do not persist. If they did, they would causemat- ing confusion. “We get a lot more pheromone into the environment andcreate longer-lastingdis- tributionandemissionof syntheticphero- mone in the environment,” she said. This divertsmales from females as they follow false plumes. Symmes said mating disruption is “a technology that modifies insect behavior. It doesnot kill anything. Rather, it prevents eggs and larvae fromever existing. It pre- ventsmatingas itdecreases theprobability of mate location and decreases the likeli- hood of successful mating.” The benefits of mating disruption are many: It can last season-long and into the postharvest. It can reduce insecti- cide inputs and pesticide residues and increase quality. Mating disruption is an option for or- ganic farmers. It addresses insecticide re- sistance, reduces hazards for workers and preservesbeneficial insects, Symmes said. (Denni s Pol lock i s a repor t er in F r e s no . He ma y b e c on t a c t e d a t agcompollock@yahoo.com.)
ByDennis Pollock One of the best ways to combat public enemy No. 1 in almonds—the navel or- angeworm—is to have it looking for love in all thewrong places. Mating disruption, as part of an inte- grated pest management program, has become possibly the singlemost import- ant tool in the arsenal of weapons that can be used to thwart this pest. The navel orangeworm, or NOW, causesmillions of dollars of losses to the almond industry each year and can produce aflatoxins, a food safety contaminant. The insect bores into the nut and feeds on the meat, opening the door to Aspergillus molds. The pest is an issue across theentireCentral Valley,withreject levels due to NOWdamage highest in the southern valley. Tools for management include winter sanitation to remove and destroy mum- my nuts, mating disruption, monitoring of NOWpopulations to time use of insec- ticidesorbiological control agentsandun- dertaking prompt harvests before a third generation of NOWdevelops. EmilySymmes, seniormanager in tech- nical field services with the pest control company Suterra, said the navel orange- wormthrivesbymoving fromfarmto farm in contiguous acreage. As total acreage
for almonds, pistachios and walnuts in- creased by 75% between 2010 and 2020, NOWfeasting took off as well. Symmes said mummy nuts can be a year-round resource for NOW, which has four generations per year statewide and possibly a fifth generation in the southern San Joaquin Valley. The pest has a high reproductive capacity. Each female can laybetween80 and200 eggs, andmultiple larvae can develop per nut. “Thatmeans there canbe extremepop- ulation build-upwhen in-season nuts are most vulnerable during hull split andhar- vest,” Symmes said. There is very low damage tolerance for the pest. A 2% loss on 1.6 million bearing acres of almonds producing a 3-billion-pound crop, amounts to a loss of $105 million. A 2% loss on 300,000 bearing acres of pistachios producing a 1.2-billion-pound crop, amounts to $60 million. And on 365,000 bearing acres of walnuts producing a 650,000-ton crop, a 2% loss totals $26 million. Symmes recommends a multi-faceted approach. Remedies include monitoring, using traps, crop phenology, visual sam- ples, degree days and harvest damage evaluation. There’salsomatingdisruption, using aerosol dispensers and sprays. Additionally, sanitation, timely har-
The Produce Safety Rule is Here; ARE YOU READY?
Farm Employers Labor Service (FELS), an a liated company of the California Farm Bureau (CAFB), has partnered with the Safe Food Alliance through a California Department of Food and Agriculture grant contract, as their designated training provider for Central and Southern California, to conduct the required Produce Safety training for growers. Presented in a free two-day remote delivery webinar format! What sets Safe Food Alliance, FELS, and Farm Bureau apart is their total of over 100 years of experience and our dedication to providing technical guidance and leadership to the California agriculture community. Most farms are required to have at least one designated supervisor who has been trained in accordance with the Food Safety Modernization Act (FSMA) Produce Safety rule. Upon completion of the course, attendees will receive an o cial certi cate from the Association of Food & Drug O cials.
The Food Safety Training Partnership is offering these training courses throughout California. You can find more information and register at foodsafetytrainingpartnership.com, or call 916-561-5672. Supported by California Department of Food and Agriculture
September 8, 2021 Ag Alert 15
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