The bug is the Striped Cuccumber Beetle. As an aside, I picked three Colorado Potato Beetles off the potatoes this morning.
Will you also be using row covers to exclude the beetles this year?
As to your link to the article about Tanos, a fungicide for downy mildew,
[url]https://www.durgan.org/11%20August%202006%20Downy%20Mildew/HTML/cuccumber%20mildew.htm[/url]
I found this information. I always find it disturbing to read about animal testing, especially when it's put in their eyes and they are made to eat it. I'm glad you will be using the torch this year.
[url]https://www.usna.usda.gov/Gardens/collections/VirtualTours/BonsaiVirtualTour.html[/url]
I also found this with lots of helpful info. It will also explain why the copper didn't work for you:
https://www.attra.org/attra-pub/downymildew.html
Resistant Varieties
One of the principal means of managing downy mildew in cantaloupe and cucumber is the use of genetically resistant cultivars. Resistance has not been developed in other cucurbits, though some squash varieties like Super Select and Zucchini Select are considered to be tolerant (5), as are cucumber varieties like Poinsett and Galaxie. (6) The Virginia Extension publication Downy Mildew of Cucurbits (3) identifies other resistant cucumber cultivars. Growers are advised to contact Cooperative Extension and local seed suppliers for assistance in selecting resistant varieties that also perform well in their location.
Alternative Pesticides
Along with resistant varieties, fungicides are considered the principal means of downy mildew control in cucurbits. There are several alternatives to synthetic fungicides.
Neem Oil
Neem oil is a botanical pesticide derived from the tree species Azadirachta indica. It is a multi-purpose insecticide, miticide, and fungicide labeled for control of both downy and powdery mildews on cucurbits. (8)
Neem products, once considered largely benign to beneficial insects, have demonstrated some negative impacts. Washington State research has found neem to be toxic to ladybeetles, especially in their early larval stages. (9) Being an oil formulation, neem can also harm bees and should be applied when they are not active in the field. (10) Therefore, while neem oil is suitable for organic production, it should not be used without clear need and plenty of caution.
Biofungicides
Serenadeâ„¢, a relatively new fungicide based on the biocontrol agent Bacillus subtilis, is available in a wettable powder formulation that can be used for downy mildew control on vegetables. (12) According to its manufacturer, Serenade turns on the plant's natural immune system. It is also said to:
"…stop plant pathogen spores from germinating, disrupt the germ tubes and mycelial growth and inhibit attachment of the plant pathogen to the leaf by producing a zone of inhibition restricting the growth of…disease causing pathogens." (13)
For sources of the product, contact the manufacturer, AgraQuest Inc. (14)
Peroxides
Organic growers and others in alternative agriculture have often mentioned hydrogen peroxide (H2O2) as a disease preventive for crops. (15) While documentation on the use of food- and/or pharmacy-grade peroxide in managing plant diseases is sketchy, BioSafe Systems has recently released a peroxigen formulation under the name of OxiDateâ„¢, which is labeled as a broad-spectrum bactericide and fungicide. Downy and powdery mildews of cucurbits are among the diseases it is said to control. Among the listed benefits are biodegradability, little to no phytotoxicity, and the ability to kill fungal spores on contact. (16)
Although the Organic Materials Review Institute (OMRI) had previously approved OxiDate for organic production, it removed the product from its listing in spring 2002 because of non-compliance with federal regulations. If reformulated, it may be approved again in the future. Contact BioSafe Systems (17) for additional details.
Bicarbonates
In 1998, Church & Dwight Co. (18)â€â€the manufacturer of Arm & Hammer Baking Sodaâ„¢â€â€received EPA registration for Armicarb 100â„¢, a potassium bicarbonate formulation, for use against downy and powdery mildews, botrytis, and alternaria leaf-spot. (19) This product is the direct result of research done at Cornell and funded by Church & Dwight. Armicarb 100 is now available from Helena Chemical Company (20) and Agri-Turf Supplies. (21) Similar products are FirstStepâ„¢ by the Cleary Chemical Corp. (22), Kaligreenâ„¢ by Monterey Chemical (23), and Remedyâ„¢ by Bonide Products Inc. (24) For additional information on the use of bicarbonates in plant disease management, see ATTRA's Use of Baking Soda as a Fungicide.
Compost Tea
Though still somewhat experimental, compost teas have proved successful in managing a number of plant diseases. For details, please see the ATTRA publication Notes on Compost Teas.
There are links for references there as well.
Newt