Vegetable pests

[Jimbone]

Been growing zucchini (courgette) and honeydew melon (cantaloupe) and the plant leaves are been mauled by  small orange beetles (you know what I'm talking about if you've ever seen one). I've seen these on a neighbors squash plant, too. I've tried to id it using the internet but, alas, no luck. 1. Does anyone know the name of this beetle, and 2) any suggestions for eradication (organically, please). I am covering the plants with the blue mesh and that has seemed to do the trick, but would be interested in other options.  Thanks.

[djayz]

Woodvinegar or neem oil has been suggested in numerous other threads over the years as an "organic" alternative. Also, companion planting can help reduce the need to spray. However, I don't know what plant repels the bug you are talking about. French marigolds, supposedly, repel a lot of critters. 

[zzaa09]

A concentrated lemongrass solution, applied topically, has been known to work quite effectively.

[drtreelove]

You can have my shelved neem, wood vinegar and lemongrass, I don't need them any more. I've found that the secret to effective pest control starts with soil fertility, and essentially involves a comprehensive, preventive IPM (Integrative Pest Management) program.

 

For beetle identification post photos, although I don't think that the ID is as important as trying to understand why any pest is there in the first place.  Which will likely be primarily low nutrient density from inadequate soil fertility.

 

 

 

Trying to control an advanced pest infestation with bio-pesticides, as a substitute for contact chemcial insecticide is usually futile.  An organic program requires forethought, anticipation of seasonal pest cycles, and early intervention or preferably preventive management. 

 

That said, if you're stuck with an advanced infestation, first consider if the damage is excessive and intolerable and is affecting the actual fruit/veggie product, or if the problem is primarily cosmetic; are the squash and melons negatively affected or only a relatively small percentage of the foliage?  A large percentage of foliar loss of course can mean reduced capacity for photosynthesis of sugars and metabolites that are required for the squash and melons to mature and become tasty and healthy. 

 

My choice for a knockdown spray for beetle pests would be a pyrethrum concentrate (pyrethrins, the chrysanthemum flower extract, which is biodegradable in 12 to 24 hours and considered organic program compatible. Not to be confused with the synthetic chemical version, pyrethroids, like permethrin and cypermethrin.) 

But I haven't purchased or looked for pyrethrins in Thailand for over 12 years so I don't know where to get it now, and its not widely understood or available. In the US I use Pyganic or Evergreen Pyrethrum Concentrate, which are wildly popular and on the shelf at most organic and cannabis growers supply shops. 

 

Azadirachtin concentrate/neem seed oil extract, wood vinegar and lemongrass and companion planting etc are best used for a preventive program when pest pressure is anticipated or in early onset. A combination may have some knockdown effect, but the pyrethrins is better if you want to see the bugs fall off the plant immediately after spraying. In California I spray oak moth caterpillars that defoliate native oak trees, and the worms fall out of the tree before I can get out of the way. 

Edited July 13, 2022 by drtreelove

[Jimbone]

I appreciate the comments and thanks for the ideas. Just yesterday, the wife showed me a video of a Thai man applying a solution containing a small amount of toothpaste. Currently I have covered my zucchini and honeydew melon with mesh screening, which has solved the problem. I tried using a concentrated solution of tobacco, but that wasn't a  deterrent.  Lemon grass sounds interesting.  Thanks for all the replies, they give me something to go on.

[djayz]

On 7/13/2022 at 10:10 AM, drtreelove said:

A combination may have some knockdown effect

What would that be?

[drtreelove]

On 7/19/2022 at 12:19 PM, djayz said:

What would that be?

Azadirachtin concentrate/neem seed oil extract, wood vinegar and lemongrass (leaf decoction/tea)

 

The Aza concentrates available in Thailand are really low in active ingredient, like this one from Thai Neem at 0.1%, so its minimally effective and the reason that most growers will experience failed treatments and say that organic biopesticides don't work (as well as lack of 1 to 2 week interval repeats). Some preventive action as repellent and reproductive disruptor properties is the best you'll get.  Botanicals work, you just have to know what to use and how to use it and what expectations to have or not have. They cannot be seen as a stand alone substitute for hard chemistry insecticide. They are effective if used as part of a comprehensive IPM program. Integrated Pest Management or I like to say Intelligent Plant Management) which includes soil fertility and water managment. 

 

Neemix from Certis USA is 4% a.i., AzaSol is 6% a.i. and will actually get some contact and translaminar knock down depending on the pest, host plant, timing of treatment. (In California when providing PHC (plant health care) for cannibis growers (legal, medicinal dispensary contract growers and hemp researchers), I used 70% neem oil during vegetative stage and swiched to AzaSol for flowering stage for control of budworms, spider mites etc, because its water soluble and doesn't leave an oily residue on the product. 

 

70% neem oil is not available here but is very popular in the US. Its very low in Aza, but overall is a good preventive hort oil with some of the complex neem chemistry that acts as an arthropod pest repellent. 

 

You can mix with wood vinegar, but be careful of this because high concentrations will burn foliage. 

Some Thai organic greens growers use a lite wood vinegar tank mix and soak a bunch of ta-kite/lemongrass leaves with it for a couple of days, and spray weekly to keep the caterpillars away.