Connect with us

Gardening: Choosing the right insecticide

Legacy Phuket Gazette

Published 

 on 

PHUKET: A good friend, Graham, an airline captain, asks “Can you recommend an all-round weed-killer, not for the garden but for the grass and weeds out in the road by my house?” He adds: “For the last two months, we have fed the pretty caterpillar population (green with blue eyes) and love the butterflies into which they develop, but we now feel we have fulfilled our obligation to nature and would like to know if there is a spray we can use, if only to persuade the butterflies to move into the next garden.”

As well as possessing a mischievous sense of humor and a wonderful villa, perched high above Kata with spectacular sea views, Graham and his charming wife, Mo, clearly have the right instincts about Mother Nature.

Since the weeds include grass and are not in Graham’s garden, I would advise the use of a non-selective weed-killer. Two that are widely employed here (although you will need to check the label) are paraquat (manufactured by Syngenta) and the much more recently developed Roundup (Monsanto). Both are contact herbicides that work by killing first the foliage and then the roots of affected weeds.

Personally, I would always prefer to use paraquat since it is deactivated once it makes contact with the soil, and leaves no toxic residues in run-off or ground water. Typically, it is diluted 50 to 100 fold in water before application. Roundup is fiercely effective stuff and remains active for a whole year, but there is growing evidence that the chemical (glyphosate) can cause limited environmental damage. Neither of them pose any threat to pets.

As for your caterpillar problem, you deserve a pat on the back for your forbearance. They are probably the larvae of the splendid oleander hawk moth, and while you don’t specify which shrubs they are molesting, I would guess either adeniums (which have few enough leaves anyway), tabernaemontanas or oleanders. Personally, I remove the sprig on which they are feeding, and throw them over the wall, but they are voracious feeders and I recognize the need for more drastic action. In any case the critters are perfectly camouflaged for their environment and hide under the leaves. So, even with the eagle eyes of a pilot, they are difficult to spot.

A systemic insecticide, which is watered in at the roots and spreads throughout the foliage is therefore – if you will pardon the pun – the obvious solution. But, while the horror chemicals – organochlorides such as DDT, dieldrin and chlordane – are now banned, the newer compounds such as carbaryl, while not retained in the food chain, still kills beneficial insects such as bees.

Alternative ‘natural’ or organic pesticides – which I would strongly advocate using – include those based on nicotine, pyrethrum and neem (a local tree) that are all produced by the plant in question (tobacco, aster or neem) to counter the munching habits of insects. Just as your toxic caterpillars protect themselves from predators because they feed on poisonous plants, so your neem and nicotine plants safeguard themselves by producing insect repellents.

If you have gardening or environmental concerns, contact Patrick at drpaccampbell@gmail.com. Many of his creative and academic publications can be found at his website: Green galoshes WordPress.

— Patrick Campbell

 

Want more from the Thaiger family?

📱 Download our app on Android or iOS for instant updates on your mobile
📝️ Join the conversation on Thaiger Talk - discuss news & life in our Thailand forums
📧 Subscribe to our daily email newsletter
👍 Like/Follow us on Facebook
🔔 Subscribe to or Join our YouTube channel for daily video updates

image

Join the conversation and have your say on Thailand news published on The Thaiger.

Thaiger Talk is our new Thaiger Community where you can join the discussion on everything happening in Thailand right now.

Please note that articles are not posted to the forum instantly and can take up to 20 min before being visible. Click for more information and the Thaiger Talk Guidelines.

Archiving articles from the Phuket Gazette circa 1998 - 2017. View the Phuket Gazette online archive and Digital Gazette PDF Prints.

Follow Thaiger by email:

Phuket2 mins ago

Indonesian fisherman rescued after 9 days adrift at sea

Thailand36 mins ago

More than 100 cats rescued from owner

Coronavirus (Covid-19)51 mins ago

Tuesday Covid Update: Cumulative case count exceeds 200,000; provincial totals

Phuket Sandbox July 1st

days
hours
minutes
seconds

Thaiger is getting behind local businesses for the restart of tourism in July - up to 50% discounts across all advertising packages in June!

Sponsored by image

Thailand1 hour ago

Thai amulets come to blockchain, blessed by grandmaster of spells and charms

Thailand2 hours ago

Dogs from Thailand and more than 100 countries banned from US due to risk of rabies

Coronavirus (Covid-19)3 hours ago

Bangkok elderly can register for vaccine

Thailand3 hours ago

“Bubble and seal” method to contain outbreaks at factories, keep business afloat

Thailand3 hours ago

Good Morning Thailand | Samui quiet/flights/reopening, Thailand’s botched vaccine roll out

Coronavirus (Covid-19)3 hours ago

Thai government says vaccine rollout is going “according to plan”

Thailand4 hours ago

Taxi driver attacks woman at bus stop, has a history of violence

Coronavirus (Covid-19)4 hours ago

Vaccine registration website for expats back up after data leak

Politics4 hours ago

Thai PM ignores demands to step down, insists he’s going nowhere

Coronavirus (Covid-19)4 hours ago

First Thai Covid-19 vaccine proceeds to human trials

Crime5 hours ago

Police officers, prosecutors may be investigated over acquittal of Red Bull heir

Coronavirus (Covid-19)5 hours ago

Tuesday Covid Update: 3,000 new cases and 19 deaths

Thailand3 months ago

Thailand News Today | Thai Airways in rehab, All go for Songkran | March 4

Tourism3 months ago

Phuket’s nightlife. Yes, bars and clubs are still open | VIDEO

Phuket3 months ago

Thailand News Today | Covid passport talks, Thai Airways heads to court | March 2

Tourism4 months ago

Phuket Thai food treats you need to try | VIDEO

Thailand4 months ago

Thailand News Today | Bars, pubs and restaurants ‘sort of’ back to normal | Feb 23

Tourism4 months ago

In search of Cat & Dog Cafés in Phuket Town | VIDEO

Thailand5 months ago

Thailand News Today | Gambling crackdown, Seafood market to reopen, Vlogger challenge | Jan 21

Thailand5 months ago

Thailand News Today | Covid testing for visas, Business impact, Vaccine approval | January 19

Thailand5 months ago

Thailand News Today | Weekend Bangkok bombs, Thailand fires, Covid update | January 18

Thailand5 months ago

Thailand News Today | Stray car on runway, Indonesian quake, 300 baht tourist fee | January 15

Thailand5 months ago

Thailand News Today | Governor off respirator, sex-trafficking arrest, condo prices falling | January 14

Thailand5 months ago

Thailand News Today | Chinese vaccine, Thailand ‘drug hub’, Covid update | January 13

Thailand5 months ago

Thailand News Today | Bangkok may ease restrictions, Phuket bar curfew, Vaccine roll out | January 12

Thailand5 months ago

Thailand News Today | Covid latest, Cockfights closed down, Bryde’s Whale beached | January 11

Thailand5 months ago

Thailand News Today | Southern floods, Face mask fines, Thai Air Asia woes | January 8

Trending