Red Spider Mite Sachets

Answered by Harrod Horticultural Posted in Category Pest Control & Nature

Dear Martin

Last year I purchased from you sachets containing the predatory mite for outdoor use in order to treat my Leylandii hedge from an infestation of red spider mite, but I notice from this year's catalogue you are only offering sachets for indoor use.
 
It is hard to tell how effective the treatment  has been, it certainly has not eliminated them completely, but I feel there has been a reduction in their numbers, this might be due to the severe winter weather.
 
It puzzles me just how the treatment works as there is no suggestion in the instructions that the sachets should be opened after hanging them from branches.
 
I'm wondering whether it would be of any use my purchasing these indoor predators for use outdoors during the summer months?
 
Kind Regards
 
Geoffrey

Dear Geoffrey

Many thanks for your spider mite-based enquiry and it’s good to hear that – for whatever reason – the population of these infamous pests of both the garden and greenhouse took a hit last year.   It is very difficult to accurately record just how effective biological pest control treatments can be, not least because nature has a way of moving the goalposts! Obviously we can follow the manufacturer’s advice with regard to the application or introduction timing and location in the crop of the predators but once the – in this case – predatory Amblyseius andersoni mites are in position, it’s up to them!   Weather conditions, environmental factors and a great many other differentials can all come into play which affect the success of the predators but having said that, these methods and the feeding habits of the predators are proven in laboratory and commercial conditions and it’s beyond question that they are successful and efficient predators of the pest!
Onto the best practice for using the sachets and hopefully the following explanation will help.

These particularly sachets work on a controlled release system and each sachet is divided into two compartments which support and maintain a breeding colony of predatory mites. As the colony and population expands, mites will gradually leave the sachets via tiny emergence holes on the inside (unprinted side) of the sachets.   As you are probably aware from your previous experience of using the product last year, each sachet is designed to ‘hang’ over a branch, leaf stem or support wire to create an inverted ‘V’ shape with the branded face outwards, protecting the sides from which the mites emerge from direct sunlight and rainwater. The controlled rate of release gives much more effective pest control results than an instant ‘hit’ of predators and the total numbers of mite released is also much higher; another advantage is that the sachets can be placed in the crop or hedge, in your case, before the spider mites are present in  any great numbers. This stops the pest gaining a foothold in or on the plants before a predator arrives. Finally, onto the range of Spider Mite Killer Sachets we are carrying this year.

You’re completely correct that in our main 116-page catalogue only the indoor sachets are featured but you’ll be pleased to hear that this was a deliberate ploy for the first catalogue of the year and that in our Easter/May catalogue, both the indoor and outdoor Spider Mite Killer will be available. 

I hope this information answers all your questions and gives you even more of an insight into how this particular fascinating form of natural pest control operates; many thanks once again for your enquiry and the best of luck with your spider mite control and garden in general this year.

Martin