Over the past few months I’ve been coming in at ten day intervals to take counts of pests. Each week something has changed and the display is really coming together nicely. Along side these changes I’ve also seen how remarkably quickly pests can spread. The mealybug have really gone to town and have established themselves on at least 12 species in the glasshouse and even more remarkably, a big population of aphids seemed to just appear on the red flowered species ‘Tiny mice‘ between my last sample and the previous one.
Whilst I’m quite happy to watch these events unfold and gather plenty of data on the pests, it’s probably not that good if I let them completely infest the display.
Therefore I have begun two minor experiments along side monitoring the pest numbers. Firstly I have released one adult and three larval harlequin ladybirds on to Cuphea ‘Tiny mice’ after Alastair and Justin kindly informed me of a supply on campus. The harlequin ladybird Harmonia axyridis is a controversial species due to it’s invasive nature in Britain. It was first discovered in the UK in 2004 after being introduced in Europe for commercial pest control and since then has been linked to the decrease in our native 2 and 7 spot ladybirds. In response to this I believe that by using the ladybirds in a controlled environment, the effect of any harlequins raised within the display on local native ladybirds will be limited. Also since they are here, I may as well use them for the reason they were introduced to Europe in the first place.
A late instar ladybird larvae
Secondly I’ve sprayed a selection of plants with something called SB plant invigorator spray that claims to leave no lasting residues and kills insects via physical means rather than chemical. I’ll be testing it’s effectiveness on whitefly and mealybug mostly. Here is the link to the instruction manual: http://www.fargro.co.uk/prodmanl/sbplantinvigorator-1106.pdf. It seems pretty legitimate but then again of course it would on the product manual. Before I began actually spraying the plants completely to remove pests I tested for scorching and so far there has been none. I’ll be doing this with every plant in the display eventually so that the spray can be used quickly when need’s be. 😀
Adult Harlequin munching on an aphid