The melon aphid Aphis gossypii is a severe pest of greenhouse cucumber, frequently developing extremely damaging populations consisting of several hundred individuals per leaf. This aphid has a short generation time and high fecundity and the presence of a moderate density population is sufficient to create leaf damage. Moreover, the honeydew produced by the aphids contaminates leaves and fruits so that plant growth decrease drastically resulting in a reduced yield.
Recently, some researchers showed that vermicomposts, which are produced by an interaction between earthworms and microorganisms, may enhance plant growth and resistance to some pests and diseases. Vermicompost has neutral pH, suitable structure and crumb, contains high population densities of beneficial organisms and has considerable aeration and water-holding capacity…. properties that make it a desirable alternative for peat and other potting media.
A recent paper by Razmjou et al showed that vermicompost is useful against aphids. Indeed, the application of vermicompost revealed a high potential for reducing A. gossypii populations in cucumber cultures. In particular, aphid numbers increase more slowly on cucumber plants growing in vermicompost-amended soil than on cucumbers growing in vermicompost-free soil. The resulting differences in the severity of infestations were substantial. Plants grown in soil containing 30% vermicompost harboured less than half as many aphids as plants grown in soil without vermicompost. Aphid populations were suppressed even more on plants grown in pots with 50% vermicompost, but at this concentration, vermicompost also had a negative effect on plant performance indices such as plant height, plant dry weight and chlorophyll content.
Previous studied showed that vermicomposts may decrease the population density of some pests such as peach potato aphid, Myzus persicae, the two-spotted spider mite Tetranychus urticae and mealy bug Pseudococcus spp. suggesting that facing pest bugs could be possible also avoiding a diffuse use of chemicals.
So… if you want to try, and most of all if you like earthworms or at at least, if you do not dislike them…. you have just to try and you will have a double gain: 1. fight aphid growth; 2. decompose and recycle the organic matter coming from your kitchen.
Razmjou, J., Vorburger, C., Mohammadi, M., & Hassanpour, M. (2012). Influence of vermicompost and cucumber cultivar on population growth of Aphis gossypii Glover Journal of Applied Entomology DOI: 10.1111/j.1439-0418.2012.01710.x