Potential value of the fibre nettle Urtica dioica as a resource for the nettle aphid Microlophium carnosum and its insect and fungal natural enemies

Abstract

The perennial stinging nettle (Urtica dioica L.) is a wild plant that provides resources for aphid natural enemies and can therefore benefit crop protection. Stinging nettles producing approximately three times more fibre than Standard nettles are under commercial development for fibre production. Here we assess the relative value of Austrian Clone 2, a high fibre nettle variety, as a resource for the nettle aphid Microlophium carnosum (Buckton) and its associated natural enemies. The intrinsic rate of increase of M. carnosum cultured on Clone 2 was not different to that on a Standard nettle nor was there an effect of nettle variety on the susceptibility of this aphid to the entomopathogenic fungus Pandora neoaphidis (Remaudière and Hennebert) Humber. The development time of the aphidophagous predator Chrysoperla carnea (Stephens) was not affected by the nettle variety on which M. carnosum was cultured whilst the parasitoid Aphidius ervi (Haliday) fed on honeydew produced by M. carnosum infesting both varieties of nettle. Fibre nettle Clone 2 is therefore able to support non-pest aphids and their natural enemies and, if grown widely in the future, may be useful within conservation biological control and a tool within integrated pest management.

Nettle, a Long-Known Fiber Plant with New Perspectives

“…The promotion of natural enemies of potential pest species is linked with the hosting of Microlophium carnosum, an aphid serving as a diversion or alternative prey for many predators present on nearby infested crops [134]. In addition, a plantation of a nettle clone selected for its fiber content was shown to be able to support this aphid species and thus promote its natural enemies [135]. Aphids hosted by nettle can be a food source that can attract aphidophagous or parasitoid insects [133].…”

Organic Control Strategies for Use in IPM of Invertebrate Pests in Apple and Pear Orchards

“…Populations of nettle aphids increase from late April [108], and provide a resource for biocontrol agents to establish during the period in which cultural control practices delay the expansion of aphid colonies on trees. Over 100 insect species have been identified on the common nettle, U. dioica L., including ladybirds, lacewings, hoverflies and parasitoids [109]. Ladybirds are generalist predators common in both commercial crops and wild habitats and are less prevalent in conventional than in organic apple [110].…”

Peran Tumbuhan Berbunga Sebagai Media Konservasi Artropoda Musuh Alami (The Role of Flowering Plants in Conserving Arthropod Natural Enemies)

“…Beetle banks adalah tumbuhan berbunga atau rumputrumputan yang ditanam di rumah kaca atau rumah plastik sebagai sumber pakan dan inang alternatif bagi musuh alami dan bertujuan untuk menjaga agar populasi hama pada tanaman utama tetap rendah. Beaverstool et al (2011) melaporkan bahwa kehadiran tumbuhan "fibre neetle" Clotica dioica sebagai tumbuhan penyeling (intercrop) ternyata mampu menjadi pengganti tanaman utama, dan menunjang baik afid herbivora Microlophium carnosum maupun musuh alaminya.…”