Capsules containing entomopathogenic nematodes as a Trojan horse approach to control the western corn rootworm
Author(s)
Hibbard, Bruce Elliott
French, B. W.
Date issued
2012
In
Plant and Soil
Vol
1-2
No
358
From page
10
To page
24
Subjects
entomopathogenic nematodes heterorhabditis bacteriophora heterorabditidae western corn rootworm diabrotica virgifera virgifera chrysomelidae application technique biological control belowground pest management plant protection chrysomelidae larval injury gas-exchange parameters biological-control steinernema-carpocapsae entomogenous nematode host location neoaplectana-carpocapsae infected cadavers calcium alginate carbon-dioxide
Abstract
Aims The use of entomopathogenic nematodes in the biological control of soil insect pests is hampered by the costly and inadequate application techniques. As a possible solution we evaluated a nematode encapsulation approach that offers effective application and may possibly attract the pest by adding attractants to the capsule shell.
Methods Heterorhabditis bacteriophora nematodes, which show high virulence against the maize root pest Diabrotica virgifera virgifera, were encapsulated in a polysaccharide shell derived from the algae Laminaria ssp. Shells of varying thickness and composition were evaluated.
Results Nematodes readily survived the encapsulation process and were able, varying with shell thickness and temperature, to break through the shell and subsequently infect hosts. The added attractants and feeding stimulants to the shell attracted the pest larvae as much as maize roots. In field trials, encapsulated H. bacteriophora nematodes were more effective in controlling D. v. virgifera than those sprayed in water over the soil surface, but in these trials the addition of stimulants did not increase the control efficiency.
Conclusions The study demonstrates that nematodes can be successfully applied in capsules in the field. Further improvements are needed to make the capsules a cost effective alternative to conventional field application of nematodes.
Methods Heterorhabditis bacteriophora nematodes, which show high virulence against the maize root pest Diabrotica virgifera virgifera, were encapsulated in a polysaccharide shell derived from the algae Laminaria ssp. Shells of varying thickness and composition were evaluated.
Results Nematodes readily survived the encapsulation process and were able, varying with shell thickness and temperature, to break through the shell and subsequently infect hosts. The added attractants and feeding stimulants to the shell attracted the pest larvae as much as maize roots. In field trials, encapsulated H. bacteriophora nematodes were more effective in controlling D. v. virgifera than those sprayed in water over the soil surface, but in these trials the addition of stimulants did not increase the control efficiency.
Conclusions The study demonstrates that nematodes can be successfully applied in capsules in the field. Further improvements are needed to make the capsules a cost effective alternative to conventional field application of nematodes.
Publication type
journal article