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Detection of
predators within Brassica crops: A search for
predators of diamondback moth (Plutella xylostella)
and other important pests
Reza Hosseini1*, Otto
Schmidt2 and Michael A. Keller2
1Department
of Plant Protection, College of Agriculture, University of
Guilan, P. O. Box 41635-1314, Rasht, Iran.
2Discipline
of Plant and Food Science, School of Agriculture, Food and
Wine, Waite Campus, University of Adelaide,
SA 5005, Australia.
*Corresponding author. E-mail:
rhosseini@guilan.ac.ir
or
r_hosseini@yahoo.com.
Accepted 28 March, 2012 |
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Techniques based on the Polymerase Chain Reaction (PCR) have
been shown to be powerful tools for ecological studies of
predator-prey interactions. By using developed
species-specific primers from the cytochrome oxidase subunit
I (COI) gene for six insect pests of Brassica crops (Plutella
xylostella, Pieris rapae, Hellula hydralis,
Helicoverpa punctigera, Brevicoryne brassicae,
and Myzus persicae) trophic relationships of selected
predators and their prey in Brassica fields
demonstrated the potential of DNA-based techniques to screen
predator communities and to identify their prey. In this
investigation, all examined predators including Nabis
kinbergii (Heimptera: Nabidae), Oechalia
schellenbergii (Hemiptera: Pentatomidae), Micromus
tasmaniae (Neuroptera: Hemerobiidae), Hippodamia
variegata, Coccinella transversalis (Coleoptera:
Coccinellidae) and four wolf spider species including
Trochosa expolita, Venatrix pseudospeciosa,
Venator spenceri and Hogna kuyani (Araneae:
Lycosidae) showed polyphagy to some extent. All tested
positive for P. xylostella, hence can be considered
as predators of this pest. Although, the records of DNA from
the guts of predators probably represent instances of real
predation, but interpretation of predation data because of
some errors is very difficult. There are limitations for
this type of interpretation which has been comprehensively
discussed in this paper.
Key words:
Molecular markers, predator, gut contents, Brassica
crop, biological control. |
