Contents - Faperta

17
Molecular Markers for Diagnosis of Insect Pests
and Their Natural Enemies
Introduction
Many insect and mite species possess an astounding potential to cause damage in fi eld crops
and storage. For developing appropriate management strategies, it is important to have a
correct identifi cation of the pest species. Correct taxonomic identifi cation is also important
for import and export of plant material and food grains to implement appropriate quarantine
procedures. Quarantine measures are critical to prevent or delay the introduction of
exotic pests into newer areas. Identifi cation of insect pests of quarantine importance has
primarily relied on morphological characters of adult life stages. However, intercepted specimens
often are not in the adult stage and may be damaged, which seriously handicaps correct
identifi cation. The molecular tools now enable precise and rapid identifi cation of insect pests
irrespective of the developmental stage and condition of the samples. The modern tools of
biotechnology can be used for detection and identifi cation of insect pests, insect biotypes,
and understand genetic diversity, population structure, tritrophic interactions, and insect
plant relationships (Caterino, Cho, and Sperling, 2000; Heckel, 2003). Molecular markers can
also be used to gain a basic understanding of insect metabolism, development, interaction
with the environment, and for developing sound strategies for pest management. Molecular
techniques have also been found to be useful for studying insect phylogeny and predatorprey
relationships (Hillis, Martiz, and Noble, 1996; Crampton, Beard, and Louis, 1997;
Osborne, Loxadale, and Woiwod, 2002; Hoy, 2003). Molecular tools also enable genetic characterization
of specifi c attributes of an organism, and if combined with a high-throughput
technology such as microarrays, they are ideally suited for rapid molecular screening.
Molecular diagnostics will play a vital role in detection and identifi cation of insect pests.
Common molecular techniques that can be used for detection of insect pests include:
• Hydrocarbons for species recognition;
•
Secondary metabolites;