169enemies, and ultimately impact the efficacy of any IPM system (Tilman and Knops
1997 ; Harwood et al. 2009 ). However, implementation of this strategy will be dif-
ficult and intricate in dryland cropping systems on a large scale or including the
surrounding landscape such as pasture cropping (Jones 1999 ; Schellhorn et al.
2008 ). Undisturbed strips of grassy non-crop intercropped with major crops will
provide a habitat conducive to the multiplication of natural enemies and enhance
pest control in the crop (Collins et al. 2003 ; Macleod et al. 2004 ; Tsitsilas et al.
2011 ).
5.5.6 Conservation Biological Control
Biological control describes the exploitation of predators, parasites and pathogens
for pest control. It is considered ecofriendly, self-perpetuating once established,
environmentally safe, target specific and best-fit in an IPM program (Dhaliwal and
Arora 2003 ; Pedigo 2003 ; van Emden 2003 ; Dhaliwal and Koul 2007 ; Jonsson et al.
2008 ; Pedigo and Rice 2009 ). It plays an indispensable role in controlling insect
pests in economic crops, fruit orchards, vegetables, ornamental plants and fodder/
pasture in any cropping system. Dryland cropping systems need to: (1) recognize
the values of natural enemies at the farm level; (2) investigate their effectiveness and
abundance in different dryland zones and prevailing seasons; (3) explore the limit-
ing biotic/abiotic factors involved in the failure of a biocontrol system; (4) deter-
mine and standardize the techniques for the collection, mass propagation, release
and conservation of indigenous biocontrol natural enemies, and (5) import and
manipulate exotic natural enemies (van Emden 2003 ; Jonsson et al. 2008 ). The
abundance and performance of natural enemies in any cropping system are regu-
lated by the conservation of floral diversity, modification and manipulation of habi-
tat, maintenance of diversity outside and/or inside the major crop fields planned for
biological control, integration and implementation of IPM tactics highly conducive
and compatible with biological control, and conservation of the natural enemies/
pest ratio through manipulation and augmentation techniques (van Emden 2003 ;
Jonsson et al. 2008 ). Habitat modification with diversified flowering species or arti-
ficial diets supports the abundance and performance of natural enemies, specifically
parasitoids. The female parasitoid, Pimpla examinator (F.) of the pine shoot moth,
Rhyacionia buoliana (S.) is not attracted to pine oil fragrance until the female has
fed on floral nectar to mature the eggs. Once the female parasitoid has fed and
matured the eggs, the female is attracted to the pine oil smell and locates the host
moth (Thorpe and Caudle 1938 ; van Emden 2003 ; Jonsson et al. 2008 ). Sometimes,
parasitizing and predatory stage(s) of parasitoids and predators, respectively, do not
synchronize with the host/prey stage or food is scarce (for host or prey). In these
conditions, the provision of obligatory or other alternate host/prey guarantees the
conservation of natural enemies (Hardy 1938 ; van Emden 2003 ; Jonsson et al.
2008 ). For example, emergence of the larval parasitoid (Diadegma fenestralis H.) of
the diamondback moth (Plutella xylostella L.) in autumn does not synchronize with
the presence of larval stages of the host (available in autumn in pupal stages) and
Insect-Pests in Dryland Agriculture and their Integrated Management