**5.3 Biological control methods**

Natural Biological control is the action of predators, parasitoids, pathogens and plant extracts in maintaining pest density. The natural enemies may help to reduce the sucking pest population from reaching the economic injury level in the Wheat. The aphid parasitoids in Pakistan have been reported by [128, 129]. In Pakistan, *Aphidius* sp. has been recorded parasitizing *S. graminum* attacking wheat crop [130]. *A. ervi* and *A. colemani* are reported by against wheat aphid [131], while *Diaeretiella rapae* reported by [126]. On wheat aphid parasitism rates started low, as the season progressed, the mean rate of parasitism increased [132].

In wheat, sucking pest populations are effectively restricted by adults and larvae of ladybird beetles, lacewing larvae and larvae of hoverflies. Predators are the parasitoids due to their broader host range and can feed on both egg and larvae stage of pests and also [129]. Coccinellids are the most abundant predator on wheat and cotton for the controlling of the aphid population [133]. *Coccinella septempunctata* is one of the most efficient predators of immature and adult aphids on wheat [134]. As the biological control agents, syrphid flies against *S. graminum* may provide a complementary management method [135]. One of the voracious predators of all the aphids exposed eggs and small nymphs are *Chrysoperla carnea* [136].

There are several botanicals derived from plant oils extracted from leaf and seeds have been used to control aphids in Pakistan. *Moringa oleifera* and *Eucalyptus oblique* leaves showed higher mortality of *S. avenae* [137]*. Azadirachta indica* seed kernel extracts to control *S. avenae* are effective as imidacloprid [138]. Abid [139] concluded that tobacco caused maximum mortality against all instars of *S. graminum* and *S. avenae* followed by neem, dhatura and onion. Iqbal et al. [140] treated the aphid by different botanicals, Orange Peel extract exhibited the maximum mortality of aphid followed by Garlic and Tobacco. *Azadirachta indica* and the entomopathogenic fungi *Beauveria bassiana* or *M. anisopliae* exhibited efficacy against *S. avenae* [126].
