Entomology

  • A Total of sixty six insects associated with maize was recorded. Out of them, only 14 insects were classified as major pest. Stem borer complex, White grubs, termites, Army worms cutworms, field cricket, Aphid red ant and tassel beetle have been recorded a major threat in field, and weevils and Angoumois grain moth are major problems in storage.

  • Maize stem borer (Chilo partellus, Swinhoe) recorded duration for eggs, larval, Pupal and entire life development were 13.2, 12.5, 12.7 and 13 0C respectively at optimum temperature 300 C. Similarly, stem borer completed 4-5 generation per year at Chitwan condition

  • The development of armyworm was (10-12, 34-52 and 15-29 days for egg, larval and pupal periods) respectively with 18.3-20.80C mean temperature. During the spring (March through April; mean temperature 32-33 0C), the egg, larval and pupal periods were 6-9, 19-22 and 7-13 days, respectively.

  • At Chitwan, early planting prior to 14th of May resulted in lighter borer infestation and less subsequent injury from the maize stem borer, than plantings later in the season.

  • For maize stem borer management, a commercial mixture of Chloropyriphos 50%and Cypermethrin 5% performed better as compare to Confidor 200SL and Furadan 3G whorl placement.

  • The efficacy of Army worm can be grouped as follows: cypermethrin> fenvalerate> deltamethrin> parathion-methyl> quinalphos> endosulfan.

  • Maize grains treated with 5% dust of malathion and 2-3 tables of Aluminium phosphide (Celphos) per metric ton found effective to protect against storage pests. In the case of botanicals, Bojho (20gm/Kg) found effective control to maize weevil, where the infestation was only 2.25% during the period of nine months of storage. Furthermore, Neem kernel seed powder @10 g/kg and timur @4g/kg of maize grain and Super grain bagĀ® was found free from storage insect pests up to 6 months.