The objective of this research work was to investigate the chemical composition and the insecticidal activity of Tranchyspermum ammi (Carom oil) against grain bugs originated in stored grains. In this study, essential oil of Tranchyspermum ammi is obtained by hydrodistillation using Clevenger apparatus. Thymol is a major chemical constituent isolated from Carom oil. Presence of thymol in Carom oil was determined and confirmed by GC, GC-MS and FT-IR analysis. Organoleptic and Physio-chemical properties of Carom oil were also analyzed. Apart from thymol, other compounds present in Carom oil were pcymene, γ-terpinene and β-pinene. 67.73 % of thymol was quantified in Carom oil.

A laboratory experiment was conducted to evaluate the efficacy of different biopesticides against the second instar larva of Helicoverpa armigera at International Crops Research Institute for the Semi-Arid Tropics during 2016-2017. Varied doses of biopesticides were used during experiment against second instar larvae of H. armigera and recorded the percent morality. Among the selected biopesticides neem seed powder, HaNPV and Spinosad showed superior and recorded maximum per cent morality at 24 hr and 48 hr day after release. The metarhizium anisopliae, Streptomyces sp. and consortia were at par with each other.

Fifty five accessions comprising both local and exotic clones were assessed for their resistance to field pest at Abarakata farm, CRIN. The accessions derived from Mambilla plateau, CRIN out-station, Taraba State were screened for resistance to infestation by leaf defoliators. Results revealed that there were significant differences among the accessions in terms of the number of holes on the leaf and plant damage both in the dry and raining season. On NGC15, NGC17, NGC19, C235, C357 tea clones recorded less number of holes and total damage of leaves and thus considered highly resistant to field insect pests. Based on the rating, clones NGC 8, NGC12, NGC14, NGC24, NGC27, NGC40, NGC41, NGC42,NGC49, NGC50,NGC51, C68, C270,C318, C359, C377 were significantly resistant to the insect infestations, while NGC18, NGC22, NGC23,NGC25, NGC26, NGC29, NGC35,NGC47, NGC48, NGC53, NGC54, NGC55, C61, C136, C143, C228, C236, C327, C353, C354, C369, C370 were moderately resistant. NGC13, NGC32, NGC37, NGC38, NGC45, NGC46, C56, C74, C108, C363, C367 and C368 were the most susceptible with the highest damage indices values (P<0.05). The range of each of the resistance indices measured in the susceptible clones in both dry and wet season were number of leaf damage (43-51)(37-46), number of leaf holes (18-19)(16-20).

A series of foraging bouts of Episyrphus balteatus (DeGeer) females were observed and recorded throughout the day in phacelia (Phacelia tanacetifolia Bentham) patches. The dominant transitions of interplant movement, approaching and probing bouts were statistically more frequent in the morning than in the afternoon. In the morning, interplant movement of foragers was significantly longer and they were moving at higher places of phacelia patches. They approached and probed flowers considerably longer in morning compared to afternoon. A significant positive relationship between the number of open flowers in a patch and the patch residence time was observed in the morning. The proportion of females having swollen abdomen filled with phacelia pollen (68.2%) in the afternoon was significantly higher than that (31.82%)in the morning. In our study, E. balteatus females spent more time foraging in phacelia patches in morning compared to afternoon. Based on the results and by considering the dual resources requirements of a female hoverfly (flower foraging and searching for aphids to lay eggs), we will discuss the effective diurnal foraging of E. balteatus females in phacelia patches.