Seasonal Abundance and Population Flactuation of Certain Midicinal Plant Pests and Their Associated Natural Enemes in Assiut Governorate, Egypt

Abstract

Field trails were undertaken to determine the seasonal abundance and population fluctuations of key insect pests infesting caraway, cumin and chamomile plants. The most pests associated with these plants were Myzus persicae (Sulzer), Aphis craccivora Koch and Thrips tabace Lindeman. The most numerous pests on caraway plants were T. tabace. It constituted about 45.47% and 62.85% out of the grand total of pests in 2013 and 2014 seasons, respectively. Whereas M. persicae was the most dominant insect pest on cumin plants, constituting about 60.97% and 58.92% out of grand total of pests in first and second seasons, respectively. On chamomile crop M. persicae was the numerous pest as compared with the other insect pests (54.17% and 71.70%). The highest level of abundance was recorded during March and April. Temperature and relative humidity significantly affected the population densities of these pests. The dominant predators were Coccinella undecimpunctata Reiche, Scymnus interruptus Gaeze, Orius spp., Chrysoperla carnea [Stephens] Paedrus alfirri Kock, Syrphus corolla F. and true spiders. These predators attained their maximum population densities during February and March.

Features of optical properties of high stable CdTe photovoltaic absorber layer

“…In general, decrease in the transmittance of thin films is mainly related with the change of surface morphology, with the grain structure and with the defect density [44,45]. After annealing a decrease of the average transmission values (increase of absorption) can be due mainly by increasing in grain size [45][46]. We note that N. Kim [36] was shown, that laser annealing of CdTe layer resulted in an increase of grain size and a decrease of surface roughness.…”