In newly reclaimed areas of the Arab Republic of Egypt, Tropinota squalida Scop. attack both fruit trees and field crops. And considered as the most district to agriculture. During the last decades the population of Tropinota squalida Scop. tend to increase thus cause great damage to various plantations. The following points were considered to govern the changes in the population density of this insect pest. Data obtainec during the course of the present study indicate that broad bean is more suitable and attractive than the other hosts to adults of T squalida while lupine, wild mustard, wheat, navel orange, pear are less attractive. Also, the highest average percentage of infestation of wild mustard and broad bean flowers were more than that of the adult hosts. Lupine, wheat, navel orange, pear and apple were showed as the less percentage of infestation. The results dear also that, all flower colours of tested plants affected markedly the daily activity of adults. The average number of adults per m² counted on plants between 12-2 p.m. was used as indicator for daily activity. The role of flower colours expressed as number of beetles, yellow (wild mustard) flowers were seem to be more attractive for adults than white flowers (wheat, lupine, pear, navel orange) and rose coloured flowers (apple) during the years of study 1994, 1995 and 1996. For 1997 the case was the other day round and white coloured broad bean flowers and lupine were more attractive than yellow coloured flowers of wild mustard. Generally, colour of flowers seems govern adults attraction to a great extent. Field experiments were also carried out by testing 5 colours blue, white, yellow, red and green of pan water traps placed in an experimental area under canola plants. Pan blue water traps proved to be the best colour for attracting the beetles either for monitoring or to control the insect.