Insect pests of a winter cereal crop
1987
Kanok Uraisakun | Arun Satthikun
Survey of the insect pests present on wheat, a winter cereal was made. The insects were collected from 1 rai (1600 Sg. m.) of wheat (var. SONORA 64) divided into 60 sub plots (4x5 sq. m.) from Nov. 1985 to Feb. 1986. Samples were collected each week using a long handled sweep net. The period of collection covered from seedling to maturity of the wheat plant. Eleven orders of insects were indentified. These were classified into three groups (i) insect pests, (ii) natural enemies, (iii) free living insects. (i) Insect pests. Most of these were piercing sucking bugs eg: aphids, plant-hoppers, Leaf hoppers thrips and some species of sucking bugs, caterpillars, beetle and short horn grass hoppers. (ii) Natural enemies These were the predatory bug: Geocoris sp and the reduviio bug, ground beetle, aphid eating beetle and many predatory hemipteran. The population density of the sucking insects was large during the tillering, elongation and booting stages of the wheat development. Initialy the population density of natural enemies was small, but by the 8th week (during flowering stage of the wheat) the population density of natural enemies had increased to outnumber that of the pests. Thus by the end of the survey period, the natural enemies could reduce the insect pests.
显示更多 [+] 显示较少 [-]