Studies on population dynamics and management of flat headed borer, Sphenoptera dadkhani obenberger in Punjab

Flat headed borer, Sphenoptera dadkhani Obenberger damage was noticed on 5-year old trees of peach whereas no incidence was visible on trees upto 4 years. The peach trees (irrespective of cultivars) were highly susceptible (70.6–81.6%) followed by plum (8.7–12.6%) and pear (0–2.7%). Other fruit crops were not found to have flat headed borer damage. The population dynamics based on the fresh exit holes and adult emergence showed that maximum exit holes were in the month of June (18.2/m) followed by May (15.8), July (14.5), October (13.7) and September (11.0), while the maximum adult emergence was recorded in the month of May (9.3/m) followed by April (5.4) though the pest was active from March to November. The maximum activity of the pest occurred at temperature from 32 to 39°C with relative humidity <50 percent and sunshine > 9 hrs/day. The efficacy of insecticides, viz. chlorpyriphos and lindane each @ 0.04 percent revealed that three applications (February-June-October each year) had remarkable reduction of S.dadkhani damage with respect to fresh exit holes (9.0/m to nil) after 4 applications. Similarly, two applications of these insecticides made during June and October every year reduced the pest incidence significantly compared to either single application (February, June and October) or two applications during February-June or February-October. The results further indicated that the continuation of insecticidal application over the years could reduce the frequency of spray.