Third Pest Surveillance 03-March-2021

Today at around 10 AM, a week after our second pest surveillance, we performed our third pest surveillance. In the past few days, we felt a gradual increase in temperature here in the Lobesa area. Marked by some light rains, the sky has been partly cloudy most of the time with light showers on two occasions (Saturday and Sunday). However, with the gradual increase in temperature, there has been a noticeable increase in relative humidity too. It was partly cloudy today, with high humidity at around 89% and the temperature from the installed thermometer on the field was 18° Celsius. We learned that our field was 200 Meter square big. The cauliflower seedlings have matured significantly.

Considering the change in weather, we decided to perform a blitz survey today. After a thorough inspection, we found more than twenty aphid’s colony, almost all the colonies were feeding on young shoots (new growths). The population density of each colony was more than 60 aphids and consequently, there were about 64 adult ladybugs in the field. We also noticed few plants with stunted growth and rapid wilting symptoms, upon digging the root part we found heavy red ant infestation. These ants were easy to diagnose because of their reddish-brown colour. They were reported to feed on seedling roots of cole crops. (NPPC, 2017). As reported earlier we noticed felled plant parts on many beds, as suspected these were obvious damages of cutworms. We found cutworms on many beds, even though the researcher has been collecting cutworms every morning.

References: National Plant Protection Center.(2017). Pests of Bhutan. http://pestsofbhutan.nppc.gov.bt/