Seasonal abundance of tea mosquito bug, Helopeltis antonii signoret infesting neem

Abstract

Seasonal abundance of tea mosquito bug, Helopeltis antonii infesting neem was studied at weekly intervals between May 2019 and April 2020 by direct counting at Forest College and Research Institute, Mettupalayam. After the northeast monsoon shower ceased, the population of tea mosquito bug started infesting neem during October-November, 2019. The bugs were active in neem until April, 2020 at varied levels of intensity and the pest population reached its peak during January, 2020. The highest number of tea mosquito bugs was recorded (9.60 per three terminal shoots per tree) during the third standard week of 2020 and the lowest numbers were recorded during 15 th standard week of 2020 (2.00 per three terminal shoots per tree). Wind velocity and maximum temperature (Tmax) were found to be negatively correlated with the population of tea mosquito bugs with the R-values of -0.632 and -0.493 and were found to be statistically significant at 1 per cent level. Rainfall and relative humidity were also found to be negatively correlated with r values of -0.159 and -0.086, respectively. Similarly, sunshine hours and evaporation rates were also negatively correlated with r values of -0.187 and -0.048, respectively. While, the minimum temperature (Tmin) was positively correlated with the population abundance of tea mosquito bug with the r value of 0.099.

Modelling of tea mosquito bug (Helopeltis theivora) incidence on neem tree: A zero inflated count data analysis

“…The graph (Fig. 2) indicates that Helopeltis theivora incidence is not normally distributed, which is a sign of zero count data (Kalloor et al, 2020). Though the data is characterised by zero count nature, Poisson and Negative Binomial models were fitted in this study to show its discrepancy in handling such data.…”

Occurrence of Tea Mosquito Bug Helopeltis antonii Signoret on Neem in Northern Karnataka

“…Likewise, Onkarappa (1993) reported H. antonii as a major sucking on pest on neem in southern parts of Karnataka. Thirumalaraj and Puttaswamy (2003) and Kalloor et al, (2020) studied the seasonal incidence of H. antonii on neem in southern Karnataka and Tamil Nadu, respectively. However, no reports are available on the occurrence of H. antonii on neem from northern Karnataka region.…”