Abstract:
The roving survey was conducted to document the seasonal incidence of insect pests of mango, guava and sapota in the Thandrampattu block of Tiruvannamalai District. During the survey on mango, it was observed pests like mango leaf hopper (Idioscopus niveoparsus), mango gall midge (Procontarinia pustulate) and mango leaf twisting weevil (Apoderus tranquebaricus). In sapota, leaf webber (Nephopteryx eugraphella), bud worm (Anarsia epotias) were seen. In Guava, tea mosquito bug (Helopeltis antonii) and mealy bug (Ferrisia virgata) were seen. The incidence of mango leaf hopper was seen higher during the 14th Standard Mean Week (SMW) with 48 percent while the minimum during the 28th SMW with 22 percent. The incidence of leaf gall was maximum during the 28th SMW with 44 percent while the minimum was seen during the 14th SMW with 28.0 percent. The incidence of mango leaf twisting weevil was seen high during the 20th SMW at 65 percent while the minimum incidence was recorded during 14th the SMW at 37 percent with 7 numbers. Considering the natural enemies, the incidence of lady bird beetle per tree was found high during the 20th SMW per plant while the minimum was seen during the 22nd SMW with 4 numbers per tree. Leaf gall and leaf twisting weevil incidence were positively correlated with maximum temperature, minimum temperature, relative humidity and wind speed and negatively correlated with rainfall while the hoppers were negatively correlated with minimum temperature, relative humidity and rainfall. In sapota, the incidence of sapota leafwebber damage was seen high during the 14th SMW with 26 percent while the minimum was recorded during 18th SMW at 18 per cent. The incidence of sapota budworm was high during 24th SMW with 42 percent while the minimum was recorded during the 22nd SMW with 8 percent. Incidence of ladybird beetle was found high during the 16th and 28th week with 7 numbers each per plant respectively while the minimum was seen during the 22th week with 4 number per plant. The incidence of spiders was seen high during 26th and 30th MSW with 9 numbers per plant respectively while the minimum was recorded during the 14th and 18th SMW with 4 numbers per plant respectively. In sapota, leaf webber was positively correlated with maximum temperature, minimum temperature, relative humidity and wind speed and negatively correlated with rain fall while the budworm was negatively correlated with minimum temperature, relative humidity and rainfall. In guava, the incidence of tea mosquito bug was high during the 14th MSW at 40 per cent while the minimum was recorded during 16th MSW at 23 percent. The incidence of mealybug was high during 28th MSW with 30 per cent while the minimum was recorded during the 14th and 16th MSW with 14 percent. The mean incidence of lady bird beetle was high during 20th MSW with 9 numbers per plant while the minimum was recorded during the 22nd and 30th SMW with 2 numbers per plant respectively. The mean incidence of spiders was seen higher during 16th SMW with 9 while the minimum was recorded during the 22nd and 26th SMW with 3 per plant. Guava tea mosquito bug was positively correlated only with wind speed and negatively correlated with maximum temperature, minimum temperature, relative humidity and rainfall whereas the mealybug incidence was positively correlated with maximum temperature, minimum temperature and relative humidity and negative correlation with wind speed and rainfall.