Effect of Weather on Diamond Back Moth, Plutella xylostella (L.) (Lepidoptera: plutilidae) in District Haripur

Abstract

C auliflower, Brassica oleracea, belongs to family cruciferace which is a very diverse group comprises 350 genera and more than 3,500 cultivated and wild plants species (Warwick et al., 2003). Cau-liflower is basically a cool season vegetable having a temperature requirement for growth and heading is between 15°C and 20°C. Pakistan is among the top ten producing countries of this vegetable in the world (FAO, 2008). The production of Cauliflower has been reduced by several factors including insect pests such Abstract | Under unprotected condition study was carried out during the months from July to November in the year 2012 and 2013 to investigate population dynamics and observe the impact of temperature, relative humidity and rainfall on population of Plutella xylostella (L.) in Cauliflower, Brassica oleracea crop at District Haripur of Khyber Pakhtunkhwa. Field studies results showed that the population of P. xylostella gradually increased from mid of July where the population was 2.1 and 2.0 larvae and pupae per plant in the year 2012 and 2013 respectively. The population increased in September to highest number of larvae and pupae per plant (8.25 and 8.4) were recorded in the years 2012 and 2013 respectively. Then population declined from September to November 3.5 and 3.1 larvae and pupae was recorded per plant in both years as the lowest number. In the year 2012, mean maximum and minimum temp showed non-significant negative and positive association (r=-0.32 and 0.07) with population of P. xylostella respectively. Similarly R.H (r=0.89) exhibited positive highly significant whereas RF (r=-0.96) showed negative highly significant relationship with P. xylostella during the year 2012. Likewise, during the year 2013, mean maximum temperature showed non-significant negative relation (r=-0.21) whereas mean minimum temperature showed positive non-significant association with P. xylostella population. Mean relative humidity (RH) also exhibited non-significant positive association (r=0.06), while the population effectively influenced by total rainfall (r=-0.82) which exhibited highly significant negative association. Regression analysis showed 87-96% (R 2 ) variability due to weather parameters on the population dynamics of P. xylostella at District Haripur.

Seasonal incidence of diamondback moth (Plutella xylostella) (Lepidoptera: Plutellidae) and its parasitoids on cabbage

“…Higher incidence of the pest was observed during September and lower incidence during July at Peshawar in Pakistan (Ahmad et al 2015). Maximum temperature and RH had a positive influence and rainfall had a negative effect on population dynamics of the pest.…”

Effects of temperature, age and stage on testis development in diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

“…The diamondback moth (DBM), Plutella xylostella (L.) (Lepidoptera: Plutellidae) is one of the most serious pests of cruciferous vegetables, and among the most widely distributed. of all lepidopterans worldwide (Odhiambo et al, 2010;Silva & Furlong, 2012;Wei et al, 2013;Fu et al, 2014;Ahmad et al, 2018;Rahman et al, 2019). High pest densities in crops result mainly from insecticide resistance (Liu et al, 1981(Liu et al, , 1982Hama, 1987;Adachi & Fujitomi, 1995;Odhiambo et al, 2010;Li et al, 2016) and pest resurgence due.…”