Analysis of morphological traits in different host plants associated with resistance to Phenacoccus solenopsis- an invasive pest in Pakistan

摘要

Phenacoccus solenopsis?Tinsley (Pseudococcidae: Hemiptera) is a sucking insect pest and is polyphagous in nature. Twenty five (25) different host plants were screened against?P. solenopsis?and their physicomorphic traits were determined to correlate their role against pest population. Among?the?tested plant species, most favorable host plants of mealy bug on the basis of population were?Gossypiumhirsutum?(69.74±10.5),?Solamum?melongena?(62.41±10.0),?Helianthus?annuus(61.83±10.0),?Hibiscus rosa-sinensis?(61.1±10.0) and?Lantana camara?(55.83±9.75), but the least preferred plants were tandla?Digera?arvensis?(1.57±1.00) and?Conyzabonariensis?(3.83±1.75). Significant variations were observed in all the morphological plant characters recorded from different plant species. The maximum leaf thickness per plant was 2.04±0.23 μm in plant species?S.?melongena?while minimum thickness of leaf was recorded from lehli (0.25±0.02 μm). Maximum trichome density per plant was 444±72.4 in sunflower followed by 411.6±19.6, 399±52, 391.6±22.0, in?C.bonariensis,?Abelmoschus?esculentus?and?Withania?somnifera?respectively but minimum were 2.33±1.45 in?Chinopodium morale, followed by 2.66±1.4, and 3±2.08 inPortulaca?oleracea?and?Trianthema?portulacastrum?respectively. The maximum hair length per plant (2.62±0.07 mm) was of sunflower followed by 2.55±0.03 mm in okra, 2.53±0.06 mm in both?S.?melongena?and?G.?hirsutum. It was concluded that plant characters including trichome density and hair length favor mealy bug population showing r-values of 0.357* and 0.190 respectively but leaf size and leaf width (leaf area and leaf thickness) exerted negative effect on pest population showing r-values of -0.172 and -0.285 respectively.