Preliminary Study on the Damage and Occurence Regularity of Desmidophorus hebes Fabricius on Mallow Plants (Malvaceae)

Purpose In order to understand the mallow plants species which were damaged by Desmidophorus hebes Fabricius and its epidemic, harm and habits in Xishuangbanna Tropical Botanical Garden.

Method We made long-term observations of the damages of D. hebes on Malvaceae shrub and analyzed the relationship between the D. hebes population dynamics and meteorological factors.

Result D. hebes preferred to feed on woody tissues, buds, flowers and leaves from genera such as Hibiscus, Malvaviscus, Abelmoschus, Kydia, Bombycidendron, and Urena, resulting in a decline of plant growth and low ornamental value. Significant differences of feeding height on different host plant were discovered (P<0.05), but the upper parts of the host plants were harmed at most. The main harmful period occurred from April to October, with two harmful peaks at the end of May and mid-July. The daily population dynamics showed a negative correlation with temperature increase and positive correlation with humidity increase. The correlation analysis of population dynamics and meteorological factor showed that D. hebes population dynamic with the ten-day-sunshine was negative correlation, but positive correlation with average temperature, maximum temperature, minimum temperature, relative humidity, rainfall of ten days, and extreme significance (P<0.01) between population dynamics of D. hebes and average temperature of ten days, and significant correlation (P<0.05) with average temperature, relative humidity of ten days. Principal component analysis (PCA) showed that the average, maximum and minimum temperature of ten days were the main meteorological factors affected the population dynamics of the D. hebes.

Conclusion This study provided a reference for the prevention of damages of D. hebes by localizing damaged areas on the plants and by showing how weather patterns can affect growth of the weevil population.