Attraction factors for Paederus fuscipes ' dispersal, a vector of Paederus dermatitis towards human residential premises

Abstract

Paederus fuscipes, a vector of Paederus dermatitis in most tropical and subtropical countries of the world have a high prevalence in human dwellings due to their positively phototaxic behaviour which has caused a tremendous impact on human health. In this paper, P. fuscipes dispersal flights were studied for two seasons of the rice cultivation phases in residential premises built close to rice field areas (≈32-60 m and 164 m) in mainland Penang, Malaysia. We examined the effects of different light illuminance, building floor level and their association with rice stages as a focal cause of P. fuscipes dispersion from the rice fields towards human dwellings. The present study showed a significant interaction between different light illuminances and rice cultivation phases in attracting P. fuscipes to disperse and invade human dwellings. The highest number of P. fuscipes was captured near the bright light. P. fuscipes flights increased in line with each floor level, and the highest captures took place at higher building floor levels (levels 2 and 3) compared to lower building floor levels (ground floor and level 1) of a three storey apartment in both rice seasons. This finding not only conveys a better understanding on P. fuscipes dispersal pattern, but also draws public attention on the occurrence of dermatitis linearis caused by the Paederus beetles.

Figure 1. Attraction of Paederus fuscipes beetles towards three different light illuminances at the same ground/land floor level. Data were expressed in mean ± SE; bright light (n = 24), low light (n = 12), and no light (n = 24). Scale bars with the same letters showed no significant difference (Tukey's HSD; p > 0.05). 'No light' data were collected from H1 and H3 land houses. Whereas 'low light' data from H2 and ground floor apartment and 'bright light' data were collected from ground floor of apartment.

Figure 2. Attraction of Paederus fuscipes beetles towards different floor levels of a three storey apartment during (a) the main season and (b) the off season of the rice cultivation phases. Data were given in mean ± SE (n = 12). Scale bars with the same letters showed no significant difference (Tukey's HSD; p > 0.05).

Figure 3. Attraction of P. fuscipes beetles towards two different light illuminances at different floor levels of an apartment building during (a) the main season, and (b) the off season. The lowercase letter refers to the comparison between floor levels, whereas the uppercase letter refers to the comparison between two light illuminances on the dispersion of P. fuscipes. Scale bars with the same letters are not significantly different (Tukey's HSD; p > 0.05).