10 th International Working Conference on Stored Product Protection 950 Julius-Kühn-Archiv, 425, 2010 Fluorescent non-toxic bait as a new method for black rat (Rattus rattus) monitoring Aulický, R.# 1 , Fraňková, M. 1,2 , Rödl, P. 3 , Eliášová, B. 2 , Frynta, D.* 2 , Stejskal, V. 1 1 Crop Research Institute, Drnovská 507, Prague 6, Czech Republic. 2 Departments of Zoology, Faculty of Science, Charles University, Viničná 7, Prague 2, Czech Republic. Email: frynta@centrum.cz 3 National Institute of Public Health, Šrobárova 48, Prague 10, Czech Republic * Corresponding author # Presenting author DOI: 10.5073/jka.2010.425.167.111 Abstract The detection of synathropic rodents may be difficult since they are animals with nocturnal activity. Methods of their detection and monitoring rely mostly on indirect signs of their activity such as the presence of faeces, urine, consumed foods and damaged materials. Our experimental hypothesis was that the production of fluorescent faeces - following consumption of fluorescent bait - may be used for rodent monitoring. For this purpose we studied the production of fluorescent faeces, temporal dynamics and detectability in wild black rat (Rattus rattus). Wild black rats were individually housed in experimental cages with the wire-mesh grid floor and faeces were collected in short-time intervals. The peak of fluorescent activity in faeces was detected 10-20 hours after bait ingestion. We found that there is only relatively short delay between bait consumption and defecation and fluorescent faeces are easily detectable at distance using an ultraviolet hand lamp. Thus, this method can contribute to effective monitoring of rodent pests. Keywords: Rattus rattus, Fluorescent bait, Monitoring, Rodent control 1. Introduction Black rat (Rattus rattus) belongs to the three most important rodent species which cause serious damages in agricultural and urban environment in Europe (Meyer et al., 1993). Rats are rodents with a nocturnal activity and most of the day is spent in hidden shelters or nests. They are good climbers, prefer dry areas above ground and are well know for their behavioural response to novel objects (neophobia) (Battersby et al., 2008), which complicates an effective control (Leung & Clark, 2005). Their presence is not easily detected by direct observation but rather according to the signs of their activity - faeces, urine, consumed foods or damaged material. Research is traditionally focused on trapping and poisoning (Shafi et al., 1992; Prakash et al., 2003, Selvaraj and Archunan, 2006). Nevertheless the precise knowledge of rodent spatial activity is also an important prerequisite for their effective control. Indirect monitoring of rodent movements was traditionally realised by administration of the marking substances into the bait and its subsequent detection in rodent bodies and tissues (Savarie et al., 1992). In the present study, we focused on a new method of monitoring rodent pests by non-toxic fluorescent bait. This bait enables detection of rodent movements via fluorescent faecal pellets without contact with the target animals. In laboratory test, we offered the bait to wild black rats and monitored temporal dynamics of production of fluorescent faeces. 2. Materials and methods Fluorescent bait- pellets were formulated by ICB Pharma Poland using encapsulation in a thermoset melamine (formaldehyde) sulphonamide resin complex. Orange fluorescence agent was composed from 2 fluorescent pigments: 2.0 % -orange and 0.4 % yellow (CIBA Specialty Chemicals). The experimental animals included wild black rat, Rattus rattus. Rats were kept solitary in cages with a wire mesh bottom. Standard food (ssniff, Germany) was removed from the feeders the day before experiment (20:00 h). The following day (at 16:00 h) 20 g of fluorescent pellets were offered to each rat. At 18:00 h fluorescent pellets were removed and replaced by standard pellets. All remaining fluorescent pellets and their fragments were collected and weighed; this enabled to estimate the amount (weight) of consumed fluorescent pellets.