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This study investigated the magnitude of wet weather overflow (WWO)-driven sewage pollution in an urban lake (Lake Parramatta) located in Sydney, New South Wales, Australia. Water samples were collected during a dry weather period and after two storm events, and tested for a range of novel and established sewage- [ Bacteroides HF183, crAssphage CPQ_056 and pepper mild mottle virus (PMMoV)] and animal feces-associated ( Bacteroides BacCan-UCD, cowM2 and Helicobacter spp. associated GFD) microbial source tracking marker genes along with the enumeration of culturable fecal indicator bacteria (FIB), namely Escherichia coli ( E. coli) and Enterococcus spp. The magnitude of general and source-specific fecal pollution was low in water samples collected during dry weather compared to storm events. The levels of HF183, crAssphage and PMMoV in water samples collected during storm events were as high as 6.39, 6.33 and 5.27 log 10 GC/L of water, respectively. Moderate to strong positive correlations were observed among the quantitative occurrence of sewage-associated marker genes. The concentrations of HF183 and PMMoV in most storm water samples exceeded the risk benchmark threshold values established in the literature for primary contact recreators. None of the samples tested was positive for the cowM2 (cow) marker gene, while BacCan-UCD (dog) and GFD (avian) animal-associated markers were sporadically detected in water samples collected from both dry weather and storm events. Based on the results, the ongoing advice that swimming should be avoided for several days after storm events appears appropriate. Further research to determine the decay rates of sewage-associated marker genes in relation to each other and enteric viruses would help refine current advice. Microbial source tracking approaches employed in this study provided insights into sources of contamination over currently used FIB.

Feeding preference tests confirm the existence of an induced food plant preference in Carausius morosus (Br.) in dual and multiple choice tests. The preference appears to be induced between the ages of 10 and 20 days and remains at a very high level for the remainder of the insect's life span. A statistical test of concordance indicates that there is less flexibility in the food plant choice of older animals. Preferences can be rapidly modified through feeding on a second food plant and age differences are apparent throughout the study. Jermy et al. (1968) postulated three possible mechanisms by which phytophagous insects might modify their dietary range within one ontogenetic phase. One of these is the induction of a specific food plant preference. It has been shown that prior feeding can affect food plant choice (Hovanitz & Chang, 1962;Freeland, 1975) and the induction of a food preference has been reported among others by Stride & Straatman (1962), Jermy et al. (1968), Wiklund (1973 and Phillips (1977).Carausius morosus (Br.) is a polyphagous insect consuming a wide variety of plant material under laboratory conditions (Korting, 1934;Meissner, 1909). Its feeding habits and host plants in the wild state are unknown. The following study looks at induction of feeding preferences in this species and the way in which the induction manifests itself in different age categories. MATERIALS AND METHODSIn order to measure food preference, the leaf disc test (Jermy, 1961) was employed. Food plant discs were cut from fresh leaves of plants obtained locally, the leaves being of equivalent condition. Food plants used for rearing were rose (Rosa canina), privet (Ligustrum vulgare), bramble (Rubus fruticosus), ivy (Hedera helix) and lilac (Syringa vulgaris).These provided a wide variety of plant types and two distinct taxonomic. divisions, bramble and rose belonging to the Rosaceae, and privet and lilac to the Oleaceae.Six food plant discs were cut out and pinned to the wax base of a perspex container ranging from 9 to 18 cm in diameter, depending on the size of the insect. Moist filter paper was used as a humidity control with discs being pinned at a height of 2.5 cm. Early results indicated a high level of individual variability in feeding