The effectiveness of 2 traps for Queensland fruit fly, Bactrocera rryoni was compared for 1 year amongst relatively low populations at Applethorpe-Stanthorpe in southeast Queensland. The Lynfield trap which is an inexpensive, non-sticky, pot-type trap was significantly more effective than the Jackson trap and was at least as reliable in the detection of fruit fly populations. Use of Lynfield traps in quarantine surveillance programs should allow for a greater trap density and a more sensitive detection system to be established without vastly increased operational costs.

Standardized levels of infestation of sorghum midge Contarinia sorghicola Coquillet were used to compare the levels of resistance in sorghum cultivars (Sorghum bicolor) in glasshouse experiments at Biloela in Central Queensland. Sorghum heads were reduced to 250 florets and ten female midges were caged over each head on three consecutive days during anthesis. Two breeding lines from the U.S.A., IS 12608C and IS 12664C were superior (P < 0.01) to Alpha and KS 19 in percentage seed set and number of midge progeny produced. The percentage seed set was 50, 54, 22, 12 for IS 12608C, IS 1664C, Alpha and KS 19, respectively. The Indian line Q 13828 was susceptible. Testing with a standardized level of infestation is a useful technique for screening parents in a breeding program aimed at incorporation of midge resistance into agronomically useful hybrid cultivars.

Diurnal oviposition activity and preference for panicles at various stages of anthesis by female sorghum midge, Contarinia sorghicolu. were investigated on grain sorghum in central and southern Queensland during I98 1-82. Peak activity was recorded between 0800 h and I 100 h, the time of maximum midge numbers being slightly modified by daily temperature. Ovipositing midges preferred panicles at mid-anthesis, while panicles prior to and finishing anthesis were the least attractive. We define criteria for optimum pest population assessment.Adults of the sorghum midge, Contarinia sorghicola (Coquillett) a major pest of sorghum, oviposit in flowering spi kelets and larval development occurs at the expense of the developing sorghum ovaries. Pupation occurs within the aborted spikelets and adults emerge early in the morning during warm weather but later in the day in cooler weather (Dean 191 I). Adult females usually live only 10-12 h and rarely more than 24 h (Walter 1941: Harris 1961. Oviposition occurs soon after emergence.In order to assess the population of sorghum midge attacking a sorghum crop, it is first necessary to know how oviposition varies with time of day and stage of anthesis. Fisher d a/. (1982) reported that peak ovipositional activity usually occurred during mid-late morning although daily midge activity patterns varied according to temperature. Summers (1 975) however, observed that peak ovipositional activity occurred between noon and mid-afternoon. Nocturnal ovipositional activity has been recorded as being nil or negligible by all researchers. Barrow (1974) found that during peak activity, panicles exposed in the 50% red and 50% yellow bloom stage attracted the highest midge number.

The mean duration of the egg stage of Austroasca viridigrisea on lucerne, at constant temperatures ranged from 19.1 ? 0.1 d at 20.0"C to 6.4 ? 0.1 d at 32' C and that of nymphs from 28.4 ? 0.5 d at I8 -C to 8.8 d at 28.9'C. The threshold temperature for egg development was 12.9'C (10.8 to I 5 . 0 T ) and that of nymphs 13.3'C (10.6 to l5.9T); 1 14 and 144 day-degrees were required for egg and nymphal development respectively. Time of development for eggs calculated from these data agreed well with observed times under ambient conditions. Survival from egg to adult was generally high (0.80) at intermediate temperatures but was reduced at high (34.4'C) and low (20°C) temperature. The mean total fecundity of mated females over an 8 w observation interval was 54.7 f 7.0 eggs on lucerne and 1 16.7 f 13.5 on potato. On lucerne most eggs were laid in petioles with few in leaves and stems. On potatoes all above ground tissues appeared suitable.Data on the development of immatures at 27°C constant and adults at 20.7 to 29.8'C ambient on lucerne gave a finite rate of increase (A) of 1.89 per week and a net reproduction rate (R,) of 29.15.

We evaluated the short-term effects on earthworms of sidedressing solid dairy cattle manure on corn. The manure rates were 40, 46 and 53 t/ha applied in 1991, and a control (no manure). From 1988 to 1990, the manure plots received solid dairy cattle manure sidedressed at an annual rate of 40 to 50 t/ha, the equivalent of 100 kg N/ha, while the control received a standard mineral fertilization. The experiment took place at the MAPAQ experimental station in St.-Lambert, Quebec, Canada. Sampling occurred in autumn 1991 and spring 1992.Sidedressing solid dairy cattle manure in spring increased earthworm populations compared with the control in fall 1991, but no significant population differences were observed among the three different manure treatments, which were then pooled for further statistical analysis. In spring 1992, the populations declined, at which time the manure treatment and the control did not differ significantly in abundance, but total earthworm biomass and Lumbricus biomass were significantly higher in the manure treatment. Cocoon production showed significant differences between treatments, which provides evidence for the potential effect of manure sidedressing on earthworm population dynamics. Although the genusAporrectodea(endogeic) was dominant among the treatments, sidedressing of solid dairy cattle manure also stimulatedLumbricuspopulations, especially juveniles and adult L terrestris (epianecic).