Fumigant Toxicity and Sublethal Effects of Artemisia khorassanica and Artemisia sieberi on Sitotroga cerealella (Lepidoptera: Gelechiidae).

Fumigant toxicity and sublethal effects of essential oils from Artemisia khorassanica Podl. and Artemisia sieberi Bess were investigated against adults of Sitotroga cerealella Olivier. To assess the sublethal effects, adult moths were exposed to the LC30 of each essential oil, and life table parameters of the surviving S. cerealella were studied. Higher fumigant toxicity of A. khorassanica (LC50: 7.38 µl/liter air) than A. sieberi (LC50: 9.26 µl/liter air) was observed against S. cerealella. Also, the insecticidal effects of A. khorassanica (LT50: 9.01 h) were faster than A. sieberi (LT50: 14.37 h). A significant extension was observed in the developmental time (egg to adult) of S. cerealella treated with the essential oils. In addition, fecundity of S. cerealella reduced by 25.29 and 35.78% following exposure to sublethal concentrations of A. sieberi and A. khorassanica, respectively. Both tested essential oils caused a significant reduction in the gross and net reproductive rates, intrinsic rate of increase (rm), and finite rate of increase of S. cerealella. The rm values following exposure to A. sieberi, A. khorassanica, and control were 0.098, 0.094, and 0.107 d-1, respectively. The results of this study suggest that tested essential oils have a good potential to apply in integrated pest management of S. cerealella.

Feeding performance and life table parameters of Khapra Beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) on various barley cultivars.

The Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), is a common pest of cereal grains and other stored products. In this study, the effects of ten barley cultivars (Abidar, Bahman, Line20, Line22, Line30, Lisuei, Lokht11, Makuyi, Sahand, and Sahraa) were evaluated on life table parameters and nutritional indices of T. granarium under the following laboratory conditions: 33 ± 1°C, 60 ± 5% RH, and a photoperiod of 14: 10 (L: D) h. Life history parameters of T. granarium could be appropriate indices in resistance and susceptibility evaluation of barley cultivars. The maximum survival rate of immature stages was observed on Makuyi and Lisuei cultivars and the minimum rate was on Abidar and Line22 cultivars. The shortest development time was on Makuyi cultivar and the longest on Line22 cultivar. Pupal weight was ranged from 2.56 mg on Lokht11 to 4.86 mg on Makuyi. Fecundity and egg-hatching rates were highest on Lisuei cultivar and the adults were long-lived on Makuyi cultivar. The highest r m values were observed on Makuyi and Lisuei cultivars but lower value of it resulted from rearing of T. granarium on Line22 cultivar (0.0350 female per female day-1). The results showed that T. granarium larvae fed on Makuyi cultivar had higher values of relative consumption rate and relative growth rate. The results indicated that Makuyi and Lisuei cultivars were relatively susceptible barley cultivars and Line22 was the most inappropriate cultivar for feeding of T. granarium, which could prove useful in the development of Integrated Pest Management programs for this pest.

Susceptibility of Five Sugar Beet Cultivars to the Black Bean Aphid, Aphis fabae Scopoli (Hemiptera: Aphididae).

The black bean aphid, Aphis fabae Scopoli (Hemiptera: Aphididae), is one of the important pests of sugar beet. The relative impact of resistance, including antibiosis and antixenosis of five sugar beet cultivars (Doroti, Perimer, Pershia, Rozier and 006) on A. fabae was studied under laboratory conditions using clip cages. The antibiosis test was based on life table parameters. Significant differences on developmental time, mean number of nymphs/aphid/day, fecundity, and adult longevity of A. fabae were found across tested sugar beet cultivars. In addition, there were significant differences among the sugar beet cultivars for population growth parameters such as the intrinsic rate of natural increase (r m ), net reproductive rate (R 0), finite rate of increase (λ), doubling time (DT), and mean generation time (T) of A. fabae. The highest and lowest (r m ) values were observed on Pershia (0.449 nymphs/female/day) and Perimer (0.358 nymphs/female/day), respectively. No significant differences were found for the preference of the black bean aphid, and antixenosis had no effect on resistance against this aphid. As a result, our findings showed that the Pershia cultivar was a relatively susceptible host plant. Two cultivars (Perimer and Rozier) were relatively resistant to A. fabae, which could prove useful in the development of IPM programs for this aphid in sugar beet fields.

Evaluation of four insecticides as Aedes aegypti larvicides

Four compounds, dimethrin, paris green, naled and trichlorfon have been evaluated as Aedes aegypti larvicides in a set of seven different types of breeding containers found in the Caribbean area. Dimethrin is considered to be a suitable larvicide for use in the drinking water breeding containers and paris green for use in the discarded automobile tyres. (AU)