The population of coffee stemborers (Coleoptera: Cerambycidae) was estimated at six sites in south-west China using two capture-recapture models. Two sampling methods (simple and systematic random sampling), each at three sampling intensities (10, 20 and 30%) were employed for two-time capture attempts from which the capture-recapture estimates were calculated. Estimates from the models were compared with that of census data from the fields. When sampling intensity was 20%, satisfactory levels of accuracy were obtained using the two models. The level of accuracy of the estimates increased as damage rate and mean density of the insect increased. Accuracy was also increased with increasing the sampling intensity, when damage rate and density of stemborers in the plots were low.

A water–oil based pheromone trap was used to monitor seasonal population changes of Coniesta ignefusalis Hampson in millet-based cropping systems at Samaru, Zaria, Nigeria for three consecutive seasons (1997, 1998 and 1999). Daily meteorological data were obtained from the Meteorological Unit of the Institute for Agricultural Research, Samaru, Zaria, for the monitoring period. Two population peaks were observed in early August and September in 1997 and 1998. The first population peak in August 1997 was earlier and bigger than the one in 1998. A delayed emergence of the insects was observed in 1999 when only one population peak occurred and this was smaller than those in 1997 and 1998. Using step-wise multiple regression analyses, the relationship between pheromone trap catches of male moths and weather factors was assessed separately for each year to determine which of the weather factors contributed most to the insect population changes. Solar radiation in the preceding 10 days and minimum air temperature in the preceding 40 and 50 days explained 84.9% of the variance in population changes and flight activity of male moths in 1997. Wind direction and speed in the preceding 20 and 60 days respectively accounted for 80.6% of the variance in 1998, while maximum air temperature and relative humidity in the preceding 40 and 20 days respectively explained 99.9% of the variance in 1999. The functional regression equations developed involving these weather factors adequately predicted the changes in each year.

—Bioassays were conducted with Bacillus sphaericus (Neide) 1593M (Bsph) and a neem based biopesticide formulation, Neemtox® (0.03% azadirachtin), independently and in different combinations, to evaluate any synergistic effects on Culex quinquefasciatus Say (Diptera: Culicidae) larvae susceptible to Bsph. The results indicated that the two biopesticides have no synergistic interaction on the larvae. These results are discussed in light of earlier experiments with resistant C. quinquefasciatus, in which Bspfc-Neemtox synergism was seen.

In a comparative situation, the moths Plodia interpunctella (Hubn.) and Ephestia cautella (Wlk.) caused more damage in groundnuts (41.85% for P. interpunctella; 29.21% for E. cautella) than in maize, when these commodities were stored for 1 month in plastic jars. For maize stored for 3 months in plastic and traditional storage gourds, the weight losses caused by the moths were: P. interpunctella—15.48% in jars; 4.53% in gourds; E. cautella—20.68% in jars; 4.12% in gourds. Orange peel suppressed two-thirds of the populations of P. interpunctella and E. cautella at a dosage of 20.0g/100g maize. Neem leaves caused 100% mortality of P. interpunctella at 15.0g/100g groundnut and suppressed more than half the population of E. cautella at 5g/100g groundnut. The results show that the plant materials utilised have some insecticidal properties against P. interpunctella and E. cautella over a short period.

Since the introduction of irrigation in the early 1950s major changes in the crop regime have taken place in Israel. These changes had greatly influenced the populations of the four species of corn borers found in Israel. Chilo agamemnon, which was the main pest during the 1960s decreased and the numbers of Sesamia nonagrioides increased. The reduction in the sorghum acreage, caused a decrease in the numbers of Sesamia cretica. In 1981 an increase in the numbers of the European corn borer, Ostrinia nubilalis, was observed. At present S. nonagrioides and O. nubilalis are the main corn pests in Israel.

Chilo agamemnon was first recorded in Israel in 1959 near the Gaza strip. In the course of 2–3 years it became a very serious pest in the southern parts of the country. Later, the spread of the pest continued throughout the country. Since 1973 a drastic decrease in the populations of C. agamemnon was recorded. The probable reasons for the decrease in the populations of this pest in Israel are:

(1) The relative increase of the areas of sweet corn, which is not its preferable host plant.

(2) Rice and sugar-cane, which are very important host plants in Egypt, are not grown in Israel.

Field experiments against C. agamemnon, carried out when populations were high, showed that dust applications were more effective than sprays.

Non-parametric statistics were used to describe the spatial distribution of eggs laid by Zabrotes subfasciatus Boh. (Coleoptera, Bruchidae) inside pods of wild Phaseolus lunatus and cultivated P. vulgaris. Eggs tended to be uniformly distributed among seeds inside the pods of P. lunatus whereas egg distribution patterns were random or aggregative inside P. vulgaris pods. These differences were explained in terms of the internal pod morphology of the two host plants. It was concluded that this bruchid normally oviposits uniformly among accessible seeds inside the pods of its host plants in the wild.

Sixty artificially infested grain sorghum genotypes were evaluated for resistance against Busseola fusca. Evaluation of leaf feeding damage indicated levels of resistance ranging from intermediate to susceptible. Genotypes were categorized according to the presence or absence of both antibiotic and tolerant characteristics. Genotypes (17%) exhibited both antibiosis against leaf feeding and tolerance for borer damage. Borer damage resulted in a 4% increase in grain yield of one genotype and a 50% increase in the number of heads of a second genotype. Tolerance and recovery resistance were the most important factors limiting yield loss in grain sorghum genotypes. In this study, the ability of sorghum for tillering (recovery resistance) was separated from the ability to produce heads on infested stems (tolerance). The importance of distinguishing between tolerance and recovery resistance in the evaluation of sorghum germplasm for borer resistance is emphasized.

Seedlings of apple variety, Yarlington mill, were sprayed with different sprays containing 0.1% cypermethrin, and were subjected for 15 min to 65.3 mm artificial rainfall. The effectiveness of deposits after rainfall were tested in the laboratory with neonate codling moth larvae.

Cypermethrin formulations sprayed with each nozzle were more persistent after artificial rain, when small droplets of volume median diameter (VMD = 30–70 μm) were applied by spinning discs (charged or uncharged) compared with larger droplets (VMD* = 90–160 μm) produced by air shear nozzle. No significant difference in effects was obtained between droplets by either charged or uncharged disc.