Electroantennogram (EAG) responses of male and female Epiphyas postvittana (lightbrown apple moth) were recorded to plant volatiles delivered from either filter paper or a gas chromatograph. Males showed significantly higher EAG responses than females with both methods (P < 0.001). Responsiveness to compounds was significantly correlated between sexes and between methods (P < 0.01). Pairs of moths were caged with access to filter paper treated with plant volatiles, and untreated filter paper, for oviposition. The number of females ovipositing, the number of eggs laid, and the proportion of total eggs laid on the treated paper were recorded to determine the attractancy or repellency of the compounds. Eugenol, geraniol, and citral deterred oviposition, whereas hexanal, linalool, nonanol, octanol, and nonanal were attractants. The proportion of females laying eggs was reduced in the presence of citral, nonanol, octanol, and n-decyl aldehyde. The number of fertile eggs laid per female was reduced by 10 of the 14 compounds tested. EAG was a poor predictor of oviposition attractancy or repellency. Stimulation with fresh plant foliage produced significantly higher EAGs in eight host plants, compared to eight nonhosts (P< 0.001).

Pheromone traps were operated in five regions to determine the impact of trap colour on catch of target and non-target insects. Red or green coloured pheromone sticky traps caught fewer native and introduced bees compared to the standard white traps, and yellow or blue traps. Honey bees (Apis mellifera) were caught mainly in white followed by blue traps, while bumble bees (Bombus spp.) were most attracted to blue traps, with most of the remainder caught in white traps. Native bee (Lasioglossum and Hylaeus spp.) catches were greatest in white traps, followed by yellow traps, with a few in green traps. There was no significant difference in catch of the target species, Cydia pomonella or Epiphyas postvittana, with trap colour. Replacement of the white traps with green or red traps is recommended to reduce nontarget impacts on bees.

Behavioral responses of newly‐emerged codling moth (Cydia pomonella L.) larvae to α‐farnesene were compared for a laboratory‐reared strain (‘lab’, 160 generations inbred) and a recently collected strain (‘wild’, 3 generations). Video recordings of single larvae placed 20 mm from Bond papers releasing a range of seven α‐farnesene concentrations were scored for head turning, head lifting, head direction, and movement across a Petri dish. The laboratory strain was significantly less successful at finding the treated papers than the wild strain. The lab strain was also significantly less active, shown by more random orientation, slower walking speed, less head turning and less head lifting. Both strains showed lower response to α‐farnesene concentrations less than 10−6 (w/v) α‐farnesene. Orientation, walking speed, and head turning rate were significantly higher in the presence of α‐farnesene concentrations > 10−7 w/v, for both strains. Head lifting did not show any effect from α‐farnesene. Head turning was associated with both head lifting and walking speed and this association improved with the presence of α‐farnesene. Increased attraction to odour source was correlated with improved direction finding at concentrations above 10−7 w/v. Activity factors such as head turning and walking speed influenced time to locate odour source more than orientation factors. Odour‐guided orientation to α‐farnesene in codling moth larvae was composed of both locomotory, and to a lesser extent, orientation responses, which increased in a directed fashion to the stimulus.

The absorption and release of the pheromone ofEpiphyas postvititana (Lepidoptera: Tortricidae),E 11-14: OAc andE,E 9, 11-14: OAc (95:5) by apple leaves was studied using electroantennograms (EAG) and sticky traps baited with pheromone-treated leaves. Leaves exposed to an airstream containing pheromone reached a constant level of pheromone release within 3 min. Release occurred over a period greater than 24 hr, following removal of leaves from the pheromone-saturated environment. Pheromone-treated leaves were effective as lures in sticky traps for at least three nights, although the average catch per night decrease logarithmically with time. In the field, pheromone was detected by EAG on leaves harvested from up to 25 cm away from a central point source of pheromone. The shape of a surface representing equal pheromone re-release from leaves around a central point source was defined by interpolation from a three-dimensional transect. Leaves harvested from 5 cm under the dispensers showed the highest pheromone release rate. Leaves downwind of the dispensers also had higher release of pheromone. In a treated orchard, significantly higher EAG measurements were recorded in the rows of trees that contained dispensers, compared to grass interrows or untreated trees. The implications of foliar pheromone adsorption and release on atmospheric concentrations and insect behavior require further investigation.

Uptake and release of pheromone and behavioral inhibitor ofEpiphyas postvittanna by apple leaves was tested using field electroantennograms (EAG), trap catches to synthetic lures and virgin females, and chemical analysis. Trap catches in single apple trees (N=3) were monitored for six cycles of six days' duration, using delta traps baited with synthetic pheromone. Polyethylene dispensers (0, 1, 10 per tree) releasing pheromone and inhibitor were present for only the first three days of each cycle. Application of 10 dispensers per tree resulted in complete disruption of trapping, which continued for one day after dispensers were removed. Over the three nights following the removal of the dispensers (days 4-6), trap catch was 0, 10, and 15% of the control catch. In contrast, the presence of only one dispenser per tree led to 0-20% of control catches, but on the three nights following dispenser removal catches were 35, 40, and 80% of the control catch. Field EAGs indicated significantly higher relative pheromone concentrations in the trees with 10 dispensers present, compared to trees with single dispensers, but removal of dispensers produced no detectable treatment effect compared to the control trees one day after dispenser removal. In a second experiment, releases of marked male moths into apple orchard plots following the removal of polyethylene dispensers (1 hr earlier that day) resulted in significantly lower catches in traps baited with virgin females in blocks that had been treated, compared to controls. Recovery of pheromone by solvent washing of leaves loaded with 50 µg of the main component of the sex pheromone (1.26 µg/cm(2)) was low (2.5%). Leaves held in a pheromone-saturated atmosphere were loaded with 0.045±0.007 µg pheromone/cm(2). Analysis of apple leaves taken from a pheromone-treated tree at different distances from the pheromone dispenser showed a decay of the pheromone load per square centimeter with increasing distance from the dispenser, as previously indicated by EAG.