The psyllid Cacopsylla chinensis (Yang & Li) (Hemiptera: Psyllidae) is a serious pest of pears in China. To determine and contrast the fitness of the psyllid on two endemic cultivars of Pyrus bretschneideri (i.e., BHXS and BSL) and two introduced cultivars of Pyrus communis (i.e., CB and CRB), we analyzed data on the development, survival, and fecundity from C. chinensis individuals reared on the four cultivars. The age-stage, two-sex life table theory was used in order to enable the inclusion of males in the analysis as well as a means of identifying the variation in developmental durations among individuals. Results indicated that C. chinensis can successfully develop and reproduce on all four pear cultivars. However, based on the lower preadult survival rate, longer preadult duration, longer total preoviposition period (TPOP), and lower fecundity that occurred on both cultivars of P. communis, these two cultivars are less favorable hosts for C. chinensis than the P. bretschneideri cultivars. The lower intrinsic rate of increase (r), finite rate of increase (λ), and net reproduction rate (R0) on CB and CRB pears showed these two introduced cultivars are more resistant to C. chinensis than the endemic BHXS and BSL pears. These resistant cultivars would be appropriate candidates for managing C. chinensis. We used the bootstrap technique to estimate the uncertainty of the population parameters (r, λ, R0, etc.), while also demonstrating that it can be used for estimating the 0.025 and 0.975 percentile confidence intervals of the age of survival rate.

1. Olfactory cues can determine the host preferences of herbivorous insects, but their role in host shifting is unclear. Host specificity and the potential for host shifts are important criteria for screening and post-release evaluation of biological control agents for invasive plants. However, the role of olfactory cues in mediating host shifts in biological control agents is not well understood. 2. To investigate the role of olfactory cues in host selection of a reportedly monophagous flea beetle (Agasicles hygrophila), an important biocontrol agent for invasive alligator weed (Alternanthera philoxeroides), we extracted and analyzed the volatiles produced by the host plant A. philoxeroides and the non-host plants A. sessilis, Beta vulgaris, and Amaranthus Accepted Article This article is protected by copyright. All rights reserved. mangostanus. Moreover, we used electrophysiologcial techniques, behavioural bioassays and field trials to test the antennal responses and behavioural preferences of A. hygrophila to combinations of different plant volatiles and treatments, and pure compounds in different dosages and combinations. 3. We show that A. hygrophila female beetles indeed use olfactory cues to select plants for feeding and oviposition and that the survivorship of larvae on the second preferred non-host plant A. sessilis, a close relative of the first preferred host plant A. philoxeroides, was over 75% in a field trail. Although female beetles responded to many volatile compounds from host and non-host plants, (E)-4,8-dimethyl-1,3,7- nonatriene (DMNT) positively encouraged the beetle’s feeding and oviposition preferences, whereas (Z)-3-hexenol displayed repellent effect. Remarkably, complementation assays with (Z)-3-hexenol on host plant or DMNT on non-host plants significantly shifted A. hygrophila host preferences to non-host plants and resulted in oviposition and egg hatching on the non-host plant A. sessilis in field trials. 4. Synthesis. We demonstrate an olfactory mechanism by which a specialized herbivorous beetle uses the ratio of two common plant volatiles, DMNT and (Z)-3-hexenol, to discriminate between its host and non-host plants in nature. This study highlights an important mechanism by which olfactory cues could lead to undesired host range expansion in biocontrol agent, thus representing an important warning of the potential for a host shift and development of invasiveness in a common biocontrol agent, the flea beetle

The oriental fruit moth, Grapholita molesta (Busck) (Lepidoptera: Tortricidae), is an important pest of most stone and pome fruits and causes serious damage to the fruit industry worldwide. This insect pest has been primarily controlled through the application of insecticides; as a result, G. molesta has developed resistance to many different types of insecticides. To identify detoxification genes, we have, de novo, sequenced the transcriptome of G. molesta (Lepidoptera: Tortricidae) and yielded 58,970 unigenes of which 26,985 unigenes matched to known proteins. In total, 2,040 simple sequence repeats have been identified. The comprehensive transcriptome data set has permitted us to identify members of important gene families related to detoxification in G. molesta, including 77 unigenes of putative cytochrome P450s, 28 of glutathione S-transferases, 46 of Carboxylesterases, and 31 of insecticide targets. Orthologs of some of these unigenes have shown to play a pivotal role in insecticide resistance in other insect species and those unigenes likely have similar functions in G. molesta.

The establishment of standardised methods for monitoring the oriental fruit moth Grapholitha molesta (Busck) (Lepidoptera: Tortricidae) requires the identification of factors that significantly affect trap catch efficacy. We examined the effects of trap height, trap location, and inter-trap spacing on trap catches in a conventional peach orchard. Traps were placed at heights of up to 3.0 m above the ground and sets of nine traps were positioned in grids with inter-trap distances of 10–50 m to determine the optimum trap height, location, and spacing. Traps were checked daily over 10 days for males during four periods corresponding to peak moth flight. Moth catches were higher when traps were placed toward the tops (2.5 m) and outside the canopy (3.0 m). Moth catches in traps located upwind and outside tended to be higher than in the central trap for all inter-trap distances. When inter-trap distances were shorter than 30 m, interference between traps occurred. Our results provide an efficient trap distribution for monitoring G. molesta in peach orchards.

The Oriental Fruit Moth Grapholita molesta (Busck) causes substantial damage to stone and pome fruit crops worldwide. Light-based traps offer a potential means for pest monitoring and management. In this study, we tested the preference of G. molesta for the following light sources: monochromatic light produced from light-emitting diodes (LEDs) (red, orange, yellow, green, blue, violet, and white), specific wavelengths of light produced from filters (405, 450, 480, 512, 540, 576, and 610 nm), and polychromatic light produced by different numbers (0, 12, 24, and 36) of green, blue, and violet LEDs. The arrangement of polychromatic lights was based on an orthogonal design matrix of L16 (4(3)). Based on the results of former studies, we further determined the optimal number of green and violet LEDs. The results showed that: 1) G. molesta strongly preferred the green, violet, and blue LEDs; 2) G. molesta significantly preferred light at 405 nm, followed by 540 nm, and showed no phototaxis to 480 nm; 3) for the polychromatic light configuration, violet and green were the factors that determined the preference of G. molesta, and the lamp with 12 violet LEDs captured the most moths; and 4) for the lamps with different light intensities, 36 violet LEDs or 12 green LEDs attracted the most moths, with the former performing better.