Plutella xylostella (L.) population control in sowings of spring rapeseed using pheromones

The diamondback moth Plutella xylostella (Linnaeus, 1758) is a common pest of rapeseed and other crops of Brassicaceae family. Annual yield losses and costs of pest control worldwide are estimated at $ 4-5 billion. The pest has an increased tendency to develop resistance to insecticides. The use of traps with synthetic sex pheromone is a modern instrumental method of monitoring P. xylostella. The use of the mating disruption method will effectively decrease pest numbers and reduce the application of insecticides. In 2017-2020, we researched the pheromone activity and evaluated the mating disruption method in the sowings of spring rapeseed at V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) (Krasnodar). We established that P. xylostella males were caught in traps with all tested dispenser types. The pheromone showed the greatest activity on the foil-film dispenser (F). The mating disruption method effectively decreased P. xylostella population in rapeseed sowing; the disruption effect by the end of crop vegetation was high and reached 82.5 %.

MATING DISRUPTION OF GRAPHOLITA MOLESTA BUSCK. TO IMPROVE QUALITY AND HEALTHY OF PEACH FRUITS

In Bulgarian fruit growing agriculture mainly chemical plant protection is applied. Applications with organophosphates and pyrethroids are carried out to control the economically most important peach pest - the oriental fruit moth (Grapholita molesta Busck.). Annually during the vegetation season 7-8 insecticide treatments are applied. This leads to contamination of fruit products and the environment, which is a prerequisite for seeking other approaches. Regarding to fruit moth, sex pheromones are one of the most widely used environmental control methods, but they are most commonly used in apples. Their introduction in the monitoring of the main peach pest can lead to a reduction of chemical treatments and production with less pesticide residues. A promising direction is the use of pheromones to control the pests through sexual disorientation of males. The trial of mating disruption in the present study were carried out with ISOMATE® OFM TT dispensers in 0.9 ha peach orchard in 2020 and 2021. Pheromone traps type "Delta" of the Hungarian company CSALOMON® were used. The ISOMATE OFM TT dispensers, installed before the first flight of OFM at the rate of 250 units per ha, efficiently reduced fruit damages - down to 0.1-0.2% at harvest. In the reference orchard with 6 insecticide treatment against OFM, the damages reached 3.0-3.6%. The results indicate that mating disruption for control of Grapholita molesta Busck. can be used in production of quality and healthy peach fruits.

Mating Disruption of the Olive Moth Prays oleae (Bernard) in Olive Groves Using Aerosol Dispensers

The olive moth (OM), Prays oleae (Bern.) (Lepidoptera: Yponomeutidae), is a major olive grove pest worldwide; however, until now, very few studies have investigated the effectiveness of mating disruption (MD) techniques against this pest. Experiments were carried out for two successive years (2019 and 2020) in three different olive groves in Andalucía (Southern Spain) to evaluate mating disruption’s efficacy in controlling the OM from the first to the third generation. The effectiveness of MD formulations against the three generations of OM was assessed by determining the percentage of infested olive fruits, the reduction of pheromone trap catches, and the number of affected inflorescences in both MD-treated and untreated control olive groves. The number of release points (one or two aerosol devices per ha) was also evaluated. In all years and trials, the mean number of males caught in traps placed in the MD-treated plots was significantly lower than untreated sites. Mating disruption registered a high suppression of male captures (>75%) in treated plots for two consecutive seasons. Concerning infested olive fruits, substantial reductions (about 80%) were observed in the MD plots of locations B and C, and a reduction of about 40% was detected in location A, compared to the control plot. Results showed that the installation of two aerosol devices/ha reduced fruit damage below 20% of infested olive fruits except for one site where a reduction of about 71% in the MD plot was recorded in 2019. Although few significant differences were associated with OM male catches and infested olive fruits between plots treated with one aerosol/ha and two aerosols/ha in most of the comparisons, significant differences in the number of olive inflorescences infested by P. oleae were found, suggesting a similar performance between the two tested aerosol densities. Results of two-year field trials in Andalucía demonstrated the potential of Mister P X841 aerosol devices as an effective tool for controlling the olive moth, P. oleae.

Pheromone-Mediated Mating Disruption as Management Option for Cydia spp. in Chestnut Orchard

(1) Background: Pheromone-based devices are successfully used to control insect pests in agriculture. (2) Methods: Investigations were conducted to evaluate the effectiveness of mating disruption (MD) to control the chestnut tortrix moths, Cydia fagiglandana and Cydia splendana. Surveys were performed in northern Italy in 2019–2020. MD was carried out using the pheromone dispenser Ecodian® CT. The effectiveness of MD was assessed by recording male adult catches in pheromone-baited sticky traps and larvae in chestnut fruits, comparing MD and control plots. (3) Results: The total number of trapped males was significantly lower in MD plots than in control ones, for all sites and years. Trap catch suppression in MD plots averaged 89.5% and 93.8% for C. fagiglandana and 57.4% and 81% for C. splendana in 2019 and 2020, respectively. The larval infestation rate in fruits did not vary between plots except for one site where a reduction of about 71% in the MD plot was recorded in 2019. (4) Conclusions: Low catches in MD plots turned out to be a good measure of the effectiveness of communication disruption, but no satisfactory data have been obtained regarding fruit infestation, highlighting how the reduction of male catches cannot always be considered as a reliable indicator of successful control. Specific investigations about background population density, dispersal and mating/oviposition behavior are thus essential for a viable management strategy.

From Insect Pheromones to Mating Disruption: Theory and Practice

Insects perceive and integrate a hierarchy of visual, chemical and tactile cues for feeding and reproductive purposes, as well as for predator and parasitoid avoidance [...]