Potential for mating disruption to reduce cone damage by the spruce seed moth, Cydia strobilella, in spruce seed orchards

Pseudococcus calceolariae, the citrophilous mealybug, is a species of economic importance. Mating disruption (MD) is a potential control tool. During 2017–2020, trials were conducted to evaluate the potential of P. calceolariae MD in an apple and a tangerine orchard. Two pheromone doses, 6.32 g/ha (2017–2018) and 9.45 g/ha (2019–2020), were tested. The intermediate season (2018–2019) was evaluated without pheromone renewal to study the persistence of the pheromone effect. Male captures in pheromone traps, mealybug population/plant, percentage of infested fruit at harvest and mating disruption index (MDI) were recorded regularly. In both orchards, in the first season, male captures were significantly lower in MD plots compared to control plots, with an MDI > 94% in the first month after pheromone deployment. During the second season, significantly lower male captures in MD plots were still observed, with an average MDI of 80%. At the third season, male captures were again significant lower in MD than control plots shortly after pheromone applications. In both orchards, population by visual inspection and infested fruits were very low, without differences between MD and control plots. These results show the potential use of mating disruption for the control of P. calceolariae.

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Predicting Damage to Hop Cones by Tetranychus urticae (Acari: Tetranychidae)

Environmental Entomology ◽

10.1093/ee/nvab008 ◽

2021 ◽

Author(s):

Joanna L Woods ◽

Anne E Iskra ◽

David H Gent

Keyword(s):

Risk Factors ◽

Tetranychus Urticae ◽

Crop Damage ◽

Equation Modeling ◽

Data Sets ◽

Current Management ◽

Late Season ◽

Model Based ◽

Predatory Arthropods ◽

Cone Damage

Abstract Twospotted spider mite (Tetranychus urticae Koch) is a cosmopolitan pest of numerous plants, including hop (Humulus lupulus L.). The most costly damage from the pest on hop results from infestation of cones, which are the harvested product, which can render crops unsalable if cones become discolored. We analyzed 14 yr of historical data from 312 individual experimental plots in western Oregon to identify risk factors associated with visual damage to hop cones from T. urticae. Logistic regression models were fit to estimate the probability of cone damage. The most predictive model was based on T. urticae-days during mid-July to harvest, which correctly predicted occurrence and nonoccurrence of cone damage in 91 and 93% of data sets, respectively, based on Youden’s index. A second model based on the ratio of T. urticae to predatory arthropods late in the season correctly predicted cone damage in 92% of data sets and nonoccurrence of damage in 77% of data sets. The model based on T. urticae abundance performed similarly when validated in 23 commercial hop yards, whereas the model based on the predator:prey ratio was relatively conservative and yielded false-positive predictions in 11 of the 23 yards. Antecedents of these risk factors were explored and quantified by structural equation modeling. A simple path diagram was constructed that conceptualizes T. urticae invasion of hop cones as dependent on prior density of the pest on leaves in early spring and summer, which in turn influences the development of predatory arthropods that mediate late-season density of the pest. In summary, the biological insights and models developed here provide guidance to pest managers on the likelihood of visual cone damage from T. urticae that can inform late-season management based on both abundance of the pest and its important predators. This is critically important because a formal economic threshold for T. urticae on hop does not exist and current management efforts may be mistimed to influence the pest when crop damage is most probable. More broadly, this research suggests that current management practices that target T. urticae early in the season may in fact predispose yards to later outbreaks of the pest.

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Effect of Pheromone Blend Components, Sex Ratio, and Population Size on the Mating of Cadra cautella (Lepidoptera: Pyralidae)

Journal of Insect Science ◽

10.1093/jisesa/ieaa128 ◽

2020 ◽

Vol 20 (6) ◽

Author(s):

Abeysinghe Mudiyanselage Prabodha Sammani ◽

Dissanayaka Mudiyanselage Saman Kumara Dissanayaka ◽

Leanage Kanaka Wolly Wijayaratne ◽

William Robert Morrison

Keyword(s):

Sex Ratio ◽

Population Size ◽

Management Practices ◽

Mating Disruption ◽

Current Knowledge ◽

Mating Status ◽

Cadra Cautella ◽

Synthetic Chemicals ◽

Population Sizes ◽

Lepidoptera Pyralidae

Abstract The almond moth Cadra cautella (Walker), a key pest of storage facilities, is difficult to manage using synthetic chemicals. Pheromone-based management methods remain a high priority due to advantages over conventional management practices, which typically use insecticides. Cadra cautella females release a blend of pheromone including (Z, E)-9,12-tetradecadienyl acetate (ZETA) and (Z)-9-tetradecadien-1-yl acetate (ZTA). The effect of these components on mating of C. cautella and how response varies with the population density and sex ratio remain unknown. In this study, the mating status of C. cautella was studied inside mating cages under different ratios of ZETA and ZTA diluted in hexane and at different population sizes either with equal or unequal sex ratio. The lowest percentage of mated females (highest mating disruption [MD] effects), corresponding to roughly 12.5%, was produced by a 5:1 and 3.3:1 ratio of ZETA:ZTA. Populations with equal sex ratio showed the lowest percentage of mated females, at 20% and 12.5% under lower and higher density, respectively. The next lowest percentage of mated females was produced when the sex ratio was set to 1: 2 and 2:1 male:female, with just 25% and 22.5% of moths mated, respectively. This study shows that mating status of C. cautella is influenced by ZETA:ZTA ratio, sex ratio, and population size. This current knowledge would have useful implications for mating disruption programs.

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Inhibitory Copulation Effect of Vibrational Rival Female Signals of Three Stink Bug Species as a Tool for Mating Disruption

Insects ◽

10.3390/insects12020177 ◽

2021 ◽

Vol 12 (2) ◽

pp. 177

Author(s):

Aline Moreira Dias ◽

Miguel Borges ◽

Maria Carolina Blassioli Moraes ◽

Matheus Lorran Figueira Coelho ◽

Andrej Čokl ◽

...

Keyword(s):

Pest Management ◽

Mating Behavior ◽

Mating Disruption ◽

Management Strategies ◽

Stink Bug ◽

Stink Bugs ◽

Vibratory Communication ◽

Communication Signals ◽

Long Duration ◽

Bean Plants

Stink bugs are major pests in diverse crops around the world. Pest management strategies based on insect behavioral manipulation could help to develop biorational management strategies of stink bugs. Insect mating disruption using vibratory signals is an approach with high potential for pest management. The objective of this work was to investigate the effect of conspecific female rival signals on the mating behavior and copulation of three stink bug species to establish their potential for mating disruption. Previously recorded female rival signals were played back to bean plants where pairs of the Neotropical brown stink bug, Euschistus heros, and two green stink bugs, Chinavia ubica and Chinavia impicticornis were placed. Vibratory communication and mating behavior were recorded for each pair throughout the experimental time (20 min). Female rival signals show a disrupting effect on the reproductive behavior of three conspecific investigated stink bug species. This effect was more clearly expressed in E. heros and C. ubica than in C. impicticornis. The likelihood of copulating in pairs placed on control plants, without rival signals, increased 29.41 times in E. heros, 4.6 times in C. ubica and 1.71 times in C. impicticornis. However, in the last case, the effect of female rivalry signals in copulation was not significant. The effect of mating disruption of female rival signals of the three stink bug species may originate from the observed reduction in specific vibratory communication signals emitted, which influences the duet formation and further development of different phases of mating behavior. Our results suggest that female rival signals have potential for application in manipulation and disruption of mating behavior of stink bugs. Further work needs to focus on the effects of female rival signals used in long duration experiments and also their interactions with chemical communication of stink bugs.

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EAG measurement of pheromone distribution in apple orchards treated for mating disruption of Cydia pomonella

Entomologia Experimentalis et Applicata ◽

10.1046/j.1570-7458.1997.00143.x ◽

1997 ◽

Vol 82 (3) ◽

pp. 289-297 ◽

Cited By ~ 30

Author(s):

Roland Milli ◽

Uwe T. Koch ◽

Jacobus J. Kramer

Keyword(s):

Mating Disruption ◽

Cydia Pomonella ◽

Apple Orchards

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Levels of outcrossing and contamination in twoPinus sylvestrisL. seed orchards in Northern Sweden

Scandinavian Journal of Forest Research ◽

10.1080/02827588909382544 ◽

1989 ◽

Vol 4 (1-4) ◽

pp. 41-49 ◽

Cited By ~ 29

Author(s):

Yousry A. EL‐Kassaby ◽

Dag Rudin ◽

Reza Yazdani

Keyword(s):

Northern Sweden ◽

Seed Orchards

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EVALUATION OF A NATURAL RUBBER SLEEVE STOPPER AS A CONTROLLED-RELEASE SUBSTRATE FOR USE IN STUDIES OF SEX-PHEROMONE-MEDIATED MATING DISRUPTION OF THE SPOTTED TENTIFORM LEAFMINER

The Canadian Entomologist ◽

10.4039/ent131137-1 ◽

1999 ◽

Vol 131 (1) ◽

pp. 137-149 ◽

Cited By ~ 2

Author(s):

R.M. Trimble ◽

C.A. Tyndall ◽

B.D. McGarvey

Keyword(s):

Sex Pheromone ◽

Natural Rubber ◽

Mating Disruption ◽

Polynomial Equation ◽

Order Polynomial ◽

Rubber Sleeve ◽

Rate Of Evaporation ◽

The Relationship ◽

Linear Decline ◽

Order Polynomial Equation

AbstractNatural rubber sleeve stoppers were impregnated with 10 mg of (E)-10-dodecen-1-yl-acetate, the major component of spotted tentiform leafminer, Phyllonorycter blancardella (F.), pheromone. In the laboratory, there was a linear decline in the amount of pheromone remaining on stoppers during 8 weeks of exposure to 10, 15, 20, and 25 °C. At 30 and 35 °C, the relationship was curvilinear and could be described using a second-order polynomial equation. The estimated rate of evaporation ranged from 0.03 mg/day at 10 °C to 0.08 mg/day at 25 °C; the rate of evaporation at 30 and 35 °C varied with the time since first exposure. There was a linear decline in the amount of pheromone remaining on stoppers during 8 weeks of exposure to fluctuating temperature regimes with average temperatures of 10 °C (i.e., 5–15 °C) and 20 °C (i.e., 15–25 °C). At a fluctuating regime with an average temperature of 30 °C (i.e., 25–35 °C), the relationship was curvilinear and could be described using a second-order polynomial equation. The estimated rate of evaporation was 0.02 and 0.09 mg/day at 5–15 and 15–25 °C, respectively; the estimated daily rate of evaporation at 25–35 °C varied with the time since first exposure. In an orchard, the estimated average rate of evaporation of pheromone from stoppers ranged from 0.05 to 0.31 mg/day and did not vary significantly with temperature. During the first 4 weeks of exposure in an orchard, the observed rate of evaporation was up to 4.4-fold greater than the rate predicted using the relationship between evaporation rate and constant temperatures observed in the laboratory. The potential for using natural rubber sleeve stoppers as controlled-release substrates in studies of sex-pheromone-mediated mating disruption of P. blancardella is discussed.

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