When the nine identified components in the effluvium of calling female codling moths were compared to pure synthetic (E,E)-8,10-dodecadien-1-ol in flight-tunnel tests, equal responses were obtained ...over a concentration range of 300-fold. When synthetic (E,E)-8,10-dodecadien-1-ol was compared to extract of female sex pheromone glands by a male wing-flutter bioassay, or in flight-tunnel tests, equal responses were obtained over a concentration range of 1000 fold. The sum total of these and previous studies indicate that the codling moth sex pheromone consists of only one component
This research was conducted to provide a theoretical basis and experimental evidence to support the hypothesis that insect larvae can be preferentially heated in dry nuts and fruits by radio ...frequency (RF) heating for pest control. We selected codling moth larvae as the target insect and in-shell walnuts as the host material for this study, and focused our attention on one RF frequency (27 MHz) and one microwave frequency (915 MHz). Dielectric properties measurements showed that the loss factor ratio between codling moth larvae and walnut kernels at 20°C was 397 at 27 MHz and 4 at 915 MHz. The theoretical prediction for a 3 min treatment at 0.27 kW/kg suggested 12.0°C preferential heating of insect larvae for the loss factor ratio of 397 (corresponding to 27 MHz) and 0.1°C for the ratio of 4 (corresponding to 915 MHz), when the heat transfer coefficient between insects and walnuts was set at 500 W/m 2 °C. To prove differential heating predicted by the theoretical model, a gellan gel with dielectric properties similar to those of insects was used as a model insect. When walnut kernels were heated at 27 MHz from 20°C to 53°C, the model insects were differentially heated from 12.6°C to 21.2°C higher than the kernel temperature, depending on the power used and the treatment time. These values corresponded to a heating rate for the model insect of 1.4 to 1.7 times greater than that for walnut kernels. As predicted by the theoretical model, microwave heating at 915 MHz caused no differential heating of insects. Preferential heating of insects in dry nuts and fruits at radio frequencies can be used in developing thermal treatments to control insects without adversely affecting product quality.
Performance characteristics of polyethylene tube dispensers containing a mixture of (E,E)-8,10-dodecadien-1-ol (I), dodecan-1-ol (II), and tetradecan-1-ol (III) were evaluated for suitability as a ...mating disruptant for codling moth control. The rate of loss of pheromone component from a dispenser at any time was found to be described by the equation: (...) where P is the amount of pheromone component in the dispenser well; t is time; k1 is the ratio of the amount dissolved in the dispenser wall to the amount in the dispenser well; k2 is the ratio of the evaporation rate to the amount dissolved in the dispenser wall; kd is the rate constant for chemical decomposition. The evaporation rate, E, of a pheromone component at any time was given by: (...). For all three components during the first three weeks, k1 decreased from ca. 0.25 to ca. 0.10 and was approximately constant thereafter. The decrease of kd with time may have been caused by weather-induced cross-linking of the polyethylene. Over time k2 was constant and was 1.27 +/- 0.26 X 10(-3)/hr for 1, 1.96 +/- 0.33 X 10(-3)/hr for 2, and 0.31 +/- 0.05 X 10(-3)/hr for 3. The kd was zero for 2 and 3 and 6.96 X 10(-4) for 1. After 150 days in an orchard in 1991, 95% of 1 was lost from the dispensers (61% of the loss was by chemical decomposition and 39% by evaporation). The heat summation units in a Yakima valley orchard during 1991 were 4.7% above the average for the 1980-1991 period, while during 1990 they were the highest for this period (26% above average). After the first three weeks of dispenser aging, the regression line half-lives for 1 for 1990 and 1991 were 31.0 and 35.1 days, respectively. The difference in temperature between 1990 and 1991 did not affect the half-life of 1 very much because so much of the loss was from photochemically induced decomposition. Based on an estimate of the required minimum evaporation rate for mating disruption of 2 mg/ha-hr and a half-life of 35 days for 1, 2345 dispensers/ha wo
Pest monitoring and control of the codling moth, Cydia pomonella L., have been developed using the main pheromone component of this species, (E,E)-8,10-dodecadienol (codlemone). However, the activity ...of codlemone is not satisfactory for pest control by mating disruption. Thus, we have synthesized halogenated analogs of codlemone to see if they could be used as new agents for pest control of the codling moth. Their biological activity was measured by electrophysiological techniques. In EAG screening, codlemone was the most active compound. F(10,11)-codlemone (E,E)-10,11-difluorododecadienol 8,10-and Cl-codlemone (E,E)-11-chloro-8,10-undecadienol elicited significant EAG responses, F(10,11)-codlemone triggering responses not significantly different from responses to codlemone. EAG cross-adaptation experiments and single sensillum recordings revealed that these compounds were detected by the same receptor neuron type as codlemone. No competitive inhibition with codlemone was observed from nonactive compounds. In field trapping, F(10,11)-codlemone and Cl-codlemone were more attractive to male codling moths than codlemone itself. Possible explanations of this activity are discussed
Neonate larvae of codling moth, Cydia pomonella (L.), modify their behavior in the presence of saccharin, monosodium glutamate (MSG), or L(+)-2-amino-4-phosphonobutyric acid (L-AP4) by commencing ...their feeding earlier. Previously published pharmacological analysis demonstrated that phagostimulatory effects of MSG and L-AP4 (which elicit umami taste sensation in humans) are reversed by adenylate cyclase activator and phosphodiesterase inhibitor. In this study, by measuring the time needed to start ingestion of foliage treated with mixtures of phagostimulants and signal transduction modulators, we show that phagostimulatory effects of l-aspartate (the third hallmark umami substance) are also abolished by both adenylate cyclase activator and phosphodiesterase inhibitor, but not by phospholipase C inhibitor. However, stimulatory effects of hemicalcium saccharin were affected only by phospholipase C inhibitor. The results suggest that codling moth neonates use different transduction pathways for perception of hemicalcium saccharin and umami.
Codling moth control options Grant, Joe; Prichard, Terry
Western Farm Press,
06/2009
Journal Article, Trade Publication Article
Chlorpyrifos applications in walnuts begin in May and cancontinue through August. Any irrigation runoff during this timeperiod can cause chlorpyrifos to enter surface waters. Significantresidues have ...been found in irrigation runoff collected as long astwo months after application.
Tebufenozide (RH-5992), a nonsteroidal ecdysone agonist, stimulated significant (P less than or equal to 0.05) growth in both testes of post-diapausing codling moth larvae and a dormant Ascogaster ...larva in its overwintering host's hemocoel. Tebufenozide elicited the same responses in post-diapausing testes and Ascogaster larvae as were reported earlier in insects treated with 20-hydroxyecdysone (20-OHE) Friedlander, J Insect Physiol 35:29 (1989); Brown et al., Endocrinological Frontiers in Physiological Insect Ecology. Wroclaw: Wroclaw Technical University Press, pp 443-447 (1988). Only a trace (less than or equal to 1%) of 14C-tebufenozide was recovered from gonads and exuviae of healthy larvae, or from Ascogaster larvae removed from parasitized hosts; however, the renewed growth of testes and Ascogaster larvae and apolysis of codling moth integument were an obvious response to the hormone agonist. Most of the injected 14C-tebufenozide was recovered from host fat body, while the alimentary canal retained approximately 40% of the 14C-tebufenozide fed in an artificial diet. Host exposure to tebufenozide did not cause apolysis in endo- or ectoparasitic hymenopterans feeding on treated codling moth larvae; however, the endoparasitoid trapped in the host's hemocoel died as its host's tissue deteriorated. Different results were observed on ectoparasitoids developing on treated hosts. Ectoparasitic Hyssopus sp. (Eulophidae) larvae feeding on tebufenozide treated hosts pupated in the normal length of time. Hyssopus adults which developed from larvae fed tebufenozide treated hosts were fertile and produced as many progeny as adults reared from solvent fed controls. There was no evidence of secondary poisoning to Hyssopus sp. and codling moth exposure to tebufenozide may actually benefit the rearing of this eulophid by maintaining the host in the susceptible larval stage and preventing the host larva from spinning a cocoon
Field tests comparing the ability of codlemone, (E,E)-8,10-dodecadien-1-ol, and isomers of codlemone to disrupt pheromonal communication of codling moth were carried out. In a pear orchard, four ...nonisomerizing, gray septa dispensers were placed in the upper canopy of each tree containing a trap baited with 10 virgin female codling moths. The dispensers were at trap height and 70 cm from the edge of each trap. Trap catches of released male codling moths in three test areas were compared simultaneously when trees in each of the test areas contained unbaited dispensers, dispensers with 1 mg of codlemone containing 1% isomers, and dispensers with 1 mg of a test communication disruptant. When the test disruptant was an equilibrium mixture of codlemone and its isomers (61% codlemone, 39% isomers), the percent communication disruption was 86.8% compared to 68.7% for codlemone (P 0.001). When the disruptant was (E,Z)-8,10-dodecadien-1-ol (94% EZ, 3% EE), the percentage disruption was 86.4% compared to 62.7% for codlemone (P 0.002). These results show that the previously reported superior disruptant potency (relative to codlemone) of compositions containing codlemone with a high percentage of isomers was not a result of the proximity of the dispensers to the traps. The percent disruption of compositions of codlemone with 10 and 20% isomers was also determined. A plot of percentage disruption versus logarithm of percentage of nonpheromone isomers in the mixture from 1% to 97% gave a straight line with R2
In flight tunnel tests, the percentages of oriented upwind flights of male codling moths culminating in contacting a source of different compositions of female sex pheromone gland components were ...determined over a dosage range of 0.1-100,000 micrograms. The following compositions were tested: (1) E,E)-8,10-dodecadien-1-ol of 99.7% isomeric purity; (2) 1 + dodecan-1-ol + tetradecan-1-ol; 3) 2 + decan-1-ol + (E)-9-dodecen-1-ol; and (4) an equilibrium mixture of 8,10-dodecadien-1-ol isomers (61% EE, 5% ZZ, 14% ZE, and 20% EZ). The ratios of the components in compositions 2 and 3 were chosen to produce vapor ratios equal to the natural ratios found in the female effluvium by Arn and coworkers. As the dose of composition 1 was increased from 0.1 to 10 micrograms, response increased from 0 to about 80% and then was approximately constant from 10 to 300 micrograms. Over the range 0.1-300 micrograms, the percentage of males contacting the septum was virtually the same as the percentage flying upwind. From 300 to 100,000 micrograms, the percentage of males flying upwind and contacting the source steadily decreased from about 80 to 0%. The male responses to compositions 2 and 3 were virtually identical to the response to 1. These results indicate, contrary to published reports, that dodecan-1-ol and tetradecan-1-ol in combination with 1 do not increase the responses of the behavioral modes determining degree of attractancy and disruption of sexual communication over that of 1 alone. These results also show that decan-1-ol and (E)-9-dodecen-1-ol do not enhance response in the five-component mixture. The response to composition 4 increased from 0% at a dose of 0.3 micrograms to 26% at a dose of 30 micrograms and then decreased to 0% at a dose of 3000 micrograms. Thus, the inhibiting effect of the isomers on response was greater at the higher doses
