Mating disruption/disruptants

Keywords Pheromones Female moth Male attractants Chemical ecology Mating disruption... 

Different from the use of ordinal insecticides, this disruption method has high target selectivity and, as would be desired, ensures the survival of natural enemies. The sex pheromone, which shows no toxicity to mammals, is an ideal insect-behavior regulator (IBR). Table 8 shows the application areas of main mating disruptants for lepidopteran insects. In addition to the use of the synthetic pheromone of P. gossypiella in large cotton fields, many disruptants are... 

Acknowledgments The authors are grateful to Dr. F. Komai of Osaka University of Arts for helpful discussions about insect taxonomy and K. Ogawa of Shin-Etsu Chemical Co. Ltd. for information on the utilization of mating disruptants. 

Haplodiploidy in N. sertifer leads to male production from unfertilized eggs, which seriously complicates the issue of mating disruption with the acetate of... 

Pheromones are used primarily for monitoring pest populations, but their use as pest suppression tools has also been proposed. These alternative uses include mass trapping, mating disruption, and lure and kill. Although these approaches have been tried with varying levels of success in field and orchard crop systems, they have had limited application for the management of stored-product insects. 

Mating disruption involves the use of artificially produced high pheromone concentrations in a confined area to impede the ability of males to... 

Carde, R.T. and Minks, A.K. 1995. Control of moth pests by mating disruption Successes and constraints. Annu. Rev. Entomol. 40, 559-585. 

Second, many bug species are polyphagous and highly mobile, moving rapidly between crops and native vegetation. For these species, strategies such as pheromone-based mating disruption cannot be employed, both because the insects may not be in the crop when the disruptant is deployed, and because previously mated females can readily immigrate into the crop. 

Male attraction to the female sex pheromone has been studied for the development of environmentally safe control methods. One important drawback of the mating disruption technique is that only male behaviour is affected, so the efficacy of pheromonal methods can be greatly enhanced by compounds that affect also female behaviour [378]. 

Evenden, M. L. and Haynes, K. F. (2001). Potential for the evolution of resistance to pheromone-based mating disruption tested using two pheromone strains of the cabbage looper, Trichoplusia ni. Entomologia Experimentalis etApplicata 100 131-134. 

Resistance to a mating disruptant composed of (Z)-l 1-tetradecenyl acetate in the smaller tea tortrix, Adoxophyes honmai (Yasuda) (Fepidoptera Tortricidae). Applied Entomology and Zoology 37 299-304. 

In addition to mating-disruption pheromones, there are a number of naturally occurring, nonpheromonal attractants and repellents. Many are typically used as food additives or in cosmetics or perfumes, and are derived from diverse plant and animal sources. Capsaicin [44], the spicy component of chili peppers, is used in several bird, deer, and rodent repellents. Maple lactone [45], a common food additive and flavoring, is used in traps to attract cockroaches with its stale beer odor. Methyl... 

Welter, S.C., Pickel, C., Millar, J., Cave, F., Van Steenwyk, R.A. and Dunley, J. (2005) Pheromone mating disruption offers management options for key pests. Calif. Agric., 59 (1), 16-22. 

The chemical and behavioral aspects of the sex pheromones of several forest defoliating insects of economic importance in eastern Canada are presented, with emphasis on the spruce budworm, Choristoneura fumiferana. Studies conducted over several years in New Brunswick on the use of pheromones as potential control agents, using in particular the air permeation technique to effect mating disruption, are discussed. The identification and the behavioral effects of minor components of the spruce budworm pheromone system are presented and the potential exploitation of their behavioral roles in the mating sequence in terms of control strategies are addressed. 

The fact that mating disruption can be commercially feasible is encouraging but the actual mechanism(s) of disruption is still unclear. The possible mechanisms involved in disruption include sensory adaptation, habituation, competition ("false-trail following") and camouflage of aerial trails from females (14, 15). These mechansims could be working in combination, simultaneously or sequentially, so that some level of disruption can and does occur under a variety of conditions. Without a better understanding of the mechanisms of "attraction" to a pheromone source and the mating disruption process, however, optimization of control methods can proceed only on an empirical basis. 

It is apparent that not all the chemicals involved in female-to-male communication in the spruce budworm are known. In monitoring and mating disruption programs, however, it may not be essential to know every minor component, although as Roelofs has pointed out (16), trap specificity and potency may be greatly increased as the synthetic lure more closely duplicates the natural pheromone and it is presumed that the efficacy of mating disruption would likewise be enhanced by the "more complete pheromone". 

Mating disruption experiments with spruce budworm in laboratory, small-scale field tests and "semi-operational" field trials have recently been reviewed (27). Work to date, on the disruption of spruce budworm mating behavior has concentrated on the use of the primary components /Zll-14 Ald s (95-97% E), and the results indicate that some mating disruption does occur. There appears to be a positive correlation between the applied pheromone concentration and the percent disruption, and based on field cage studies, percent disruption is inversely related to insect density (27) as would be predicted (32). 

Pheromone releaser distributions and/or point-source release rates have pronounced effects on the disruption of trap captures of spruce budworm (39). Small field plot studies with hand-placed releasers in moderate- to-high density budworm populations indicate an increase in trap disruption as the point sources of the synthetic pheromone are increased in release rate and decreased in number per unit area (Fig. 1). Identical pheromone dosages per plot were present in each treatment. Optimizing the releaser spacing and point-source release rate is therefore important and implies the need for a formulation re-design. This effect of releaser distribution and point-source release rate on trap disruption and mating disruption has been demonstrated in several insect species (40). 

Until a more detailed understanding of mating behavior, dispersal behavior and a complete identification of additional pheromone components is achieved, further field work on mating disruption with budworm can only proceed on an empirical basis. Additionally, treatment effects will be difficult to interpret unequivocally due to the local and long range movements of budworm adults into and out... 

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