Knowledge of how insects are actually affected by sex pheromones deployed throughout a crop so as to disrupt mating has lacked a mechanistic framework sufficient for guiding optimization of this environmentally friendly pest-control tactic. Major hypotheses are competitive attraction, desensitization, and camouflage. Working with codling moths, Cydia pomonella, in field cages millions of times larger than laboratory test tubes and at substrate concentrations trillions of times less than those typical for enzymes, we nevertheless demonstrate that mating disruption sufficiently parallels enzyme (ligand) -substrate interactions so as to justify adoption of conceptual and analytical tools of biochemical kinetics. By doing so, we prove that commercial dispensers of codling moth pheromone first competitively attract and then deactivate males probably for the remainder of a night. No evidence was found for camouflage. We generated and now validate simple algebraic equations for attraction and competitive attraction that will guide optimization and broaden implementation of behavioral manipulations of pests. This analysis system also offers a unique approach to quantifying animal foraging behaviors and could find applications across the natural and social sciences. Mating disruption of insects is the agricultural practice of dispensing synthetic sex attractant into a crop so as to suppress pest reproduction by interfering with mate finding (1). The Environmental Protection Agency expects this environmentally friendly pest management tactic to effectively supplement the "softer" insecticides as well as to fill critical control gaps left as "harder" insecticides face withdrawal from the marketplace due to tightening governmental regulations (2-4), e. g., azinphos methyl (Guthion) in apple production. There are now more than 100 EPA registrations of insect pheromones for use as pest control agents in agriculture and forestry. Mating disruption for all pests encompasses ≈700,000 ha (5), 160,000 of which target codling moth, Cydia pomonella, the proverbial worm in the apple.Despite 40 years of research and the emergence of a vigorous and expanding worldwide pheromone industry (5, 6), knowledge of how sex pheromones actually interact with target insects as individuals and groups under disruption has lacked a mechanistic framework sufficient for judging whether current practices for implementing mating disruption have been optimized. Here, we introduce and experimentally validate both attraction and competitive-attraction equations as well as a unique analysis system. Their utility in understanding and manipulating animal behaviors might parallel those of the Michaelis-Menten equation and classical enzyme kinetics in biochemistry.Derivation of Equations. Wind traversing a pheromone point source sweeps out an odor plume whose active space and interactions with male moths are schematically represented in Fig. 1. Cumulative catch (C) of male moths (♂) in a trap (T) (Fig. S1 presents pictures of apparatus) baited with a pheromone...

Two anthelmintic drugs used as cattle dewormers, ivermectin and moxidectin, were tested for their lethal and sublethal effects on the malarial vectors Anopheles gambiae s.s. and An. arabiensis. In the laboratory, direct addition of ivermectin to bovine blood reduced the survivorship and fecundity of mosquitoes fed on the blood. The median lethal concentration (LC(50)) of ivermectin in the bloodmeal, for the laboratory populations of An. gambiae s.l., was 19.8 ppb. In the field, commercially available formulations containing ivermectin or moxidectin were injected into cattle at three times the recommended dose. Most (90%) of the An. gambiae s.s. that fed on the ivermectin-treated cattle within 2 weeks of treatment failed to survive more than 10 days post-bloodmeal. No eggs were deposited by An. gambiae s.s. that fed on ivermectin-treated cattle within 10 days of treatment. In contrast, the survivorship and egg production of the mosquitoes that fed on the moxidectin-treated cattle were no different from those feeding on untreated cattle. These results indicate that treatment of cattle with ivermectin could be used, as part of an integrated control programme, to reduce the zoophilic vector populations that contribute to the transmission of the parasites responsible for human malaria.

A scheme updating that of Dethier et al. (1960) (J. Econ. Entomol. 53: 134-136) for chemicals influencing insect locomotor behavior is introduced. Attractant, repellent, and arrestant retain their previous definitions. However, attractants or repellents are now recognized to operate both by kinetic and tactic mechanisms. Locomotor initiator is a new term for stimuli that activate normal levels of kinetic locomotion. Locomotor stimulant is reserved for activation of abnormally high kinetic locomotion, like that arising upon sublethal exposure to certain insecticides. The new terms engagent and disengagent apply to chemicals that, by their effects on locomotion, increase or decrease interaction with the source of stimulation, respectively. With these clarifications, insect behavioral terms unique to medical entomology but contradicting Dethier et al.'s classical scheme can be reconciled with the vocabulary of formal behavioral science.

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A novel emulsiWed wax dispenser (SPLAT-OFM) of pheromone was evaluated in concert with a custom-built, tractor-mounted applicator, designed for fast application of dispensers for mating disruption of Oriental fruit moth, Grapholita molesta (Busck), in apple. The formulation consisted of microcrystalline wax emulsiWed in water. It was loaded with G. molesta pheromone (93:6:1 blend of (Z)-8-dodecen-1-yl-acetate:(E)-8-dodecen-1-yl-acetate:(Z)-8-dodecen-1-ol) at 10% by weight. The hydraulically driven applicator dispensed the wax formulation as discrete particles from a rotating double-oriWce distributor positioned directly above the tree canopy. Wax-drop size averaged ( §SEM) 0.38 § 0.16 g and 4.3 § 0.5 drops adhered per tree. Following a single mechanized application of SPLAT-OFM on 24 April at 8 ml per tree (1.6 kg/ha) to 0.8 ha blocks of apple, male G. molesta orientation to optimally attractive pheromone traps was disrupted by 98% relative to untreated control plots for the whole season. Furthermore, on 17 weekly deployments of tethered virgin females (1,016 females deployed and 732 recovered for dissection) throughout the season, no mating was detected in SPLAT-OFMtreated blocks, while mating in control blocks averaged 27%. During the Wrst 17 days following deployment in sticky traps, SPLAT-OFM drops attracted ca. 1/46th of the number of male G. molesta attracted to optimized synthetic lures. However, following 17 days of Weld aging, SPLAT-OFM drops became equally attractive to optimized synthetic lures for the remainder of the season. The release rate of pheromone from wax drops 0-14 and 15-76 days following deployment averaged 21.4 and 5.3 g/h, respectively. The trapping and release rate data were consistent with competitive attraction as the mechanism mediating disruption. Shoot injury following the Wrst moth generation was sevenfold less in SPLAT-OFM treated blocks compared with controls and fruit injury at the end of the season in treated blocks was approximately half of that recorded in controls.