J. R. McLaughlin

Chemical composition of some components of the arrestment pheromone of the black-legged tick, Ixodes scapularis (Acari: Ixodidae) and their use in tick control.

Abstract Chemical analysis (high-performance liquid chromatography) and bioassay demonstrated the presence of compounds that seem to be components of the Ixodes scapularis arrestment pheromone. Only two purines, guanine and xanthine, were found in acidified saline extracts made from cast skins after molting of fed nymphs, fed larvae, and fecal/excretory exudates deposited by unfed adults on substrates in their environment. The ratio of guanine to xanthine was 10.6:1 in an extract from the nymphal skins versus 0.95:1 in an extract from the larval skins. Guanine, xanthine, and traces of a third purine, tentatively identified as 8-azaguanine, were found in extracts made from filter paper strips or washings from glass vials contaminated with tick feces and excreta left by unfed adults. 8-azaguanine may be a product of microbial degradation of the other purines rather than a natural product from the ticks. Low concentrations of ammonia also were detected in saline extracts of excreta from feeding ticks. Hematin also was found in NH4OH extracts of the black fecal/excretory exudates deposited by the unfed ticks. Hematin was tentatively identified by comparison of spectra with that of the authentic standard. Bioassays demonstrated a strong positive arrestment response to cast skins found to contain a mixture of guanine and xanthine and to black fecal/excretory exudates containing guanine, xanthine, the putative 8-azaguanine, and hematin. A Noldus video tracking system using a CCD video camera and Ethovision Pro tracking software showed statistically significant increases in the frequency of visits to the treated zone versus the control. Ticks were significantly more likely to assemble in response to the tick exudates within as little as 3 h compared with the controls. Previous bioassay studies also showed strong positive responses to guanine, xanthine, other purines, and hematin. Comparisons with the arrestment pheromones of other tick species are described. The inclusion of the pheromone components in a permethrin-impregnated oily matrix, Last Call, increased the lethal activity of the product to 95% compared with only 65% in the formulation with permethrin alone. More detailed knowledge of I. scapularis arrestment pheromone may be useful for improving the efficacy of this tick-killing technology even further.

Identification of the white peach scale sex pheromone

Micro techniques were used to obtain spectroscopic and degradative information from less than 5μg of the sex attractant of female white peach scale,Pseudaulascaspis pentagons (Targioni-Tozzetti) isolated from airborne collections. The pheromone was identified as (Z)-3,9-dimethyl-6-isopropenyl-3,9-decadien-1-ol propionate. Both enantiomers of theZ isomer and also the enantiomers of theE isomer were prepared from (R)-or (S)-limonene. Bioassays of material with minimum enantiomeric purity of 95% showed that at extreme dilution only theR,Z isomer attracted male white peach scale; however activity of theS,Z enantiomer could not be completely excluded.

Use of paired and single traps to assess perception and discrimination of sex pheromone mixtures in the field byTrichoplusia ni (Hübner)

Paired wind-oriented traps (WORT) and single traps were deployed simultaneously in the same field to investigate whether or not inferences about the central nervous system processes of discrimination and perception can be made from differences in moth captures. The stimulus levels deployed were those that typically may be found downwind of a calling virgin female cabbage looper,Trichoplusia ni (Hübner), so that inferences are relevant to natural stimulus intensities. Captures of male cabbage loopers in the WORT traps paralleled prior laboratory measures of pheromone mixture discrimination. The pattern of captures by the two trapping systems probably reflects perceptive and discriminative processing differences in the central nervous system. Captures in traps baited withZ7–12: Ac alone were equal to, or better than, captures in traps baited with three- and six-component mixtures that containedZ7–12: Ac.

Field and Laboratory Evaluation of Mating Disruptants of Heliothis Zea and Spodoptera Frugiperda in Florida

The corn earworm (cotton bollworm, tomato fruit worm), Heliothis zea (Boddie), is one of the most destructive pests of many valuable crops in the United States and in Central and South America. Estimated losses within the United States attributable to this pest exceed

Air permeation tests with (Z,Z)-3,13-octadecadien-1-ol acetate for reduction in trap catch of peachtree and lesser peachtree borer moths.

500 million annually (unofficial estimates of USDA entomologists per authors’ survey).

Behavioral response of male white peach scale to the sex pheromone, (R,Z)-3,9,-dimethyl-6-isopropenyl-3,9-decadien-1-ol propionate and corresponding alcohol

Air permeation trials were conducted to determine whether trap catches of the peachtree borer (PTB)Synanthedon exitiosa (Say) and lesser peachtree borer (LPTB)S. pictipes (Grote and Robinson) could be reduced through application of the synthetic pheromone of the PTB, (Z,Z)-3,13-octadecadien-1-ol acetate (Z,Z-ODDA), at 92% isomeric purity. The pheromone was released into the air of peach orchard test plots with hanging laminated plastic dispensers or hollow fiber dispensers in the trees and by aerial dispersal of microcapsules containing a solution of the lure. Results showed that all formulations ofZ, Z-ODDA reduced trap catches of both PTB and LPTB in treated plots relative to catches in traps in untreated plots. In one air permeation experiment, three types of laminated dispensers and one type of hollow fiber dispenser each reduced trap catch of PTB by 93–100% and of LPTB by 75–95%. In a separate test, two formulations of microencapsulatedZ,Z-ODDA did not reduce trap catch of male PTB as effectively as the laminated dispenser; results for LPTB were similar for both the dispensers and microcapsules. Catches of male PTB moths in traps baited with laminated and or fiber pheromone dispensers containing ODDA (94∶6%Z,Z∶E,Z) were not significantly different. LPTB male moths were also captured in these traps, the catches being dependent upon the initial pheromone loading and the type of dispensers.

Pheromone trap for the eastern tent caterpillar moth

Males of the white peach scale,Pseudaulacaspis pentagona (Tar-gioni-Tozzetti), in Florida differ from this scale in France in their responses to putative pheromonal chemicals presented in a laboratory bioassay. Males from Florida were attracted to, and exhibited sexual (coputatory) behaviors at, the locus of evaporation of (R,Z)-3,9-dimethyl-6-isopropenyl-3,9-deca-dien-1-ol propionate (P) (previously identified from effluvia of Florida females). Addition of the corresponding primary alcohol (A) to the propionate did not alter the attraction of Florida males to the synthetic P and did not alter their sexual responses from those exhibited by males exposed to P alone. In contrast, the effluvia from French scales has been reported to contain P and A, and the alcohol has been reported in laboratory studies to be required to release sexual behavior in French males. This suggests that the conspecific status of the scale in Florida and France should be reexamined. Field trap baits with 2.5 μg of a 1∶ 1 mixture of P and A captured significantly fewer Florida males than traps baited with 1.25 μg of P alone, but traps similarly baited with 0.125 μg of each material captured the same number of insects as traps baited with 0.125 μg of P alone.

Periodicity of pheromone release from female white peach scale.

Abstract The discovery that the eastern tent caterpillar Malacosoma americanum (F.) causes mare reproductive loss syndrome (MRLS), and thus has the potential to continue to result in major economic losses to the equine industry of Kentucky, has resulted in an intensive effort to identify practical means to monitor and control this defoliator, including these experiments to optimize a sex pheromone trap for this pest. A pheromone-baited delta trap with a large opening, such as InterceptST Delta, was more effective than other tested traps. Orange delta traps caught more moths than other tested colors. ETC males are caught at all tested heights within the tree canopy. For monitoring flights, setting traps at 1.5 m would allow easy counting of moths. A 9:1 blend of (E,Z)-5,7-dodecadienal (ETC-Ald) and (E,Z)-5,7-dodecadienol (ETC-OH) was most effective in capturing males. Increasing loading doses of a 3:1 blend (Ald:OH) resulted in the capture of increasing numbers of moths, but a 9:1 blend was more effective than 3:1 blend even at a nine-fold lower loading rate. Pheromone-impregnated white septa caught more moths than gray septa at the same loading dose. The advantages and limitations of using pheromone traps for monitoring M. americanum are discussed.

Perception of Z-7-dodecen-1-ol and Modification of the Sex Pheromone Response of Male Loopers

ABSTRACT The sex pheromone of the female white peach scale, Pseudaulacaspis pentagona (Targioni‐Tozzetti), is released by newly‐mature females to correspond with the daily eclosion rhythm of males. As with male eclosion, pheromone release commences relative to the onset of light and is suppressed by increasing temperature. Once pheromone release begins it is maintained until the initiation of the scotophase. Pheromone release does not occur during the scotophase. When sexually mature females remain unmated for 5 days, the release of pheromone begins earlier in the day than it does with newly mature females.