Enniatins fromFusarium avenaceum isolated from balsam fir foliage and their toxicity to spruce budworm larvae,Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae)

Material extracted from hyphae ofFusarium avenaceum, isolated from foliage of balsam fir,Abies balsamea, was toxic to spruce budworm larvae when incorporated into insect diet. The major insecticidal component of the toxic fraction was identified by chemical and spectroscopic methods as enniatin complex, rich in enniatin A/A₁. Possible ecological implications of these observations are considered.     

Repellency of oral exudate to eastern and western spruce budworm larvae (Lepidoptera: Tortricidae)

A two-choice feeding bioassay was used to investigate the intra-specific repellency of the larval oral exudate of eastern and western spruce budworms,Choristoneura fumiferana (Clem.) andC. occidentalis Free., respectively. Results of the bioassay indicated that feeding behavior on artificial diet-drop feeding stations was modified in the presence of exudate, with feeding stations treated with conspecific exudate being avoided when an untreated station was available 3 cm away. Feeding was suppressed when a single, exudate-treated station was provided, or when the treated and untreated stations were separated by only 1 cm. The repellent effect functioned both inter- and intraspecifically. When induced to produce exudate,C. occidentalis larvae were not immediately repelled by either their own or other individuals' exudate. However, 24 hr after induction, test larvae were repelled by exudate from either source. In both species, larval oral exudate probably functions to repel conspecific competitors.     

Tests for induction of feeding preferences in larvae of eastern spruce budworm using extracts from three host plants

Feeding preferences to extracts from three host plants were determined for sixth-instar eastern spruce budworm larvae reared on one of three hosts or on artificial diet. Preferences of foliage-reared larvae were compared to those of diet-reared, or naive, larvae. No effect of plant induction was found using amino acids and bases and chloroform extracts on test disks in three-choice experiments. Possible effects of habituation for sugars and glycosides from white spruce were shown. Organic acids contributed to a phenomenon of avoidance learning in larvae reared on all three hosts, showing that this fraction from balsam fir was the least deterrent, while that from black spruce was the most deterrent.     

Olfactory response of eastern spruce budworm larvae to red spruce needles exposed to acid rain and elevated levels of ozone

Second-instar eastern spruce budworm larvae,Choristoneura fumiferana (Clem.), were tested in a two-choice, Y-type, wind-tunnel olfactometer for preferences for red spruce,Picea rubens Sarg., needles exposed for eight weeks to charcoal-filtered air (CFA) or 0.15 ppm ozone (O₃) in combination with acidified rainfall at pH 4.2 or 3.0. Volatiles from needles treated with CFA plus pH 4.2 rain (control) were preferred over those from needles exposed to pH 3.0 rain + O₃ or O₃ alone; O₃-treated needles were chosen over those exposed to pH 3.0 rain + O₃. No preference was shown between the pH 4.2 and 3.0 rain treatments. Larvae chose purified air flowing through the olfactometer in preference to needle volatiles from the pH 3.0 rain + O₃ treatment.The use of trade, firm, or corporation names in this paper is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the U.S. Department of Agriculture or the Forest Service of any product or service to the exclusion of others that may be suitable.     

Behavioral responses of the female eastern spruce budwormChoristoneura fumiferana (Lepidoptera,Tortricidae) to the sex pheromone of her own species

Female eastern spruce budworm moths respond to the synthetic sex pheromone of their own species (a mixture ofcis- andtrans-11-tetradecenal) by walking, antennal grooming, flexation of the body, extension of the ovipositors, and oviposition. The sex pheromone is perceived by receptors on the antennae. Electroantennogram responses from the female are approximately two-thirds the amplitude of those obtained from males.     

Feeding preferences of eastern spruce budworm larvae in two-choice tests with extracts of mature foliage and with pure amino acids

The feeding preferences and feeding rates of eastern spruce budworm on extracts from mature foliage normally avoided by larvae indicate that the chemical composition of four major host plants does not account for this avoidance. Other factors such as the degree of lignification and/or moisture content of the older foliage may play a more important role. Of 14 amino acids tested, alanine, lysine, proline, and serine stimulated feeding. The interactions of amino acids and sucrose were studied, and the results are discussed in relation to feeding preferences and feeding rates.     

Sex pheromone chemistry of the western spruce budwormChoristoneura occidentalis Free

SCOT capillary Chromatographic and SCOT capillary chromatographic-mass spectrometic analyses of gland washes and effluvia of virgin femaleChoristoneura occidentalis Free, have been conducted with both a diapausing and nondiapausing strain of this insect. The following compounds were identified in gland washes and effluvia in both strains:E andZ11–14Ald,E andZ11–14Ac,E andZ11–14OH and 14Ald, 14Ac, and 14OH. The average aldehyde: acetate: alcohol ratio found by analysis of single glands by virgin females (nondiapausing strain) was 170.73. Analysis of virgin female effluvia gave this ratio as 1038 (diapausing strain: %Z=8, 11, 15, respectively) and 1036 (nondiapausing strain: %Z=8, 11, 12, respectively). The saturated components were generally 1–2% of theE isomer in each case. Comparisons of EAG responses of bothC. occidentalis andC. fumiferana toE11–14Ald,E11–14Ac andE11–14OH were made. Correlations with both laboratory and field data previously published were also made betweenC. fumiferana andC. occidentalis.Lepidoptera: Tortricidae.     

Feeding preferences of spruce budworm (Choristoneura fumiferana Clem.) larvae to some host-plant chemicals

Single-choice and three-choice tests were used to determine the relative importance of host-plant chemical extracts in eliciting feeding by spruce bud worm larvae. Water-soluble components of the host trees are the most important and, of these, the sugar and glycoside fractions are the most stimulating. The amino acid and organic base fractions have no apparent effect. The organic acid fractions deter feeding slightly.Lepidoptera: Tortricidae.Supported by the National Sciences and Engineering Research Council of Canada, Operating Grant No. A9723 to P.J.A.     

Synthesis of pungenin,a foliar constituent of some spruce species,and investigation of its efficacy as a feeding deterrent for spruce budworm [Choristoneura fumiferana (Clem.)]

Pungenin was synthesized from 3,4-dihydroxyacetophenone by a short sequence involving manipulation of protecting groups on the 3 and 4 hydroxyl functions. Bioassays indicated that the glucoside is a modest feeding deterrent for sixth-instar spruce budworm larvae, but it does not appear to retard the development of small larvae or lead to increased mortality.     

Attraction of male spruce budworm moths,Choristoneura fumiferana (Clemens), to pheromone-baited traps in small-tree thinnings

Mean catches of spruce budworm,Choristoneura fumiferana (Clemens), moths were not significantly different among four small-tree thinning treatments of young spruce-fir-hemlock regeneration. Significant inverse relationships were found between trap catches and distances to nearby spruce-fir-hemlock overstory. Prevailing wind directions indicated that moths were attracted anemotactically to upwind pheromone sources. No definite trends were detected between catches and temperature or precipitation.Lepidoptera: Tortricidae.A contribution to the Canada/ United States (CANUSA) Spruce Budworms Program. Mention of proprietary products does not constitute an endorsement of those products by the USDA.     

Effect of foliage proximity on attraction ofChoristoneura occidentalis andC. retiniana (Lepidoptera: Tortricidae) to pheromone sources

Pheromone-baited traps located close to both host and nonhost crowns were more attractive than traps located between crowns for bothC. occidentalis Freeman andC. retiniana (Walsingham) at both 10 m and at 1.5 m above the ground. At 10 m height, traps located in host foliage were more attractive than those located in nonhost foliage, but at 1.5m height there was no significant difference. These results were obtained for both dense and sparse populations ofC. occidentalis and sparse populations ofC. retiniana. We conclude that the tree species on which a virgin female is located is not an important factor restricting mating between closely relatedChoristoneura spp. Also, the tree species on which a trap is located may not be an important factor that must be standardized in developing pheromone monitoring systems forC. occidentalis andC. retiniana.     

Feeding responses of eastern spruce budworm larvae to sucrose and other carbohydrates

Spruce budworm larvae reared on an artificial diet were tested for preference of twelve carbohydrates over a water control. A strong preference for sucrose was seen, followed by fructose, inositol, and glucose. Male and female larvae do not differ in their responses to sucrose. The behavioral threshold for sucrose is at 10^–4 to 10^–3 M, with a peak response in the range of 0.01 to 0.05 M sucrose. Choristoneura fumiferana (Clem.) (Lepidoptera: Tortricidae).Work leading to this publication was funded in part by a USDA Forest Service sponsored program entitled Canada/United States Spruce Budworms Program (grant 23–352), and in part by the National Sciences and Engineering Council of Canada (operating grant A9723), and in part by the Whitehall Foundation.     

Spruce budworm (Choristoneura fumiferana) pheromone chemistry and behavioral responses to pheromone components and analogs

This paper reviews the sex pheromone chemistry and pheromone-mediated behavior of the spruce budworm and related coniferophagous (Choristoneura) budworms. InC. fumiferana, temporal changes in pheromone-gland monounsaturated fatty acids (pheromone precursors) enable the prediction of the primary sex pheromone components. This technique may also be applicable for predicting additional pheromone components. Tetradecanal (14 Ald), previously shown to enhance close-range precopulatory behavior, lowers the threshold of response by males for upwind flight to a pheromone-component source. Spruce budworm males maintain upwind flight to 955 (E/Z)-1,12-pentadecadiene (diolefin analog) after initiating upwind flight to a primary-component pheromone source (955E/Z11-14Ald). This is the first demonstration of apparently normal male flight responses to a pheromone analog.Lepidoptera: Tortricidae     

Behavioral effects of secondary components of sex pheromone of western spruce budworm (Choristoneura occidentalis) free

In a laboratory wind tunnel, upwind flight and close-range orientation to a pheromone source by maleC. occidentalis were facilitated by the addition of the secondary componentsE/Z11-tetradecen-1-ol acetate (8911) andE/Z11-tetradecen-1-ol (8515) to low source concentrations of the primary components,E/Z11-tetradecenal (928). Male responses to the blends tested never equalled their responses to virgin females. The primary components alone, when released at a rate similar to that of a calling female, never elicited male upwind flight or source location. However, the addition of the secondary components enhanced these behavioral sequences.Lepidoptera: Tortricidae.     

(E)-11,13-tetradecadienal: Major sex pheromone component of the eastern blackheaded budworm,Acleris variana (Fern.) (Lepidoptera: Tortricidae)

(E)-11,13-Tetradecadienal (E11,13–14:Ald) is the major sex pheromone component of the eastern blackheaded budworm (EBB),Acleris variana (Fern.). The compound was identified in female pheromone gland extracts by coupled gas chromatographic-electroantennographic detection (GC-EAD), coupled GC-mass spectrometry in selected ion monitoring mode, and retention index calculations of candidate pheromone components.E11,13–14:Ald alone as trap bait was very attractive to male EBB. Addition of the corresponding diene alcohol or acetate or both did not enhance attraction. (Z)-11,13-Tetradecadienal in binary combination with (E)-11,13–14:Ald neither enhanced nor reduced trap catches. Increasing the amounts of pheromone from 0.01 to 10 µg increased trap catches, but increase of pheromone quantity above 100 µg proportionately reduced attraction. Stabilization of slowly polymerizingE11,13–14:Ald and development of a sustained, adequate release rate is required for pheromone-based monitoring of EBB populations.     

Calling behavior and pheromone titer in the smaller tea tortrix moth,Adoxophyes sp. (Lepidoptera: Tortricidae)

The calling behavior and pheromone titer in the female smaller tea tortrix moth,Adoxophyes sp., were investigated under a 1410-hr light-dark photoperiod. Quantitative gas chromatographic analysis of ovipositor extract for (Z)-11-tetradecenyl acetate (Z11–14Ac) and (Z)-9-tetradecenyl acetate (Z9–14Ac), the major pheromone components of this species, obtained on the third day postemergence, indicated that extractable amounts of sex pheromone were present throughout the period of observation. Maximal pheromone titer and calling activity was reached at 8 and 10 hr after onset of scotophase, respectively. The ratio ofZ11–14Ac toZ9–14Ac through the 24-hr period varied significantly. The significance of the sex pheromone component ratio variation on the attraction of males was tested in a field experiment. The ratio of males trapped by the most attractive blend versus the least attractive one was 2.16.     

(Z,Z)-7,9-Dodecadienyl acetate,sex pheromone ofEpinotia tedella clerck (Lepidoptera: Tortricidae)

(Z,Z)-7,9-dodecadienyl acetate, a reported male attractant for several New World spp. ofEpinotia, was identified as the primary pheromone of femaleE. tedella (European spruce budmoth) through chemical analysis of pheromone gland washes, the electrophysiological study of male antennal receptor types, and field-trapping tests. The washes contained this compound at a level of approximately 0.4 ng per FE, along with a similar amount of the corresponding alcohol, (Z,Z)-7,9-dodecadien-1-ol. Each compound activated its own specialized type of male receptor cell. No traces of stereoisomers or monoenes were found in the washes. In field-trapping tests conducted in stands of Norway spruce in southern Germany, (Z,Z)-7,9-do-decadienyl acetate as a single chemical proved highly attractive to maleE. tedella over a range of lure doses. The corresponding alcohol or aldehyde did not show attractivity; rather, in binary combinations with the primary pheromone, these compounds, and also the (E,Z)-7,9 stereoisomeric acetate, reduced captures. A 101 blend of (E)-9- and (Z)-9-dodecenyl acetates, reported as anE. tedella male attractant, did not reveal significant captures. No otherEpinotia spp. besidesE. tedella responded to the various 7,9-do-decadienyl test baits during this study.     

Application of sex attractants for monitoring the pea moth,Cydia nigricana (F.) (Lepidoptera: Tortricidae)

The use of sex attractants to monitor the pea moth,Cydia nigricana (F.) in the United Kingdom is decribed. Two systems are currently available: one for use in combining (dry-harvested) peas for human consumption or seed, and one for use in vining peas for freezing or canning. The development and details of both systems are reviewed and their commercial application discussed.     

Individual variation in sex pheromone of smaller tea tortrix moth,Adoxophyes sp. (Lepidoptera: Tortricidae)

Female smaller tea tortrix mothsAdoxophyes sp. (Lepidoptera: Tortricidae), which initiated calling at 1, 2, or 3 days old, respectively, were analyzed individually for (Z)-11-tetradecenyl acetate (Z11-14:OAc) and (Z)-9-tetradecenyl acetate (Z9–14: OAc) in the pheromone gland via GLC. Among different age groups, broad and similar distributions were found for pheromone quantity (¯X=58.6±52.9 ng/female; range 1.3–219.8 ng/female). The ratio of the two pheromone components averaged 6535 but ranged from 8416 to 4060. The significance of the pheromone blend variation to the attraction of males was tested in a field experiment. The ratio of males trapped by the most attractive blend versus the least attractive one was 2.2.     

Sex pheromone ofPandemis heparana (Den. and Schiff.) (Lepidoptera:Tortricidae)

90% (Z)-11-tetradecen-1-yl acetate, 5% (Z)-9-tetradecen-1-yl acetate, 5% (Z)-11-tetradecen-1-ol, dodecyl acetate (<1%), and tetradecyl acetate (<1%) were identified from gland extracts ofPandemis heparana females by gas chromatography and gas chromatography-mass spectrometry analysis (including mass fragmentography studies), chemical characterization, total synthesis, laboratory and field bioassays. In the field, a mixture of (Z)-11-tetradecen-l-yl acetate and (Z)-9-tetradecen-l-yl acetate (955) was found to be essential for attractiveness ofP. heparana males.