Sex pheromone of the scarab beetle Phyllophaga (Phytalus) georgiana (horn).

The sex pheromone of Phyllophaga (Phytalus) georgiana was characterized as valine methyl ester, tentatively the L-enantiomer. This is the first sex pheromone identified from the Phyllophaga subgenus Phytalus. The pheromone was extracted from female glands, the active component isolated by coupled gas chromatography-electroantennogram detection analysis, characterized by mass spectrometry, and shown to be active in field tests. The seasonal flight pattern was determined for P. georgiana as well as for three other species, P. anxia (both northern and southern genitalic forms), P. gracilis, and P. postrema. The latter three species were captured in traps baited with L-isoleucine methyl ester.

Evaluation of Vaccinium spp. for Illinoia pepperi (Hemiptera: Aphididae) performance and phenolic content.

Host acceptance and population parameters of the aphid Illinoia pepperi (MacGillivray) (Hemiptera: Aphididae) were measured on highbush blueberry, Vaccinium corymbosum L. 'Elliott', and the wild species Vaccinium boreale Hall and Aalders, Vaccinium tenellum Aiton, Vaccinium pallidum Aiton, Vaccinium hirsutum Buckley, Vaccinium myrsinites Lamarck, and Vaccinium darrowi Camp. After 24 h of exposure, significantly fewer aphids remained in contact with V. boreale and V. hirsutum compared with V. corymbosum Elliott, V. darrowi, and V. pallidum. Length of the prereproductive period of I. pepperi was significantly longer on V. boreale and V. myrsinites, in contrast to V. corymbosum. Fecundity was also lower on V. boreale, V. hirsutum, V. myrsinites, and V. darrowi. Survivorship of I. pepperi 42 d after birth was significantly lower on V. hirsutum compared with the remaining Vaccinium spp. Reduced I. pepperi performance resulted in significantly lower intrinsic rate of increase (r(m)) values being associated with V. myrsinites, V. boreale, V. hirsutum, and V. darrowi, compared with V. corymbosum. Net reproductive rate (R(o)), generation time (T), and doubling time (T(d)) of I. pepperi also were affected by the Vaccinium spp. Total phenolic and flavonol content varied between Vaccinium spp., with some high phenolic content Vaccinium spp. having reduced aphid performance. However, no significant correlation between phenolics and I. pepperi performance was detected. Results from this study identified several potential sources of aphid resistance traits in wild Vaccinium spp.

Trapping Phyllophaga spp. (Coleoptera: Scarabaeidae: Melolonthinae) in the United States and Canada using sex attractants.

The sex pheromone of the scarab beetle, Phyllophaga anxia, is a blend of the methyl esters of two amino acids, L-valine and L-isoleucine. A field trapping study was conducted, deploying different blends of the two compounds at 59 locations in the United States and Canada. More than 57,000 males of 61 Phyllophaga species (Coleoptera: Scarabaeidae: Melolonthinae) were captured and identified. Three major findings included: (1) widespread use of the two compounds [of the 147 Phyllophaga (sensu stricto) species found in the United States and Canada, males of nearly 40% were captured]; (2) in most species intraspecific male response to the pheromone blends was stable between years and over geography; and (3) an unusual pheromone polymorphism was described from P. anxia. Populations at some locations were captured with L-valine methyl ester alone, whereas populations at other locations were captured with L-isoleucine methyl ester alone. At additional locations, the L-valine methyl ester-responding populations and the L-isoleucine methyl ester-responding populations were both present, producing a bimodal capture curve. In southeastern Massachusetts and in Rhode Island, in the United States, P. anxia males were captured with blends of L-valine methyl ester and L-isoleucine methyl ester.

Comparative effectiveness of different insecticides for organic management of blueberry maggot (Diptera: Tephritidae).

Laboratory and field assays using insecticides for organic pest management were conducted on the blueberry maggot, Rhagoletis mendax Curran. Topical exposure of flies to spinosad (Entrust), pyrethrum (PyGanic 1.4 EC), azadirachtin (Aza-Direct), and phosmet (Imidan 70-W) resulted in significantly higher mortality compared with the water control after 2 and 24 h. After 24 h, there were no significant differences in fly mortality among treatments of Entrust, PyGanic, or Imidan, whereas fly mortality to Aza-Direct was significantly lower. Another laboratory assay evaluated mortality of flies after residual exposure to these insecticides on leaves, after 24 and 48 h. In this assay, there were no significant differences in fly mortality after 48 h among treatments of PyGanic, Aza-Direct, and the water control, whereas significantly higher fly mortality resulted from exposure to Entrust and Imidan. A repellency assay found no measurable effects of Aza-Direct. Large-scale field trials found no treatment effect for number of adults of the blueberry maggot captured in sticky traps; however, there were significantly lower levels of fruit-infesting larvae in treated plots compared with the untreated control. Spinosad bait (GF-120 NF Naturalyte Fruit Fly Bait), Entrust, and PyGanic were not different from imidacloprid (Provado 1.6 F). However, there was a significantly higher infestation in the plot treated with azadirachtin (Agroneem) compared with Provado. Overall, the insecticides evaluated in these trials showed good ability to control blueberry maggot, suggesting that they can be incorporated in a blueberry maggot management program under organic standards.

Identification of a sex pheromone component for the blueberry leafminer, Caloptilia porphyretica.

Coupled gas chromatographic-electroantennographic detection (GC-EAD) of both gland extracts and effluvial collections from female blueberry leafminer, Caloptilia porphyretica Braun (Lepidoptera: Gracillariidae), showed that females produced a single EAD-active compound. The amount of the compound collected from virgin female C. porphyretica was below GC and mass spectrometry (MS) detection thresholds, even with highly concentrated gland extracts (approximately 150 female equivalent). (E)-11-Hexadecenal (E11-16:Ald) was determined to be a sex pheromone component mainly by comparison of retention times with authentic standards on both polar and nonpolar capillary columns, microreaction-GC-EAD analyses, and field trapping tests. GC-EAD experiments showed that synthetic E11-16:Ald exhibited extraordinarily high electrophysiological activity, stimulating significant male antennal responses at as low as 10 fg. Traps baited with E11-16:Ald alone were attractive to males. Addition of 1 or 3% of its geometric isomer, Z11-16:Ald, to E11-16:Ald did not significantly increase trap captures, but an inhibitory effect was observed at the 10% level. The influence of two kinds of rubber septa on attraction was also evaluated. Male moth captures were higher in traps baited with red rubber septa than with gray rubber septa at 30-300-microg doses. Monitoring of adult flight activity with 3-microg doses of E11-16:Ald indicated at least three distinct flight periods throughout the 2003 season.

Feeding activity and attraction of blueberry maggot (Diptera: Tephritidae) to protein baits, ammonium acetate, and sucrose.

Attraction and feeding assays were conducted on blueberry maggot, Rhagoletis mendax Curran, to three protein baits, ammonium acetate, and sucrose. Flies fed significantly longer on concentrations of 25 and 50% SolBait than they did on any of the concentrations tested for Nu-Lure, AY50% (Mauri Yeast Australia), or a water control. The number of flies arriving at SolBait in an attraction assay was significantly higher than for Nu-Lure and a water control but was not different from AY50%. Flies fed less on aqueous solutions of 1 and 4% ammonium acetate, a known fruit fly attractant, than they did on either 0.25% ammonium acetate or water. Aqueous concentrations of 8, 16, and 32% sucrose elicited greater feeding responses from flies than either 4% sucrose or water. These findings suggest that SolBait is a superior protein bait based on attraction and feeding assays. Development of alternative baits should contain at least 8% sucrose, as a significant feeding stimulant, and some amount of ammonium acetate as an attractant. Future work should determine whether the feeding deterrence of ammonium acetate could be reduced or even eliminated in the presence of sucrose.

Phenology and infestation patterns of plum curculio (Coleoptera: Curculionidae) on four highbush blueberry cultivars.

The plum curculio, Conotrachelus nenuphar (Herbst), is a well known pest in apple and peach orchards, but it also is capable of having an economic impact in highbush blueberries. Host phenology and plum curculio oviposition patterns were determined on four highbush blueberry cultivars differing in fruit maturation period. Numbers of oviposition scars were higher on early- ('Weymouth') and mid-season ('Duke' and 'Bluecrop') blueberries than on late-season 'Elliott' in 2001, 2002, and 2003. In 2002, eggs were first present on the three earliest cultivars 21 d before those on 'Elliott', whereas eggs were found on 'Elliott' >40 d after the last sample with eggs for the other three cultivars. The pattern of host phenology and infestation levels suggested that plum curculio oviposition synchronizes well with the availability of suitable fruit for oviposition on early and mid-season cultivars compared with a late-season cultivar of highbush blueberries. The implications of a transition to use of reduced-risk insecticides are discussed in relation to plum curculio management.

Evaluation of traps and toxicants in an attract-and-kill system for Rhagoletis mendax (Diptera: Tephritidae).

A series of laboratory and field assays were performed to evaluate new methods for an attract-and-kill approach to control blueberry maggot, Rhagoletis mendax Curran. In laboratory assays, fly mortality was similar among insecticide-treated matted paper, plastic, and biodegradable sphere traps. Plastic and biodegradable traps baited with ammonium acetate captured significantly more flies than baited matted paper traps in field assays, whereas fly captures were similar in baited matted paper traps and unbaited plastic sphere traps. Treatments containing imidacloprid resulted in the highest amount of fly knockdown, and spheres coated with this insecticide still had significant knockdown after 6 wk of field exposure. Fly mortality was comparable on sphere traps coated with fipronil and imidacloprid, with both resulting in significantly more fly mortality than the control when flies were exposed to traps that had been weathered for 4 wk in the field. Spheres coated with acetamiprid resulted in fly mortality, but further evaluation is necessary to determine the potential of this compound. Deltamethrin was ineffective in causing fly knockdown at the rate tested. Our results indicate that fipronil and imidacloprid have potential as insecticidal coatings on either plastic or biodegradable spheres in an attract-and-kill system for control of R. mendax.

Sex pheromone of the cranberry blossom worm, Epiglaea apiata.

The cranberry blossom worm, Epiglaea apiata (Grote) (Lepidoptera: Noctuidae), is a major pest of cranberries in New Jersey. The female sex pheromone of this moth was identified as a blend of (Z)-9-hexadecenyl acetate (Z9-16:Ac), (Z)-9-tetradecenyl acetate (Z9-14:Ac), and tetradecyl acetate (14:Ac) by gas chromatographic-electroantennographic detection and gas chromatography-mass spectrometry. The ratio of the components in extracts of the female pheromone gland was determined to be 65:2:33 of the Z9-16:Ac, Z9-14:Ac, and 14:Ac, respectively. The double bond positions of the pheromone components were confirmed by dimethyl disulfide derivatization. In addition to the above three components, a mixture of C4-C10 aliphatic acids was present in both gland extracts and effluvia collections, and the acids elicited significant EAD responses from male moth antennae. However, addition of the C4-C10 aliphatic acids to the pheromone blend did not significantly increase trap captures. Three-hundred- and 1000-microg doses of a synthetic blend containing Z9-16:Ac, Z9-14:Ac, and 14:Ac (65:2:33), on a rubber septum were more attractive to males than lower doses.