Tachinid flies (Diptera: Tachinidae) reared from deciduous plant-feeding lepidopteran larvae at Hokkaido University Tomakomai Forest (Japan), with descriptions of three new species

Seven species of tachinid flies reared from herbivorous lepidopterans collected from the deciduous forest canopy at Hokkaido University Tomakomai Experimental Forest (0.2 ha plot), Hokkaido, Japan, are recorded and described: Blepharomyia brevicornis sp. nov. ex Erannis golda Djakonov (Geometridae), Catocala lara Bremer and Orthosia odiosa (Butler) (both Noctuidae); Ctenophorinia grisea Mesnil ex Himeropteryx miraculosa Staudinger (Notodontidae); Blepharipa carbonata (Mesnil) ex Marumba jankowskii (Oberthür) (Sphingidae); Cyzenis equifacialis sp. nov. ex Faristenia geminisignella Ponomarenko (Gelechiidae), Archips crataegana (Hübner), A. nigricauda Walshingham, Epinotia exquisitana Christoph and Pseudohedya gradana Christo (all Tortricidae); Cyzenis tetrasetosa sp. nov. ex Lomographa simplicior (Butler), Operophtera brunnea Nakajima and O. relegata Prout (Geometridae); Eulasiona zimini Mesnil ex Archips crataegana (Hübner), Pseudohedya gradana (Christoph), Rhopobota naevana (Hübner) and Rhopobota sp. (all Tortricidae); Panzeria sp. (nr. japonica Shima) ex Erannis golda Djakonov (Geometridae). The genus Eulasiona Townsend is moved to the subfamily Tachininae from its present position in the subfamily Dexiinae, and the female and puparium of Eulasiona zimini Mesnil are described for the first time. The parasitization rates and life habits of these tachinids are briefly discussed.

Insect pests of wild cranberry, Vaccinium macrocarpon, in Newfoundland and Labrador

Cranberry (Vaccinium macrocarpon) has been commercially developed since the late 1990's in Newfoundland and Labrador. At that time, the insect fauna of the extensive stands of native, wild cranberry was not known, although these might provide a reservoir for pests to move to commercial sites. The occurrence and distribution of cranberry-feeding insects were assessed in wild stands to help cranberry growers prepare for the insect pests they might have to manage. Adults of the cranberry fruitworm, Acrobasis vaccinii were recovered in pheromone traps and larvae found in berries. The fruitworm was common and widespread. Moths of the cranberry girdler, Chrysoteuchia topiaria were caught in pheromone traps, but larvae were not recovered from plant or soil samples. There was no evidence of the black-headed fireworm, Rhopobota naevana, the cranberry weevil, Anthonomus musculus, the red-headed flea beetle, Systena frontalis, or the cranberry tipworm, Dasineura oxycoccana, serious cranberry pests in other areas. However, larvae of the lingonberry fruitworm, Grapholita libertina, were found infesting cranberry at one site in 1998. Of the species found in this study, A. vaccinii probably represents the most serious threat to the industry.

Pheromone released from polyvinyl chloride dispensers disrupts mate-finding and pheromone-source location by Rhopobota naevana (Lepidoptera: Tortricidae) in cranberries

Blackheaded fireworm (Rhopobota naevana (Hbn.)) mating can be disrupted by pheromone components released from spiral polyvinyl chloride (PVC) dispensers in large field plots on cranberry (Vaccinium macrocarpon (Aiton) (Ericaceae)) farms. The main pheromone component ((Z)-11-tetradecen-1-ol acetate (Z11-14:Ac)) or a blend similar to natural pheromone (Z11-14:Ac, (Z)-11-tetradecen-1-ol (Z11-14:OH), and (Z)-9-dodecen-1-ol acetate (Z9-12:Ac)) was released from PVC dispensers into 0.8-ha plots on cranberry farms. Regardless of the treatment, free-flying males in treatment plots located fewer than 5% of individually caged virgin females, whereas mate location in most control plots ranged from 14%–75%. Location of pheromone lures loaded with 1.0 mg of the three-component blend was reduced in both treatments, but not to the same extent as was location of females. The magnitude of mating disruption indicated by 0.01-mg lures was similar to that indicated by caged females. Estimated release rates from dispensers loaded with Z11-14:Ac alone were linear and similar in both years of the study, declining from 575–720 mg/ha per day to 175–220 mg/ha per day after 100 days. Three-component dispensers placed in the field in July 1994 showed a steeper decline in release rates of Z11-14:Ac and a change in component ratios from 6.2:2.5:1 to 8:2:1 (Z11-14:Ac: Z11-14:OH: Z9-12:Ac) over the 60-day release period. After one season of mating disruption, the number of eggs and the number of foliar samples with larval feeding shelters were not consistently reduced in treatment plots. Mated females may have dispersed into the plots and oviposited. PVC dispensers effectively disseminate pheromone for mating disruption but are labor-intensive to use. In the cranberry system, their use might be limited to research plots and isolated farms of <8 ha.

Reoccurrence of Rose Bloom Caused by Exobasidium oxycocci in Cranberry in Massachusetts

Cranberry (Vaccinium macrocarpon Ait.) vines (cv. Howes) from a commercial cranberry bed on Nantucket Island displayed typical symptoms of rose bloom disease in June, 1997. The affected area (1.5 × 30.0 m) consisted of less than 1% symptomatic uprights and was not covered by sprinkler heads of the chemigation system. The same area that did not receive insecticides or fungicides was damaged by black-headed fireworm (Rhopobota naevana) feeding during the 1996 growing season. The surface of the leaves on the abnormal branches displayed the typical white, powdery external appearance, which consisted of basidia and basidiospores of the pathogen Exobasidium oxycocci Rostr. ex Shear that were hyaline, fusiform with a slight curvature, and measured 14 to 18 × 2 to 3 μm, matching a previous description (2). Plants showing symptoms had been infected during 1996. Abnormal lateral shoots with swollen pink leaves grew from infected axillary buds on the previous year's wood (3). Cranberry plants were inoculated with basidiospores but symptoms may take longer than 1 year to develop. Rose bloom was formerly a common disease affecting cranberry in Massachusetts and control strategies were addressed in the disease management recommendations sent out by the Cranberry Experiment Station to growers through 1954. Bergman (1) reported that the disease was found almost every year before 1945, but since then there were no serious outbreaks, possibly due to changes in cultural practices. The fungicide ferbam (ferric dithiocarbamate) largely replaced Bordeaux mixture as a fungicide to combat fruit rot in the late 1940s. The disease was not brought in with imported vines from the Pacific Northwest, where the disease is common, because the vines in this bed were planted in 1910. The disease has not been observed in either wild or abandoned cranberry beds that have not received fungicide applications. This is the first report of this disease in Massachusetts in nearly 50 years. References: (1) H. F. Bergman. 1953. Yearbook of Agriculture, p. 792. (2) F. L. Caruso and D. C. Ramsdell, eds. 1995. Compendium of Blueberry and Cranberry Diseases. American Phytopathological Society, St. Paul, MN. (3) C. L. Shear et al. 1931. U.S. Dep. Agric. Tech. Bull. 258.