Adult Black Vine Weevil Research Articles

Association of Beauveria bassiana with grapevine plants deters adult black vine weevils, Otiorhynchus sulcatus

ABSTRACTFungal entomopathogens are known as microbial pathogens of insects, colonising multiple habitats and ecosystems. Besides being an entomopathogen, the fungus Beauveria bassiana can also establish as an endophyte in plants. Limited knowledge is so far available on the ability of plant-associated B. bassiana to influence plant-feeding insects. Here, we assessed the capability of adult black vine weevils Otiorhynchus sulcatus to select grapevine as a host plant in the presence of plant-associated B. bassiana after foliar application of a commercially available mycoinsecticide (product Naturalis®) on young potted grapevine plants. Three pairwise comparisons of weevil behaviour were conducted when weevils were released in a two-choice olfactometer and were given the choice between (i) control plants and plants treated with Naturalis®, (ii) control plants and plants treated with the formulation of Naturalis® without fungal propagules, and (iii) plants treated with Naturalis® and plants treated with the formulation. Adult O. sulcatus were significantly deterred by plants treated with Naturalis® or the formulation in comparison to control plants. In a direct comparison between plants treated either with Naturalis® or the formulation weevils significantly preferred plants treated with the formulation and avoided Naturalis® treated plants, where B. bassiana putatively had established as an endophyte. These results suggest that adult black vine weevils are able to detect and subsequently avoid plants treated with B. bassiana and indicate a new mode of action of plant-associated entomopathogenic fungi when integrated in pest management programmes.

Systemic Insecticides Reduce Feeding, Survival, and Fecundity of Adult Black Vine Weevils (Coleoptera: Curculionidae) on a Variety of Ornamental Nursery Crops

Systemic activity of the neonicotinoids clothianidin, dinotefuran, and thiamethoxam and the anthranilic diamide chlorantraniliprole was tested against adult black vine weevils, Otiorhynchus sulcatus (F.) (Coleoptera: Curculionidae), on Astilbe, Euonymus, Heuchera, Rhododendron, Sedum, and Taxus. Insecticide treatments were applied to the soilless substrate of containerized plants. Bioassays were conducted 12 or 13, 26, and 42 d after treatment (DAT) and ran for 7 d; and feeding, mortality, and weight gain or loss by weevils were evaluated. Foliage was removed from test plants and then placed in arenas with adult black vine weevils. The neonicotinoids reduced feeding and weight gain by adult black vine weevils on most plant species with residual activity 42 DAT on some plant species. At 12 DAT, mortality was caused by the three neonicotinoids on Astilbe and by thiamethoxam on Sedum; and at 26 DAT dinotefuran caused mortality on Astilbe. Chlorantraniliprole reduced feeding on Taxus at 12 DAT, with no activity detected in other bioassays. Another set of bioassays was conducted to examine survival and fecundity of adult black vine weevils during prolonged feeding on Heuchera and Taxus systemically treated with dinotefuran or thiamethoxam. Bioassay procedures were similar to those described above, except they ran continuously for 56 d. Prolonged feeding on dinotefuran and thiamethoxam treated Heuchera and Taxus resulted in high mortality of adult black vine weevils and reduced fecundity. These studies show that the systemic activity of neonicotinoids is influenced by plant species and that systemic neonicotinoids have the potential to suppress black vine weevil populations in containerized nursery crops.

Systemic Insecticides for Control of Black Vine Weevil (Coleoptera: Curculionidae) in Container- and Field-Grown Nursery Crops

Black vine weevils, Otiorhynchus sulcatus (F.) (Coleoptera: Curculionidae), are serious pests of container- and field-grown nursery crops. Management programs usually target the larval stage in container-grown plants and the adults in field-grown plants. We tested several new systemic insecticides for efficacy against black vine weevil in container-grown Sedum spp. and field-grown Taxus spp. In 2006 and 2007, clothianidin, dinotefuran, and chlorantraniliprole were applied as surface drenches to containerized Sedum plants, and suppression of larval densities and adult feeding were evaluated. Sedum leaf bioassays were used to further examine the influence of clothianidin, dinotefuran, and chlorantraniliprole on adult feeding. In 2006, pots were infested with adult black vine weevil 1 d after treating, and in 2007 pots were infested 1 or 43 d after treating. All three insecticides significantly reduced the numbers of larvae in 2006, but not in 2007, because of low numbers of larvae in the untreated control plants. Dinotefuran and clothianidin reduced feeding by adult black vine weevil on containerized Sedum plants, resulting in more blossoms, fewer damaged leaves, and a lower percentage of leaves damaged compared with control plants. In bioassays with detached leaves, all three insecticides reduced feeding compared with control plants. Efficacy and timing of clothianidin, imidacloprid, and acephate soil drenches and imidacloprid and acephate soil injections were evaluated for black vine weevil control over a 1-yr period in field-grown Taxus plants. All insecticide treatments significantly reduced the numbers of larvae in field-grown Taxus plants compared with control plants; and all but the spring acephate drench improved the appearance of the Taxus (foliar rating) plants compared with untreated plants. All of the tested insecticides showed potential for preventing infestations of black vine weevil larvae and reducing feeding by the adults in ornamental plants.

Black Vine Weevil (Coleoptera: Curculionidae) Performance in Container- and Field-Grown Hosts

The black vine weevil (Otiorhynchus sulcatus F.) feeds on a variety of plant species and is a serious pest of ornamental nursery crops. The larval stage has a more restricted diet than the adult stage, but the larvae are more damaging because they feed on roots and often stunt or kill their hosts. Performance and establishment of larvae in various container- and field-grown nursery crops were examined. In trials on containerized plants, adult black vine weevil were caged with various combinations of known larval hosts. In these trials, most larvae were found in Sedum and Heuchera versus Astilbe, redbud, and Taxus. Larvae collected from Sedum weighed significantly more than those from Heuchera or Taxus. In one field trial, adult black vine weevils were released, and establishment of larvae among potential hosts was examined. In this trial, Sedum was a better host than hemlock or Rudbeckia. Based on the numbers of larvae found in the different plant species, Sedum was the best host for larvae. Another field trial examined the influence of mulch on the occurrence of larvae. The presence of mulch around small field-grown Taxus plants did not increase the numbers of larvae compared with bare soil. The presence of aged pine bark or Taxus needle mulches did not influence the occurrence of black vine weevils in field plots of young Taxus. Data from monitoring adults suggest they either emigrated from these plots within several weeks of emergence, although suitable hosts were present, or there was high mortality.

Prevalence and Potential Impact of Soil-dwelling Pests and Insect Pathogenic Nematodes in Strawberry Fields

Surveys mailed to strawberry growers in 1999 determined the state of nematode and root weevil awareness and practices for their management. Based on the survey response, 41 fields representative of various practices were selected for sampling throughout Connecticut. Adult black vine weevils (Otiorhynchus sulcatus) were found in only 3 fields, but notched leaves characteristic of their feeding were found in 40 fields, indicating a greater prevalence than perceived by growers. The percentage of notched leaves was positively correlated with years in production, suggesting that it took some time for the flightless weevils to migrate into and to increase to damaging numbers in fields. In fields older than 2 years, bifenthrin insecticide reduced leaf feeding compared to untreated fields or to fields treated with endosulfan or azinphos-methyl. Lesion nematodes (Pratylenchus penetrans) were detected in 31 fields and were present in about 58% of plants. When present, nematode numbers were greater in the margins of poor areas than in adjacent healthy plants (735 vs. 428 per g root, respectively). Lesion nematode numbers were also greater in replanted strawberries than rotated fields (760 vs. 304, respectively). Soil fumigation with methyl bromide, but not methyl dithiocarbamate or the combination of 1,3-dichloropropene and chloropicrin, reduced nematode densities in the following strawberry crop. Based on an economic model, nematodes reduced accumulated profit over 4 fruiting years by more than the percent loss of fruit yield. Beneficial insect pathogenic nematodes, predominantly Heterorhabditis bacteriophora and Steinernema feltiae, were found in 75% of fields to which commercially obtained nematodes had been applied, and to 14% of the remaining fields. Presence of naturally occurring insect pathogenic nematodes in strawberry fields may control root weevil populations and lead to more years of productivity.

021 Assessment of Insecticide Efficacy For Root Weevil Control

The efficacy of new formulations and application techniques were compared to existing standard pesticides for adult root weevil control. A known number of adult black vine weevils (Otiorhynchis sulcatus) were added to Rhododendron `Cunningham's Blush' growing in 1-gal containers. Spray or hand-applied treatments were assigned to three plants each within the six blocks of a randomized complete-block design. Treatments were evaluated for percentage adult mortality at 7 and 14 days after treatment (DAT). Orthene (16 oz/100 gal), Pinpoint (2.0 g and 3.0 g prod/pot), Talstar (20 oz/A; both day- and night-applied), and CGA 293 343 (8.5 oz thiamethoxam/100 gal) provided greater than 90% control of root weevil adults 2 weeks after treatment. Although providing less than 50% control at 7 DAT, the low rate of Pinpoint (0.5 g prod/pot), Cryolite bait (30 lb/A), and Kryocide (50 lb/A) treated blocks showed greater than 60% mortality by 2 weeks after treatment. Bifenthrin-treated weed barriers (1.5% ai) placed on the surface of the growing medium provided more than 50% control 14 days after treatment. Differences in speed of control may reflect differing modes of action or application methods. One possible benefit in use of the slower-acting stomach poisons and systemic insecticides is reduced risk to nontarget organisms such as predator mites.

Evaluation of some Fragaria chiloensis x ( F. X ananassa) seedlings for resistance to black vine weevil

A sample of 483 Fragaria chiloensis (L.) Duchesne x ( F. X ananassa Duchesne) seedlings, derived from four crosses, exhibited highly significant variation in resistance to adult black vine weevil, Otiorhynchus sulcatus (F.), feeding. In some tests, resistance to feeding was negatively correlated with the degree of pubescence, but only about 1% of the variation in resistance could be explained in terms of hair number, and leaves of some resistant seedlings bore few hairs. This is the first study to show that selection for black vine weevil resistance among F. chiloensis x ( F. X ananassa) crosses is possible. The bases for resistance are unknown, and it appears that resistance can be expressed without a dense covering of simple hairs.

Effect of Taxus Foliage and Extract on the Toxicity of Some Pyrethroid Insecticides to Adult Black Vine Weevil (Coleoptera: Curculionidae)

The pyrethroid insecticides fenvalerate, permethrin, and fluvalinate were more toxic to adult black vine weevil, Otiorhynchus sulcatus (F.), on yew, Taxus media Rehder, foliage rather than on leaves of strawberry, Fragaria × ananassa Duchesne, or cranberry, Vaccinium macrocarpon Ait. Feeding weevils untreated yew foliage or an ethanolic extract of yew needles for 24 h before placing them on fenvalerate-treated strawberry leaves greatly increased knockdown. Host plant species must be considered when pyrethroids are used for control of adult black vine weevil.

The influence of leaf pubescence on the resistance of selected clones of beach strawberry ( Fragaria chiloensis (L.) Duchesne) to adult black vine weevils ( Otiorhynchus sulcatus F.)

Adult black vine weevils fed significantly more on some beach strawberry clones than on others when a 25-clone sample was studied using no-choice tests. Weevil fecundity was correlated with feeding. The density of simple hairs on the abaxial leaf surface varied significantly between clones, and hair density was negatively correlated with weevil feeding. These results suggest that leaf pubescence plays a role in the resistance of certain beach strawberry clones to feeding by adult black vine weevil.

Single vs. Multiple Applications of Pydrin for Control of Adult Black Vine Weevil, 1987

Abstract Two-hundred Japanese yews (18-inch-diam canopy) heavily infested with black vine weevil larvae were transplanted in April 1986 into a field of 5 rows of 10 plots. Each plot contained 4 plants. Plants were spaced 2 ft apart within plots, and plots were 5 and 7 ft apart within and between rows, respectively. A barrier constructed of 6-inchwide aluminum edging, coated with Fluon and buried 2 inches deep, was installed around each plot to prevent adult weevil migration. The field was irrigated with 1 inch of water/wk by overhead sprinkler. All plots except checks were treated with 0.15 lb (AI) 100 gal until runoff on 13 Jun, 2 wk after the first adults had emerged from the soil. The 4 treatments, 2 wk apart, consisted of 1-4 applications of Pydrin with a Solo backpack sprayer at 30 psi. Treatment efficacy was evaluated in May 1987 by sifting the soil beneath the canopy of each plant to a depth of 1 ft for larvae.

Role of Leaf Hairs in Resistance of a Clone of Beach Strawberry, Fragaria chiloensis, to Feeding by Adult Black Vine Weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae)1

Beach strawberry, Fragaria chiloensis (L.) Duchesne, clone CL-5, is resistant to feeding by adult black vine weevil (BVW), Otiorhynchus sulcatus (F.). Using a membrane filter feeding bioassay, no evidence for a chemical basis for this resistance could be obtained. Leaf toughness of a susceptible Fragaria × ananassa (Duchesne) cultivar and clone CL-5 did not differ. Removal of tomentum from the underside of fresh or freeze-dried CL-5 leaf disks rendered them as susceptible to BVW feeding as disks from a nonresistant cultivar. This, and other evidence, demonstrates that antixenosis exhibited by leaves of beach strawberry clone CL-5 to BVW is due, at least in part, to the dense covering of simple hairs on their abaxial surface.

Activity Chamber and Computerized Data Acquisition System for Monitoring Crawling Insects

The combination of an insect activity chamber using interrupted infrared light beams and a microcomputer to monitor activity of a crawling insect, adult black vine weevil, Otiorhynchus sulcatus (F.), is described. The microcomputer provides television screen monitoring of the weevil's location and time at each location, and transfers data to a cassette tape recorder.

Black Vine Weevil (Coleoptera: Curculionidae) Feeding and Oviposition on Leaves of Weevil-resistant and -susceptible Strawberry Clones Presented in Various Quantities

Adult black vine weevils, Otiorhynchus sulcatus (F.), were fed ‘Totem’ strawberry or clone CL-5 of the wild beach strawberry, Fragarta chiloensis (L.) Duchesne weekly for 14 weeks after eclosion. Amounts of leaf provided were varied to give a food supply ranging from insufficient to abundant. In general, amount of leaf eaten increased, preoviposition period decreased, and number of eggs laid increased as leaf disk size increased. With equal food supply, feeding was less, preoviposition period was longer, and oviposition was less on CL-5 than on ‘Totem’. This indicated that resistance is due in part to less feeding on CL-5 than on ‘Totem’. However, preoviposition period was longer and fewer eggs were laid on CL-5 than on ‘Totem’ even when daily food intake was equal, indicating that factors in addition to antixenosis are involved in resistance of CL-5 to adult black vine weevil.

Effect of Age on the Feeding Pattern of the Adult Black Vine Weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae)1

In 24-h feeding tests conducted at 14-day intervals over a 1-year period, adult black vine weevils, Otiorhynchus sulcatus (F.), fed most heavily on ‘Alpine’ strawberry, Fragaria vesca L., leaves in the first few weeks after eclosion. Feeding on phagostimulant-treated membrane filter discs was also heavy immediately following eclosion, but decreased with time. There was large test-to-test variability in feeding on both leaves and inert substrates. Feeding on membrane filters treated with sucrose showed a linear relationship to sucrose concentration during the first 14 weeks after eclosion. A significant linear relationship between sucrose concentration and weevil feeding was found for 9 of the last 19 test dates.

Laboratory Tests of Insecticides Against Adult Black Vine Weevil, 1983-84

Abstract Strawberry or red raspberry leaves were dipped in emulsions, suspensions, or solutions of commercial formulations of insecticides. The leaves were allowed to dry and petioles were inserted into vials of water which were placed in wide-mouth 1-pt glass jars. The insides of the jars were coated near the top with Fluon to prevent the flightless weevils from crawling out. Treatments were replicated 4 or 5 times with 4 or 5 weevils/replicate. Mortality was recorded every 24 h for 4 days. Symptoms of poisoning ranged from complete absence of motion by weevils to lying on their sides and waving their legs. The latter might later die or completely recover. Therefore, all weevils displaying any of those symptoms were recorded as “dead”.

Black Vine Weevil Control, 1983-84

Abstract Plots, 2 ft x 4 ft, were surrounded by 12-inch-high aluminum barriers. The metal was coated with Fluon to keep the flightless adult weevils from crawling either in or out. Treatments were replicated 4 times in a randomized complete block design and were applied in 1983 on the dates shown in the table. Sprays were applied at the rate of 300 gal of water/acre. Granules were broadcast over the plots by use of a “salt shaker” applicator. Plots were infested with 10 adult black vine weevils on both 1 Jun ’83 and 25 Jun ’83. Sprays were allowed to dry before the weevils were placed on the soil under the vines. Treatments were evaluated on 16 Apr ’84. All vines were pulled from each plot and then vine and root vigor were rated subjectively on a scale of 1 (poorest) to 5 (best). All larvae were collected from the soil and counted.

Evaluation of Adult Black Vine Weevil Control on Taxus and Effect on Fecundity, 1984

Abstract Individual taxus in 3-gal containers were treated using a 5-liter Burgess hand-pump sprayer. Plants were sprayed to the point of run-off on 28 Aug. Soil applications of Mavrik and Cygon were made in 500 ml of water to each plant. Plants were in a loamy sand (84% sand) potting medium with a CEC = 12, 3.7% organic matter, and soil pH of 5.1. Rainfall (inches) occurred on 30 Aug (0.25), 1 Sep (0.13), and 3 Sep (0.03). The treated foliage was replaced with untreated foliage following this 2-day rating. A replicate consisted of 8 weevils in a Telan petri dish. There were 5 replicates/treatment. A 2 to 3-inch section of taxus was placed in each petri dish, 8 days after treatment (DAT). The weevils were maintained at ambient temperature and light conditions in the laboratory. At the end of the test, ill eggs from each dish were pooled by treatment and counted to obtain the total eggs during the 5 day test. Mortality was evaluated by gently prodding and examining weevils in a darkened room and observing their movement 30 min later after they were placed on a 3 x 3 in sq of paper.

Resistance of Clones of Wild Strawberry, Fragaria chiloensis , to Adult Otiorhynchus sulcatus and O. ovatus (Coleoptera: Curculionidae)

Several clones of the wild beach strawberry, Fragaria chiloensis (L.) Duchesne, were compared with clones of commercial strawberries, F. × ananassa Duchesne (both species are octoploid), for resistance to feeding by adult black vine weevil, Otiorhynchus sulcatus (F.), and strawberry root weevil, O. ovatus (L.). Weevils fed less and had lower fecundity on F. chiloensis leaves than on F. × ananassa leaves. The F. chiloensis clones CL-5 and GCL-8 also increased the preoviposition period of newly eclosed adults. Egg production correlated closely with the amount of feeding on a clone.

Black Vine Weevil, Otiorhynchus sulcatus (Coleoptera: Curculionidae), Phagostimulants from ‘Alpine’ Strawberry

Adult black vine weevils, Otiorhynchus sulcatus (F.), fed on membrane filter disks treated with leaf extracts of ‘Alpine’ strawberry, Fragaria vesca L. A mixture of several sugars present in an aqueous extract stimulated feeding. Sitosterol was identified as one of several lipid phagostimulants. Sucrose and sitosterol were synergistic in promoting weevil feeding. Phagostimulants were active at the same levels as present in leaves (area basis).

Black Vine Weevil:1 Reproductive Potential on Selected Plants23

Host suitability of several plant species for adult black vine weevil, Otiorhynchus sulcatus (F.) (Col.: Curculionidae), was investigated during 1976–79 by measuring length of the maturation feeding period, fecundity, and longevity. Taxus were generally more suitable than Rhododendron; R. smirnowii Trautvetter, a species with heavily indumented leaves, was non-preferred and unsuitable for maturation feeding. Oviposition peaked 3 weeks after it commenced, but continued until the light-dark cycle had been at 12/12 for several weeks. Egg production resumed 3 weeks after the photoperiod was increased to 16 hours.