Cranberry Fruitworm Research Articles

Advances in cranberry insect pest management: A literature synthesis

Over the past three decades, an increasing body of entomological research has been published on integrated pest management (IPM) in cranberries (Vaccinium macrocarpon Aiton). However, no paper has been published that synthesizes the existing literature. This paper fills this gap by analyzing 139 peer- and editor-reviewed articles that were data driven and had direct relevance to the subject of insect pests or insect pest management of V. macrocarpon. Results show that the top three studied insect pests of cranberries have been Sparganothis fruitworm (Sparganothis sulfureana Clemens), blackheaded fireworm (Rhopobota naevana Hübner), and cranberry fruitworm (Acrobasis vaccinii Riley). The regions with the most published entomological papers on cranberry IPM research have been New Jersey, Massachusetts, and Wisconsin in the United States, followed by British Columbia in Canada. Among IPM tactics, published research on chemical control, as well as on host-plant resistance, has increased likely due to recent advances on newer, reduced-risk insecticides and high-yielding cultivars; while published research focusing on behavioral control has declined likely due to the cost of these tactics. There are no consistent trends in published research on natural and biological control or cultural control. These historical research trends are important when considering regulatory changes on insecticide use, such as the Food Quality Protection Act of 1996 in the United States, which resulted in the banning and restrictions of certain broad-spectrum insecticides. As more insecticides are banned or restricted and global and organic cranberry production increases, we anticipate further advances in research related to sustainable IPM tactics.

Drones That Deliver: Pheromone-Based Mating Disruption Deployed via Uncrewed Aerial Vehicles in U.S. Cranberries.

Cranberry fruitworm (Acrobasis vaccinii Riley (Lepidoptera: Pyralidae)) and blackheaded fireworm (Rhopobota naevana Hubner (Lepidoptera: Tortricidae)) threaten cranberry production annually by causing significant fruit damage. Up to four pesticide applications are made each year to control these insects, which are costly to producers and elevate pesticide residues in fruit. Pheromone-based mating disruption technology can provide control of these pests in cranberry production, with the potential to minimize, or eliminate, pesticide applications. In 2016, an uncrewed aerial vehicle (UAV) was investigated to apply a thick paraffin emulsion containing insect sex pheromones. Traditional agricultural equipment is not capable of applying the paraffin emulsion to cranberry beds due to the product's viscous, paste-like consistency. The first objective of this study was to retrofit an UAV (octocopter) with a novel extrusion device that had been engineered to deliver the pheromone-loaded paraffin at regular intervals during flight. The second objective was to confirm adequate distribution of the pheromones by measuring the mating disruption efficacy by monitoring male moth trap catches. The UAV was able to fly autonomously along a prescribed itinerary, deploying the paraffin product uniformly; however, the increased mass of the retrofitted UAV limited flight times to ~12 min. The number of male cranberry fruitworm and blackheaded fireworm moths caught in lure-baited traps were reduced in the paraffin-treated beds compared with untreated beds, indicating adequate distribution of the pheromones. The UAV-applied pheromones concept could be developed into a production scale application method in the future, although issues of battery life and lifting capacity will need to be resolved.

Cranberry Fruitworm Acrobasis vaccinii Riley (Lepidoptera: Pyralidae)

Cranberry fruitworms (Acrobasis vaccinii Riley) are native to North America and have been classified as pests since the introduction of cranberry as an agricultural product (Tomlinson 1960). As larvae, these moths are the primary pest of large fruit cranberries and a significant pest of highbush blueberries (Fitzpatrick 2008).
 
 Also published on the Featured Creatures website at http://entnemdept.ufl.edu/creatures/FRUIT/MOTHS/Acrobasis_vaccinii.html

Incidence of Oscheius onirici (Nematoda: Rhabditidae), a potentially entomopathogenic nematode from the marshlands of Wisconsin, USA.

In a search for an entomopathogenic nematode to control cranberry insect pests, three Oscheius populations (Rhabditidae) were recovered through the Galleria-bait method from one sample taken in a wild cranberry marsh in Jackson County, Wisconsin, USA. Morphological studies with light microscopy and scanning electron microscopy, as well as molecular analyses of the near-full-length small subunit rDNA gene, D2/D3 expansion segments of the large subunit rDNA gene, internal transcribed spacer, and mitochondrial cytochrome oxidase subunit 1 (CoxI) genes revealed this as Oscheius onirici, a species recently described from a karst cave soil of central Italy. The species belongs to the dolichura-group and is characterized by its DNA sequences; hermaphroditic reproduction; and males not found. A Bacillus-like bacterium appears to be associated with this nematode based on our microscopic and SEM observations; however its identity and persistent association with the nematode has not been confirmed. Nonetheless, this nematode is capable of infecting and killing the sparganothis fruitworm Sparganothis sulfureana Clemens (Lepidoptera: Tortricidae), the brown-banded cockroach Supella longipalpa Fabricius (Blattodea: Ectobiidae), and the cranberry fruitworm Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), under laboratory conditions, and each in less than 72 hr. The mealworm Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae) and the greater wax moth Galleria mellonella Linnaeus (Lepidoptera: Pyralidae), are also susceptible, but take 3.5 and 5.2 days to die, respectively. This species is a new potential bio-control agent on insects.

Multi-Species Mating Disruption in Cranberries (Ericales: Ericaceae): Early Evidence Using a Flowable Emulsion.

Pheromone-based mating disruption has proven to be a powerful pest management tactic in many cropping systems. However, in the cranberry system, a viable mating disruption program does not yet exist. There are commercially available pheromones for several of the major pests of cranberries, including the cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae) and blackheaded fireworm, Rhopobota naevana (Hübner) (Lepidoptera: Tortricidae). Previous studies have shown that mating disruption represents a promising approach for R. naevana management although carrier and delivery technologies have remained unresolved. The present study examined the suitability of Specialized Pheromone & Lure Application Technology (SPLAT; ISCA Technologies, Inc., Riverside, CA), a proprietary wax and oil blend, to serve as a pheromone carrier in the cranberry system. In 2013 and 2014, we tested a blend of pheromones targeting A. vaccinii and R. naevana in field-scale, replicated trials. Pheromones were loaded into SPLAT and the resulting “SPLAT BFW CFW” formulation was deployed in commercial cranberry marshes. We compared moth trap-catch counts within SPLAT-treated blocks to those of conventionally managed blocks. In 2013, applications of SPLAT BFW CFW resulted in highly successful disruption of R. naevana and promising, though inconsistent, disruption of A. vaccinii. To improve disruption of A. vaccinii, the pheromone load was increased in 2014, providing 92% and 74% reductions in trap-catch for R. naevana and A. vaccinii, respectively. Importantly, larval infestation rates in SPLAT-treated blocks were lower than those of conventionally managed blocks. These results suggest that a multispecies mating disruption system (SPLAT BFW CFW) may represent an effective pesticide-alternative for serious pests of cranberries.

Flight Synchrony among the Major Moth Pests of Cranberries in the Upper Midwest, USA.

The cranberry fruitworm (Acrobasis vaccinii Riley), sparganothis fruitworm (Sparganothis sulfureana Clemens), and blackheaded fireworm (Rhopobota naevana Hübner) are historically significant pests of cranberries (Vaccinium macrocarpon Aiton) in the Upper Midwest (Wisconsin), USA. Their respective natural histories are well documented but correlations between developmental benchmarks (e.g., larval eclosion) and degree-day accruals are not yet known. Treatment timings are critical to the optimization of any given control tactic, and degree-day accrual facilitates optimization by quantifying the developmental status of pest populations. When key developmental benchmarks in the pest life cycle are linked to degree-days, real-time weather data can be used to predict precise treatment timings. Here, we provide the degree-day accumulations associated with discrete biological events (i.e., initiation of flight and peak flight) for the three most consistent moth pests of cranberries in Wisconsin. Moths were trapped each spring and summer from 2003 to 2011. To characterize flight dynamics and average timing of flight initiation, pheromone-baited trap-catch data were tallied for all three pest species within each of seven growing seasons. These flight dynamics were then associated with the corresponding degree-day accumulations generated using the cranberry plant’s developmental thresholds. Finally, models were fit to the data in order to determine the peak flight of each species. The initiation of the spring flight among all three moth species was highly synchronous, aiding in the timing of control tactics; however, there were substantial differences in the timing of peak flight among the moth species. Characterization of the relationship between temperature and pest development allows pest management professionals to target specific life stages, improving the efficacy of any given pest control tactic.

Population Densities of Lepidopteran Pests in Selected Cranberry Cultivars in Wisconsin.

Host plant resistance, an important strategy of integrated pest management, was examined in the American cranberry, Vaccinium macrocarpon Aiton (Ericaceae). Despite the pressure on cranberry growers to reduce pesticide usage, host plant resistance is not used to help manage insect populations. This study measured field population densities of the three most economically important pest insects in Wisconsin, namely, cranberry fruitworm (Acrobasis vaccinii Riley), sparganothis fruitworm (Sparganothis sulfureana Clemens), and blackheaded fireworm (Rhopobota naevana Hübner), in five different cranberry cultivars, i.e., 'Stevens', 'Ben Lear', 'GH1', 'Mullica Queen', and 'HyRed'. Population densities of male moths of all three species were assessed using pheromone traps in beds of the different cranberry cultivars in commercial marshes in central Wisconsin. For each cultivar, damaged cranberries were collected, and the number of damaged berries and the number of larvae feeding within berries were compared among cultivars. More than 99% of larvae collected were cranberry fruitworm. Mullica Queen and Ben Lear had more damaged berries than Stevens or GH1, and had more larvae than GH1. Conversely, fewer adult male sparganothis fruitworm were found in Ben Lear and Mullica Queen beds than in beds of Stevens or GH1. Adult populations of cranberry fruitworm and blackheaded fireworm were not different among cultivars. Our findings provide evidence of different levels of resistance in common cranberry cultivars, which should inform future plantings and breeding programs.

Temperature-Mediated Growth Thresholds of Acrobasis vaccinii (Lepidoptera: Pyralidae).

Degree-day models link ambient temperature to the development of insects, making such models valuable tools in integrated pest management. These models increase management efficacy by quantifying and predicting pest phenology. In Wisconsin, the top insect pest of cranberry production is the cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae). Control of this species is often complicated by the fact that the larvae feed entirely within the fruit. Timing of control tactics, therefore, is critical and generally targets the adult and egg stages. However, the commencement of oviposition and egg hatch are extremely difficult to track empirically, forcing pest management strategies to rely on proxy events that are more apparent but less informative as indicators of cranberry fruitworm egg presence. This research provides the upper and lower temperature-mediated growth thresholds of this pest, which represents the first steps toward the creation of a degree-day model. Using field-collected A. vaccinii, we reared the larvae within cranberry fruit and monitored larval growth at nine different constant temperatures. We determined the average growth rate at each temperature and modeled growth rates as a function of temperature. We then calculated the precise upper and lower developmental temperature thresholds of this species. Future work will be able to use these thresholds to generate degree-day accumulations that correspond to phenological events in the field, providing a powerful predictive tool for pest management in cranberry production.

Evaluation of Foliar Insecticides and the Addition of an Adjuvant for the Control of Cranberry Fruitworm and Sparganothis Fruitworm in Cranberry, 2015: Table 1

The objective of this experiment was to assess the efficacy of insecticides currently labeled for use on cranberry (Altacor, Delegate, Intrepid, Confirm), softer chemistry insecticides labeled on cranberry (Grandevo and Venerate), and insecticides not currently labeled on cranberry (cyclaniliprole, Fanfare, and Exirel). Selected insecticides were applied with and without the addition of the non-ionic adjuvant Apsa (spreader/activator) on first generation CFW and SFW eggs and early instar larvae. This experiment was conducted in a 4-yr-old cranberry planting on a commercial farm near Plainfield, WI. The trial consisted of 17 main effect treatments arranged in a complete randomized block design with 4 experimental replicates. Each …

Control of Cranberry Fruitworm in Blueberry, 2014: Table 1

The objective of this trial was to test the efficacy of various insecticide programs to limit CBFW infestation in blueberry clusters. The test materials were applied to mature “Jersey” blueberry bushes (6 by 12 ft spacing) at the Felker Farm (1 mile South of Trevor …

Evaluation of the Addition of an Adjuvant on Foliar Insecticides for the Control of Cranberry Fruitworm and Sparganothis Fruitworm in Cranberry, 2014: Table 1

The objective of this experiment was to assess the efficacy of insecticides currently labeled for use in cranberry (Altacor, Delegate, Intrepid, Confirm), softer chemistry insecticides labeled on cranberry (Grandevo and Venerate), and an insecticide not currently labeled on cranberry (Exirel) in combination with the adjuvant Bond (spreader/sticker) on first generation CFW and SFW eggs and larvae. This experiment was conducted in a mature cranberry planting on a commercial farm near Warrens, Wisconsin. The trial consisted of 14 main effect treatments arranged in an RCB design with four experimental replicates. Each …

Exploring host‐associated differentiation in the North American native cranberry fruitworm, Acrobasis vaccinii, from blueberries and cranberries

AbstractThe factors explaining host‐associated differentiation (HAD) have not yet been fully characterized, especially in agricultural systems. It is thought that certain characteristics within a system may increase the probability for HAD to occur. These characteristics include relatively long‐standing evolutionary relationships between insects and their host plants, endophagy, and allochrony in host‐plant phenologies. We assessed the status of these characteristics as well as the presence of HAD in the cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), a pest associated with blueberry and cranberry in eastern North America. We reveal the occurrence of two distinct populations of A. vaccinii that are allochronically isolated by the phenological stage of their respective host plants (cranberries or blueberries). Laboratory‐reared A. vaccinii adults collected from blueberries emerge at least 1 week earlier than adults from cranberries and the antennal sensitivity of adults to host‐plant volatiles differs between A. vaccinii collected from blueberry and cranberry. Despite finding characteristics indicative of HAD, we did not detect a genetic signature of HAD in A. vaccinii. These findings suggest that HAD may occur through behavioral and phenological mechanisms before there is sufficient genetic variation to be detected.

Activity of Broad-Spectrum and Reduced-Risk Insecticides on Various Life Stages of Cranberry Fruitworm (Lepidoptera: Pyralidae) in Highbush Blueberry

Laboratory and semifield bioassays were conducted to determine the life-stage activity of insecticides for controlling cranberry fruitworm, Acrobasis vaccinii Riley (Lepidoptera: Pyralidae), a key lepidopteran pest of highbush blueberry, Vaccinium corymbosum L. The organophosphates azinphosmethyl and phosmet, the pyrethroid esfenvalerate, and the carbamate methomyl were lethal to all life stages. The neonicotinoids thiacloprid and acetamiprid demonstrated strong larvicidal and ovicidal activity but were somewhat weaker adulticides than the conventional broad-spectrum compounds. Bacillus thuringiensis, indoxacarb, and emamectin benzoate were shown to control A. vacinii primarily through their larvicidal activity. Spinosad was toxic to all life stages, including eggs laid on top of residues and those that were treated topically, but larvicidal activity was short lived. The growth regulators pyriproxyfen and novaluron had strong ovicidal activity when eggs were laid on top of residues but had limited larvicidal activity. Tebufenozide was not directly toxic to eggs, but demonstrated larvicidal activity, and ovilarvicidal activity when topically applied to eggs. Azinphosmethyl, phosmet, indoxacarb, thiacloprid, and acetamiprid were all toxic to the egg parasitoid Trichogramma minutum Riley. In contrast pyriproxyfen, emamectin benzoate, methomyl, novaluron, and spinosad did not negatively affect the survival of T. minutum within Acrobasis vacinii eggs. These results help inform the ongoing development of integrated strategies for insect management in blueberry.

Susceptibility of Highbush Blueberry Cultivars to Cranberry Fruitworm and Japanese Beetle

The susceptibility of ten highbush blueberry cultivars, Vaccinium corymbosum L., to infestation by two key insect pests was compared. Over 5 years of assessing infestation by cranberry fruitworm, Acrobasis vaccinii (Riley), in a replicated field planting, “Duke” received the greatest infestation in 3 of the 6 years. Susceptibility of the 10 cultivars to Japanese beetle feeding was measured over 3 years in laboratory assays designed to measure relative feeding on fruit and foliage. “Brigitta” was the most susceptible cultivar to fruit feeding, while “Elliott” and “Legacy” were the least susceptible cultivars to foliage feeding. “Elliott” and “Legacy” also had the lowest level of Japanese beetle feeding on leaves of blueberry bushes in the field. These results suggest the presence of plant-based resistance to foliage and fruit feeding insect pests in some cultivars of V. corymbosum, which could be exploited within integrated pest management strategies.

DEVELOPING INTEGRATED FRUITWORM CONTROL STRATEGIES FOR BLUEBERRY IN PREPARATION FOR PESTICIDE RESTRICTIONS

DEVELOPING INTEGRATED FRUITWORM CONTROL STRATEGIES FOR BLUEBERRY IN PREPARATION FOR PESTICIDE RESTRICTIONS

Is fruit size important in the selection of oviposition sites by cranberry fruitworm, Acrobasis vaccinii?

AbstractUnder laboratory conditions, females of Acrobasis vaccinii (Riley) (Lepidoptera: Pyralidae) oviposit significantly more often on larger than on smaller cranberry fruit. This behaviour ensures that neonate larvae have access to maximum resources and are larger when moving to the next fruit. However, while there is some evidence that on a large spatial scale females may lay eggs in patches of larger fruit, there was no evidence of such an oviposition preference within patches in natural bogs. These results may be explained by the fact that the oviposition period for A. vaccinii begins early in the cranberry season, before fructification is completed, leading to potential competition among females for the first fruit present in the environment. Laying eggs on the first fruit available may be advantageous as this behaviour increases the probability that females select unexploited fruit. This strategy would be particularly effective for maximizing female fitness in grazer frugivorous species (such as the cranberry fruitworm) that live in environments where severe climatic conditions induce limited flowering/fruit formation and where hosts thus are rare.

Fall flooding for management of cranberry fruitworm ( Acrobasis vaccinii) and dewberry ( Rubus hispidus) in massachusetts cranberry production

To evaluate the potential for using postharvest fall floods as a pest management tool, designated sections of several commercial cranberry farms in Southeastern Massachusetts were flooded for 3–4 weeks in September–October. Seeded hibernacula of cranberry fruitworm ( Acrobasis vaccinii) placed into flooded beds for 3 or 4 weeks had 85% lower moth emergence compared to unflooded beds. Fall flooding may reduce dewberry ( Rubus hispidus) crown numbers and suppress weed coverage in some situations, but the effects were inconsistent. Fall flooding did not adversely affect percent fruit set, yield, or the new growth of cranberry uprights in the year following the flood. Incorporating fall flooding into commercial farm operations should not be difficult since cranberry growers currently use flooding at other times of year as a standard horticultural practice.

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.

Seasonal Abundance of Ground Beetles in Highbush Blueberry (Vaccinium corymbosum) Fields and Response to a Reduced-Risk Insecticide Program

Seasonal patterns of ground beetle activity were examined at six highbush blueberry (Vaccinium corymbosum L.) farms in southwestern Michigan. On each farm, pitfall traps were used to monitor ground beetle activity in two adjacent Þelds: one managed under a conventional insecticide program (grower standard) and the other with reduced-risk insecticides. Overall, more active in- gredient was applied in grower standard than reduced-risk Þelds, with the greatest amount used in June and July. During the 6-mo sampling period, we collected 11,322 ground beetles comprised of 34 species, with Harpalus pensylvanicus DeGeer representing 70.7% of the total beetles collected. The greatest amount of ground beetle activity occurred in August and September, mostly because of increased captures of the autumn breeding species H. pensylvanicus and H. erraticus Say. Only H. erraticus responded to the different insecticide programs, with eight-fold greater captures in reduced-risk compared with grower standard Þelds. Because H. erraticus are in the soil as larvae or pupae during June and July, we suggest that greater insecticide use in the grower standard Þelds resulted in increased mortality of immature H. erraticus. At one farm, where ground cover was absent between blueberry rows,H. erraticus activity did not respond to the difference in insecticide program. This suggests that enhancement of ground beetle activity may require suitable habitat in addition to a reduction in broad-spectrum insecticide use. HIGHBUSH BLUEBERRIES, Vaccinium corymbosum L., are the most signiÞcant small fruit crop grown in Michi- gan, producing32 million kilograms of fruit annually on 7,300 ha. Harvested fruit is primarily for the pro- cessing market, although 25% of the fruit is sold fresh. The key insect pests include cranberry fruit- worm (Acrobasis vaccinii Riley), blueberry maggot (Rhagoletismendax Curran), and Japanese beetle (Po- pillia japonica Newman). The zero tolerance for fruit contamination with insects forces many growers to make multiple foliar applications of organophosphate and carbamate insecticides before harvest. Because these pests spend part of their life overwintering on the soil surface (A. vaccinii) or in the soil (R. mendax and P. japonica), predation by ground beetles (Co- leoptera: Carabidae) may be an important source of biological control of these pests. Ground beetles are generalist arthropod predators that are natural enemies of several insect pests (Sunder- land 2002). Increasing ground beetle activity under blue- berry bushes has been shown to result in greater removal

The Importance of Behavioral Plasticity for Maximizing Foraging Efficiency in Frugivorous Lepidopteran Larvae

In this study, we present evidence that the larvae of Acrobasis vaccinii (Lepidoptera: Pyralidae), a species that feeds on cranberry fruit, are able to take into account at least three cues (fruit size, fruit color, and the distance between fruits) when searching for food. In laboratory experiments, the relative impact of each cue depended on which cues were presented in a given bioassay. Fruit color was the dominant cue in some contexts (e.g., larvae showed a significant perference for green fruit over red ones regardless of fruit size when fruits were equidistant from the larvae) but not in others (e.g., when given a choice between a large red fruit placed close to the larvae and a small green fruit placed farther away, a significantly higher proportion of larvae chose the former). This plasticity in foraging behavior allows larvae to maximize foraging efficiency under conditions of differing fruit and larval densities, which this species experiences in nature.