Synanthedon Pictipes Research Articles

Comparison of Mating Disruption and Insecticide Application for Control of Peachtree Borer and Lesser Peachtree Borer (Lepidoptera: Sesiidae) in Peach.

Simple SummaryThe peachtree borer and lesser peachtree borer are destructive insect pests of peach and other stone fruit. Damage is caused by larval feeding on the vascular cambium, which reduces tree health and vigor and can lead to tree death. The traditional method to control these pests is with directed trunk sprays of the organophosphate insecticide, chlorpyrifos. However, the ongoing review of pesticide tolerances mandated by the United States Environmental Protection Agency (US-EPA) makes the option of future long-term use of chlorpyrifos uncertain. Mating disruption is an alternative method of control that uses synthetic sex pheromones to disrupt male mate-finding behavior and prevent mating. We conducted field studies to compare the efficacy of mating disruption and application of chlorpyrifos insecticide for control of this pest complex. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities of the pest species, problems with maintaining adequate pheromone coverage in orchards, and the need for area-wide implementation.The peachtree borer, Synanthedon exitiosa, and lesser peachtree borer, S. pictipes, are economically important indirect pests of peach in West Virginia. The purpose of this 3-year study was to compare the efficacy of mating disruption and post-harvest trunk sprays of chlorpyrifos insecticide for control of this pest complex in a commercial peach orchard. Overall, Isomate PTB-Dual disruption dispensers applied at a rate of 371/ha significantly disrupted the male mate-finding behavior of S. exitiosa and S. pictipes. In addition, the infestation of peach trees by S. exitiosa larvae did not vary significantly between mating disruption and insecticide treated plots. Hot-spot maps of S. exitiosa infestation showed significant spatial clusters of infestation predominately near the perimeter of all orchard plots, or where trees were missing within and/or between rows. The generation of standard deviational ellipses revelated that the location of S. exitiosa infestations in orchard plots remained relatively constant between years, and were generally oriented in a north and easterly direction, which coincided with the prevailing wind direction. Although our data indicated that mating disruption can provide growers with an effective non-chemical alternative to chlorpyrifos trunk sprays, several variables may affect its long-term success in West Virginia peach orchards; most notably the presence of high population densities, problems with maintaining adequate pheromone coverage, and the need for area-wide implementation.

Aspectos biológicos del anillador de la guayaba Carmenta theobromae (Lepidoptera: Sesiidae) en Santander, Colombia

El anillador de la guayaba es un lepidóptero recientemente identificado como Carmenta theobromae que ha causado pérdidas significativas en cultivos de guayaba de la Provincia de Vélez, Santander. El objetivo de esta investigación consistió en estudiar los estados de huevo y larva del anillador en campo y laboratorio durante el primer semestre de 2014. En campo, los sitios de oviposición se describieron en árboles barrenados y, en laboratorio, se examinaron las posturas en cortezas del tallo de guayaba. Se evaluó la supervivencia y duración del estado larval de inmaduros recolectados en campo en cuatro dietas semi-artificiales: aserrín de guayabo, dos dietas formuladas para Spodoptera frugiperda y otra para Synanthedon pictipes. Se describieron las características morfométricas del huevo y la larva con especímenes recolectados en cultivos de guayaba. Los sitios de oviposición se encontraron en la corteza principalmente del tallo donde las posturas fueron simples, espaciadas y de forma oblonga o elipsoidal. No se encontraron diferencias estadísticas en los tratamientos supervivencia y duración del estado larval. La duración promedio de la fase larval fue de 13,92 ± 1,36 días para individuos con longitud mayor a 10,63 ± 0,31 mm. El huevo midió 0,22 ± 0,012 mm de ancho y 0,37 ± 0,011 mm de longitud. Se identificaron cuatro estadios larvales a través del coeficiente de Dyar y distribución de frecuencias de medidas del ancho cefálico. La larva madura tiene ganchos (“crochets”) distribuidos uniordinalmente y un par de bandas en el pronoto como C. theobromae, barrenador de cacao en Venezuela.

Efficacy of Steinernema carpocapsae plus fire gel applied as a single spray for control of the lesser peachtree borer, Synanthedon pictipes

The efficacy of aboveground applications of entomopathogenic nematodes (Heterorhabditis spp. and Steinernema spp.) can be severely limited by the nematode’s susceptibility to UV radiation and desiccation. The lesser peachtree borer, Synanthedon pictipes, is a major pest of stone fruit; larvae attack trees aboveground by tunneling into the trunk and scaffold limbs. In previous research, Steinernema carpocapsae, caused high levels of S. pictipes mortality when a sprayable fire gel (Barricade®) was applied on top of the nematode application as a protectant. One drawback to the approach is that two applications must be made (first nematodes are applied followed by the fire gel); furthermore, the previous experiments did not compare nematode application to the existing standard chemical insecticide. Therefore, the objectives of this study were to (1) determine if a diluted rate of fire gel can protect nematodes when applied as a single spray, and (2) compare the efficacy of nematode applications with the chemical insecticide, chlorpyrifos. The experiment was conducted in a peach orchard in Quincy, Florida in 2013 and 2014. Treatments included: (1) chlorpyrifos, (2) S. carpocapsae applied in aqueous suspension only or (3) with a full rate (approximately 4% applied separately) or (4) 2% Barricade® (applied with nematodes in a single spray), and (5) a non-treated control. The treatments were applied post-harvest (in the fall) to S. pictipes-infested bark wounds; S. pictipes survival was assessed 8 (2013) or 14 (2014) d post-application. In 2013, chlorpyrifos and nematodes with Barricade® at 2% or the full rate reduced S. pictipes survival relative to the non-treated control and nematodes without Barricade®. In 2014, nematodes applied with 2% Barricade® was the only treatment that reduced S. pictipes survival. We conclude that S. carpocapsae and Barricade® can be applied as a single spray, and in our experiments the treatment was at least as effective as the chemical standard.

Lesser Peachtree Borer (Lepidoptera: Sesiidae) Oviposition on Prunus Germplasm

The lesser peachtree borer, Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sesiidae), is a serious pest of peach, Prunus persica (L.) Batsch, across the southeastern United States. We examined oviposition by S. pictipes on field-grown Prunus scion and rootstock cultivars and two endemic Prunus spp. when sawn limbs, not roots, were assayed in the laboratory. A choice test compared oviposition on the peach scion 'Harvester', peach rootstock 'Guardian', plum×peach hybrid rootstock 'MP-29', and the plum hybrid rootstock 'Sharpe'. A significantly lower percentage of eggs occurred on limbs of Sharpe rootstock than other choices. A choice test using two endemic hosts, black cherry (P. serotina Ehrh.) and Chickasaw plum (P. angustifolia Marsh.), along with Sharpe rootstock, found a lower percentage of eggs on limbs of Sharpe than either endemic host. However, when only limbs of Sharpe and a decoy were used, almost all eggs were laid on Sharpe. Interestingly, when Harvester and Sharpe limbs were paired side by side, a higher percentage of eggs were recovered from the Harvester limb than from the Sharpe limb. An analysis of volatiles from Sharpe may identify why fewer eggs were laid on it. Because S. pictipes attacks host trees above ground and Sharpe rootstock on grafted trees grows below ground, this rootstock might be a management option against the congeneric, root-attacking peachtree borer, S. exitiosa (Say). Our results suggest that high budding a peach scion onto Sharpe rootstock, thus allowing the rootstock to serve as the trunk, warrants further investigation against S. exitiosa under orchard conditions.

Laboratory Virulence and Orchard Efficacy of Entomopathogenic Nematodes Against the Lesser Peachtree Borer (Lepidoptera: Sesiidae)

The lesser peachtree borer, Synanthedon pictipes (Grote & Robinson) (Lepidoptera: Sesiidae), is indigenous to eastern North America. It is a pest of commercially grown Prunus spp., especially to southeastern peach orchards where earlier regulatory changes affected pesticide use on peach leading to increased S. pictipes damage. Pest management practices are now having a positive effect toward control of this pest, but cost-competitive biological control solutions that promote environmental stewardship are needed. Here, we tested four Steinernema species and five Heterorhabditis species of entomopathogenic nematodes against larval S. pictipes. Included were four strains of S. carpocapsae (All, DD136, Sal, and Hybrid2) and three strains of S. riobrave (3-8b, 7-12, and 355). Larvae treated with any strain of S. carpocapsae always resulted in <20% survival, whereas larval survival was always >50% when treated with any other Steinernema or Heterorhabditis spp. These differences were always significant for the Hybrid2 strain of S. carpocapsae and similarly for other tested S. carpocapsae strains except for when larvae were treated with the 3-8b strain of S. riobrave. In addition, we determined the susceptibility of different size S. pictipes larvae, because they occur simultaneously in orchards, and we found that larvae rated as "medium" and "large" were significantly more susceptible than "small" larvae. Last, we demonstrated that moisture-retaining covers (placed over S. pictipes-infested wounds on peach limbs) increased efficacy of nematode treatments against larval S. pictipes. Even when using highly virulent nematodes against S. pictipes, it is likely that an aboveground application will require an environmental modification to remain efficacious.

Comparison of mating disruption and mass trapping with Pyralidae and Sesiidae moths

Mating disruption and mass trapping for control of lepidopteran pests use synthetic sex pheromone to prevent males from finding and mating with females. Here, we identify the behavioral mechanism underlying mating disruption and mass trapping of American plum borer, Euzophera semifuneralis (Walker) (Lepidoptera: Pyralidae), peachtree borer, Synanthedon exitiosa Say, and lesser peachtree borer, Synanthedon pictipes (Groeten) (Lepidoptera: Sesiidae). In addition, we derive relative dispenseractivity(RelativeDa)fromthecompetitiveattractionequationtocomparethedisruptiveactivity of the devices used in mating disruption and mass trapping. Dispensers and traps were deployed in replicated 0.14-ha cherry or peach plots with E. semifuneralis or the Synanthedon moths, respectively. Dispenser densities were 0, 10, 20, 59, 185, and 371 per ha, whereas trap densities were 0, 10, 20, 40, 79, and 158 per ha. Moth catch in a centrally placed, pheromone-baited monitoring trap in each plot was used to evaluate the treatments. The profile of moth captures in mating disruption and mass trapping with the three species indicates that competitive attraction is the behavioral mechanism responsible for trap disruption. Relative Da is 0.27, 0.23, and 0.53 with American plum borer, peachtree borer, and lesser peachtree borer, respectively, which indicates that the traps are 1.9‐4.4 times more effective in reducing moth catch than the dispensers. Relative Da can be used to compare devices for pheromone-based behavioral manipulation of these and other species that are competitivelyattractedtoartificialpheromone sources. Whenthesametypeoftrap is employed formonitoringandmasstrapping,RelativeDaisthesameasdispenseractivityDa.

Tree Height Influences Flight of Lesser Peachtree Borer and Peachtree Borer (Lepidoptera: Sesiidae) Males

Capture of male lesser peachtree borer, Synanthedon pictipes (Grote & Robinson), and peachtree borer, S. exitiosa (Say) (Lepidoptera: Sesiidae), in pheromone traps positioned from 0 m to 6 m above ground was affected by surrounding tree height. In a peach orchard with a 3 m canopy height, more S. pictipes were captured within the canopy zone at 1.8 m than above at 5.5 m. Trap capture was similar for S. pictipes in a mating disruption orchard with more caught at 2 m than at 4 m or 6 m. Capture at 1.8-5.5 m in mixed deciduous woods, with an average canopy height of 22 m, was not significantly different. In orchards, more S. exitiosa were captured at 1.8 m rather than at 5.5 m but no difference was detected in numbers captured from 0 m to 5.5 m in mixed deciduous woods. In a peach-pecan interplanted orchard, where pecan trees were three times taller but only one-ninth the density of peach, capture of both species was similar to capture in peach orchards when traps were entirely surrounded by peach. However, when traps were adjacent to a single, taller non-host pecan tree, capture was similar to mixed deciduous woods. These data suggest that habitat structure supersedes presence/absence of host plants affecting vertical flight activity of male S. pictipes and S. exitiosa.

Efficacy of Steinernema carpocapsae for control of the lesser peachtree borer, Synanthedon pictipes: Improved aboveground suppression with a novel gel application

Safe and effective tactics are needed for control of the lesser peachtree borer, Synanthedon pictipes (Grote & Robinson), which is a major pest of stone fruits ( Prunus spp) in eastern North America. Virulence of the entomopathogenic nematode, Steinernema carpocapsae (Weiser) , to S. pictipes has been demonstrated in the laboratory. However, achieving field efficacy has been difficult because S. pictipes attacks the tree aboveground where nematodes are subjected to damaging environmental conditions, e.g., UV radiation and desiccation. We investigated the potential of various formulations to improve the efficacy of aboveground applications. First, we screened five potential adjuvants at 2%, 20%, and 40% concentrations in water for toxicity to S. carpocapsae in the laboratory: Anti-Stress, Moisturin®, Nu-Film®, Shatter-Proof, and Transfilm®. In general, the adjuvants did not adversely affect nematode survival except at the highest rate. Subsequently, Shatter-Proof was tested in field trials in 2008 and 2009. S. carpocapsae was applied alone or with Shatter-Proof to peach limbs pre-infested with S. pictipes larvae. Furthermore, the experiments included the following treatments: S. carpocapsae followed by a post-application covering of latex paint, moistened diaper, or a gel spray (Barricade®). Controls of water-only, or water plus Shatter-Proof, Barricade®, or paint (without nematodes) were also included. The nematodes-only treatment failed to reduce S. pictipes survival relative to the water-only control in either year. Additionally, the nematode treatments with Shatter-Proof or paint did not differ from nematodes-only, water-only or their respective control treatments without nematodes. The diaper treatment with nematodes showed some potential as an efficacy enhancer (e.g., insect survival was reduced relative to nematodes-only in one year). In contrast, in both years, nematodes plus Barricade® reduced S. pictipes relative to the controls and the nematodes-only treatment; survival in the Barricade® treatment was 30% and 0% in 2008 and 2009, respectively. We conclude that nematode treatments followed by application of a sprayable gel such as Barricade® can enhance control of S. pictipes and possibly other aboveground pests as well.

Reduced-Risk Pest Management Programs for Eastern U.S. Apple and Peach Orchards: A 4-Year Regional Project

Studies were conducted from 2002 to 2005 to determine the effectiveness of reduced-risk (RR) tactics for managing key pests in 50 commercial apple orchards (114 ha) in Michigan, North Carolina, New York, Pennsylvania, Virginia, and West Virginia; and 20 peach orchards (190 ha) in Michigan, New Jersey, Pennsylvania, and West Virginia. At each apple site, a block of up to 5 ha received a seasonal program of selective RR and organophosphate-replacement insecticides, with or without pheromones for mating disruption of key lepidopteran pests of apple (codling moth, oriental fruit moth, and obliquebanded leafroller) and peach (oriental fruit moth, lesser peachtree borer, and peachtree borer). A comparison block at each site with the same varieties and tree training was managed using each grower's standard program of conventional insecticides (STD). Pheromone traps for lepidopteran species were hung in all plots and monitored weekly. Foliar samples were taken during the season to estimate phytophagous and predator mite densities. Red sphere traps baited with fruit volatiles were used to monitor apple maggot adults in apple orchards. Fruits were inspected for insect damage at harvest, and graded according to USDA standards. Partial budget analysis was used to assess the net profitability of RR programs to produce apples and peaches for their intended market in each state. Fruit damage at harvest caused by direct fruit pests was generally low across all blocks and treatments. There were no statistically significant differences in fruit damage or mite populations between the RR blocks, with or without pheromones, and the growers' standards. Insecticide use patterns in the RR plots represented up to 88 and 78% reduction in the amount of active ingredient applied per hectare, and an 85 and 77% decrease in their Environmental Impact Quotient for apples and peaches, respectively. However, RR programs were more expensive and generally less profitable compared with growers' standard programs. Regression analysis estimated that RR apple programs with and without mating disruption were on average &dollar;465 and &dollar;144/ha more expensive, and &dollar;544 and &dollar;159/ha less profitable, respectively, compared with standard programs. RR+MD programs for peaches cost an average &dollar;314/ha more and returned about &dollar;284/ha less than STD peach programs.

Influence of &lt;I&gt;Prunus&lt;/I&gt; spp., Peach Cultivars, and Bark Damage on Oviposition Choices by the Lesser Peachtree Borer (Lepidoptera: Sesiidae)

An examination of oviposition choices by the lesser peachtree borer, Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sesiidae), showed that wounded peach, Prunus persica (L.) Batsch, bark was attractive to females for oviposition. Females responded to bark that was injured mechanically (e.g., hammer blows, knife cuts, pruning wounds), infested by lesser peachtree borer larvae or injured by disease. In fact, there was no difference in female oviposition response to knife cut wounds and knife cut wounds infested with lesser peachtree borer larvae. Oviposition on wounded bark from three different high chill peach cultivars was similar and strongly suggests that the narrow genetic base of high chill peach cultivars grown in the southeastern United States has little inherent resistance to the lesser peachtree borer. In stark contrast, when provided different Prunus spp., i.e., exotic peach and the native species P. angustifolia and P. serotina, the exotic peach was highly preferred for oviposition by the native lesser peachtree borer.

Genetic Variation of the Lesser Peach Tree Borer, Synanthedon pictipes (Lepidoptera: Sesiidae) in Arkansas

The lesser peach tree borer, Synanthedon pictipes (LPTB), belongs to the economically important Lepidopteran family Sesiidae. No studies on genetic variation or population structure on the genus Snyanthedon have been previously published. We examined DNA sequence variation in a 603 bp region of the mitochondrial cytochrome oxidase I gene (COI), tRNA-leu and cytochrome oxidase II gene (COII) from three LPTB populations in Arkansas. From 114 LPTB collected from three populations, a total of 53 nucleotide positions were polymorphic, and 12 distinct haplotypes were observed. The most frequent haplotype occurred in 88% of the sampled LPTB's and in all three populations. Sequence divergence among haplotypes ranged from 0.2% to 8.8%. According to the standard molecular clock proposed for lepidopteran mtDNA, the haplotypes have been diverging for up to 2.5 million years. The greatest amount of haplotype diversity was observed in the Fayetteville population where borer management is not maintained. High levels of gene flow were observed among the Clarksville, Springdale and Fayetteville populations suggesting the LPTB has a broad dispersal range. Examination of the genealogical relationships and phylogenetic analysis of the 12 haplotypes supports the existence of three genetically distinct but morphologically indistinguishable subspecies.

MOLECULAR DIAGNOSTICS OF ECONOMICALLY IMPORTANT CLEARWING MOTHS (LEPIDOPTERA: SESIIDAE)

Larvae of many species of Sesiidae, the clearwing moths, are important pests in commercial nurseries, urban landscapes, timber stands, vineyards, and orchards. They cause economic loss by larval boring in stems and roots of herbaceous and woody plants. Researchers and growers often monitor for the presence of economically important sesiid adults with pheromone traps. These traps often attract more than one species of Sesiidae and specimens often degrade making identification difficult or impossible. This can cause problems in monitoring programs where species-specific control programs are used. Polymerase chain reaction (PCR) was used to amplify a 606-bp region of the mitochondrial DNA cytochrome oxidase I (COI), tRNA leucine, and COII gene. This region exhibited 7.7-19.5% genetic variability among 8 species of Sesiidae. Samples were sequenced and restriction sites identified. PCR-restriction fragment length polymorphism (PCR-RFLP) analysis was conducted on 8 species of Sesiidae, Melittia satyriniformis, Paranthrene simulans, Pennisetia marginata, Synanthedon pictipes, S. exitiosa, S. scitula, S. rileyana, and Vitacea polistiformis, with 2 restriction enzymes, Dra I and Hinf I. This method is time efficient requiring less than 8 h to perform and cost efficient with each sample about $1. PCR-RFLP provides an accurate method to differentiate 8 species of adult clearwing moths commonly found in traps baited with commercially available pheromone lures.

Susceptibility of the Lesser Peachtree Borer (Lepidoptera: Sesiidae) to Entomopathogenic Nematodes Under Laboratory Conditions

Abstract The lesser peachtree borer, Synanthedon pictipes (Grote and Robinson), is an important pest of Prunus spp. We determined the susceptibility of S. pictipes to six entomopathogenic nematode species: Heterorhabditis bacteriophora Poinar, H. indica Poinar, Karunakar and David, H. marelatus Liu and Berry, Steinernema carpocapsae (Weiser), S. feltiae (Filipjev), and S. riobrave Cabanillas, Poinar and Raulston. Nematode virulence in S. pictipes was compared with virulence in two known susceptible hosts, Galleria mellonella L. and Tenebrio molitor L. In S. pictipes, the steinernematids were more virulent than the heterorhabditids, the virulence of S. carpocapsae was greater than S. riobrave, with S. feltiae being intermediate between the two, and no differences in virulence were detected among the heterorhabditids. Each nematode exhibited similar or greater virulence to S. pictipes than to T. molitor, and the steinernematids’ virulence to S. pictipes was greater or similar to H. bacteriophora or H. marel...

Increased Suberin Accumulation in Peach × Almond Hybrids

Suberin accumulation in mechanically wounded bark tissue was determined fluorimetrically in greenhouse-grown peach [Prunus persica (L.) Batsch] and F2 progeny from peach × almond [P. amygdalus (Mill.) DA. Webb] hybrids. In general, suberin accumulation following wounding was significantly greater for progeny from almond-type than for peach-type hybrids. Hybrids from parents with almond tree type combined with peach fruit type accumulated the highest suberin levels. These data may partially explain the differences observed among peach and peach × almond hybrids in relative susceptibility to Leucostoma canker [Leucostoma persoonii Hohn. and L. cincta (Fr.) Hohn.] and injury caused by lesser peachtree borer. The association of higher suberin accumulation with specific phenotypic characteristics could simplify the selection of desirable seedlings in a breeding program that includes canker resistance as an objective.

Reduced Incidence of Lesser Peachtree Borer and Leucostoma Canker in Peach-Almond Hybrids

Damage by lesser Peachtree borer (LPB) (Synanthedon pictipes Grote &amp; Robinson) and Leucostoma canker that had accumulated during 6 (Orchard A) and 8 (Orchard B) years were compared in peach (Prunus persica L.) and peach-almond [P. amygdalus (Mill.) D. A. Webb] hybrids. Afterward, the main trunk and scaffold limbs of the trees received 10 wounds 26 mm in diameter and a subset of these trees in Orchard A had wounds inoculated with Leucostoma persoonii Hohn. Before wounding, Leucostoma canker infection and LPB infestations that had accumulated for 6 to 8 years on peach-almond hybrids was ≈60% and 98% less than on peach in Orchard A and B, respectively. One month after wounding the trees, no significant differences in Leucostoma canker infection and LPB infestations were found among the peach-almond hybrids, treated or not treated with L. persoonii, or untreated peach. Yet, Leucostoma- treated and untreated peach-almond hybrids had 33% and 25% less Leucostoma canker and LPB, respectively, when compared with Leucostoma- treated peach. Ten months after wounding, peach-almond hybrids treated with L. persoonii still had significantly less Leucostoma canker (60%) and LPB (25%) when compared with Leucostoma- treated peach. Wound gumming and wound closure rates seemed to influence the degree of LPB infestation and Leucostoma canker. Based on these data, peach-almond hybrids could be valuable sources of resistance to LPB and Leucostoma canker.

Effects of Abamectin on Peachtree Borers in the Laboratory and in Peach Orchards (Lepidoptera: Sesiidae)2

Abamectin was effective in reducing egg hatch, larval survival, adult mating behavior and oviposition of the lesser peachtree borer, Synanthedon pictipes (Grote and Robinson) LPTB, and egg hatch and larval survival of the peachtree borer, Synanthedon exitisoa (Say) PTB, in the laboratory at rates of 10 and 20 ppm. Subsequently, tests in peach orchards with comparable rates of abamectin were effective in reducing PTB populations in Peach and Taylor counties, Georgia. Although abamectin was less effective than chlorpyrifos (standard recommendation) for PTB control, it warrants consideration as an alternative for control because it is a natural product derivative and probably poses little threat to the environment.

Mating Disruption for Reduction of Damage by Lesser Peachtree Borer (Lepidoptera: Sesiidae) in Virginia and Pennsylvania Peach Orchards

Polyethylene dispensers containing the sex pheromone, (E,Z)-3,13-octadeca-dien-I-ol acetate «E,Z)-ODDA), of lesser peachtree borer, Synanthedon pictipes (Grote & Robinson), were placed in peach orchards in Virginia and Pennsylvania. Dispenser containing 40 mg (E,Z)-ODDA were placed in the Virginia orchard (SOO/ha)at the outset of each lesser peachtree borer generation; those used in Pennsylvania contained 70 mg (E,Z)-ODDA and were placed only once at the beginning of each season. Three generations of lesser peachtree borer were subjected to mating disruption at each site. Male attraction to traps was totally disrupted in blocks treated with pheromone. Relative to blocks treated with insecticide, counts of pupal exuviae on peach trees were reduced by 19-97% in treated blocks. Thus, the level of control achieved with the pheromone was superior to that obtained with insecticides that are currently recommended for lesser peachtree borer control.

Field Comparison of Nonsticky and Sticky Pheromone Traps for Monitoring Fruit Pests in Western New York

Pheromone traps play an important role in monitoring insect pest populations of agricultural crops. Several different trap designs have been developed to monitor insects. The relative effectiveness of the following six commercially available pheromone traps was compared: Multi-pher 1, 2, and 3 nonsticky traps and Scentry wing, Pherocon lC, and Delta sticky traps. Traps were set for the following six major fruit pests in commercial fruit orchards during the 1986 and 1987 seasons: spotted tentiform leafminer, Phyllonorycter blancardella (F.); redbanded leafroller, Argyrotaenia velutinana (Walker); codling moth, Cydia pomonella (L.); obliquebanded leafroller, Choristoneura rosaceana (Harris); peachtree borer, Synanthedon exitiosa (Say); and lesser peachtree borer, Synanthedon pictipes (Grote and Robinson). Trap efficiency, in terms of quantity of moths captured, varied with the species of moth being monitored and with the trap design. However, sticky traps generally captured more moths than nonsticky traps regardless of species. Multi-phers 1 and 3 nonsticky traps and all sticky traps were able to indicate the first flights and population fluctuations. All of the nonsticky traps required less preparation and handling time in the field than sticky traps because they were easier to use. Specimens were also easier to identify in nonsticky traps than those caught in the sticky traps. Nonsticky traps cost more initially but are reusable from season to season and could result in considerable savings in trapping costs for yearly monitoring programs. In conclusion, the nonsticky pheromone traps, Multi-pher 1 and 3, offer considerable promise for monitoring insect pest populations in fruit orchards.

Control of Peachtree Rorer on Tart Cherry, 1988

Abstract Materials were applied to 5-yr-old ‘Montmorency’ tart cherry trees in a commercial orchard near Sutton’s Bay, Mich. Treatments consisted of trees replicated 5 times in a completely randomized design. Materials were applied dilute to runoff to the lower trunk and to the soil in a 1-ft radius around the trunk until each area was soaked. Dates of application were 25 May (petal fall)–peak first-generation American plum borer emergence, 17 Jun–peak lesser peachtree borer emergence, and 25 Jul–peak peachtree borer emergence. Trees were evaluated by digging up the soil around the trunks with garden trowels to a depth of 10 inches and carefully examining the soil for larvae. Then the crown and upper roots were carefully examined for old and new damage and larvae. New damage was distinguished from old by the presence of fresh reddish frass and gummosis. Old damage had either no frass or dark brown frass and no gummosis. Extensive surface damage and tunneling meant that the larvae often had to be excavated with hammers and wood chisels from the roots. A damage rating of 0-3 was assigned for no, slight, moderate, and heavy damage and averaged as an index of values 1-3. This index does not distinguish between old and new damage.

Ovipositional behavior of lesser peachtree borer in presence of host-plant volatiles

Reactions of lesser peachtree borer [Synanthedon pictipes (G&R)] to volatiles of peach wood, either natural or chemically fractionated, were observed. Mated females were stimulated by and responsive to such materials and deposited significantly more eggs on substrates, including unnatural hosts, that had been treated with aqueous mixtures of bark-canker materials. Stimulation to oviposit occurred even when the female was blinded, indicating the presence of chemical cues. Natural canker-bark extracts immediately stimulated ovipostion and for a few hours significantly increased the number of eggs laid. However, average fecundity was not increased. Antennectomy did not significantly decrease response to volatiles by gravid females, and alternate sites of such chemoreception were not located. Complex mixtures derived by solvent extraction, steam distillation, and volatiles trapping from bark, canker, and gum all had activity. Observations of insect behavior in outdoor cages and also in the laboratory indicated that visual, chemosensory, and mechanosensory receptors are involved in host finding and oviposition.