Epiphyas Postvittana Walker Research Articles

Freeze-Dried Artificial Diet-Based Technique for Screening Plant Extracts Against Epiphyas Postvittana (Lepidoptera: Tortricidae)

A bioassay method based on freeze-dried artificial diet for assessing feeding and contact toxicity in light brown apple moth, Epiphyas Postvittana Walker, larvae is described. Diet disks were vacuum freeze-dried. Organic solvent extracts were added to the disk (120 μl), vacuum evaporated for 3 h, and reconstituted with distilled water before adding the neonate larvae(40 per replicate). This technique took 42 min per extract to set up and evaluate. Results for a range of foliage extracts of New Zealand gymnosperms are discussed. Ability to test the activity of extracts dissolved in volatile organic solvents was seen as a major advantage of this technique.

Hot-water immersion for disinfestation of lightbrown apple moth (Epiphyas postvittana) and longtailed mealy bug (Pseudococcus longispinus) on persimmons

The mortality response of lightbrown apple moth (LBAM; Epiphyas postvittana Walker) and longtailed mealy bug (MB; Pseudococcus longispinus Targioni-Tozetti) on persimmons to hot-water immersion treatments between 44 and 54 °C was examined. The calyx of the persimmon was found to offer thermal protection for both LBAM and MB resulting in lower insect mortality under the calyx compared to that on the outside of the fruit. The mean immersion time for mean 99% mortality (LT99) of LBAM at 44 °C was 32.5 min, and this time decreased with increasing temperature to 7.4 min at 54 °C. MB were found to be much more tolerant to hot-water immersion than LBAM. The mean LT99 of MB at 44 °C was 74.2 min, which decreased to 15.1 min at 54 °C. Hot-water immersion appears to be a potentially useful disinfestation method.

Effect of a vertical object on the sex pheromone-mediated flight and landing behaviors of the male lightbrown apple moth,Epiphyas postvittana (walker) (Lepidoptera: Tortricidae)

A small (2.5-cm-wide) vertical (10-cm-high) white object influenced the sex pheromone-mediated flight and landing behaviors of maleEpiphyas postvittana. When the vertical object was positioned on a horizontal surface to the side (3–5 cm) and upwind of a pheromone source (in the middle of the surface), the distribution of landing positions of males on the surface was different from that when the object was not present; males tended to land in positions skewed toward the side of the source that the object was on. The closer the object was positioned to the source, the greater the number of males that landed on the object (rather than on the horizontal surface). This difference in landing positions (when the object was present) corresponded with changes in the flight tracks; the tracks of males flying to the surface with an object were skewed toward the object and had higher amplitude intertrack reversal distances than the tracks of males flying to a surface without a vertical object. Positioning of a vertical object progressively upwind of the source resulted, apparently, in decreased effects on the landing (and presumably flight) behavior of males. The effect of the vertical object on the flight and landing behaviors of males corresponded largely with changes in pheromone plume structure (visualized with smoke) induced by the extra turbulence in the airflow over the source. Thus it appears that the vertical object influences the behavior of maleE. postvittana largely through the olfactory sensory modality. However, when a clear, Mylar object, in place of the white object, was placed on the surface, more males landed on the Mylar object (than did on the white object), suggesting that the vertical object may also influence the behavior of males through the visual modality.

Field Electroantennogram and Behavioral Responses of Epiphyas postvittana (Lepidoptera: Tortricidae) Under Low Pheromone and Inhibitor Concentrations

Mating disruption of Epiphyas postvittana (Walker) was studied in two O.l-ha plots at a 10.6-ha apple orchard each with either 0, 100,200, or 400 dispensers per hectare; the dispensers released an attractive blend of pheromone (54.9 mg [E]-ll-tetradecenyl acetate and 2.5 mg of [E, EI-9, 11-tetradecadienyl acetate) and inhibitor (19.7 mg of [Z]-ll-tetradecenyl acetate). The incidence of mating of tethered females placed in treated or untreated plots Significantly increased with the increased numbers of males released. Mating was reduced with estimated pheromone release rates at dusk from 1.1-4.4 mg/ha/h. In the control plots, trap catch (mean ± SEM) over 173 d was 0.207 ± 0.074 males per trap per day. In the pheromone and inhibitor treatments, 0.004 ± 0.003 males per trap per day were caught in the 100-dispensers-per-hectare plots and 0.001 ± 0.001 males per trap per day in the 200-dispensers-per-hectare plots. No moths were caught at 400-dispensersperha level. Mating frequency averaged 12.9% of the control level at 173 d after treatment, with release rates from 0.15-0.51 mg/ha/h. Electroantennogram signals recorded in treated apple-orchard plots showed a significant effect from increasing the rate of dispenser application after 83 d. Pheromone and inhibitor levels had higher variance in the grass between rows of trees than within the tree rows. By 140 d after treatment, no electroantennogram response to pheromone and inhibitor was distinguishable above the orchard background volatiles. However, the standard error of electroantennogram responses was negatively correlated with release rate. Time series of continuous electroantennogram recordings over 30-60 s also showed significant differences in root mean square of the signal between treated and untreated plots after 4 mo, with higher variance in the samples taken above grass rows.

Biology ofAncistrocerus gazella(Hymenoptera: Vespoidea: Eumenidae) in New Zealand

Ancistrocerus gazella(Panzer, 1798) is common in Central Otago, New Zealand. Details are provided of its typically tubular, generally multicelled nests in hollow stems, artificial trap nests, abandoned wood-boring insect galleries, cracks and holes in stone walls and old nail and bolt holes in cement, concrete and wood. After an egg is suspended by a slender thread from the roof of the cell near its inner end, 2-19 (mode =8) lightly paralysed lepidopterous larvae are placed in the cell. The cell is then sealed with a plug of moulded mud. Host species so far identified are Planotortrix octo Dugdale, Ctenopseustis obliquana (Walker), Epiphyas postvittana Walker. Eurythecta zelaea Meyrick, Hannologa amplexana (Zeller), H. sisyrana Meyrick, Harmologa sp., Crocidosema plebejana Zeller, Pyrgotis plagiatana (Walker) (all Tortricidae), an unidentified species of Gelechiidae, Epiphthora melanombra Meyrick (Gelechiidae) and Chloroclystis filata Guenee (Geometridae).

Geographic changes in leafroller species composition in Nelson orchards

Abstract Pheromone traps placed along a transect across the Nelson district from Waimea to Riwaka were used to determine the distribution of three native and one introduced species of leafroller of importance to fruit growing in the Nelson district. The light brown apple moth, Epiphyas postvittana (Walker), was dominant throughout the district. The brownheaded leafrollers, Ctenopseustis obliquana (Walker) and C. herana (Felder & Rogenhofer), and the greenheaded leafroller, Planotortrix excessana (Walker), were each recorded in various proportions at all trap sites. Ctenopseustis obliquana was dominant from Moutere Bluffs to Riwaka, while C. herana was dominant nearer to Nelson.

Distribution and decay of phosmet residues in the canopy of “T-bar” trellised kiwifruit

Abstract Phosmet was applied in mid season to “T-bar” trellised kiwifruit (Actinidia deliciosa) by airblast sprayer at 112.5 g a.i/100 litres and 2250 litres/ha. Residue levels on the upper and lower surfaces of leaves from two canopy zones and two shoot types were assessed by chemical and biological assays. Chemical assays used a brief solvent wash of a fixed area of the separate leaf surfaces. In the bioassays neonate Epiphyas postvittana (Walker) larvae were cagedon each surface. These procedures were repeated 1, 3, 8, 14, and 29 days after spray application in mid summer. Mean initial residues ranged from 2.1 μg/cm2 to 9.0 μg/cm2, with levels 2–3 times greater on lower surfaces than upper surfaces. Residue half-lives calculated for lower leaf surfaces ranged from 6 to 20 days. The half-life for upper surface residues was estimated graphically at 3 days. Differences in the initial residue levels between canopy zones and shoot types tended to be offset by subsequent decay rates. Chemical assays and mort...

Modified atmospheres for the posthavest disinfestation of New Zealand persimmons

Abstract The responses of lightbrown apple moth (LBAM—Epiphyas postvittana Walker) and long tailed mealy bug (Pseudococcus longispinus Targioni-Tozetti) on persimmons to controlled (CA) and modified atmosphere (MA) postharvest disinfestation treatments were determined. Atmospheres were generated using fruit (1) exposed to a continuous gas-flow apparatus (CA); (2) contained in a polymeric film bag with an oxygen scrubber (MA + scrubber); and (3) in a polymeric film bag under vacuum (MA + vac). LBAM larvae on fruit under CA were all killed after 4–7 days exposure to 0.5% O2, 5.3% CO2 but 0.2% of the mealy bug larvae and adults survived. LBAM and mealy bugs were not killed after 7 days at 20°C under MA + scrubber conditions, but were killed after 28 days at 0°C. Only LBAM were killed under MA + vac. The time needed for complete kill of LBAM and mealy bugs under MA conditions was reduced to 14 days at 0°C when fruit were held for 4 days at 20°C before coolstorage at 0°C. The MA treatment shows commercial pote...

Influence of Larval Rearing Conditions on the Body Size and Flight Capacity of Epiphyas-Postvittana Moths

Effects of rearing conditions of larvae on the body weight and flight duration of the light brown apple moth, Epiphyas postvittana (Walker), were evaluated in the laboratory. The body weight of both male and female moths at emergence decreased with increasing temperature from 15 to 28-degrees-C during larval stages; in contrast, flight duration increased with rising temperature. There was no effect of larval density on flight duration, although the body weight of moths decreased as density increased. Variation in water content of artificial diet showed a significant influence on flight duration of female moths, but not on body weight in either sex. Flight duration was different only for females when their larvae were reared on young leaves of four host plants. Female moths from larvae on Rumex crispus and Plantago lanceolata flew for significantly longer periods than those from larvae on Trifolium repens and Pyrus malus. Larvae fed on young leaves yielded adults that flew for longer periods than those fed on senescent leaves. Inconsistency in relationships between body weight and flight duration of moths with respect to influences of different environmental factors during the larval stages indicates that flight capacity is unlikely to be influenced by body size in this species.

Electrophoretic variation at flight-related enzyme loci and its possible association with flight capacity inEpiphyas postvittana

Variations at three flight-related enzyme loci, delta-glycerophosphate dehydrogenase (delta-Gpdh), glucose-6-phosphate dehydrogenase (G6pd), and phosphoglucomutase (Pgm), of Epiphyas postvittana (Walker) moths were investigated using starch gel electrophoresis. Among the three enzyme loci, delta-Gpdh and G6pd were found to be monomorphic, but Pgm was polymorphic, with a total of seven different genotypes and five alleles identified in this study. Comparisons of allozyme variability at the Pgm locus showed significant differentiation among five natural populations sampled from geographically distinct localities in New Zealand and Australia and between laboratory populations differentiated by artificial selection on flight capacity. The Pgm polymorphism was shown to be associated with the variation of flight capacity, but the role of the enzyme locus in the evolution of flight behavior is to be demonstrated in this species.

Leafroller oviposition on larval host plants

Caged greenheaded leafroller (Planotortrix excessana (Walker)) (Lepidoptera: Tortricidae) and lightbrown apple moth (Epiphyas postvittana (Walker)) (Lepidoptera: Tortricidae) adults were provided with the leaves of known larval host plants to determine the relative amount of oviposition on the different hosts. Relative to apple leaves, lightbrown apple moth oviposited fewer eggs on narrow-leaved plantain (Plantago lanceolata L.), and blackberry (Rubus strigolosus agg.) and equal numbers on poplar (Populus nigra L.). Greenheaded leafrollers laid more eggs on poplar leaves than on apple leaves. Close examination of the likely factors determining oviposition sites revealed that hairs on the dorsal leaf surface could affect the choice of oviposition sites. Lightbrown apple moths therefore tended to oviposit more frequently on the less hairy mature leaves of apple shoots compared to more hairy, emerging leaves which had a greater density of dorsal surface leaf hairs. Arrangement of host plant leaf clusters may...

Monitoring Azinphosmethyl Resistance in the Light Brown Apple Moth (Lepidoptera: Tortricidae) in New Zealand

The extent of azinphosmethyl resistance in light brown apple moth, Epiphyas Postvittana (Walker), in the Nelson region of New Zealand was determined in 1982. Light traps were used to capture females from which laboratory colonies were established for testing. Resistance was detected by spraying larvae directly with a Potter tower. In later resistance surveys (1983–85) topical application to pheromone-attracted males was used to assess resistance. Two populations (at Mariri and at the Moutere Bluffs) resistant to azinphosmethyl, but of confined distribution, were found. Resistant male moths were collected from apple orchards and nearby scrub areas and were more abundant outside orchards during the period of insecticide spray application. Subsequent reinvasion of orchards by moths from nearby scrub areas within the orchard area was indicated by the similarity in proportion of resistant individuals in the two habitats and by catches in pheromone-baited sticky traps from orchards and scrub areas. Two percent fruit damage occurred in an affected orchard in which the grower applied azinphosmethyl, compared with a normal level of ca. 0–0.2% damage elsewhere in the district.

Pheromone Use in Insecticide Resistance Surveys of Lightbrown Apple Moths (Lepidoptera: Tortricidae)

To determine the distribution of azinphosmethyl-resistant Epiphyas postvittana (Walker) in an apple orchard district in New Zealand, female sex pheromone was used to collect males from different habitats in a 125-ha area. Dosage-mortality regressions generated by topical application experiments showed the greatest proportion of resistant moths to be in the center of the sprayed area. This method permits decisions on control tactics to be made once the problem areas are delineated.

Insecticide Resistance in the Light Brown Apple Moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae): Larval Response to Azinphosnlethyl

Azinphosmethyl resistance in the light brown apple moth Epiphyas postvittana (Walker) was confirmed with four methods: topical application of larvae, a Potter tower direct-spray method, and two residue exposure methods using middle instars and newly hatched larvae. The Mariri population exhibited a 140-fold resistance factor, using topical application of larvae. A 20-fold resistance factor was obtained by using a Potter tower to spray the insects directly. The first residue exposure method, using a Potter tower to treat apple leaf discs with the 50 WP formulation, produced a 13-fold resistance factor when third- and fourth-instar larvae were caged on the discs for 48 h. In the second residue exposure method, when first-instar larvae were caged onto leaf discs for 16 h, the resistance factor was 5-fold. The Potter tower, acetone-spray method was found to be the most satisfactory technique for evaluation of azinphosmethyl resistance in larvae. The application of this technique for monitoring resistance in the field is suggested.

New Zealand host and locality records for an introduced tortricid parasite,Trigonospila brevifacies(Diptera: Tachinidae)

The tachinid fly, Trigonospila brevifacies (Hardy), is recorded from 3 previously unpublished New Zealand endemic tortricid hosts: Ctenopseustis obliquana (Walker), “Cnephasia” jactatana (Walker), and Epalxiphora axenana Meyrick. The Australian tortricid, Epiphyas postvittana (Walker), is also recorded as a host in New Zealand. First records are given for T. brevifacies reared from the pterophorid Platyptilia falcatalis Walker, the oecophorid Heliostibes atychioides (Butler), the stathmopodid Stathmopoda “skelloni” (Butler), and an unidentified psychid. Records of the parasite from a mixed collection of larvae including the geometrid Pasiphila lunata (Philpott) and the pterophorid Aciptilia monospilalis Walker are also given. Notes are included on the biology and locality records of T. brevifacies collected as adults.

Parasitism of the Light Brown Apple Moth, Epiphyas Postvittana (Walker), by Its Larval Ectoparasite, Goniozus Jacintae Farrugia (Hymenoptera: Bethylidae), in Natural Populations in Victoria.

Host-parasitoid relationships of Epiphyas postvittana (Tortricidae) and its larval ectoparasite, Goniozus jacintae were studied for 16 generations in an apple orchard and for 10 generations in a pear orchard between 1971 and 1977. G. jacintae is arrhenotokous and parthenogenetic, with unmated females producing males. It is a multiple parasitoid laying from one to seven eggs per host larva in the field, with a mean of 1.8. Parasitism is restricted to caterpillar instars III-VI, instar IV being predominantly parasitized. The life cycles of the host and the parasitoid are well synchronized, the former having three generations a year. Parasitized host larvae are found during most months of the year; numbers are maximum from October to March, when the host larvae are also in peak numbers. E. postvittana is polyphagous, occurring both on fruit trees and on dicotyledenous weed hosts in the undergrowth. G. jacintae was found in both these situations and its occurrence was related to the presence of the host larvae rather than to any association with flora or microclimate. In general, the degree of parasitism of host generations ranged from 0 to 8.3%. The impact of G. jacintae as a mortality factor of E. postvittana was insignificant. The host-parasitoid relationship was of the delayed density-dependent type.

Inorganic bromide residue in bananas, bell capsicums (sweet peppers), cherries and apples following fumigation with ethylene dibromide and methyl bromide

Inorganic bromide residues were evaluated from fumigation schedules available in Australia for use against Queensland fruit fly, Dacus tryoni (Froggatt) and light brown apple moth, Epiphyas postvittana (Walker) in fruit and vegetables. Capsicums were fumigated for two hours at 20�C with 22 g m-3 ethylene dibromide (EDB). Bromide residues (40-45 �g g-1) were in excess of the maximum residue limit of 10 �g g-1 of the United States Food and Drug Administration (U.S.F.D.A.) and the current 20 �g g-1 recommendation of the Australian National Health and Medical Research Council (N.H.M.R.C.). Bananas were fumigated with dosages of 10, 12 and 14 g m-3 EDB for two hours at 20�C. Bromide residues increased with increasing dosages, and ranged from 11.7 to 15.6 �g g-1. Residues were within the recommended 20 �g g-1 limit of the N.H.M.R.C., but exceeded the 10 �g g-1 limit of the U.S.F.D.A. Cherries were fumigated for two hours at 15�C with 24 and 48 g m-3 methyl bromide (MB). Bromide residues (up to 8 �g g-1) were well within the 20 �g g-1 N.H.M.R.C. and U.S.F.D.A. limits. Apples were fumigated for two hours at 15�C with 24 g MB m-3 and at 7�C with 32 g MB m-3. Residues approximated or were less than the 5 �g g-1 limit of the U.S.F.D.A. and considerably lower than the 20 �g g-1 N.H.M.R.C. recommendation.

A chemically defined medium for rearingEpiphyas postvittana(Lepidoptera: Tortricidae)

Three successive generations of the light brown apple moth, Epiphyas postvittana (Walker), were reared axenically on a chemically defined medium formulated from 18 amino acids, a salt mixture, 2 sugars, 11 vitamins, safflower oil, cholesterol, RNA, cellulose powder, and agar. The average generation cycle of about 49 days (at 25 ± l°c, 50–60% R.H., and 12‐h photoperiod) comprised 7 days incubation, 31.5 days larva, 10 days prepupa/pupa, and 2 days adult (pre‐oviposition). The average fecundity was 347 eggs ; 78 % of established larvae reached adulthood ; and the sex ratio was 1.3 ?: 1 ?.

Aseptic rearing ofEpiphyas postvittana(Lepidoptera: Tortricidae) on a meridic diet

The light brown apple moth, Epiphyas postvittana (Walker), was reared aseptically from newly hatched larvae to adults for three generations on a meridic diet. Growth and development on this diet were comparable with that on oligidic diets and on host‐plants. At 25 ± 1°C, 50–60% R.H., and 12‐h photophase, the average larval period was approx. 28 days, pre‐pupal and pupal 11–12 days, and pre‐oviposition approx. 2 days; the incuva‐tion period of eggs was approx. 7 days. The average developmental period from egg to adult was thus about 49 days; 89 % of larvae reached the adult stage. The average fecundity was 598 eggs per female, and the sex ratio was nearly 1:1. There were no differences in the rate of development or in fecundity of insects reared on media with and without a mould inhibitor.

NATURAL ENEMIES OF THE LIGHT BROWN APPLE MOTH, EPIPHYAS POSTVITTANA, IN THE AUSTRALIAN CAPITAL TERRITORY

AbstractThe light brown apple moth, Epiphyas postvittana Walker, is a highly polyphagous native pest of Australia that has recently caused widespread damage to pome, citrus, and vine crops in Victoria and Tasmania. Populations of the pest were followed in a young pesticide-free orchard for two seasons and showed a survival trend of less than 1% of the total eggs laid in each season. An evaluation of its natural enemies by numerical, serological, and forced feeding techniques showed that spiders, particularly the theridiid Achaearanea veruculata (Urquhart), were valuable predators and that they were supported by chrysopids and mirids for short periods of time. Egg, larval, and pupal parasites also contributed to mortality. Brief biological notes on some of the predators are given.