Bagworm Larvae Research Articles

Identification of bagworm (Metisa plana) instar stages using hyperspectral imaging and machine learning techniques

• Young larvae can be detected using hyperspectral imaging and machine learning. • The best model was obtained using green bands and weighted k-nearest neighbour. • Larvae activities gave a significant impact on the selection of the best dataset. • Larvae size is nearly identical, therefore morphological features underperform. A serious outbreak of leaf-eating insects namely bagworm (Lepidoptera: Psychidae), especially Metisa plana species, may cause a 43% yield loss in oil palm production due to late proper control of bagworm populations. Identification of the bagworm instar stage is important to ensure proper control measures are applied in the infested area. This study aims to distinguish the bagworm larvae from second (S2) to fifth (S5) instar stages using hyperspectral imaging and machine learning technique. The capability of spectral reflectance and morphological features namely area, perimeter, major axis length, and minor axis length to classify the instar stage were studied. A total of 2000 sample points of larva were extracted from hyperspectral images. It was then followed by the identification of sensitive wavelengths of each stage using analysis of variance (ANOVA). Results show that seven wavelengths from the blue and green band (i.e., 470 nm, 490 nm, 502 nm, 506 nm, 526 nm, 538 nm, and 554 nm) gave the most significant difference in distinguishing the larval instar stages. To provide a more economical approach, only two wavelengths were used for model development. Later, the classifications models were developed separately using five different types of datasets: (A) significant morphological feature, (B) all significant wavelengths, (C) two wavelengths from the same spectral region, (D) two wavelengths from different spectral regions, and (E) two significant wavelengths and a significant morphological feature. Results have shown the dataset which used green bands at 506 nm and 538 nm with a weighted k-nearest neighbour classifier achieved the best value of accuracy (91% – 95%), precision (0.83 – 0.87), sensitivity (0.77 – 0.99), specificity (0.94 – 0.96) and F1-score (0.81 – 0.91). It was mainly due to green pigments which strongly correlates with the chlorophyll content of the frond leaves fed by the larvae to build and enlarge the case. The capability of the model to detect the young larval instar stages (S2 - S3) where an active feeding activity takes place allows quick decisions about outbreak control measures.

GLASSHOUSE EVALUATION ON THE EFFICACY OF BACILLUS THURINGIENSIS (BT) AGAINST BAGWORM, METISA PLANA AND NON-TARGET EFFECT ON OIL PLAM POLLINATOR, ELAEIDOBIUS KAMERUNICUS (FAUST)

Evaluations on the performance of selected bioinsecticides and recommended chemical insecticides to suppress the bagworm, Metisa plana (Walker) infesting oil palm, were carried out in a glasshouse environment. The results showed that a series of biological products using Bacillus thuringiensis (Bt) is effective in killing 80 per cent of bagworm larvae within 7 to 15 days after application (DAA). Among the biological products, the Bt1 product showed the highest efficacy, killing 99.72 per cent of the bagworm population at 7 DAA. Although slow in reacting, Bt products were highly toxic to the adults, and less effective on the emergence of pollinator weevil,Elaeidobius kamerunicus (Faust). The chemical insecticide, cypermethrin was the most effective compared to all other treatments (p<0.05), killing 100 per cent of the bagworm larvae in only 3 DAA. All non-Bt based insecticides, including cypermethrin, were toxic to both adults and emergence of the weevils. There was no significant difference in the number of adult emergence between the non-treated (control) and Bt-insecticides, but significantly was lower when treated with other insecticides (F= 93.75 p<0.05). Based on its high performance, the biopesticide Bt1 product has a higher potential to be tested in the field for integrated leaf-eating caterpillar management programme. To ensure consistency in their efficacy, these bio-insecticides need further evaluation in large-scale trials, especially in oil palm fields infested with bagworms in epidemic proportions. Keywords: Bagworms, Bacillus thuringiensis, non-target effect, pollinator, oil palm

Evaluation of Acephate and Dimehypo Against the Bagworm, Dapula (Clania) tertia by Trunk Injection

A field trial was conducted to evaluate the efficacy of two insecticides to control a large species of bagworm, i.e. Dapula (Clania) tertia, by trunk injection. The two insecticides evaluated were acephate (in two formulations, i.e. as a soluble powder and a liquid) and dimehypo (liquid formulation only). Acephate was tested in two rates for soluble powder formulation (7.5 g a.i. and 9.4 g a.i. per palm) and two rates for liquid formulation (6 g a.i. and 8 g a.i. per palm). Dimehypo was also tested at two rates, i.e. 6 g a.i. and 8 g a.i. per palm. Post-treatment assessment of live bagworm larvae population was carried out at 7, 14, 21 and 28 days after the trunk injection treatments. The treatments of acephate soluble powder formulation at 7.5 g a.i. per palm and dimehypo at 6 g a.i. per palm were least effective as these two treatments recorded the highest number of larvae at the end of the trial compared to the other treatments. Liquid formulation of acephate at 6 g a.i. per palm and dimehypo at 8 g a.i. per palm caused some reduction in the population of bagworm larvae, but the desired maximum kill was not achieved. Both soluble powder and liquid formulations of acephate at the rate of 9.4 g a.i. per palm and 8 g a.i. per palm respectively were the best amongst the treatments, and resulted in fast and complete control of the bagworm larvae population at 21 days after treatment. Keywords: Bagworm, Dapula (Clania) tertia, acephate, dimehypo, trunk injection

Bagworm bags as portable armour against invertebrate predators

Some animals have evolved the use of environmental materials as “portable armour” against natural enemies. Portable bags that bagworm larvae (Lepidoptera: Psychidae) construct using their own silk and plant parts are generally believed to play an important role as a physical barrier against natural enemies. However, no experimental studies have tested the importance of bags as portable armour against predators. To clarify the defensive function, I studied the bagworm Eumeta minuscula and a potential predator Calosoma maximoviczi (Coleoptera: Carabidae). Under laboratory conditions, all bagworm larvae were attacked by carabid adults, but successfully defended themselves against the predators’ mandibles using their own bags. The portable bags, which are composed mainly of host plant twigs, may function as a physical barrier against predator mandibles. To test this hypothesis, I removed the twig bags and replaced some with herb leaf bags; all bag-removed larvae were easily caught and predated by carabids, while all bag-replaced larvae could successfully defend themselves against carabid attacks. Therefore, various types of portable bags can protect bagworm larvae from carabid attacks. This is the first study to test the defensive function of bagworm portable bags against invertebrate predators.

Inventarisasi Hama Persemaian Di Hutan Tanaman Rakyat Desa Ngambur Kecamatan Bengkunat Belimbing Kabupaten Lampung Barat

Forest pest inventory is research activity to gather and arrange the data of pests existing in seedling periode. Pest inventory activites are used to determine pest types, the number and crop damage order to apply appropriate control. This research was aimed to identity the pest types and its attack levels at community plantation forest nursery. This research was conducted at Community Plantation Forest in Ngambur Village of Bengkunat subdistrict, West Lampung on April to May 2012. The collected data was identified taxonomically. The data was included of pest types, pest density, attack levels, and demages. All samples were collected using systematic method in diagonal pattern. The results was obtained 9 types in kadam nurseries, white albizia, and umbrella tree, which caterpillars (Daphnis hypothous), locust (Locusta migratoria),moths (Hyblaea puera), bag worm (Pteroma plagiophelps), bug (Cosmoleptrus sumatranus), mealy bug (Planococcus citri), leaf caterpillar (Doleschallia polibete), yellow butterfly (Eurema spp.), snail (Achatina fulica) and 1 type of insect predators that weaver ants (Oecophylla smaragdina). Insect population was high enough but not damage the plant nursery while the most dangerous insect pest was a bag worm (Pteroma plagiophelps) and moth (Hyblaea puera). Bag worm larvae cause severe damage, the loss on the leaves. The extent of damage by insect pests classified in the category of still mild attacks. Pest control can be done mechanically or chemically.

Oiketicus kirbyi (Lepidoptera, Psychidae), a key pest in Peruvian orchards of avocado

In recent years, the bagworm Oiketicus kirbyi (Guilding) has become a pest of increasing importance in Peruvian avocado orchards. A study conducted in six commercial orchards evaluated the ecology of, and feeding damage caused by, bagworms on avocado on the southern coast of Peru. In March 2009, the population of live individuals at different locations consisted of second to sixth larval instars. The sex-ratio in the previous generation of bagworms (the parents of larvae) was female-biased, and the mortality rate was higher for females than males. The percentage of mated females varied between 76.7 and 99.1% and declined when the proportion of males was low. The damage caused by bagworm larvae usually results from defoliation, but in the case of O. kirbyi on avocado, the presence of larvae on the fruits was associated with blemishes that limit the marketability of fruits; thus bagworms cause direct economic losses for avocado growers. Future studies are needed to assess the timing of larval emergence with a view to preventing widespread infestation by dispersing neonate bagworms.

Dispersal and development of bagworm larvae (Lepidoptera: Psychidae) on three host plants

AbstractThe present study investigated the development and dispersal of bagworm larvae, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: Psychidae), on three hosts: arborvitae, Thuja occidentalis, blue spruce, Picea pungens, and juniper, Juniperus virginiana. The biomass of larvae was recorded at repeated intervals at 21 field sites. The relative quality of plants varied during larval development: early in the season, larvae were heavier on juniper and arborvitae than on blue spruce; late in the season, in contrast, larvae and pupae were lighter on juniper than on the two other plants. Larvae on blue spruce pupated later than those on arborvitae. In the laboratory, feeding rate and larval growth were not influenced by the density of larvae on the foliage of arborvitae up to a range which greatly exceeded that observed at any of our experimental sites. The incidence of dispersal among neonates emerging on arborvitae was high, as indicated by the high number of larvae captured on sticky traps, and the relatively low number of early instars on arborvitae foliage in relation to the reproductive output of females in the parental generation. The high rate of dispersal among early instars may be due to potential resource depletion over successive generations of bagworms.

Fitness consequence of pupation site for bagworms (Lepidoptera: Psychidae) on arborvitae

The present study investigated the fitness consequence of pupation site of bagworms, Thyridopteryx ephemeraeformis, on arborvitae. The abundance and survival of pupae were higher on trees with a southern exposure than on those with a northern exposure. Neither sex-ratio nor female mating success was influenced by the exposure of trees. The ratio of females per male, survival of pupae, and mating success of females all increased from the bottom to the top of arborvitae. Our results suggest that bagworm larvae may enhance their fitness by pupating in locations most suitable for pupal survival and female mating success. Because adult female bagworms can not disperse, pupation by female larvae may further influence the performance of their larval progeny, either by favouring the long-range dispersal of ballooning larvae or by providing neonates with suitable foliage nearby their site of emergence.

Conservation biological control in urban landscapes: Manipulating parasitoids of bagworm (Lepidoptera: Psychidae) with flowering forbs

Abstract We conducted field experiments to test the hypothesis that regulation of herbivorous pests in urban landscapes can be enhanced with forbs that provide floral resources for adult natural enemies. The herbivore was bagworm, Thyridopteryx ephemeraeformis (Haworth) (Lepidoptera: Psychidae), which is attacked by a guild of hymenopterous parasitoids. We established host shrubs in common garden plantings, encircling some with flowering forbs, released bagworm larvae on shrubs, and assessed survivorship. The hypothesis was supported: parasitism rates of bagworm were 71% higher in shrubs that were surrounded by flowering forbs than in shrubs that lacked flowers. This study also suggested that white-footed mice and European sparrows were important predators of bagworms. The most abundant parasitoid species was the exotic ichneumonid Pimpla (=Coccygominus) disparis (Vierick), an introduced biological control agent of gypsy moth. In a second experiment, parasitism rates were at least three times higher in shrubs encircled by a high density of forbs compared to those having fewer or no forbs. In a third experiment, parasitism rates exceeded 70% in shrubs that were adjacent to a central bed of flowering forbs, but less than 40% in shrubs that were farther away. We conclude from these studies that flowering forbs have a localized effect on host-searching behavior of female parasitoids, encouraging them to parasitize bagworms in the immediate vicinity. This study provides further evidence that ecological methods of pest management can be integrated into the design of urban landscapes to improve regulation of herbivorous pests.

Bagworm Survival and Feeding Preferences as Indicators of Resistance among Maples

Abstract The bagworm (Thyridopteryx ephemeraeformis (Haworth)) is a polyphagous, native pest of numerous deciduous and evergreen ornamental plants. Bagworm larvae were used to investigate host plant susceptibility among ten species and cultivars of maples that are economically important and commonly encountered in landscapes in the eastern United States. Data analyses from 48-hour choice assays, conducted in the laboratory during 2000 and 2001, indicated that differences existed among maples for bagworm feeding preferences and host plant susceptibility. Results from the 48-hour trials were not as accurate as seasonal no-choice assays, however. No-choice assays during both seasons quantified resistance among maples that limited larval bagworm survival and development. Measurements of larval feeding injury demonstrated resistance in paperbark maple (Acer griseum (Franch.) Pax) and trident maple (A. buergerianum Miq.) when compared with other maples. Laboratory results were corroborated during 2001 by a no-choice field assay, in which early instar bagworm larvae performed well on the majority of maples. In contrast, paperbark maple and trident maple were resistant to bagworm feeding, while ‘Autumn Blaze’ Freeman maple (A. x freemanii E. Murray), a hybrid cross obtained by breeding A. rubrum with A. saccharinum, showed moderate resistance.

Dispersal by bagworm larvae, Metisa plana: effects of population density, larval sex, and host plant attributes

Abstract 1. The work reported here investigated the incidence of dispersal by bagworm larvae Metisa plana (Walker) (Lepidoptera: Psychidae), a species with apterous females and winged males.2. A mark–recapture study conducted in a plantation of oil palm revealed that a significant proportion of larvae undertakes multiple episodes of ballooning, and suggested that ballooning represents a strategy for foraging both within and between hosts.3. Experiments conducted in a controlled cage environment indicated that increasing population density and defoliation of oil palm both promote dispersal by larvae.4. Neonatal larvae typically remained on the host where they emerged, indicating that pupation site of late‐instar females influences the distribution of their progeny, and suggesting a high level of genetic relatedness in localised bagworm populations.5. Density‐dependent dispersal may generate relatively uniform distributions of M. plana in plantations of oil palm, by simultaneously stabilising populations on heavily infested palms and redistributing larvae on lightly infested palms.6. The rate of ballooning was greater for female than for male larvae, possibly resulting from the sex‐specific impact of population density on reproductive success or from late‐instar females seeking suitable oviposition sites for their future progeny.

Control of Bagworm, 1991

Abstract Eastern red cedar (approx. 15 ft. tall) in Urbana, 111. were sprayed to control bagworm larvae on 8 Jul. Insecticides were applied with a 30 gal hand-pressurized portable sprayer to the point of run-off in the morning under rising temperatures. Insecticide treatments were diluted with water; controls consisted of water only. Temperature at the end of spraying was 83°F. Larval mortality was recorded at 2 and 4 DAT, with 10 larvae sampled for each of 3 replications in a CRD. Larvae sampled at 2 DAT were removed during the sampling process. Larval cases were 23—40 mm long, averaging 31.4 mm.

Microbial Control of Bagworm on Virginia Pine, 1992

Abstract Virginia pine, 6-8 ft. tall, growing in an ornamental planting located in Payne Co. were used to evaluate efficacy in controlling bagworm larvae. Three rates of Agree 50WP (a Bacillus thuringensis var. Kurstaki/aizawai product) and Dipel were applied on 5 Jun using a Macro R-20 sprayer which delivered 1.2 gal/min of spray at 150 psi. Efficacy was determined at 5 and 10 DAT by randomly collecting 10 bagworm cases from each tree, opening the bag and determining mortality by examining each larva.

Erosion of Biogenically Weathered Clarens Sandstone by Lichenophagous Bagworm Larvae (Lepidoptera; Pyschidae)

AbstractLichenophagous larvae of a bagworm moth species, associated with endolithic lichens occur in the Golden Gate Highlands National Park, South Africa. Endolithic lichens weather Clarens sandstone in the park by dissolving the cementing material of the sandstone. Bagworm larvae use such loosened quartz crystals to construct the bags in which they live. By erosion of the weathered sandstone, the bagworm larvae contribute to pedogenesis in the park at an estimated rate of 4.4 kilograms per hectare per year. In addition, bagworm larvae utilize endolithic lichens as a food source and contribute to dispersal of the lichens. The larvae further contribute an estimated 200 g of organic matter per hectare per year to the park and partake in the cycling of elements in the micro-ecosystem.

Nutritional performance of first and penultimate‐final Instar bagworm larvae on two unrelated hosts as influenced by host of origin

AbstractNutritional performance of early and late instar bagworm (Thyridopteryx ephemeraeformis Haworth) larvae was investigated as a function of host of origin and host type, using two taxonomically distant wild hosts, Salix nigra (Marshall) and Juniperus virginiana (L.). First instar growth and survival were higher on S. nigra; overall performance was similar on the two hosts in penultimate‐final instars. There was no evidence for host associated differentiation with respect to nutritional performance. There were, however, significant genotype & environment interactions for several characters studied, suggesting that the potential for host associated differentiation exists.

Control of Bagworm, 1988

Abstract Mature arborvitae in Champaign, 111., were sprayed to control bagworm larvae 17 Jun with Dipel and Dylox and on 27 Jul with Dipel, Dylox, and Tempo. Insecticides were applied with a 3-gal hand-pressurized portable sprayer to the point of run-off. Larval mortality was recorded at 5 DAT, with 5 samples of 20 larvae taken for each treatment. Larval cases on 17 Jun (young larvae) were 3-6 mm long; larval cases on 27 Jul (older larvae) were 20-37 mm long.

Bagworm Control on Juniper, 1987

Abstract Bagworm control measures were evaluated on container-grown junipers. Treatments were applied to run-off on 7 Jul, using a 1-gal B & G compressed-air sprayer operating at 30 psi. One h after application, 15 bagworm larvae collected from a bagworm-infested white pine were placed on each of 3 replicates/treatment. Bagworms were collected 7 DAT and subjected to high temperature (>100°F) in the laboratory. Mortality was determined by counting the number of larvae that failed to become active 30 min after initiation of temperature stress. Temperature at application was 89°F, and plants were watered daily for 20 min using an overhead sprinkler system.

Selected Effects of Sublethal Dosages of Three Insecticides on the Bagworm

A survey was made under field conditions of the effects of sublethal dosage by ingestion of bagworm larvae, Thyridopteryx ephemeraeformis placed on diazinon, carbaryl, or toxaphene treated juniper. Low dosage ingestion did not affect survival, egg number, pupation duration, or emergence patterns. Test populations on diazinon treated trees completed development through the pupation stage in significantly higher numbers. Treatments with toxaphene resulted in significantly larger egg size but treatment with carbaryl produced a significant decrease in egg size.

Differential stratification, movement and parasitism of sexes of the bagworm, Thyridopteryx ephemeraeformis on redcedar

Abstract. 1. Male and female bagworm larvae develop and pupate at different heights on redcedar trees.2. Habitat segregation by height of male and female bagworms is apparent by the third instar, and results in part from differential movement of male and female larvae on redcedar foliage during their development. Females gradually ascend the crown, whereas males remain at the same height on the tree.3. Parasitism of male bagworm pupae was greater than for female pupae. Pupal parasitism is heaviest in the bottom of redcedar trees, where most male bagworms pupate.4. Several hypotheses are offered concerning the origin and maintenance of differential habitat utilization by male and female bagworms, despite apparently strong selection against males pupating low in the crowns of redcedar.

Arborvitae, Bagworm Control, Zanesv1Lle, Ohio, 1976

Abstract A commercial planting of 3m American arborvitae, lightly infested with 1.5 cm long bagworm larvae, was selected for insecticide evaluation. Five larvae on each of 4 replicate trees/treatment were ragged prior to application of insecticides July 19. Trees were sprayed to runoff (ca. 1 gal finished spray/tree) with a Myers Baronet wheelbarrow hydraulic sprayer under sunny skies (ca. 30°C) when larvae were actively feeding. Treatment effectiveness was evaluated 1 week after application by counting the number of tagged larvae surviving on each tree. A second, preliminary test, was conducted later with newly available experimental materials. Single trees were sprayed Aug 4; efficacy was evaluated 1 week later (as above).