DEVELOPMENT AND EVALUATION OF A SAMPLING SCHEME FOR THE GYPSY MOTH EGG PARASITOID OOENCYRTUS KUVANAE (HYMENOPTERA: ENCYRTIDAE)

1981 ◽  
Vol 113 (7) ◽  
pp. 575-584 ◽  
Author(s):  
M. W. Brown ◽  
James L. Rosenberger ◽  
E. Alan Cameron
Keyword(s):  
Gypsy Moth ◽  
Negative Binomial ◽  
Sampling Methods ◽  
Field Evaluation ◽  
Egg Parasitoid ◽  
Sampling Scheme ◽  
Egg Mass ◽  
Egg Masses ◽  
Coefficients Of Variation ◽  
Ooencyrtus Kuvanae

AbstractFour sampling methods for Ooencyrtus kuvanae (Howard) populations were compared for efficiency using coefficients of variation. On this basis, none of the sampling methods was uniformly superior to any other, but a cluster of 0.01 ha subplots was chosen as the best method because of the aggregation of both gypsy moth egg masses and parasitoids. From the estimated population variance per egg mass it was calculated that 150 egg masses should be sampled per plot to provide an error bound of 0.2 parasitoid per egg mass (α = 0.1). An analysis of variance indicated that variation among study areas was the largest source of variation, and that among day, within day, and plot configuration variation were significant. Estimates of parasitoid activity are most reliable during the period between 1300 and 1600 h EST. Activity of parasitoids was reduced on overcast days. In August, the distribution of O. kuvanae approximates that of the negative binomial but with too many individuals in the high frequency classes. In a compromise between cost and accuracy, the sampling scheme selected consists of thirty 0.01 ha subplots per plot sampled between 1300 and 1600 h EST on sunny days. This sampling scheme was found satisfactory using field evaluation.

scholarly journals Implementing Mass Rearing of Trissolcus japonicus (Hymenoptera: Scelionidae) on Cold-Stored Host Eggs

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 840
Author(s):  
Barbara Bittau ◽  
Maria Luisa Dindo ◽  
Giovanni Burgio ◽  
Giuseppino Sabbatini-Peverieri ◽  
Kim Alan Hoelmer ◽  
...  
Keyword(s):  
Mass Rearing ◽  
Classical Biological Control ◽  
Egg Parasitoid ◽  
Egg Mass ◽  
Severe Damage ◽  
Progeny Production ◽  
Asian Origin ◽  
Egg Masses ◽  
Trissolcus Japonicus ◽  
Promising Solution

Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), a pest of Asian origin, has been causing severe damage to Italian agriculture. The application of classical biological control by the release of Trissolcus japonicus (Ashmead) (Hymenoptera: Scelionidae), an exotic egg parasitoid, appears to be one promising solution. In Italy, releases of T. japonicus in the field were authorized in 2020. In this study, some parameters that could influence the rearing of T. japonicus in insectaries were investigated. A significantly higher production of progeny was observed on host eggs stored at 6 °C (86.5%) compared to −24 °C (48.8%) for up to two months prior to exposure to parasitism. There were no significant differences in progeny production from single females in a vial provided with only one egg mass (83.2%) or 10 females inside a cage with 6 egg masses (83.9%). The exposure of parasitoids to refrigerated (6 °C) egg masses of H. halys for 72 h led to a significantly higher production of progeny (62.1%) compared to shorter exposures for 48 (44.0%) or 24 h (37.1%). A decline in production of progeny by the same female was detected between the first (62.1%) and the second parasitization (41.3%). Adult parasitoids stored at 16 °C for up to 90 days had an 87.1% survival rate, but a significant decrease in progeny production was detected. These parameters could be adjusted when rearing T. japonicus for specific aims such as the production of individuals for field release or colony maintenance.

Augmenting Nucleopolyhedrovirus Load in Gypsy Moth (Lepidoptera: Lymantriidae) Populations with Egg Mass Treatments

2003 ◽  
Vol 38 (2) ◽  
pp. 300-313 ◽  
Author(s):  
R. E. Webb ◽  
G. B. White ◽  
K. W. Thorpe
Keyword(s):  
Gypsy Moth ◽  
Early Treatment ◽  
Adult Emergence ◽  
Field Studies ◽  
Host Population ◽  
Egg Mass ◽  
Moth Population ◽  
Egg Masses ◽  
Entomophaga Maimaiga ◽  
Virus Dose

Previous observations show that gypsy moth, Lymantria dispar L., mortality induced by the fungus Entomophaga maimaiga Humber, Shimazu & Soper is quickly manifested as host population density increases. However, the gypsy moth nucleopolyhedrovirus (LdMNPV) lags behind the rebounding gypsy moth population. In this study, egg masses were contaminated with virus to successfully augment LdMNPV in gypsy moth populations in Virginia. Laboratory bioassays determined the approximate LdMNPV dose to apply to egg masses with and without the addition of the virus enhancer Blankophor BBH to the spray mixture. The highest dose of virus (5.3 × 105 PIBs/mL) tested without Blankophor BBH gave 82.3% mortality. Mortality for this virus dose increased to 91.8% when 1% Blankophor BBH was added. Field studies established that application of virus at an earlier date (04 April) was as efficacious as an application made at a later date (12 April); this study also included a further assessment of the addition of Blankophor BBH to the spray mixture. While application of LdMNPV + Blankophor BBH resulted in faster kill, levels of kill were similar (88.0% for early treatment and 78.8% for later treatment for virus applied alone versus 87.8% for early treatment and 89.1% for later treatment for virus + Blankophor BBH). However, a higher than expected number of cadavers in the LdMNPV + Blankophor BBH treatments had few or no polyhedral inclusion bodies (PIBs). Finally, virus infection resulting from the application of LdMNPV to pupae in June 1998 was compared with infection levels seen after the application of virus to egg masses in April 1999. The April 1999 treatment to egg masses clearly resulted in a higher kill of emerging larvae (=79.3% mortality) compared to the June 1998 treatment to female pupae (with virus incorporated into the egg masses laid by females after adult emergence) (=13.7% mortality). The virus was recovered season-long from larvae collected from populations in the treated plots (but not from control plots), indicating within season spread.

SPATIAL DISTRIBUTION OF ADULTS OFOOENCYRTUS KUVANAE(HYMENOPTERA: ENCYRTIDAE), AN EGG PARASITE OFLYMANTRIA DISPAR(LEPIDOPTERA: LYMANTRIIDAE)

1982 ◽  
Vol 114 (12) ◽  
pp. 1109-1120 ◽  
Author(s):  
M. W. Brown ◽  
E. Alan Cameron
Keyword(s):  
Spatial Distribution ◽  
Gypsy Moth ◽  
Tree Species ◽  
Small Sample ◽  
Egg Mass ◽  
Parasite Abundance ◽  
Egg Masses ◽  
Positive Correlation ◽  
Wide Range ◽  
Mass Volume

AbstractThe spatial distribution of adultOoencyrtus kuvanae(Howard) (Hymenoptera: Encyrtidae) was examined in central Pennsylvania during 1978–1980. Data were gathered over a wide range of gypsy moth (Lymantria dispar(L.) (Lepidoptera: Lymantriidae)) densities and from all phases of population growth. There was a linear relationship between the log variance and log mean, fitting Taylor's Power Law with a power of 1.27. The degree of aggregation inO. kuvanaepopulations, as measured by the variance-to-mean ratio, was correlated positively with the abundance of the parasite, and was independent of host density. Aggregation was believed to result from the habit of the female parasite ovipositing repeatedly on the same egg mass, and the resultant progeny emerging synchronously. Behavior and density ofO. kuvanaepopulations were found to depend upon the gypsy moth population condition, i.e., low, rising, high stable, outbreak, or collapsed. The frequency distribution ofO. kuvanaepopulations fit the Poisson at densities less than 0.2 parasite adult per egg mass, a condition which occurred early and late (July, November) in the season, and the negative binomial above this density; a few distributions fit the log normal. The data were also analyzed using analyses of variance (multivariate and univariate), correlation, and regression techniques. All main effects, i.e., study area, host egg mass volume, egg mass height from the ground (within the 0–2 m sampling universe), aspect of the egg mass on the tree, and tree species, were important in explaining the variance in parasite abundance; study area differences were the most important. The effects of aspect and tree species were explained on the basis of small sample sizes, and not studied further. There was a positive correlation between host egg mass volume (= size) and parasite abundance. There was also a positive correlation between the height of the egg mass and parasite abundance during the summer; however, this relationship became negative by late fall. This seasonal change in vertical distribution was attributed to the tendency ofO. kuvanaeto be closer to the ground where they overwinter. Variation in adult abundance was generally greater among gypsy moth egg masses on different trees than among egg masses on the same tree, except at low parasite densities. This was attributed to the parasites searching for egg masses on one tree before dispersing to another.

Influence of burlap-band colour on larval, pupal, and egg-mass counts of Lymantria dispar (Lepidoptera: Lymantriidae)

2003 ◽  
Vol 135 (6) ◽  
pp. 869-877
Author(s):  
David B. Roden
Keyword(s):  
Gypsy Moth ◽  
Lymantria Dispar ◽  
Field Experiments ◽  
Quercus Rubra ◽  
Egg Mass ◽  
Egg Masses ◽  
Band Position ◽  
The Mean ◽  
Pupation Site ◽  
Selection Of

AbstractThis paper describes the effect of the colour of burlap bands (black versus naturally coloured or tan burlap) affixed to red oak, Quercus rubra (L.) (Fagaceae), and how it influences selection of larval resting site, pupation site, and egg-mass counts of gypsy moth, Lymantria dispar (L.). In field experiments with half black and half tan burlap bands, the mean number of larvae, pupae, and egg masses were significantly greater under the black section of burlap. Individual burlap bands composed of either black or tan burlap affixed to separate trees produced similar significant results for larvae and pupae. When two burlap bands composed of opposite colours (black versus tan) were affixed to the same tree, significantly more larvae were found under the upper band, regardless of colour. In contrast, pupa and egg-mass densities were significantly greater under black bands, regardless of band position.

Destruction of Gypsy Moth Egg Masses (Using Surfactants, Detergents, Oils or Conventional Insecticides) for Quarantine and Community Action Programs2

1994 ◽  
Vol 29 (3) ◽  
pp. 305-317
Author(s):  
R. E. Webb ◽  
W. H. McLane ◽  
J. A. Finney ◽  
L. Venables ◽  
G. B. White ◽  
...  
Keyword(s):  
Soybean Oil ◽  
Gypsy Moth ◽  
Agricultural Research ◽  
Community Action ◽  
Egg Mass ◽  
Mass Destruction ◽  
Egg Masses ◽  
Highly Active ◽  
Methods Development ◽  
Development Center

A series of studies were conducted, beginning in 1976, at the Otis Methods Development Center, Otis ANGB, MA, and beginning in 1982 at the Beltsville Agricultural Research Center, Beltsville, MD, to evaluate surfactants, detergents, oils, and insecticides as egg mass destruction agents for use in quarantine and community action programs. Surfactants, oils, and detergents tended to be more active when applied in the fall, while conventional insecticides were generally more active when applied in the spring. Some products, especially soybean oil, were highly active throughout the gypsy moth egg stage (July–March). A soybean-oil based product has been registered for this use. A 50% concentration of soybean oil is recommended for quarantine purposes, while a 25% concentration should be suitable for homeowners and arborists.

scholarly journals Occurrence, Seasonal Abundance, and Superparasitism of Ooencyrtus kuvanae (Hymenoptera: Encyrtidae) as an Egg Parasitoid of the Spotted Lanternfly (Lycorma delicatula) in North America

Forests ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 79 ◽  
Author(s):  
Houping Liu
Keyword(s):  
North America ◽  
Biological Control Agent ◽  
Egg Parasitoid ◽  
Seasonal Abundance ◽  
Egg Mass ◽  
Laboratory Incubation ◽  
Significant Difference ◽  
Lycorma Delicatula ◽  
Ooencyrtus Kuvanae ◽  
Oviposition Sites

The occurrence of egg parasitoid Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae) on its new host, the spotted lanternfly (Lycorma delicatula (White) (Hemiptera: Fulgoridae)), was surveyed at 4 study plots in 2016 and 10 additional plots in 2017 in Pennsylvania through field collection and laboratory incubation. O. kuvanae adults were found on L. delicatula egg mass surfaces at two plots (ODSouth and Lutz) in 2016, but at none in 2017. The results of laboratory incubation showed that O. kuvanae adults were only recovered from host eggs collected at plot ODSouth in 2016, with adults emerging between 22 April and 2 May 2016 at 22 ± 1 °C, 40% ± 5% relative humidity (RH), and a 16:8 h photoperiod (light/dark). The overall parasitism at this study plot was 6.0% by egg mass and 1.2% by egg. Two oviposition sites contained parasitized L. delicatula eggs, with 12.3% (9.5–15.0%) host egg masses and 3.1% (1.3–5.0%) host eggs utilized by the parasitoid. O. kuvanae parasitism by egg was significantly higher on oviposition site ODSouth #7 than on ODSouth #8. No O. kuvanae adults were reared out of field-collected host eggs from the 10 plots in 2017. Seasonal abundance and superparasitism of O. kuvanae was examined at plot ODSouth in 2017. O. kuvanae-parasitized L. delicatula eggs were found on all four oviposition sites based on field monitoring of parasitoid adult emergence, resulting in a parasitism of 35.4% (18.8–55.6%) by egg mass and 2.2% (0.5–3.9%) by egg. No significant difference in parasitism by egg was observed among oviposition sites. O. kuvanae adults emerged in the field between 2 May and 1 June 2017. Superparasitism was confirmed for O. kuvanae on L. delicatula eggs based on parasitoid production (1.0–3.3 adults/parasitized egg) and adult exit holes (1–3 exit holes/parasitized egg). As the first parasitoid recorded from L. delicatula in North America, O. kuvanae has the potential to become an important biological control agent for L. delicatula in North America, with its well-synchronized life history in the spring, century-long field establishment, superparasitism, and female-biased progeny population. L. delicatula complements the gypsy moth well as an alternative host for O. kuvanae in the field.

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