Relationship of Gypsy Moth (Lepidoptera: Lymantriidae) Egg Mass Age to Persistence and Color, and an Evaluation of Two Methods to Distinguish New and Old Egg Masses

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.

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

The Canadian Entomologist ◽

10.4039/ent1141109-12 ◽

1982 ◽

Vol 114 (12) ◽

pp. 1109-1120 ◽

Cited By ~ 13

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.

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

The Canadian Entomologist ◽

10.4039/n03-015 ◽

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.

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

Journal of Entomological Science ◽

10.18474/0749-8004-29.3.305 ◽

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.

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

The Canadian Entomologist ◽

10.4039/ent113575-7 ◽

1981 ◽

Vol 113 (7) ◽

pp. 575-584 ◽

Cited By ~ 4

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.

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INFLUENCE OF NATURAL DIETS AND LARVAL DENSITY ON GYPSY MOTH, LYMANTRIA DISPAR (LEPIDOPTERA: ORGYIIDAE), EGG MASS CHARACTERISTICS

The Canadian Entomologist ◽

10.4039/ent1091313-10 ◽

1977 ◽

Vol 109 (10) ◽

pp. 1313-1318 ◽

Cited By ~ 28

Author(s):

John L. Capinera ◽

Pedro Barbosa

Keyword(s):

Gypsy Moth ◽

Egg Size ◽

Larval Density ◽

Field Studies ◽

Forest Composition ◽

Egg Mass ◽

Natural Diet ◽

Egg Masses ◽

Egg Number ◽

Host Tree Species

AbstractLaboratory and field studies indicate that differences in gypsy moth egg mass characteristics can be related to larval density and natural diet. Egg mass characteristics are valuable indices of population quality as well as future population levels. Laboratory crowding reduced number of eggs/mass but did not affect egg size. Field collected egg masses from various population levels in Massachusetts also varied in egg number/mass, but egg size could not be directly correlated to density. Laboratory rearing of larvae on several natural diets produced differences in both egg number and size. Maple diets produced egg masses with fewer, smaller eggs, as compared with oak diets. Field collected egg masses also varied in mean egg size, according to host tree species. Thus, forest composition may directly affect the quality of gypsy moth populations, as well as numerical levels. Increasing density could affect egg size indirectly, by forcing gypsy moth larvae to feed on unfavorable host foliage.

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New terpenoid metabolites from the skin extracts, an egg mass, and dietary sponges of the Northeastern Pacific dorid nudibranch Cadlinaluteomarginata

Canadian Journal of Chemistry ◽

10.1139/v97-094 ◽

1997 ◽

Vol 75 (6) ◽

pp. 773-789 ◽

Cited By ~ 34

Author(s):

Eric J. Dumdei ◽

Julia Kubanek ◽

John E. Coleman ◽

Jana Pika ◽

Raymond J. Andersen ◽

...

Keyword(s):

Structure Elucidation ◽

Egg Mass ◽

The Novel ◽

Egg Masses ◽

Northeastern Pacific ◽

First Time

Chemical investigations of Cadlinaluteomarginata skin extracts, egg masses, and dietary sponges have led to the identification of the novel terpenoids cadlinaldehyde (30), spongian 32, seco-spongian 35, 20-acetoxy-12-marginatone (38), and lutenolide (39) from the nudibranch skin extracts, the new drimane sesquiterpenoid 1α,2α-diacetoxyalbicanyl acetate (40) from the nudibranch's egg mass, and the new sesquiterpenoids O-methyl-9-oxofurodysininlactone (47), 2-oxomicro-cionin-2-lactone (48), and O-methyl-2-oxomicrocionin-2-lactone (49), from the dietary sponge Pleraplysilla sp. The known terpenoids furodysinin (1), furodysin (16), marginatafuran (21), and 9,11-dihydrogracillin A (37), which have been frequently isolated from C. luteomarginata skin extracts, were found for the first time in extracts of the dietary sponges Pleraplysilla sp. and Aplysilla sp. One of the new terpenoids, cadlinaldehyde (30), has an unprecedented degraded sesterterpenoid skeleton. Keywords: nudibranch, sponge, terpenoids, structure elucidation.

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GROUND RELEASES OF TRICHOGRAMMA MINUTUM RILEY (HYMENOPTERA: TRICHOGRAMMATIDAE) AGAINST THE SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE)

The Canadian Entomologist ◽

10.4039/ent119251-3 ◽

1987 ◽

Vol 119 (3) ◽

pp. 251-263 ◽

Cited By ~ 7

Author(s):

S.M. Smith ◽

M. Hubbes ◽

J.R. Carrow

Keyword(s):

Optimal Strategy ◽

Choristoneura Fumiferana ◽

Spruce Budworm ◽

Egg Mass ◽

Northern Ontario ◽

Inundative Release ◽

Egg Masses ◽

Trichogramma Minutum ◽

Spruce Stands ◽

Natural Parasitism

AbstractDuring 1982 and 1984, ground releases of Trichogramma minutum Riley were assessed for control of the spruce budworm, Choristoneura fumiferana (Clemens), on 12- to 20-year-old, white spruce stands in northern Ontario. Maximum parasitism of susceptible egg masses was 16 and 87% following the release of 480 000 and 12 million female T. minutum per hectare, respectively. Releases at intervals of 1 week maintained parasitism of susceptible egg masses at constant levels throughout the oviposition period of spruce budworm. When parasitism of susceptible egg masses was maintained above 78.2% during the ovipositional period, total egg mass parasitism averaged 58.0% and resulted in an 80.3% reduction of overwintering 2nd-instar larvae. The optimal strategy for reducing spruce budworm was two releases of T. minutum at an interval of 1 week in the ovipositional period. This allowed a second generation of parasitoids to emerge from the spruce budworm eggs that were more efficient in maintaining high levels of parasitism than those emerging from the standard rearing host. Natural parasitism of spruce budworm egg masses was less than 4% and there was no carryover of parasitism in the years following inundative release. The rate of T. minutum release necessary to achieve effective mortality of spruce budworm during outbreak populations is discussed briefly.

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Sexual reproduction and larval development of Rhaphidrilus nemasoma Monticelli, 1910 (Polychaeta: Ctenodrilidae)

Canadian Journal of Zoology ◽

10.1139/z89-331 ◽

1989 ◽

Vol 67 (10) ◽

pp. 2345-2351 ◽

Cited By ~ 4

Author(s):

Pei-Yuan Qian ◽

Fu-Shiang Chia

Keyword(s):

British Columbia ◽

Sexual Reproduction ◽

Larval Development ◽

Intertidal Zone ◽

Vancouver Island ◽

Benthic Diatoms ◽

Egg Mass ◽

High Fecundity ◽

Egg Masses ◽

Trochophore Stage

Adult specimens and egg masses of Rhaphidrilus nemasoma were collected in the low intertidal zone from Execution Rock, Bamfield, Vancouver Island, British Columbia, in June of 1986. Each egg mass contained about 1000 eggs. The eggs were green, spherical, and measured 125–145 μm in diameter. Larval development took place within the egg mass until the three-or four-setiger stage, at which time they emerged from the egg mass. Newly emerged larvae crawled on the bottom of the culture beakers and fed on benthic diatoms. Metamorphosis took place soon after emergence and was completed within 2 weeks. Paddle cilia were observed at the early trochophore stage, and their possible function, and the extremely high fecundity of this polychaete, are discussed.

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

Insects ◽

10.3390/insects12090840 ◽

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.

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