DEVELOPMENT RATES OF TRICHOGRAMMA MINUTUM (HYMENOPTERA: TRICHOGRAMMATIDAE) AND IMPLICATIONS FOR TIMING AUGMENTATIVE RELEASES FOR SUPPRESSION OF EGG POPULATIONS OF CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1985 ◽  
Vol 117 (5) ◽  
pp. 557-563 ◽  
Author(s):  
Robert K. Lawrence ◽  
Mark W. Houseweart ◽  
Daniel T. Jennings ◽  
Susan G. Southard ◽  
William A. Halteman
Keyword(s):  
Host Species ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Oviposition Period ◽  
Sitotroga Cerealella ◽  
Development Rates ◽  
Trichogramma Minutum ◽  
Augmentative Releases ◽  
Parasitoid Development

AbstractDevelopment rates of the parasitoid, Trichogramma minutum Riley, were studied to provide information required in timing field releases of T. minutum for suppression of egg populations of the spruce budworm, Choristoneura fumiferana (Clemens). Development was observed in eggs of 2 host species, C. fumiferana and Sitotroga cerealella (Olivier), at constant temperatures of 14, 21, and 27 °C. Parasitoid development varied directly with temperature. Parasitoids developed more rapidly in eggs of S. cerealella than in those of C. fumiferana. Parasitoid males developed faster than females in some host-temperature treatments. Development of T. minutum is apparently rapid enough to allow progeny of parasitoids released early in the spruce budworm's oviposition period to mature and be available to oviposit in budworm eggs deposited later in the budworm oviposition period. Potential release strategies are discussed.

PROGENY PRODUCTION BY TRICHOGRAMMA MINUTUM (HYMENOPTERA: TRICHOGRAMMATIDAE) UTILIZING EGGS OF CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE) AND SITOTROGA CEREALELLA (LEPIDOPTERA: GELECHIIDAE)

1983 ◽  
Vol 115 (10) ◽  
pp. 1245-1252 ◽  
Author(s):  
Mark W. Houseweart ◽  
Daniel T. Jennings ◽  
Celeste Welty ◽  
Susan G. Southard
Keyword(s):  
Life Span ◽  
Significant Relationship ◽  
Choristoneura Fumiferana ◽  
Oviposition Period ◽  
Sitotroga Cerealella ◽  
Progeny Production ◽  
Trichogramma Minutum ◽  
Total Progeny

AbstractMean daily progeny production by Trichogramma minutum (“Maine strain”) was 15.2 in Choristoneura fumiferana and 10.9 in Sitotroga cerealella eggs. Total progeny production was higher in S. cerealella, but not significantly different from that of C. fumiferana eggs. Significantly more eggs were deposited by T. minutum the first day than in subsequent days regardless of host. We found no significant relationship between progeny produced by females and the day of male death as previously reported. Ratio of females:males decreased significantly with increasing age and opposition activity of the mother. The oviposition period spanned 68% of the female's life span when S. cerealella eggs were available; whereas females spent significantly less time (60%) ovipositing in C. fumiferana eggs.

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

1987 ◽  
Vol 119 (3) ◽  
pp. 251-263 ◽  
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.

3.5 SUPPRESSION OF SPRUCE BUDWORM POPULATIONS BY TRICHOGRAMMA MINUTUM RILEY, 1982–1986

1990 ◽  
Vol 122 (S153) ◽  
pp. 56-81 ◽  
Author(s):  
S.M. Smith ◽  
D.R. Wallace ◽  
G. Howse ◽  
J. Meating
Keyword(s):  
Choristoneura Fumiferana ◽  
Host Density ◽  
Spruce Budworm ◽  
Mass Rearing ◽  
Egg Parasitoid ◽  
Curvilinear Relationship ◽  
Egg Masses ◽  
Trichogramma Minutum ◽  
Egg Parasitism ◽  
Release Timing

AbstractThe ability of the egg parasitoid, Trichogramma minutum Riley, to suppress outbreak populations of the spruce budworm, Choristoneura fumiferana (Clemens), was studied annually near Hearst, Ont., from 1982 through 1986. Timing of broadcast parasitoid-releases was linked to spruce budworm moth emergence and oviposition. These phenological relationships were predicted from a regression based on larval development at least 2 weeks before expected emergence; this allowed sufficient time to regulate (program) parasitoid emergence during mass-rearing. Emergence of caged spruce budworm adults was used to monitor moth eclosion in the field. Pheromone traps provided daily information on the activity of male moths and helped to synchronize the parasitoid releases with spruce budworm oviposition. Information on parasitoid activity was obtained from sentinel (laboratory-reared) and naturally occurring spruce budworm egg masses. A curvilinear relationship between the rate of parasitoid release and parasitism of sentinel egg masses was developed. Two parasitoid releases, 1 week apart, early in the oviposition period of spruce budworm, significantly increased parasitism of host eggs by 14–83% and reduced larval populations correspondingly from 42 to 82%. Single releases were less effective and increased parasitism by 0.3–52% (single ground release, 1986). Two parasitoid releases, combined with a spring application of Bacillus thuringiensis Berliner to larval populations, was the most effective strategy and resulted in 83% egg parasitism and 93% larval reduction. Release rates greater than 12–16 × 106 ♀ ♀ T. minutum per hectare were not warranted based on impact and costs. The effects of release timing, weather, host density, and parasitoid quality on the future successful use of T. minutum are discussed.

NUTRITIONAL STUDIES OF EASTERN SPRUCE BUDWORM (LEPIDOPTERA: TORTRICIDAE): I. SOLUBLE SUGARS

1974 ◽  
Vol 106 (4) ◽  
pp. 353-365 ◽  
Author(s):  
G. T. Harvey
Keyword(s):  
Choristoneura Fumiferana ◽  
Soluble Sugars ◽  
High Protein Diet ◽  
Spruce Budworm ◽  
Eastern Spruce Budworm ◽  
Development Rates ◽  
Absolute Requirement ◽  
Sugar Levels ◽  
Faster Development ◽  
Nutritional Studies

AbstractAn absolute requirement for sugar could not be shown but laboratory rearing experiments using artificial diets have demonstrated a definite increase in weight of adult spruce budworm (Choristoneura fumiferana (Clem.) Freeman) with increasing dietary levels of certain sugars. Males exhibit a threshold of 0.9% soluble sugars above which higher sugar levels produce no further increases in size. Females respond with an increase in size up to 4.0%, the highest level tested. Generally, faster development rates accompany greater mature weights on diets with higher nutrient levels.Maltose, raffinose, glucose, sorbitol, sucrose, and fructose are all good sugar sources. Galactose and trehalose are only slightly inferior. Lactose, ribose, melibiose, xylose, mannose, arabinose, and melezitose in the diet are little different from the sugarless control. Sorbose is somewhat inhibitory.Results of transfer experiments confirm the importance of sugar particularly during late larval development. They also indicate that a high protein diet during early instars has a significant effect on development rates. These results suggest that departure from the normal synchrony of development in the insect and its host can affect both rate of development and mature size of the insect.

LIFE HISTORY CHARACTERISTICS OF ELACHERTUS CACOECIAE (HYMENOPTERA: EULOPHIDAE), AN ECTOPARASITOID OF SPRUCE BUDWOR LARVAE, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1998 ◽  
Vol 130 (2) ◽  
pp. 215-229 ◽  
Author(s):  
Jeffrey G. Fidgen ◽  
Eldon S. Eveleigh
Keyword(s):  
Choristoneura Fumiferana ◽  
Abies Balsamea ◽  
Pupal Stage ◽  
Spruce Budworm ◽  
Oviposition Period ◽  
Host Feeding ◽  
Adult Males ◽  
Alternate Host ◽  
Laboratory Development ◽  
The Mean

AbstractWe carried out a 2-year study to elucidate the biology of the gregarious, idiobiont ectoparasitoid Elachertus cacoeciae (Howard) by placing (implanting) laboratory-reared spruce budworm larvae [Choristoneura fumiferana (Clemens)] on current-year balsam fir (Abies balsamea L.) shoots in the field, simulating low (endemic) densities of the budworm. Spring female E. cacoeciae attacked fourth-, fifth-, and sixth-instar budworm larvae, beginning near the predicted peak of the fourth instar and ending about 10–12 days after the predicted peak of the pupal stage of the wild budworm population. The mean (±SE) brood size of spring females was 2.9 ± 0.3 E. cacoeciae pupae per host. The proportion of females increased during the season, with many broods consisting of 100% females late in the season. In 1994 and 1995, the mean proportion of females was 0.74 ± 0.05 and 0.79 ± 0.05, respectively. In the laboratory, development time from eggs to adults was approximately 20 days at 20.6 °C. Adult males provided with honey water lived 43.6 ± 3.2 days, whereas females provided with hosts and honey water lived 90.1 ± 6.6 days. Spring females had a pre-oviposition period of 11.5 ± 1.3 days, resulting in a generation time (egg to egg) of ~31 days. The oviposition period lasted 76.3 ± 7.7 days during which time spring females parasitized 19.2 ± 1.9 hosts, and produced a clutch size of 4.9 ± 0.4 eggs per host, for a lifetime fecundity of 96.8 ± 14.7 eggs. The post-oviposition period was 18.5 ± 3.7 days. Throughout their lifetime, spring females host fed only (host feeding without oviposition) on an additional 9.3 ± 1.9 hosts. Approximately 2% of pupae developing from spring females overwintered, whereas approximately 95% of pupae developing from summer females overwintered. Laboratory results for summer females suggest that they may be adapted to parasitizing alternate host(s) rather than spruce budworm.

SIZE DIFFERENCES OF LABORATORY REARED AND WILD POPULATIONS OF TRICHOGRAMMA MINUTUM (HYMENOPTERA: TRICHOGRAMMATIDAE)

1982 ◽  
Vol 114 (8) ◽  
pp. 693-698 ◽  
Author(s):  
Susan G. Southard ◽  
Mark W. Houseweart ◽  
Daniel T. Jennings ◽  
William A. Halteman
Keyword(s):  
First Generation ◽  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Head Width ◽  
Wild Populations ◽  
Body Dimensions ◽  
Female Parasitoid ◽  
Trichogramma Minutum ◽  
Three Body ◽  
Large Host

AbstractThree body dimensions (body length, head width, and abdomen width) were used to determine size differences between laboratory-reared and wild populations of Trichogramma minutum Riley. Six separate groups of T. minutum were measured: three groups were from Sitotroga cerealella (Olivier) eggs, two from spruce budworm Choristoneura fumiferana (Clemens) eggs, and one from wild populations of spruce budworm.Female T. minutum from spruce budworm (large host) eggs were significantly larger for all body dimensions than T. minutum from S. cerealella (small host) eggs. Male T. minutum from field-collected spruce budworm eggs were significantly larger for all body dimensions than T. minutum reared for more than one generation in S. cerealella eggs.A significant reduction in female parasitoid size was observed during the initial generations of T. minutum reared in the smaller host (S. cerealella). However, this size reduction was not permanent. Following numerous generations in the S. cerealella host eggs, a significant increase in female parasitoid size was noted within the first generation of T. minutum reared in the spruce budworm host eggs.

FIELD RELEASES OF TRICHOGRAMMA MINUTUM (HYMENOPTERA: TRICHOGRAMMATIDAE) FOR SUPPRESSION OF EPIDEMIC SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE), EGG POPULATIONS IN MAINE

1984 ◽  
Vol 116 (10) ◽  
pp. 1357-1366 ◽  
Author(s):  
Mark W. Houseweart ◽  
Daniel T. Jennings ◽  
Robert K. Lawrence
Keyword(s):  
Point Source ◽  
Choristoneura Fumiferana ◽  
Single Point ◽  
Spruce Budworm ◽  
Point Sources ◽  
Slight Improvement ◽  
Parasitism Rates ◽  
Trichogramma Minutum ◽  
Multiple Releases ◽  
Better Than

AbstractTrichogramma minutum Riley was released in the field for suppression of epidemic spruce budworm, Choristoneura fumiferana (Clemens), egg populations in Maine from 1977 to 1981. Commercially reared California-strain T. minutum were released from the ground at single-point sources in 1977. In 1978, using 4-point-source releases, we found that the native Maine-strain performed better than the California strain. In 1979, broadcast and multiple releases from the ground gave slight improvement in parasitism over 4-point releases. In 1981, three closely timed, aerially broadcast releases from a helicopter yielded increases in parasitism rates significantly higher than those in control plots, but not sufficient to suppress epidemic spruce budworm populations. Important variables and suggestions for future aerial releases are discussed.

DIAPAUSE INDUCTION AND POST-DIAPAUSE EMERGENCE IN TRICHOGRAMMA MINUTUM RILEY (HYMENOPTERA: TRICHOGRAMMATIDAE): THE ROLE OF HOST SPECIES, TEMPERATURE, AND PHOTOPERIOD

1995 ◽  
Vol 127 (1) ◽  
pp. 103-110 ◽  
Author(s):  
J.E. Laing ◽  
J.E. Corrigan
Keyword(s):  
Low Temperature ◽  
Host Species ◽  
Choristoneura Fumiferana ◽  
Good Survival ◽  
Low Temperature Storage ◽  
Trichogramma Minutum ◽  
Temperature Storage ◽  
Do So

AbstractTrichogramma minutum Riley entered diapause, in the prepupal stage, in eggs of Lambdina fiscellaria fiscellaria Guenée held at 15°C, 12L:12D, but failed to do so in eggs of Ephestia kuehniella (Zeller), Sitotroga cerealella (Olivier), or Choristoneura fumiferana (Clemens) held under these conditions. The parasitoids emerged without diapause from eggs of all host species held at 25°C, 16L:8D, indicating a role of temperature or photoperiod, or both, in the diapause of the parasitoids in eggs of L. fiscellaria held at 15°C, 12L:12D. Percentage emergence of parasitoids from eggs of L. fiscellaria was virtually the same (>80%) after passing the winter outdoors or after approximately 3 months at 2 °C in the laboratory as it was when reared indoors in this host at 25°C, 16L:8D. Emergence of T. minutum was very poor (<20%) after long-term, low-temperature storage in eggs of C. fumiferana, E. kuehniella, or S. cerealella. Apparently, T. minutum must parasitize diapause host eggs in order to enter diapause, and good survival after long-term low-temperature storage is possible only when T. minutum is in diapause. Trichogramma minutum will enter diapause in L. fiscellaria after 14 days at 15°C, 12L:12D, but the parasitoids need a period of storage at 2°C, 0L:24D for a high percentage of emergence to happen. Over 50% emergence was recorded for T. minutum, held for 300 days in eggs of L. fiscellaria.

THE EFFECTS OF ZECTRAN ON THE PARASITOIDS OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1974 ◽  
Vol 106 (5) ◽  
pp. 545-554 ◽  
Author(s):  
D. E. Leonard ◽  
G. A. Simmons
Keyword(s):  
Choristoneura Fumiferana ◽  
Spruce Budworm ◽  
Lower Percentage ◽  
Aerial Application ◽  
Percentage Parasitism ◽  
Trichogramma Minutum ◽  
Absolute Population ◽  
Population Numbers

AbstractWhere the insecticide Zectran was used to protect foliage from feeding of the spruce budworm, Choristoneura fumiferana (Clemens) (Lepidoptera: Tortricidae), the per cent parasitism of dipteran parasitoids (Tachinidae) showed a statistically significant lower value. In treated areas, the per cent parasitism of the hymenopteran Ephialtes ontario (Cresson) (Ichneumonidae) was lower; Meteorus trachynotus Viereck was about the same; Apanteles fumiferanae Viereck, Glypta fumiferanae (Viereck) (Braconidae), and Trichogramma minutum Riley (Trichogrammatidae) were greater. None of these differences was statistically significant. Results were consistent for the 2 years of study with the exception of E. ontario which showed a significant lower percentage parasitism in areas treated 1 year. Absolute population numbers of parasitoids were lower than is suggested by comparisons of apparent parasitism levels. The lowest absolute numbers were found in tachinids and E. ontario. Parasitic hymenopterans and dipterans were among the adult insects killed by the aerial application of Zectran but none of the species collected was a major spruce budworm parasitoid.

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