HEMOGRAMS OF SELECTED STAGES OF THE SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1980 ◽  
Vol 112 (5) ◽  
pp. 443-450 ◽  
Author(s):  
Gary B. Dunphy ◽  
Richard A. Nolan

AbstractFive types of hemocytes (plasmatocytes, granular cells, spherule cells, oenocytoids, and prohemocytes) were identified in the larval, prepupal, and pupal stages of the spruce budworm, Choristoneura fumiferana (Clem.). Hemocyte numbers (total hemocyte counts and absolute hemocyte counts) increased during larval development. The absolute counts were greater in female larvae than in the male larvae during the fourth instar but were higher in the males during the fifth and sixth instars. Hemocyte numbers peaked in the prepupal stage in females and in the early pupal stage in males. The plasmatocytes and granular cells were the predominant hemocytes in both sexes. The plasmatocytes decreased and the granular cells increased throughout larval development of both sexes. There were more plasmatocytes in the males than in the females in all stages of development. There were more granular cells in the males than the females until the sixth instar when the reverse occurred.

1961 ◽  
Vol 93 (7) ◽  
pp. 594-602 ◽  
Author(s):  
George T. Harvey

In eastern Canada larvae of the spruce budworm, Choristoneura fumiferana (Clem.), complete their development in one year, undergoing only one period of winter diapause in the second instar, whereas in certain parts of British Columbia, at high altitudes, two years are normally required for development, the larvae spending a second period of winter diapause in the fourth instar (3, 9). Among laboratory-reared eastern budworm there are a few individuals that enter a similar second diapause (7). The low incidence and somewhat irregular occurrence of this second diapause in eastern budworm, even in laboratory rearings, have hitherto made detailed studies almost impossible, but unusual storage times and treatments used recently in rearing experiments had the unexpected effect of increasing the incidence of this tvpe of behaviour to a level where experimental analysis became possible. This paper describes these larvae and their behaviour; an account of the effects of various conditions upon the incidence of second diapause will be presented later.


1983 ◽  
Vol 115 (9) ◽  
pp. 1109-1117 ◽  
Author(s):  
G. T. Harvey

AbstractLaboratory studies of the mean weights of initial eggs (Ei) of the spruce budworm, Choristoneura fumiferana (Clem.), show that this value is determined by the genetic constitution of the female moth and is relatively independent of environmental control. Dietary differences experienced by the female during larval development, and originating from different hosts or from reduced nutrient levels in artificial diets, did not affect Ei values; however, depletion of nutrients sufficient to reduce fertility greatly did reduce Ei. Temperature conditions during the ultimate larval and pupal stages influence Ei values which vary inversely. Mean egg weights are strongly heritable and are readily selected for, thereby demonstrating the presence of strong genetic control.


1976 ◽  
Vol 108 (4) ◽  
pp. 383-386 ◽  
Author(s):  
G. G. Wilson

AbstractThe mass production of Nosema fumiferanae spores using second, third, and fourth instar larvae of Choristoneura fumiferana is described. In general, second instar larvae inoculated with 2 × 105 spores per millilitre of suspension resulted in a maximum spore yield of 1.3 × 108 spores per larva. A spore concentration of 2 × 107 reduced larval weights and increased larval mortality.


1969 ◽  
Vol 101 (12) ◽  
pp. 1269-1285 ◽  
Author(s):  
F. T. Bird

AbstractCytoplasmic polyhedrosis viruses are, in general, more infectious to spruce budworm, Choristoneura fumiferana (Clemens), and forest tent caterpillar, Malacosoma disstria (Hübner), than the nuclear polyhedrosis viruses which affect these insects. The cytoplasmic polyhedrosis viruses interfere with and retard development of the nuclear polyhedrosis viruses.Larvae of both insects, as they grow older, develop resistance to both viruses. Resistance develops more rapidly and to a greater degree against the nuclear polyhedrosis than against the cytoplasmic polyhedrosis viruses.The nuclear polyhedrosis viruses are more lethal than the cytoplasmic polyhedrosis viruses, and all larvae infected with the nuclear polyhedrosis viruses die except those infected so late in larval development that they are able to pupate. Most young larvae infected with the cytoplasmic polyhedrosis virus die or are seriously affected, but infection has progressively less effect as the larvae mature.


1972 ◽  
Vol 104 (7) ◽  
pp. 1051-1054
Author(s):  
J. F. Stewart ◽  
N. R. Brown

AbstractA series of low-volume spray treatments were conducted to study the contact and residual effect of two concentrations of the insecticide phosphamidon to fourth instar spruce budworm, Choristoneura fumiferana (Clem.), on balsam fir, Abies balsamea (L.) Mill, and red spruce, Picea rubens Sarg. Treatment of sprayed larvae on sprayed trees, unsprayed larvae on sprayed trees, and sprayed larvae on unsprayed trees, resulted in two principal conclusions: (a) Higher concentrations of phosphamidon (1% versus 0.5% active) accelerated mortality in all instances and (b) no statistical difference (P = 0.1%) was found in the final mortalities between treatments in which only the foliage was treated and where both larvae and foliage were treated with phosphamidon.


2020 ◽  
Vol 46 (4) ◽  
pp. 613-622
Author(s):  
Rolando Ramírez C. ◽  
Marcela Sánchez-Ocampo

Maternal care (subsociality): characterization of the different stages of maternal care and its efficiency as a strategy. Maternal care and larval development of Omaspides bistriata Boheman, 1862 (Coleoptera: Chrysomelidae: Cassidinae: Mesomphaliini) are described; including characteristics and manner in which maternal care is given across the different stages of development of the specie (eggs, larvae, pupae and teneral adults). We report the oviposition of eggs, the duration to hatch the eggs, and the duration of larval period, pupal stage, and emergence. A life table and survival curve is presented covering all life stages. Changes in the behavior and feeding habits are also noted for the immatures and the attending mother.


1975 ◽  
Vol 107 (8) ◽  
pp. 883-886 ◽  
Author(s):  
Arthur Retnakaran ◽  
Larry Smith

Abstract1-(4-chlorophenyl)-3-(2,6-difluorobenzoyl)-urea when ingested by the last two larval instars of the spruce budworm, Choristoneura fumiferana, inhibits cuticle development leading to morphogenetic deformities in the pupal stage. Laboratory and greenhouse studies indicate that this material could be used to control natural populations of spruce budworm.


2016 ◽  
Vol 149 (2) ◽  
pp. 227-240 ◽  
Author(s):  
Kees van Frankenhuyzen ◽  
Jacques Régnière

AbstractAerial application of Mimic® 2LV to rising outbreak populations of the spruce budworm (Choristoneura fumiferana (Clemens); Lepidoptera: Tortricidae) in Québec, Canada, resulted in high levels of population reduction at spray deposits of 0.5–1.2 μg tebufenozide/g of foliage. Application to potted host trees in outdoor enclosures followed by bioassays revealed multiple effects on spruce budworm survival and recruitment. Chronic (14-day) exposure of late-instars to treated foliage reduced larval survival and also pupal survival, mating success, and fecundity, depending on the product concentration applied. Treatments that produced foliar deposits of ~ 0.5–1.5 μg tebufenozide/g caused high larval mortality. Exposure to deposits of ~ 0.15–0.5 μg/g caused delayed mortality during the pupal stage and reduced the mating success of survivors, while exposure to ~ 0.07–0.15 μg/g reduced the fecundity of mated females. Sublethal exposure did not affect the progeny of survivors, either in egg hatch, survival during diapause, or survival and performance after diapause. Reduced survival during late-larval and pupal stages combined with lower recruitment as a result of reduced mating success and fecundity are likely to play a role in the suppression of Mimic®-treated spruce budworm populations in the years following treatment.


1998 ◽  
Vol 130 (2) ◽  
pp. 215-229 ◽  
Author(s):  
Jeffrey G. Fidgen ◽  
Eldon S. Eveleigh

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.


1959 ◽  
Vol 37 (6) ◽  
pp. 817-830 ◽  
Author(s):  
H. C. Coppel ◽  
H. L. House ◽  
M. G. Maw

Agria affinis (Fall.), a holarctic parasite of Lepidoptera, Orthoptera, and Hymenoptera and one of the more common of the native sarcophagid parasites of Choristoneura fumiferana (Clem.) in British Columbia, deposits first stage larvae on or near the late larval and pupal stages of the host. The larvae penetrate the host integument and complete their development inside the host, dropping to the ground to overwinter as puparia. Adults emerge the following spring. The species was reared in the laboratory continuously on pork liver. Mated females had a prelarviposition period of about 21 days and deposited larvae for up to 45 days. Larval development was completed in 5 to 8 days, and at 21 ± 1 °C and 60% R.H. the puparia formed within 24 hours. The adults emerged from puparia after 10 to 14 days if dormancy did not intervene. A. affinis is propagated continuously in the laboratory, as the stock now appears to have no significant pupal diapause. Among the important characters for identifying its immature stages are the forms of the buccopharyngeal apparatus and of the anterior and posterior spiracles.


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