scholarly journals The Gut Microbiome of the Eastern Spruce Budworm Does Not Influence Larval Growth or Survival

2018 ◽  
Author(s):  
Melbert T. Schwarz ◽  
Daniel Kneeshaw ◽  
Steven W. Kembel

ABSTRACTMicrobial communities have been shown to play an important role for host health in mammals, especially humans. It is thought that microbes could play an equally important role in other animal hosts such as insects. A growing body of evidence seems to support this, however most of the research effort in understanding host-microbe interactions in insects has been focused on a few well-studied groups such as bees, cockroaches and termites. We studied the effects of the gut-associated microbial community on the growth and survival of the eastern spruce budworm Choristoneura fumiferana, an economically important lepidopteran forest pest in eastern Canada and the northeastern United States. Contrary to our expectations, the gut microbial community of spruce budworm larvae does not appear to influence host growth or survival. Our results agree with the hypothesis that lepidopteran larvae lack resident microbial communities and are not nutritionally dependent on bacterial symbionts.

1975 ◽  
Vol 107 (7) ◽  
pp. 717-728 ◽  
Author(s):  
G. T. Harvey

AbstractAmylopectin added to a sugar-free wheat-germ diet was equal to or better than sucrose as a carbohydrate source, and appears to be readily utilized by the eastern spruce budworm (Choristoneura fumiferana (Clem.)). Larval growth on diets containing dextrins or potato starch shows that they are partly utilized. Starches from other sources, including those isolated from mature balsam fir (Abies balsamea (L.) Mill.) or white spruce (Picea glauca (Moench) Voss) needles, are not utilized to any extent, on the basis of larval growth on diets to which they have been added.Sixth-instar budworm reared on artificial diets contain amylase(s) in midgut and salivary gland homogenates, which show a low rate of digestion of starches from host foliage. However, the presence of appreciable starch in frass from foliage-fed insects and the apparent low utilizability of foliar starch indicate that the latter is not an important nutrient for the budworm under natural conditions.


2007 ◽  
Vol 37 (3) ◽  
pp. 523-529 ◽  
Author(s):  
Shawn Fraver ◽  
Robert S. Seymour ◽  
James H. Speer ◽  
Alan S. White

Using dendrochronological analyses, we reconstructed a 300 year history of eastern spruce budworm ( Choristoneura fumiferana (Clem.)) outbreaks in northern interior Maine. By analyzing radial growth patterns from the budworm host, red spruce ( Picea rubens Sarg.), and nonhost, northern white cedar ( Thuja occidentalis L.), we identified five outbreaks beginning ca. 1709, 1762, 1808, 1914, and 1976, all of which have been documented from eastern Canada. However, little or no evidence was found in our study for the 1830s, 1870s, or 1940s outbreaks also documented there. The mean outbreak return interval in our study (67 years) was roughly twice that postulated for eastern Canada. Differences in forest types, and associated stand dynamics, between the regions may explain the longer return intervals, and consequently the absence of these three outbreaks in Maine. Results also indicate that small, slow-growing trees exhibit a budworm signal very similar to that of overstory trees, once tree-ring series have been properly standardized.


1975 ◽  
Vol 107 (9) ◽  
pp. 967-977 ◽  
Author(s):  
C. J. Sanders

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.


1990 ◽  
Vol 122 (6) ◽  
pp. 1271-1272 ◽  
Author(s):  
Hemendra Mulye ◽  
Roger Gordon

The eastern spruce budworm, Choristoneura fumiferana Clemens, is the most widely distributed and destructive forest insect pest in North America. Although much is known about the ecology, population dynamics, and impact of C. fumiferana on tree growth (Sanders et al. 1985), there is very little information available on the physiology of this forest pest. Physiological studies are crucial to the development of novel strategies for spruce budworm control.


1958 ◽  
Vol 36 (4) ◽  
pp. 453-462 ◽  
Author(s):  
H. C. Coppel

Phorocera incrassala Smith, which was transferred from Western to Eastern Canada for release against the spruce budworm, Choristoneura fumiferana (Clem.), deposits microtype eggs on leaves, which are later ingested by the host. Eggs hatch immediately after ingestion, but the parasite does not develop beyond the first instar until the host pupates. The larva then develops rapidly, matures in 10 days, and forms its puparium within the host pupal case. The adult emerges in 12 to 14 days. No information is available on the overwintering habits. Among the important characters for identifying the immature stages of P. incrassala are the buccopharyngeal apparatus and the anterior and posterior spiracles.


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 (7) ◽  
pp. 815-822 ◽  
Author(s):  
O. N. Morris ◽  
A. Moore

AbstractFifty Bacillus thuringiensis (B.t.) isolates representing K-1, galleriae, K-73, thuringiensis, aizawai, dendrolimus, tolworthi, kenyae, darmstadiensis, alesti, and entomocidus crystal antigen types were bioassayed against fifth-instar spruce budworm, Choristoneura fumiferana (Clem.), larvae. In addition, larvae reared on diet with and without aureomycin were tested for their susceptibility to B.t. The data indicated no significant differences in susceptibility to B.t. among insects reared on aureomycin or on aureomycin-free diet, but differences were evident in larval growth and mortality among untreated controls. None of the 50 isolates bioassayed was any more toxic to the budworm than is the strain used at present in commercial preparations of B. thuringiensis.


BMC Genomics ◽  
2020 ◽  
Vol 21 (S6) ◽  
Author(s):  
Musfiqur Sazal ◽  
Kalai Mathee ◽  
Daniel Ruiz-Perez ◽  
Trevor Cickovski ◽  
Giri Narasimhan

Abstract Background Microbe-microbe and host-microbe interactions in a microbiome play a vital role in both health and disease. However, the structure of the microbial community and the colonization patterns are highly complex to infer even under controlled wet laboratory conditions. In this study, we investigate what information, if any, can be provided by a Bayesian Network (BN) about a microbial community. Unlike the previously proposed Co-occurrence Networks (CoNs), BNs are based on conditional dependencies and can help in revealing complex associations. Results In this paper, we propose a way of combining a BN and a CoN to construct a signed Bayesian Network (sBN). We report a surprising association between directed edges in signed BNs and known colonization orders. Conclusions BNs are powerful tools for community analysis and extracting influences and colonization patterns, even though the analysis only uses an abundance matrix with no temporal information. We conclude that directed edges in sBNs when combined with negative correlations are consistent with and strongly suggestive of colonization order.


1992 ◽  
Vol 124 (6) ◽  
pp. 1101-1113 ◽  
Author(s):  
Richard A. Fleming ◽  
Kees van Frankenhuyzen

AbstractSingle aerial applications of Bacillus thuringiensis Berliner (Bt) to control infestations of the eastern spruce budworm (Choristoneura fumiferana Clemens) have had varied operational success. Double applications are too expensive for general use, but might prove useful if directed to areas where the initial application was unsuccessful. This requires forecasts of the efficacy of the initial application in operational spray blocks within 4–5 days.Data were collected in 30 spray blocks in 1989 in a feasibility study to determine if such forecasts of spray efficacy could be made from the prespray budworm population density, N0, and from the proportion of the population that had ingested a lethal dose Bt within 2 days of application, M. A mathematical model forecasting the postspray budworm population density, NF, was derived from population-dynamic considerations and fitted (r2 = 0.48, p < 0.0001):The proportion of current foliage defoliated, D, depended (r = 0.81) on N0 and on whether the block was sprayed (I = 0) or not (I = 1):Only one measure of defoliation involved M in any statistically significant way. The predicted (from values of N0) proportion of defoliation prevented by Bt application, dD, was weakly (r2 = 0.25, p = 0.002) related to M:The large proportion of the variation in efficacy that remains unexplained by the models involving M limits the operational utility of this approach as it now stands for specific sites. The potential for further development of these models as decision support tools for fairly large spray blocks is discussed in terms of improving the sampling plan and including additional predictor variables.Methods are also presented that reduce bias in calculations of population reduction (Abbott 1925) and foliage protection when data are available from few control and many treatment blocks.


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