Western Spuce Budworm

Counts of western spuce budworm (Choristoneura freemani) across seven developmental stages (five larval instars, pupae, and adults) on 12 sampling occasions.

data(budworm)

Format

A data frame with the following variables.

ddeg

Degree days.

total

Sum of stages 1–7.

stage1, stage2, stage3, stage4

Successive stages.

stage5, stage6, stage7

Successive stages.

Details

This data concerns the development of a defoliating moth widespread in western North America (i.e., north of Mexico). According to Boersch-Supan (2021), the insect passes hrough successive stages \(j=1,\ldots,r\), delimited by \(r-1\) moults. The data was originally used in a 1986 publication but has been corrected for two sampling occasions; the data appears in Candy (1990) and was analyzed in Boersch-Supan (2021). See the latter for more references.

Source

Candy, S. G. (1990). Biology of the mountain pinhole borer, Platypus subgranosus Scheld, in Tasmania. MA thesis, University of Tasmania, Australia. https://eprints.utas.edu.au/18864/.

References

Boersch-Supan, P. H. (2021). Modeling insect phenology using ordinal regression and continuation ratio models. ReScience C, 7.1, 1–14.

Examples

budworm
#>    ddeg total stage1 stage2 stage3 stage4 stage5 stage6 stage7
#> 1    58    16     16      0      0      0      0      0      0
#> 2    82    10     10      0      0      0      0      0      0
#> 3   107    30     23      7      0      0      0      0      0
#> 4   155    47      3     44      0      0      0      0      0
#> 5   237    64      0      6     45     13      0      0      0
#> 6   307    74      0      2      9     48     15      0      0
#> 7   342    72      0      0      1     34     37      0      0
#> 8   388   103      0      0      1     10     87      5      0
#> 9   442    81      0      0      0      7     53     21      0
#> 10  518    76      0      0      0      0     10     65      1
#> 11  609    40      0      0      0      0      0     14     26
#> 12  685    42      0      0      0      0      0      0     42
summary(budworm)
#>       ddeg           total            stage1           stage2      
#>  Min.   : 58.0   Min.   : 10.00   Min.   : 0.000   Min.   : 0.000  
#>  1st Qu.:143.0   1st Qu.: 37.50   1st Qu.: 0.000   1st Qu.: 0.000  
#>  Median :324.5   Median : 55.50   Median : 0.000   Median : 0.000  
#>  Mean   :327.5   Mean   : 54.58   Mean   : 4.333   Mean   : 4.917  
#>  3rd Qu.:461.0   3rd Qu.: 74.50   3rd Qu.: 4.750   3rd Qu.: 3.000  
#>  Max.   :685.0   Max.   :103.00   Max.   :23.000   Max.   :44.000  
#>      stage3           stage4           stage5          stage6     
#>  Min.   : 0.000   Min.   : 0.000   Min.   : 0.00   Min.   : 0.00  
#>  1st Qu.: 0.000   1st Qu.: 0.000   1st Qu.: 0.00   1st Qu.: 0.00  
#>  Median : 0.000   Median : 0.000   Median : 0.00   Median : 0.00  
#>  Mean   : 4.667   Mean   : 9.333   Mean   :16.83   Mean   : 8.75  
#>  3rd Qu.: 1.000   3rd Qu.:10.750   3rd Qu.:20.50   3rd Qu.: 7.25  
#>  Max.   :45.000   Max.   :48.000   Max.   :87.00   Max.   :65.00  
#>      stage7     
#>  Min.   : 0.00  
#>  1st Qu.: 0.00  
#>  Median : 0.00  
#>  Mean   : 5.75  
#>  3rd Qu.: 0.25  
#>  Max.   :42.00