Pagination by issue in biblatex-apa

Question

Another biblatex-apa question here. It seems it has not been asked before. The APA 6th edition prescribes that when formatting journals (and other periodical references), the issue number is included (in parenthesis) after the volume number when the journal is paginated by issue. Otherwise (if the journal is continuously paginated), it is not included (see p. 198 of the 6th edition of the APA Publication Manual).

It seems that, by default, version 6.0 of biblatex-apa formats a journal following the continuous pagination format. How can I specify that a particular entry is paginated by issue, and, hence, the issue number should be printed?

bibliography.bib:

@article{myers,
author = {Scott W. Myers and Michael Ballweg and John L. Wedberg},
title = {Assessing the impact of {European} corn borer on corn grown for silage},
url = {http://www.uwex.edu/ces/crops/uwforage/ECB.htm},
urldate = {2013-07-09},
journaltitle = {Focus on Forage},
volume = {3},
issue = {4},
organization = {University of Wisconsin Wisconsin Team Forage},
keywords = {jared},
}

sample.tex:

\documentclass{article}

\usepackage[american]{babel}
\usepackage{csquotes}
\usepackage[style=apa, backend=biber]{biblatex}
\DeclareLanguageMapping{american}{american-apa}
\addbibresource{bibliography.bib}

\begin{document}

\nocite{*}
\printbibliography

\end{document}

Answer 1

Use the number field for issue number. From the BibLaTeX manual:

Quarterly journals are typically identified by a designation such as ‘Spring’ or ‘Summer’ which should be given in the issue field.

So your bibliography.bib file will look like this:

@article{myers,
author = {Scott W. Myers and Michael Ballweg and John L. Wedberg},
title = {Assessing the impact of {European} corn borer on corn grown for silage},
url = {http://www.uwex.edu/ces/crops/uwforage/ECB.htm},
urldate = {2013-07-09},
journaltitle = {Focus on Forage},
volume = {3},
number = {4},
organization = {University of Wisconsin Wisconsin Team Forage},
keywords = {jared},
}

Making that change, I get the following output: