[Biopython] How to restrict blast query to proteins of a certain species

[bar tomas]

Hi,

I'd like to use blast to measure homology  between protein sequences of a
species and polyketide sequences from a database.
I've been looking in the Biopython tutorial(p.73) in the section about
blast.
I'd like to do something similar,  like this:

result_handle = NCBIWWW.qblast("blastp", "genbank", record.format("fasta"))

Is it possible to add an option to restrict the search to genbank records
that correspond to a given species?

Thanks very much