I didn’t know that! The Torah portion of Bechukosai is sometimes read together with Behar and sometimes not. Several factors enter into this determination, among them Ezra the Scribe's ordinance that Bechukosai be read at least two weeks before Shavuos.
The reason for the two-week hiatus is based on our tradition that Shavuos is considered a New Year, a Day of Judgment for the fruits of the tree. We are careful, therefore, to be finished with Parshas Bechukosai - in which the Tochachah, the Admonition and its curses, occupy a central role -- before this Day of Judgment and New Year begin.
For the same reason, we are careful to read Parashas Ki Savo, where the other portion of the Tochachah is written, at least two weeks before Rosh Hashanah, so that "the old year may be ushered out along with its curses".
In the past, deciding whom to call to the Torah for the reading of the Tochachah was a serious point of contention. Many people felt that being called to the Torah for this portion was a bad omen that would result in tragedy and misfortune. It got to a point where people would actually fight in shul over who should take the aliyah. Consequently, it has become customary in many shuls for the Torah reader himself to be called upon to read the Tochachah, with varying opinions as to whether he is called by name or not.
