Q:

What is the story of Mahabali's sister's attempt to destroy the world?

In the Bala Kanda of the Ramayana, Rama is hesistant to kill the Rakshasi (demoness) Thataka because she's a woman, but the sage Vishwamitra tells him that even Indra king of the gods has fought women when they were engaged in evil:

Compassion regarding the elimination of a female is ungermane, oh, best one among men, since a prince has to effectuate it intending the welfare of four categories of society....  To the nominee who bears the burden of kingdom this is the age-old duty, and hence oh, Rama, the legatee of Kakutstha, eliminate this infamy, as goodness is inevident in her, isn't it?  Oh, Rama, the protector of people, we have heard that Indra once eliminated Manthara, the daughter of Virochana, when she wished to annihilate earth, haven't we?

Well, "we" may have heard about this, but I haven't!  So my question is, what is the story of Manthara daughter of Virochana?  For those who don't know, Virochana was a famous demon killed by Indra.  He was the son of Prahlada and the father of Mahabali.  So that would make Manthara Mahabali's sister.  
Unfortunately, the Puranas often focus on male genealogy, so they're not much help here; the Vishnu Purana just says "Prahláda had a son named Virochana; whose son was Bali" and similarly the Srimad Bhagavatam says "Prahlāda had one son, Virocana, whose wife gave birth to Bali Mahārāja."  However, later on in the Ramayana there is some indication that Virochana had a daughter; this excerpt from the Uttara Kanda of the Ramayana describes the wife of Ravana's brother Kumbhakarna:

[T]hat master - Lanka's lord - going (back) to the city married his brothers.  And Ravana married the grand-daughter of Virochana (on the maternal side) named Vajrajwala to Kumbhakarna.

So assuming Virochana had only one daughter, that would make Manthara Kumbhakarna's mother-in-law!
In any case, what is the story of Manthara's attempt to "destroy Earth", to the point where Indra needed to kill her?  By the way, Virochana's daughter Manthara is not to be confused with Virochana's uncle Mandara, whom I discuss in this question.  (And she is different from Kaikeyi's evil servant Manthara, although this translator claims that Kaikeyi's servant Manthara was named after Virochana's daughter.)

A:

I found the answer on page 337 of this book:

In fact, most [North Indian] manuscripts replace the name of Manthara with Dirghajihva, "Long-tounged"[.]... Dirghajihva is a rakshasa woman known to the Mahabharata (3.276.4). There she is said to be slain by Indra.

Here is what the relevant chapter of the Vana Parva of the Mahabharata says:

Even the celestials with Indra at their head, and the Asuras have to tread in the path that is trod by thee! It was after such afflictions that the wielder of the thunderbolt, aided by the Maruts, slew Vritra, and the invincible Namuchi and the Rakshasi of long tongue! 

In any case, the story of Indra killing the demoness Dirghajihvi is told in this excerpt from the Panchavimsha Brahmana of the Sama Veda:

There is the Saumitra (Saman). A (certain) female, sacrifice-destroying, Ogre, Dirghajihvi, kept here licking at the (butter of the) sacrifices.  Indra despaired of killing her by any strategies whatever.  Now Sumitra, the Kutsa, was a handsome (young man). To him he (Indra) said, "Call her to thee." He called her to him. She said to him "This truly is unheard by me, but it is rather pleasant to my heart." He (Sumitra) came to an understanding with her. At the trysting place they both (Indra and Sumitra) slew her.  That forsooth, had been at that moment their wish. Through this (Saman) he obtains the fulfillment of his wish. (But) an (inauspicious) voice addressed him (Sumitra) thus: "Being Sumitra, thou hast done a bloody deed." Grief tormented him; he performed austerities, he saw this Saumitra (Saman).  Through it he drove away his grief. He who, in lauding, has applied this Saumitra (Saman), drives away his grief.

The story is told in more detail in this excerpt from the Jaiminiya Brahmana of the Sama Veda, but warning, it's quite inappropriate.
In any case, I haven't come across any scriptures which identify Dirghajihvi as the daughter of Virochana.

