Locus are a larger version of a grasshopper. When they breed they do it abundantly and they can cause serious crop damage when they fly in swarms. By the way this would be more of a science question. ;)
Your second question is a history one: I believe the answer is Nelson Mandela. He was the first democratic president of the Republic of South Africa. He was "sworn in" in 1994 at the age of 74 or 75 I believe.
The issues were mostly economic because the money had lost all value and the country was in a lot of debt that was accumulated during the war.
The first war they fought in was the revolutionary war.
Sea explorations were made by many countries centuries ago. These were headed by the European countries long back. The impulses or urges that influenced the explorers are to desire to take hold of other land for territorial expansion.
Another very important thing to consider as well was the trading. One country had to exchange products to another country. Hence, there were need for them to cross the seas.
