Madison Mendoza, her feet aching and her face burned by the sun, wept as she said she had nothing to feed her 2-year-old son who she’d brought with her on the long trek toward the United States. Mendoza, 22, said an aunt in Honduras had convinced her to join the migrant caravan, which she did two weeks ago in the capital of Tegucigalpa. The aunt said she’d have no problems, that people along the route in Mexico would help as they did for a large caravan that moved through the area in October.But this time, the help did not come. The outpouring of aid that once greeted Central American migrants as they trekked in caravans through southern Mexico has been drying up. Hungrier, advancing slowly or not at all, and hounded by unhelpful local officials, frustration is growing among the 5,000 to 8,000 migrants in the southern state of Chiapas. “What causes me pain is that the baby asks me for food and there are days when I can’t provide it,” said Mendoza, who fled Honduras with almost no money because she feared for her life after receiving threats from the father of her son. “I thought that with the baby, people would help me on road.” Members of the caravan in October received food and shelter from town governments, churches and passers-by. Drivers of trucks stopped to give them a lift. Little of that is happening this time. And local officials who once gave them temporary permits to work in Mexico, now seem to snare them in red tape.