Pine processionary maximum recorded of . The species flies from May to July. "T. pityocampa" is a highly social organism. Throughout its life cycle, a pine processionary will make several shelters. The first of these are flimsy and temporary, but in the third instar, they build a permanent nest. Once their permanent nest is built, the caterpillars become foragers staying in the vicinity of the nest. The nest has no openings, so caterpillars force themselves through the layers of the shelter. The waste from the larvae's diet accumulates at the bottom of the nest. The pine processionary caterpillar is responsible for most
California Office of Environmental Health Hazard Assessment California Office of Environmental Health Hazard Assessment The Office of Environmental Health Hazard Assessment, commonly referred to as OEHHA (pronounced oh-EEE-ha), is a specialized department within the cabinet-level California Environmental Protection Agency (CalEPA) with responsibility for evaluating health risks from environmental chemical contaminants. OEHHA is the scientific adviser within CalEPA and provides the health effects assessments that assist regulatory decision makers within CalEPA, the California Department of Public Health, and other agencies and non-governmental organizations (see below). This includes assessing health and environmental risks from: In May 2009, Governor Arnold Schwarzenegger proposed to "eliminate and transfer the functions" of OEHHA