Small animals in the hot, dry Australian outback have a hard life. Every day of their lives, they are faced with the risk of dehydration. The thrips is among the smallest insects found on the Australian continent, and it has its own way of dealing with these challenges.
The thrips is only 2 to 3 mm long, which puts it at great risk for dehydration. Its prime strategy involves the formation of galls on various acacia plants. These galls – growths on the plants in reaction to an insect – protect the insect against the elements. New research has now demonstrated that a specific thrips species (Dunatothrips aneurae) has also developed another strategy for its protection. Leaf-like structures on the acacia tree are stuck together with a silken material secreted from the anus of the thrips. This compound forms a little house in which the humidity can be kept constant. As the small silken chambers are extremely fragile, even a gust of wind can cause it to break up. When that occurs, thrips individuals come rushing to make repairs, to keep their young from falling out of the house and drying out.
These tiny houses contain groups of older thrips individuals, together with the young. It appears to be a kind of day-care arrangement, because when the one adult dies, the other thrips can take on the care of the young. This discovery is the first evidence in the insect world of a kind of active parental care aimed at preventing dehydration.