The Naturalist on the River Amazons [122]
saucepans, mandioca ovens, coffee-pots, washing-vessels, and so forth, of the poorer classes, throughout the country, are made of this same plastic clay, which occurs at short intervals over the whole surface of the, Amazons valley, from the neighbourhood of Para to within the Peruvian borders, and forms part of the great Tabatinga marl deposit. To enable the vessels to stand the fire, the bark of a certain tree, called Caraipe, is burned and mixed with the clay, which gives tenacity to the ware. Caraipe is an article of commerce-- being sold and packed in baskets at the shops in most of the towns. The shallow pits, excavated in the marly soil at Mahica, were very attractive to many kinds of mason bees and wasps, who made use of the clay to build their nests with--so we have here another example of the curious analogy that exists between the arts of insects and those of man. I spent many an hour watching their proceedings; a short account of the habits of some of these busy creatures may be interesting.
The most conspicuous was a large yellow and black wasp, with a remarkably long and narrow waist, the Pelopaeus fistularis. This species collected the clay in little round pellets, which it carried off, after rolling them into a convenient shape, in its mouth. It came straight to the pit with a loud hum, and, on alighting, lost not a moment in beginning to work-- finishing the kneading of its little load in two or three minutes. The nest of this wasp is shaped like a pouch, two inches in length, and is attached to a branch or other projecting object. One of these restless artificers once began to build on the handle of a chest in the cabin of my canoe, when we were stationary at a place for several days. It was so intent on its work that it allowed me to inspect the movements of its mouth with a lens while it was laying on the mortar. Every fresh pellet was brought in with a triumphant song, which changed to a cheerful busy hum when it alighted and began to work. The little ball of moist clay was laid on the edge of the cell, and then spread out around the circular rim by means of the lower lip guided by the mandibles. The insect placed itself astride over the rim to work, and, on finishing each addition to the structure, took a turn round, patting the sides with its feet inside and out before flying off to gather a fresh pellet. It worked only in sunny weather, and the previous layer was sometimes not quite dry when the new coating was added. The whole structure takes about a week to complete. I left the place before the gay little builder had quite finished her task; she did not accompany the canoe, although we moved along the bank of the river very slowly. On opening closed nests of this species, which are common in the neighbourhood of Mahica, I always found them to be stocked with small spiders of the genus Gastracantha, in the usual half-dead state to which the mother wasps reduce the insects which are to serve as food for their progeny.
Besides the Pelopaeus, there were three or four kinds of Trypoxylon, a genus also found in Europe, and which some naturalists have supposed to be parasitic, because the legs are not furnished with the usual row of strong bristles for digging, characteristic of the family to which it belongs. The species of Trypoxylon, however, are all building wasps; two of them which I observed (T. albitarse and an undescribed species) provision their nests with spiders, a third (T. aurifrons) with small caterpillars. Their habits are similar to those of the Pelopaeus- - namely, they carry off the clay in their mandibles, and have a different song when they hasten away with the burden to that which they sing whilst at work. Trypoxylon albitarse, which is a large black kind, three-quarters of an inch in length, makes a tremendous fuss while building its cell. It often chooses the walls or doors of chambers for this purpose, and when two or three are at work in the same place, their loud humming keeps the house in an uproar. The cell is a tubular structure about three inches in length. T. aurifrons,
The most conspicuous was a large yellow and black wasp, with a remarkably long and narrow waist, the Pelopaeus fistularis. This species collected the clay in little round pellets, which it carried off, after rolling them into a convenient shape, in its mouth. It came straight to the pit with a loud hum, and, on alighting, lost not a moment in beginning to work-- finishing the kneading of its little load in two or three minutes. The nest of this wasp is shaped like a pouch, two inches in length, and is attached to a branch or other projecting object. One of these restless artificers once began to build on the handle of a chest in the cabin of my canoe, when we were stationary at a place for several days. It was so intent on its work that it allowed me to inspect the movements of its mouth with a lens while it was laying on the mortar. Every fresh pellet was brought in with a triumphant song, which changed to a cheerful busy hum when it alighted and began to work. The little ball of moist clay was laid on the edge of the cell, and then spread out around the circular rim by means of the lower lip guided by the mandibles. The insect placed itself astride over the rim to work, and, on finishing each addition to the structure, took a turn round, patting the sides with its feet inside and out before flying off to gather a fresh pellet. It worked only in sunny weather, and the previous layer was sometimes not quite dry when the new coating was added. The whole structure takes about a week to complete. I left the place before the gay little builder had quite finished her task; she did not accompany the canoe, although we moved along the bank of the river very slowly. On opening closed nests of this species, which are common in the neighbourhood of Mahica, I always found them to be stocked with small spiders of the genus Gastracantha, in the usual half-dead state to which the mother wasps reduce the insects which are to serve as food for their progeny.
Besides the Pelopaeus, there were three or four kinds of Trypoxylon, a genus also found in Europe, and which some naturalists have supposed to be parasitic, because the legs are not furnished with the usual row of strong bristles for digging, characteristic of the family to which it belongs. The species of Trypoxylon, however, are all building wasps; two of them which I observed (T. albitarse and an undescribed species) provision their nests with spiders, a third (T. aurifrons) with small caterpillars. Their habits are similar to those of the Pelopaeus- - namely, they carry off the clay in their mandibles, and have a different song when they hasten away with the burden to that which they sing whilst at work. Trypoxylon albitarse, which is a large black kind, three-quarters of an inch in length, makes a tremendous fuss while building its cell. It often chooses the walls or doors of chambers for this purpose, and when two or three are at work in the same place, their loud humming keeps the house in an uproar. The cell is a tubular structure about three inches in length. T. aurifrons,