INQUILINE, in'kwi-lin (from Lat. linus, one dwelling in a place not one's own, from ineola, inhabitant, from ineo/cre, to inhabit, from in, in colerc, to cultivate). An insect which lays its eggs in a nest of some other insect, thus living parasitically at the expense of the host. The Inquilinm form a group of gall-flies called 'guest gall-flies,' which are unable to produce galls themselves, since they do not secrete the gall-producing poison. though possessing a well-developed ovipositor. Bence, like the No 'nada, etc.. among bees, they arc 'cuckoo-flies,' laying their eggs in galls already formed, the lame feeding on the inside of the gall in earn pally with the lame of their host. These in quilines strikingly resemble their hosts, and are difficult to separate. There are several hundred species. The Inquilime, forming a section of the family Cynipidce. are, according to Walsh. dis tinguished from the true gall-ffies by the sheaths of the ovipositor always projecting more or less beyond the 'dorsal valve.' which is a small hairy tubercle at the top of the seventh abdominal seg ment. This dorsal valve also projects greatly. In almost all the species the ovipositor projects from between the tips of the sheaths. Among the inquiline genera are Synophrus, Amblynopus, Synerges. and .Aulax, which are 'guests' of vari ous species of Cynipides. The cuckoo-flies (Chrysididm) are all inquilines, laying their eggs in the nests of wasps and solitary bees; some are true parasites.
One of the eight species of British wasps is said by Sharp to be a guest wasp. Guest bees are not rare; they do not work, the organs for col lecting and carrying pollen having been lost by disuse. Guest bees enter the nests of both soli tary and social bees and lay their eggs. the young feeding upon the pollen stored up for the young of their hosts. but not directly destroying their young hosts. Nomada (q.v.) is a gaily-col ored bee which boards with species of Halietus, Andrena, etc. Packard states that there seemed enough food in the nest for the young of both host and boarder, as they were found to live har moniously together, and their hosts and their parasites are disclosed both at the same time. The species of Cwlioxys live on the leaf-cutting bee (_Ilegachile), those of Psithyrus on the bumblebee. In this guest bee the mandibles of the female are acute and two-toothed. their legs (tibiae) are convex, so that they cannot carry pollen. while they have no pollinigerous organs. The habits of these guest bees afford interesting examples of the effect of change of habits on their structure. For the guests of ants and termites see INSECT, paragraph Soeiti I Inserts.