Electron and light microscope studies of the development of the virus rods of insect polyhedroses

In 1915 Glaser demonstrated for the first time that a nuclear polyhedrosis of a lepidopterous larva (Lymantria dispar), was induced by an invisible filterable virus isolated from the blood of diseased larvae. Nuclear polyhedroses of the larvae of over a 100 insect species are now known, and those of them which have been investigated have been shown to be due to viruses. In these polyhedroses the nuclei of susceptible cells, hypodermis, tracheae, fat and blood cells, etc., enlarge and become packed with infectious crystalline inclusion bodies, the polyhedra, from which the diseases get their name. The pupae and imagos of these insects are not generally susceptible to polyhedral virus diseases, and so far no nuclear polyhedrosis of imaginal tissues in the larvae has been reported. This has led to the suggestion that imaginal tissues are not susceptible to polyhedral virus diseases.

NESTING HABITS OF SPHEX XANTHOPTERUS (CAM.) (HYMEN.)

Certain of the nesting habits of the wasp, Sphex xanthopterus (Cam.), have been observed at and near Los Angeles, California. The insect nests for the most part in the moist or wet, sandy soil of the river bed. It digs a short tunnel and enlarges it into a cell at the end. Into this is stored a stung lepidopterous larva, often the young of the moth, Zale lunata (Drury) and its varieties, to the side of which is fastened the egg of the wasp. The entrance to the tunnel and nest is then closed and in due time, if all goes well the egg hatches, the larva devours the prey, spins its cocoon, pupates, and later emerges an adult wasp. A more detailed account of some of the facts in its nesting habits and life history is given below.

On some New Cephaline Gregarines

Host: Xylocopa aestuans (Linn.). Locality: Lahore, India.The gregarine described below has been found abundantly in the alimentary canal of many specimens of the carpenter bee, Xylocopa aestuans (Linn.), and is the first to be described from any Hymenopteran host. Keilin (1918), in describing Leidyana tinei in a Lepidopterous larva, remarked that no gregarines had been found till then in the two large orders of holometabolic insects: Lepidoptera and Hymenoptera. He further observed as follows: “The fact that gregarines have not been previously recorded in these two orders cannot be considered as due to lack of observation, since large numbers of these insects have been dissected for many different purposes. Possibly we can account for the infrequency of their occurrence because of the habits of the larvae of Lepidoptera and Hymenoptera. These are often parasites in other Arthropods (Hymenoptera) or they are gallicolous (Hymenoptera) or phytophagous (Lepidoptera and Hymenoptera) or they live in nests and cells (Hymenoptera).” We have examined about 200 specimens of Xylocopa and found them practically always infected.

NOTES ON FENESICA TARQUINIUS, Fabr.

In his interesting article “On the History and the Preparatory Stages of Fenesica tarquinius” (Canadian Entomologist, xviii., pp. 141–153) Mr. Wm. H. Edwards makes some comments upon my article in Science of last April (30th), in which I announced the carnivorous habit of the larva of this species. He has been led to do so in part by the incorrect report in Entomologica Americana of the Proceedings of the Entomological Society of Washington for January 6th last. In that report “Mr. C. L. Johnson” is said to have observed “a lepidopterous larva feeding on a species of Aphid,” but the report is incorrect both as to the fact and as to the name. Judge Lawrence C. Johnson, an old-time correspondent and for a while one of my assistants in Mississippi, was the correspondent intended, and his communication, which I was familiar with, particularly states that “he thought he saw the larva eating the plant-lice, but failed to convince himself of the fact.” Mr. Lugger, in the very report quoted by Mr. Edwards (Can. Ent., xviii., 142, lines 2 and 3) expressly states that “he had never actually seen them (Fenesica larvæ) feeding upon the Aphids,” and as he previously remarked that he had “made the same observations” as Mr. Johnson, the report in Entomologica Americana is inaccurate and contradictory on its face.

NOTES ON AN UNDETERMINED LEPIDOPTEROUS LARVA

We have found a caterpillar which lve cannot identify, nor can any one to whom we have shown the description and a water-color drawing.“Papilio,” Vol. iii., No. I., p. 14, has a description which is nearest it, but is not exactly like our larva, as ours has no tufts.Our first specimeu was found Sept. 12th, 1883, and our last one Aug. 13th, 1886. Between these we have three others; all of them pupated, but none emerged.The larva is 1½ inches long; the head is brownish-green with a whitish bloom over it; mouth parts dark; no marks or hairs.