قراءة كتاب Journal of Entomology and Zoology, March 1917

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Journal of Entomology and Zoology, March 1917

Journal of Entomology and Zoology, March 1917

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دار النشر: Project Gutenberg
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Many individuals were found in copulo on April 12, 1913, and on April 14, 1915. Eggs were laid in great numbers April 15, 1913, but not until the first of May in 1915, due to a long stretch of cold wet weather. By May 18 many eggs were to be found but usually no larvae. The eggs are laid in masses (Pl. I, Fig. 3) of from two to fifteen in a cluster with an average of between seven and nine. They are deposited usually on the lower surface of the leaf. No eggs are deposited until the foliage is well along usually, as this is the food of the larvae. The writer observed a female during oviposition. She thrusts out the egg and by a mucilagenous substance causes the egg to adhere fast to the leaf. She decorates the egg, as it were, with a fluid which later turns black and appears as a streak across the ova. The adults do not live long after egg deposition, usually about a week and a half. A number of females were observed to lay from forty to fifty eggs each.

The length of the egg stage was found to vary considerably even in the insectary, due no doubt largely to the weather conditions. In indoor observations it ranged from seven to fifteen days, with an average of twelve. In the open, eggs under screen cloth were deposited on May 24, 1913, and hatched June 10, 1913, a duration of seventeen days. By June, 1913, practically all of the egg masses had hatched and scarcely an adult could be found anywhere. The larvae are at first yellow, changing over to a black after a short period of time (Pl. I, Fig. 7). The eggs split at the side when the young emerge and the larvae remain quiet for some time apparently feeding first on the remaining egg juices. After a while they begin to move about for convenient feeding spots. The larvae moult three times, and after each moulting appear yellow, soon changing to a black. Several of the grubs usually work on the same leaf, continuing to eat small irregular holes, through, or nearly through, the leaf until it appears skeletonized (Pl. I, Fig. 7), when they seek new pastures.

When full grown the larvae drop to the soil and after burrowing to a depth of about an inch or less, they construct soil cells of earth (Pl. I, Fig. 6), not unlike the cell of the common cherry and pear slug, in which they pupate. By July 3, 1913, many larvae were falling to the soil. The length of the larval stage varies from fifteen to twenty-five days with an average of twenty days. By July 10 many pupae (Pl. I, Fig. 4) were found in the soil. The writer neglected to ascertain the exact length of the pupal stage, but from the meager observations made up to this time ventures the opinion that it is about eighteen days. By the first of August many adults could be found. They are a beautiful metallic color when just emerged. The writer bred from the adults a species of Diptera a Tachinid but has not been able to ascertain the species. Subsequent observation revealed no eggs, so undoubtedly the species is single brooded. The life-cycle is calculated to last about fifty-five days from eggs to adults, but this is greatly influenced by the weather conditions. The length of the adult stage is about ten months, depending, of course, upon the time the warm days approach in the spring and upon the cold stretches which intervene, conditions which influence emergence from their hibernating quarters.

DESCRIPTION OF THE VARIOUS STAGES

The Eggs (Pl. I, Fig. 3) are of an orange color, oblong oval or bean-shaped. The egg has a delicate covering by which it is attached to the leaf. Nearly every egg has a sort of spine-shape structure attached, although it is not exactly a spine but a part of the egg covering, which, when it has dried, gives it a black streaked appearance at that point. The egg measures 1 mm. in length by .25 mm. in width.

The Larvae (Pl. I, Fig. 7) when full grown have the body wider at the anterior end, tapering gradually to the anal segment and covered with many hairs. They are covered with an oily substance in which they often collect their excrement as they feed and travel. The entire larva is black and the segments of the body possess numerous tubercles bearing setae. Each segment of the abdomen has a group of tubercles on a side above the spiracles. When full grown the larvae measure from 6 to 8 mm. in length.

The Pupa (Pl. I, Fig. 4) is yellow, 4 to 6 mm. in length, with the wing pads and legs of a paler yellow to nearly white. Two setae are located on the vertex and two on the occupit of head. The prothorax, mesothorax, and metathorax bear spines varying in number. The abdomen possesses three rows of setae on each side above the spiracles.

The Adult (Pl. I, Fig. 1) is green bronze, entire upper surface polished and strongly shining sculpture throughout, nearly as in Haltica ignita. Antennæ piceous, slightly more than half the length of the body, joints 2-3-4 gradually increasing in length, the fourth very nearly three times as long as wide. Eyes rather small and not very prominent, their width as seen from the front distinctly less than half the interocular distance. Prothorax two-thirds wider than long, sides parallel in basal half, convergent anteriorly. Elytra fully two-thirds as wide as long, and nearly three-fourths wider than the prothorax. Body beneath piceous; abdomen alutaceous, rather coarsely punctate and transversely rugulose. Length 3.7 mm. to 4 mm.

EXPLANATION OF PLATE

Figure 1. The adult beetle (greatly enlarged).

Figure 2. The adult beetle (natural size).

Figure 3. Eggs in situ on leaf greatly enlarged.

Figure 4. Pupa greatly enlarged.

Figure 5. Rose leaves showing work of adult beetles.

Figure 6. Pupal soil cell.

Figure 7. Larvae at work skeletonizing leaf.


Notes on Birds of Laguna Beach and Vicinity for 1916

H. H. NININGER

In addition to the work done by Mr. Leon Gardener and others on the distribution of birds in the vicinity of Laguna Beach I noted the

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