. Bulletin of the Department of Agriculture. Agriculture. Fig. 3.—The horse- radish flea-beetle : Egg. Highly mag- nified. (Original.) 4 BULLETIN 535, TJ. S. DEPARTMENT OF AGRICULTURE. THE EGG. The egg (fig. 3) is oval, capsule-like, deep orange in color, with no special characteristic marking or reticulations visible under a 4-milli- meter objective. The following are the measurements taken from 22 eggs: Maximum, mm. b}^ mm.; minimum, mm. by mm.: average, mm. by mm. THE LARVA. The immature larva.—The larva, just after hatching from the egg, is about mm.
. Bulletin of the Department of Agriculture. Agriculture. Fig. 3.—The horse- radish flea-beetle : Egg. Highly mag- nified. (Original.) 4 BULLETIN 535, TJ. S. DEPARTMENT OF AGRICULTURE. THE EGG. The egg (fig. 3) is oval, capsule-like, deep orange in color, with no special characteristic marking or reticulations visible under a 4-milli- meter objective. The following are the measurements taken from 22 eggs: Maximum, mm. b}^ mm.; minimum, mm. by mm.: average, mm. by mm. THE LARVA. The immature larva.—The larva, just after hatching from the egg, is about mm. long by mm. wide: the color of the entire body is whitish, the head, thoracic plates, and anal plate varying from whitish to pale brown. Within a few hours the head, thoracic plate, and anal plate become darker, and a day or more later turn deep brown. In other major respects, excepting the numerous transverse wrinkles and the relative proximity of the setae, the young larva is very similar to the older larva. The mature I a era.—The larva (fig. 4), when full grown, is slender subcylindrical, pale yellowish white, with dark brown head, thoracic plate, and anal plate: mandibles distinctly quadridentate; head with the usual V-shaped epicranial suture and dark median line caused by attachment of tentorium; five setae on epicranium each side of median line, several setae distrib- uted irregularly about lateral mar- gins of head as shown in figure 4; thoracic plates divided by distinct suture: row of three set» along an- terior lateral margin of each plate; one on lateral posterior angle: four minute setae on posterior inner mar- gin of each [date; one seta on inner anterior angle; mesothorax with pale chitinous plates bearing setae, two in anterior row, four in pos- terior row. four on slightly elevated pleural area: metathorax similar. The thoracic legs each bear one claw. The abdominal segments bear dorsally three rows of slightly ele- vated chitinous {dates, each of w
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculture, bookyear
