The species was first described by Dr. H. C. Fall in 1910.[A] Mr. Arthur Gibson[B] mentions it as attacking leaves of strawberry plants at Nelson, British Columbia. The species is referred to as Haltica evicta Lec., but after a comparison with specimens in the writer’s collection and later in Dr. Fall’s collection at Pasadena, California, I am led to believe that the species reported by Mr. Gibson as evicta is not evicta but probata. It has been reported from Spokane, Washington, on strawberries, and at various times has been reported feeding on cultivated crops in Oregon.
The species is distributed along the Pacific Coast from British Columbia to California. It has been reported from Nelson in British Columbia; Everett and Spokane in Washington; from Corvallis, Pamelia Lake, Mary’s Peak, the Three Sisters, and Josephine County in Oregon; and from Santa Rosa, Belmont, Siskiyou, and Trinity Counties in California.
[A] Transactions of the American Entomological Society of America, Vol. 36, pp.
[B] Canadian Entomological Circular No. 2. 152-159.
SEASONAL LIFE-HISTORY AND HABITS OF THE SPECIES
With the approach of warm weather in the spring, when the buds of the wild rose are showing their green, the little bronze beetles ([Pl. I, Fig. 2]) come from their winter quarters, about the middle of April or earlier depending on the spring weather conditions, and commence feeding on the tender small leaves of the expanding buds. The beetles possess a very brilliant lustre and when approached manifest a saltatorial habit, and may leap for a considerable distance. The insect passes the winter in the adult stage and during that time may be found concealed in convenient places. The writer has taken numerous individuals from beneath the moss of the scrub oak, which grows abundantly along the creeks in the Willamette Valley in Oregon. The first individuals were taken on April 11, 1913, feeding on a species of wild rose, Rosa nukatana Presl. near Corvallis, Oregon. The adults were at the time resting in the sun on the dried fruits of the rose and also on the moss which covered the oaks. In 1915, the first beetles were out on March 19 or somewhat earlier. Sometimes the March weather is too severe so that the beetles do not appear until later, and the inclement weather frequently puts a stop to the activity of the beetles and retards oviposition.
After emerging from their hibernating quarters, the beetles jump or fly to the nearest rose bush and soon begin to satisfy their appetite after the long winter’s fast. At this time the tender bursting rose buds seem to be the favorite food, and the beetles engorge themselves with bites from the prospective crop of leaves, then locked up in the buds. The beetles seem to be most active during the warmer sunshiny portions of the day, when they may be seen jumping and flying about the rose bushes. When touched or jarred, they at once drop quickly to the ground, where they feign death for a short time, later returning to the foliage. Their shining bronze color renders it easy to discover and watch them at their destructive work. They begin gnawing an unsightly hole into either the side or top of the bursting leaf bud, often boring into the bud so far as to be almost hidden from view. It usually takes the beetles a few days to satisfy their vigorous spring appetites; then they turn their attention to the propagation of their kind. The later emerging adults feed voraciously on the foliage ([Pl. I, Fig. 5]) eating out irregular places in the leaves.
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.