Egg Punctures Research Articles

Apple, Insect and Mite Control, 1978

Abstract Test materials were applied to apple trees at Monmouth (Test 1) and Winthrop, Maine, (Tests 2 and 3) as dilute sprays with a hand gun from a hydraulic sprayer operating at 300 psi and at 250-350 gal/acre. In Test 1, the trees were sprayed on May 31 (petal fall), June 7, 16, 29, July 12, 26, August 8, and 21 (first cover through seventh cover). Each material was applied on all dates. The fungicide program (formulations are rates/100 gal) consisted of Polyram 80W 1 lb and Benlate 50W 2 oz at 11 dates; Solubar .5 lb on May 16; Omite 6EC 4 oz on May 23, 31, and June 6; Epsom salts 15 lb on June 6 and 20; and Amid-Thin 8.4W .25 lb on June 13. In addition, Polyram 80W 2 lb was tank-mixed with each insecticide at each spray. In Tests 2 and 3, trees were sprayed on June 1 (petal fall), 9, 21, July 6, 19, August 2, and 15-16 (first cover through sixth cover). Each material was applied on alldates. The fungiside program (rates/100 gal) consisted of Difolatan 4F 4 qt at half-inch green and Polyram 80W 2 lb at each cover; Polyram was tank-mixed with each treatment. There were 4 to 5 single-tree replications per treatment. A randomized, complete-block design was utilized with 2 Mcintosh and 2 Spartan cultivars per treatment in Test 1; 4 Mcintosh per treatment in Test 2; and 2 Melba, 2 Cortland, and 1 Red Delicious per treatment in Test 3. Except for the test trees, these orchards were unsprayed. On August 29-30, three-fourths box of apples was picked from each tree and generally ca. 430 to 520 apples were examined per treatment on September 5-16 for external egg punctures (apple maggot), egg-laying scars (plum curculio), and typical feeding injuries (codling moth and lesser appleworm). Apple with maggot egg punctures were sliced to determine success of egg hatch and/or of maggot survival (success indicated by a larval penetration of more than 1/4 inch). Aphid and leafhopper counts were based on 10 randomly selected vegetative terminals around each tree. All live aphids found on July 17 and 24 (also August 11 for Test 3) on the distal 4 unfurled and 1 furled leaves and on the stem included by these leaves were recorded. Leafhopper evaluation was based on speckling feeding spots found on August 24-25 on the fifth and seventh leaves. European red mites were counted on July 24-28 and August 7-10 on 25 leaves collected mostly at chest-height around the periphery of each tree. The leaves were brought into the laboratory and brushed onto glass plates coated with a Tween 20-alcohol mixture; mites were counted the same day. No pest population exerted very serious pressure in these tests. July and August were unusually hot and dry.

Apple, Insect and Mite Control, 1977

Abstract Test materials were applied to apple trees at Winthrop, Maine, as dilute sprays with a hand gun from a hydraulic sprayer operating at 300 psi and at a rate of 250-300 gal per acre. The trees were sprayed on May 25 (petal fall), June 3, 14, 28, July 12, 26, and August 9 (first cover through sixth cover). Each material was applied on all dates except as noted in Tables. The fungicide program consisted on Difolatan 4F (4 qt/100 gal)at half-inch green and Polyram 80W (2 lb/100 gal) at each cover; Polyram was tank-mixed with each treatment. There were 4 single-tree replications per treatment. A randomized complete block design was utilized with 2 Mcintosh and 2 Cortland cultivars per treatment in Test 1 and 4 Mcintosh per treatment in Test 2. Except for the test trees, these orchards were unsprayed. On August 26, 3/4 box of apples was picked from each tree and ca 550-610 apples were examined per treatment on September 4-11 for external egg punctures (apple maggot), egg-laying scars (plum curculio), and typical feed-ing injuries (codling moth and lesser appleworm).

Apple Insect and Mite Control, 1976

Abstract Test materials were applied to apple trees as dilute sprays with a hand gun from a hydraulic sprayer operating at 300 psi and at a rate of ca 250 gal per acre in Test 1 and 350 gal per acre in Tests 2 and 3. The trees in Test 1 at Monmouth, Maine, were sprayed on May 25 (petal fall), June 3, 17, July 2, 14, 29, and August 13; and the trees in Tests 2 and 3 at Winthrop, Maine, were treated on May 30 (petal fall), June 5, 2 1 , July 6, 19, August 2 and 16. Each material was applied on all dates except as noted in Tables. The fungicide program consisted of Difolatan 4F (4 qt/100 gal) at half-inch green and Polyram 80W (2 lb/100 gal) at each cover; Polyram was tank-mixed with each treatment. There were 4 single-tree replications per treatment. A randomized complete block design was utilized with 4 Mcintosh cultivars per treatment in Tests 1 and 3 and 1 Red Delicious, 2 Cortland, and 1 Mcintosh per treatment in Test 2. Except for the test trees, these orchards were unsprayed. On August 30, 3/4 box of apples was picked from each tree and ca 500-600 apples were examined per treatment on August 30-September 11 for external egg punctures (apple magot), egg-laying scars (plum curculio), and typical feeding injuries (codling moth and lesser appleworm). Apples with maggot egg punctures were sliced to determine success of egg hatch and/or of maggot survival (success indicated by a larval penetration of more than 1/4 inch). European red mites were counted on 25 leaves per tree collected mostly at chest-height around the periphery of each tree. The leaves were brought into the laboratory and brushed onto glass plates coated with a Tween 20-alcohol mixture; mites were counted the same day. Except for apple maggot and plum curculio, no pest population exerted serious pressure. July and early August were unusually wet.

Apple Insect and Mite Control, 1975

Abstract Test materials were applied to 15-year-old apple trees at Winthrop, Maine, as dilute sprays with a hand gun from a hydraulic sprayer operating at 250 psi and at a rate of 300 gallons per acre. Spray dates were May 30 (petal fall), June 9, 23, July 7, 22, August 4, and 18; each material was applied on all dates. The fungicide program consisted of Difolatan 4F (5 qt/ 100 gal) at half-inch green and Polyram 80W (2 lb/100 gal) at each cover; Polyram was tank-mixed with each treatment. There were 4 single-tree replications per treatment. A randomized complete block design was utilized with 1 Cortland and 3 Mcintosh cultivars per treatment in Test 1; and 2 Melba, 1 Golden Delicious, and 1 Mcintosh per treatment in Test 2. In Test 3, trees were selected in a 3 x 3 Latin Square design, with 3 Mcintosh per treatment. Except for the test trees, this orchard was unsprayed. On September 4, 3/4 box of apples was picked from each tree and ca. 300-500 apples were examined per treatment on September 6-12 for external egg punctures (apple maggot), egg-laying scars (plum curculio), and typical feeding injuries (codling moth and lesser appleworm). Apples with maggot egg punctures were sliced to determine success of egg hatch and/or of maggot survival (success indicated by a penetration of more than 1/4 inch). Evaluation of apple aphid control was based on a count of all live aphids found on the distal 4 unfurled and 1 furled leaves and on the stem included by these leaves on each of 10 terminal vegetative shoots located around the periphery of each tree at a height of 3-6 feet. All mines of the spotted tentiform leafminer which were found on 10 vegetative terminals selected at chest-height around the periphery of each tree were recorded. European red mites were counted on 25 leaves per tree (33 or 34 leaves per tree in Test 3) collected mostly at chest-height around the periphery of each tree. The leaves were brought into the laboratory and brushed onto glass plates coated with a Tween 20-alcohol mixture; mites were counted the same day. Fall webworm control was evaluated from estimates made on September 6 of the length of each and every web encompassing a branch and leaves of each tree. Except for European red mite, no pest populations exerted serious pressure.

Emergence of Pissodes strobi (Coleoptera: Curculionidae) from Previously Attacked Sitka Spruce1

Preliminary studies in southwestern Washington indicated that more Sitka spruce weevils, Pissodes strobi (Peck), emerged from previously unweeviled Sitka spruces, Picea sitchensis (Bong.) Carr, than from previously attacked trees. Weevil emergence was sampled at a plot 7 miles south of Humptulips composed of one hundred and fifty 12-year-old trees; half of the trees had been attacked that spring (1971). Stem cages (Gara et al. 1971) were placed over leaders of trees which contained egg punctures. Later in the fall, emerging adults were collected from the cages and counted daily. The study revealed that 70% of the weevils, emerging between August and September, originated from trees attacked for the 1st time. The mean number of weevils emerging per tree also was considerably higher from terminals showing no indication of previous infestation than from stems weeviled 2—3 years previously.

The Relation of Thrips to Pansy Spot on Apples

AbstractPansy spot, a discoloration of the skin of McIntosh and Spartan apples, was shown to be a reaction of the apples to the egg punctures of thrips. Periodic sampling of apple blossoms and native hosts associated with apple orchards showed that Frankliniella occidentalis (Pergande) was the dominant species. The adult thrips moved from host to host as each came into flower, and apples were but one of several hosts attacked during the early spring.The thrips were most numerous in apple blossoms during the bloom period, and oviposited in the flower parts. The adult thrips left the apples after the bloom period, and the nymphs that hatched from the eggs developed in the calyx end of the young fruit. When the nymphs matured they oviposited in the young apple before leaving for other hosts. The area of apple skin surrounding the thrips egg developed the typical pansy spot symptoms. Other apple varieties were also attacked, but did not develop pansy spots.It was evident that the best time to apply control measures was at the petal fall period, when nymphal thrips were present but before damage was caused to the young apples.

Concepts of Population Dynamics and Estimation of Boll Weevil Populations1

Information on recovery, movement, and mortality of the boll weevil, Anthonomus grandis Boheman, was obtained from field-cage studies in North Carolina during 1962. The average recovery of weevils on cotton plants was 65.5%, and 88.8% of the recovered weevils were found on squares, flowers, and bolls. Variation from the average recovery (65.5%) in excess of 10% occurred in about 1 of 4 examinations. This variation appeared to be due to many factors acting together rather than to single factors such as generation, age, sex, and number of weevils or date and time of day of examination. However, plant maturity enhanced recovery. Migration by first-generation weevils (mostly females) was indicated on July 28 and 30, but the tendency to escape did not persist. The mortality rate of overwintered and second-generation weevils was approximately 2% per day, while that of first-generation weevils was 1%. The estimation of weevil populations at 7-day intervals is based upon (1) adult weevils recorded multiplied by appropriate correction factor which yields number of weevils present, (2) squares with egg punctures multiplied by percentage adult emergence from caged, flared squares which yields number of weevils expected to emerge during 2-week period, (3) progressive mortality of overwintered and first-generation adults at 14% and 7%, respectively, prior to emergence of second generation or beginning of migration, after which constant mortality of approximately 25% is used for all weevils. The expected population is within certain minimum and maximum limits. The minimum limit equals weevils present the previous week minus expected mortality plus emergence being completed during current week (second week) of a 2-week emergence period. The maximum limit equals minimum limit plus emergence expected during current week (first week) and following week (second week) of next 2-week emergence period. Net migration is indicated when the population present is not within expected limits. Weevils present minus maximum expected limit equals migrants to area, or minimum expected limit minus weevils present equals migrants from area.

The Biology of the Boll Weevil in Relation to Cotton Type

Life history of the boll weevil, Anthonomus grandis Boheman, was investigated on five cotton types; Gossypium hirsutum Lin. var. Hopi and Deltapine 15, G. barbadense Lin., G. arboreum Lin. var. Nanking, and G. herbaceum Lin. to determine if genetic type influenced the developmental stages, adult size, feeding, and egg-laying habits. Duration of development was not significantly different. G. barbadense received the greatest number of feeding punctures and Hopi (race of G. hirsutum ) received the greatest number of egg punctures. Survival as indicated by percent emergence was significantly lower from G. herbaceum than from other cotton types tested. There was a correlation of square size to weevil size from G. barbadense and G. arboreum .

Draeculacephala Mollipes Say, a Cicadellid Pest of Apples

An account of the injuries caused to the fruit and twigs of the apple, by crescent-shaped oviposition punctures of the sharp-nosed leafhopper, Draeculacephala Mollipes Say. The females make a crescent-shaped cut, 3-4 mm. long, through the skin of the apple or twigs and deposit from a few to more than twenty eggs within each egg puncture. As many as 125 egg punctures have been found on a single apple. The injury is largely restricted to the fruit and twigs on the lower portion of the tree.

Two Species of Thrips Injurious to Apples in the Pacific Northwest1

So-called Pansy spot or thrips injury on apples is caused by the egg laying punctures of two species of thrips: Frankliniella occidentalis and Aeolothrips fasciatus . Injury of this character produced by thrips has been reported from most of the apple growing sections of the Pacific Northwest. In some instances the grade of the fruit has been lowered fully twenty per cent. Pansy spot derives its name from the shape of a discolored area which develops about the egg punctures. The color of this pansy shaped spot varies from white through various shades of pink. Egg laying begins shortly after bloom time, continuing until the fruit has reached the size of large walnuts. The life history of the insect in the orchard is not fully known. Sprays of oil and Black leaf applied while the trees were in full bloom showed that injury can be materially reduced but do not give complete control. The Black Leaf appears to be the active ingredient in bringing about this benefit.

The Breeding of Boll Weevils from Infested Cotton Squares1

From a total of over 95,000 infested squares, about 37,000 boll weevils, Anthonomus grandis, were obtained, which represents an emergence of 39.2 per cent. These weevils were used in the toxicity work of the Chemical Warfare Service along with 60,000 additional field weevils. The best results were obtained by infesting field cotton at the rate of one weevil to five squares, and picking the infested squares a week or ten days after they had been punctured. If the percentage weevils to squares ran higher than one weevil to five squares, the weevils were hand picked down to this ratio. This prevents feeding and egg punctures on the same squares. The infested squares were then placed in an incubator, one layer thick, on shallow 1Published by permission of the Chief of the Chemical Warfare Service, U.S.A. trays containing about an inch of moist sand. They were kept from becoming too brittle by spraying lightly with water as necessary. It normally required about two weeks in the incubator for completion of each batch. Weevils were supplied at the rate of more than 2,000 per week until sufficient field weevils were available for the work.

Cotton Boll Growth in Relation to Boll Weevil Injury

This paper gives evidence that as the cotton bolls grow older they are less suceptible to boll weevil, Anthonomus grandis , injury, and the immunity at given ages varies with the variety. Dixie Triumph, Webber 49 and Humco Cleveland were the varieties studied, the first mentioned is the most susceptible and the last the most resistant. There is no correlation between the number of feeding punctures or the number of egg punctures and the percentage of cotton loss. Neither is there any relation between the thickness of hull and susceptibility to weevil damage, in spite of the fact that the weevils lay fewer eggs in the thick-hulled varieties. The determining factor is the hardness of bolls because varieties with the hardest bolls, as determined by the number of grams pressure required to puncture them, show also the least per cent of cotton loss.