Overwintering rice water weevils, Lissorhoptrus oryzophilus Kuschel, were held at different temperatures with and without food to determine the response of indirect flight muscle regeneration. Flight muscle regeneration has a temperature threshold of ca. 18°C. The rate of regeneration is greater at higher temperatures and when adults feed. Emergence of adult weevils from overwintering sites was monitored with sticky traps for 4 years near Stuttgart, Ark., and for 2 years near Crowley, La. The date adults emerged in the spring is closely related to springtime temperatures.
Journal Article Mosquito Control from Applications Made for Control of Rice Water Weevil Get access J. L. Lancaster, Jr., J. L. Lancaster, Jr. Division of Timber Management, Forest Service, USDA, Ogden, Utah Search for other works by this author on: Oxford Academic PubMed Google Scholar N. P. Tugwell N. P. Tugwell Division of Timber Management, Forest Service, USDA, Ogden, Utah Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 62, Issue 6, 1 December 1969, Pages 1511–1512, https://doi.org/10.1093/jee/62.6.1511a Published: 01 December 1969 Article history Received: 20 February 1969 Published: 01 December 1969
Abstract Rice was planted in Crowley silt loam May 9 and flodded June 13. Three tests were each arranged in a randomized complete block design with 3 (Test 2) or 4 (Test 1 and 3) replications. Granular treatments (Test 1) were applied with a hand shaker just prior to flooding on June 13 to plots 3.5 x 15 ft. Spray treatments (Test 2) were applied 1 day preflood with CO2 powered sprayer except for Furadan 3G which was applied with a hand shaker. Plots were 6 x 15 ft. Plots in Test 3 were circular (5 ft dia). Each was surrounded by sheet aluminum flashing used as a levee to prevent water movement between plots. The 5 day postflood treatments were applied to the water surface on June 18. Cymbush, Pydrin and Ambush were each mixed with the hydrocarbon Exxon 5357-9. Plots in all tests were sampled for root-feeding rice water weevil larvae on July 8 and 9 by taking 5 soil cores (9 dia x 7 cm deep) from drill rows in each plot. The samples were processed by working each through a No. 40 U.S. Standard soil testing sieve and floating larvae out in brine.
At intervals of 3 to 56 days, propanil (3′,4′-dichloropropionanilide) at 4.5 kg/ha was applied after treatments of carbofuran (2,3-dihydro-2,2- dimethyl-7-benzofuranylmethyl carbamate) at 0.7 kg/ha. Their interaction injured rice ( Oryza sativa L., ‘Starbonnet’) vegetatively, but did not reduce grain yields, milling quality, or seed viability. Leaf chlorosis and necrosis developed within 7 days after propanil treatment and lasted for 2 to 4 weeks. As the time interval between carbofuran and propanil treatments increased, leaf injury decreased. Older rice recovered more quickly than younger rice. Interaction of carbofuran and propanil did not cause chlorosis or necrosis of rice leaves when the insecticide was applied 5 days after the herbicide. Propanil alone, applied once at 4.5 kg/ha, or applied sequentially at 4.5 kg/ha each time, caused only slight chlorosis of rice leaves.
The indirect flight muscles of the rice water weevil, Lis sorhoptrus oryzophilus Kuschel, undergo cyclic degeneration and regen eration. Examination of field collected adults indicated that the pro gressive changes in these muscles could be characterized by the number of distinct muscle bundles, their width and firmness of attachment. This description of indirect flight muscle degeneration and regeneration presents one aspect of a more general study dealing with the seasonal history and dispersal of the rice water weevil (RWW), Lissorhoptrus oryzophilus Kuschel. Adults of this important rice pest characteristically invade ricefields soon after flooding, quickly reach a peak of abundance, then within a few days after flooding decline in numbers (Isely and Schwardt, 1934). This decline and the infestation of other newly flooded fields has been interpreted to mean that adults moved from field to field (Rolston and Rouse, 1964; Isely and Schwardt, 1934). Typically, at least some adults invade a newly flooded ricefield regardless of when during the season it is flooded, but this may not involve field-to-field movement at all. Adults may come directly from overwintering sites during early season and from first gener ation weevils during late season. Muda et al. (1981) observed that RWW dispersal was closely associated with changes in indirect flight muscles and implied that adult vagility was restricted to brief periods. The authors did not, however, de scribe in detail the progressive changes in muscular tissue, although a standard means of characterizing the degree of muscle change could provide a basis for better anticipating and understanding dispersal of this pest. The objective of this study was to determine ways of characterizing the pro gressive changes in indirect flight muscles in different stages of regeneration prior to adult movement to fields and in different stages of degeneration after they had entered a ricefield. Materials and Methods RWW adults were collected from overwintering sites and later from flooded fields when their indirect flight muscles were expected (Muda et al., 1981) to be in the various stages of change. Weevils were fixed in Brasil's fluid for 24 hours followed by a 70% ETOH wash (Kennedy, 1932). For general observations and measurements, 20 weevils from those collected on each sampling date were dissected by opening the elytra and removing the thoracic tergum. This exposed the intact indirect flight muscles. The muscles then were stained in a 1% acid fuchsin for ca. 5 min, washed in 70% ETOH and 1 Published with the approval of the Director, Arkansas Agricultural Experiment Station. Accepted for publication 22 May 1982. This content downloaded from 157.55.39.59 on Sat, 15 Oct 2016 04:41:07 UTC All use subject to http://about.jstor.org/terms VOLUME 56, NUMBER 2 165 photographed. The following observations and measurements were made: 1) the fiber bundles were counted, 2) the firmness of muscle attachment was characterized on the basis of the ease of detachment of muscles when dissecting and 3) width of the median dorsal longitudinal muscles (MDL), or the left or right dorso-ventral muscle (DV) was determined by measuring across a distinct muscle bundle. In preparation for muscle sectioning, the MDL and DV muscles from 10 in dividual weevils per sampling date were placed in separate vials and passed through a dehydration, infiltration, clearing and embedding schedule: 80% ETOH for 1 h, 1% eosin in 95% ETOH, 2 h, and 100% ETOH, 3 changes, 1 h. The muscles were then cleared by submersion in methyl benzoate for 12 h and benzene for 1 h. Then the tissue was infiltrated with: 1) a 50:50 mixture of benzene and Paraplast for 12 h, 2) a 50:50 mixture of Paraplast/Tissue Prep for 12 h and 3) a fresh change of this mixture for 10 h. Embedding was then done in a 50:50 mixture of Paraplast and Tissue Prep. The muscles in tissue blocks were cut in 10 jum longitudinal sections and stained with Meyer's hematoxylin and eosin (Luna, 1968). Sectioned RWW muscles were examined for evidence of muscle breakdown, but no attempt was made to describe the fine-structure of muscle regeneration or degeneration. This subject has been extensively studied for several different insects such as Leptinotarsa decemlineata Say (Stegwee et al., 1963), Ips confusus (LeConte) (Bhakthan et al., 1970) and Solenopsis spp. (Jones et al., 1978). Results and Discussion The nuclei in well developed RWW muscles were about 7.0 ?im long and contained little chromatin material against the nuclear membrane. In regenerating muscles the nuclei were relatively large (20.4 ??m long) and contained relatively large amounts of chromatin material. In degenerate muscles, nuclei were 10.7 ??m long and the chromatin material was fragmented, suggesting a breakdown of the muscle. Changes in the number of distinct bundles making up the MDL muscles pro vided a simple way of characterizing muscle stages. Adults collected in January from their overwintering quarters possessed six thin, fragile bundles consisting apparently of only the sarcolemma (Fig. la). As development progressed, the number of visible bundles was reduced to four (Fig. Id) and eventually to two large, compact bundles during May (Fig. If). By contrast, the DV muscle consisted of only 1 bundle regardless of the state of regeneration. Degenerating muscles showed what appeared to be simply a reversal of the sequence, in that at the beginning of the degeneration process the muscles changed from two bundles to four then to six. Although firmness of muscle attachment is a somewhat subjective way of char acterizing stages of muscle change, it seemed useful in recognizing degenerate muscles. Regenerating and fully-developed muscles possessed firm attachments with the integument and were not easily detached by dissection. On the other hand, the degenerating muscles often appeared to be detached or in the process of detaching from the integument at the time of dissection. When still attached, degenerating muscles were easily detached. The width of distinct muscle bundles provided a more definitive way of char acterizing muscle stage. The mean width of both the MDL and DV muscles ranged This content downloaded from 157.55.39.59 on Sat, 15 Oct 2016 04:41:07 UTC All use subject to http://about.jstor.org/terms 166 JOURNAL OF THE KANSAS ENTOMOLOGICAL SOCIETY
Journal Article Survival of Immature Telenomus podisi (Hymenoptera: Scelionidae) and Rice Stink Bug (Hemiptera: Pentatomidae) Embryos After Field Applications of Methyl Parathion and Carbaryl Get access Hamim Sudarsono, Hamim Sudarsono Department of Entomology, University of Arkansas, Fayetteville, Arkansas 72701 Search for other works by this author on: Oxford Academic PubMed Google Scholar J. L. Bernhardt, J. L. Bernhardt Department of Entomology, University of Arkansas, Fayetteville, Arkansas 72701 Search for other works by this author on: Oxford Academic PubMed Google Scholar N. P. Tugwell N. P. Tugwell Department of Entomology, University of Arkansas, Fayetteville, Arkansas 72701 Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Economic Entomology, Volume 85, Issue 2, 1 April 1992, Pages 375–378, https://doi.org/10.1093/jee/85.2.375 Published: 01 April 1992 Article history Received: 16 July 1990 Accepted: 03 December 1991 Published: 01 April 1992
Abstract Two trials to evaluate the efficacy of chlorpyrifos-mefhyl to control TPB were conducted in cotton planted 17 May on the UA Cotton Branch Experiment Station in Marianna, AR. The 8 row (38 inch centers) X 50 ft plots were separated by 2 rows of buffer zone. Treatments were arranged in a RCBD with 3 replications. In Trial I insecticides were applied 21 Jul using a 2-row, CO2-charged back pack sprayer calibrated to deliver 10 gpa at 20 psi with 1, TX6 nozzle per row. In Trial II insecticides were applied 4 Aug using a 4-row CO2-charged back pack sprayer calibrated to deliver 13 gpa at 20 psi with 1, TJ-60 8002vs nozzle per row. For each study, 3 organdy sleeve cages, 9 inches diam by 22 inches long, had been secured to individual plants in each plot by tying the lower end of each cage around the plant ca 1 ft from the terminal with twist ties. The cages were rolled down to the tie and covered with aluminum foil. Following application the foil was removed, the cage pulled up, and 5 TPB were placed into each cage. Cage tops were secured with twist ties. Insects had been collected by sweep net on blooming mustard immediately prior to testing and held in 15 ml plastic vials (5/vial) on ice. After 72 hr, plants were cut below the cage and taken to the laboratory where TPB mortality was determined.
Abstract Insecticides were evaluated in five experiments at the Rice Res. and Ext. Cent, in Stuttgart, Ariz. Rice was planted in Crowley silt loam: ‘Starbonnet’ on 11 May for tests I to IV and ‘Lebonnet’ on 8 June for test V. Each test was arranged in a randomized complete block design with four (Tests I and II) or three (Tests III to V) replications. All plots were sampled for root-feeding larvae by taking five soil cores (9 cm diam x 7 cm deep) from the drill rows of each plot; they were processed by washing through a #40 US Standard soil testing sieve and floating the larvae out in brine.
The fungal entomopathogen, Beauveria bassiana (Balsamo) Vuillemin, was isolated from a naturally-infected tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), in Arkansas. This is the first report of a tarnished plant bug naturally infected with B. bassiana. In laboratory tests this isolate (ARSEF 3769) was highly infective to L. lineolaris nymphs and adults. The LC50 for nymphs and adults was 9 × 104 and 8.4 × lfj4 conidia per ml deionized water containing 0.01% Tween 80, respectively, when mortality was recorded 7 days after treatment. In a 1993 field test, cotton plants treated with ARSEF 3769 conidia at a rate of 5.8 × 107 conidia per ml deionized water containing 0.01% Tween 80 resulted in 88.8% and 100% mortality (n = 143) in exposed L. lineolaris adults at 5 and 7 days after treatment, respectively, compared with 7.4% and 11.4% mortality in the controls (n = 150). Persistence tests on field cotton showed that B. bassiana conidia could infect adult L. lineolaris for up to 4 days under ambient environmental conditions. A 1995 field test with the commercial B. bassiana product, Mycotrol WP, and the insecticide imidacloprid (Provado formulation) on L. lineolaris adults caged on canola resulted in 97.9% mortality at 5 days after treatment in L. lineolaris adults when Mycotrol (280 g per ha) and imidacloprid (50 g ai. per ha) were applied together, compared with 67.3% in the imidacloprid alone (50 g a.i. per ha), 52% in the Mycotrol alone (280 g per ha), and 7.6% and 13.6% mortality in the controls. The combination of Mycotrol and imidacloprid was significantly more effective than either material alone. These studies show that the fungus B. bassiana may be useful for control of L. lineolaris in cotton and other crops.
