Note on Oviposition in Plant Stems by Grasshoppers (Orthoptera: Acrididae)

1963 ◽  
Vol 95 (5) ◽  
pp. 556-557
Author(s):  
R. Pickford ◽  
M. E. Taylor

Most species of grasshoppers in North America appear to lay their eggs in soil or among grass roots. A variation of this habit was reported in Manitoba by Criddle (1933) who states that Chloealtis conspersa Harr. and Neopodismopsis abdominalis (Thom.) oviposit exclusively in decaying wood or in dung.Recently, a few stems of sweet clover, Melilotus alba Desv., and Russian thistle, Salsola kali L. var. tenuifolia Tausch, that contained insect eggs, were sent to the Saskatoon Research Station by A. Vadeboncoeur of Val Marie in southwestern Saskatchewan. These eggs were laid in the pithy centres of the stems in groups of eight or nine (Fig. 1). According to the sender, the clover had been cut during the summer and the thistle was about two years old. Both were lying in the ditch on the railroad right-of-way. At our request, Mr. Vadeboncoeur sent in a few more infested stems. From a total of about 10 samples it seems evident that oviposition in plant stems is typical of the grasshopper involved. The exact egg-laying procedure is difficult to visualize in view of the small diameter of the pith (approximately 3 mm.), and the lack of any sign of penetration through the side of the stem. Inserting its abdomen into the narrow stem and depositing the eggs 25 to 30 mm. from the cut end of the stem must have involved considerable gymnastic manoeuvring by the female grasshopper.

1958 ◽  
Vol 36 (3) ◽  
pp. 411-420 ◽  
Author(s):  
H. Baenziger ◽  
J. E. R. Greenshields

In crosses involving derivatives of interspecific crosses of (Melilotus alba × Melilotus dentata) and (M. officinalis × M. alba) with pure Melilotus alba, irregular ratios were shown to be common. Previous studies using pure M. alba have indicated simple Mendelian inheritances for many of the characters studied herein. However, when interspecific derivatives are involved, some plants give F2 families that do not fit any Mendelian ratio. Data are presented indicating that in segregations where the deficiency occurs it is always in the genotype that has contributed the gene from the non-recurrent species. Investigations carried out in this study are designed to determine possible causes for these "blurred" ratios.


Author(s):  
E. Rehleckaya ◽  
A. Dymkov ◽  
L. Lazarets ◽  
A. Maltsev

Purpose: Install the influence of the «small diameter of the egg» on the living mass and the reproductive qualities of chickens of meat crosses and the quail of meat breeds.Materials and methods. The selection was carried out along egg production and mass of eggs and additionally on the average small diameter of 5 eggs by value of ≥0.5σ from the average for the herd, while the evaluation on the basis of the «small diameter of the egg» was carried out in chickens aged 238 days of life, quails — 70 days of life. Calculated the average for each female and the average for the herd. For further reproduction, chickens carrying eggs with a small egg diameter ≥0.5σ from the average for the herd. Studies were held in SibNIP on quail and on the courses.Results. In the initial period of the egg laying, the individual variability of the small diameter of the egg — more than 10% (in the future, the figure decreased). The close correlation rate of the small egg diameter in the first half of the egg laying with such at the end of the bird's operation period was revealed. It has been established that the large diameter of the egg has a positive reliable connection with a lively mass, but negative with egg production. The reliable correlation rate of the small diameter of the egg with a live weight at a 42-day age, as well as with the derivation of eggs. The inheritance coefficients of the small diameter of the egg are comparable to the inheritance coefficients of the mass of eggs and significantly exceed those for a large diameter of the egg. The selection according to the small diameter of the eggs by ≥0.5σ from the average for the herd led to the fact that the chickens of the experimental groups reliably exceeded the live weight in the SB level of 1.57%, in the line G8 — by 1.35%. The superiority of a lively mass of quail of experienced groups was more pronounced than that of the chickens: the Pharaoh breed — by 4.15%, the Texas white breed is 4.22%. In relation to the derivation of eggs, a similar trend was traced. The derivation of eggs in quails of experienced groups was more than 4.59–4.98%; Country, respectively, 4.57–5.22%. Egg production of females of comparable groups of both chickens and quail was almost on the same level, and the difference was unreliable.Conclusion. It was established that a new method of breeding the poultry of the meat direction of productivity allows without decreasing egg production to increase the living mass of chickens of meat crosses by 1.5%, rewinds of meat breeds — by 4%, the derivation of eggs, respectively, by 4–5%. The method is intended for early prediction of females productivity during breeding selection.


1967 ◽  
Vol 99 (11) ◽  
pp. 1229-1229 ◽  
Author(s):  
P. G. Pilley ◽  
R. A. Trieselmann

The first record of the occurrence in North America of the white-tipped clover case-moth, Coleophora frischella L., was made in June 1966 when a single adult was taken by Heinemann on Picton Island, N.Y., in the St. Lawrence River (Freeman, personal communication). Independently, Trieselmann collected the larvae from white sweet-clover, Melilotus alba Desr., on 28 July through to 8 August 1966 at many points around Pembroke, Ont. Detailed examinations made at two of the collection points indicated that between 15 and 20% of sweetclover seeds were damaged. Because of its potential economic significance, the authors wish to make the presence of this species known to agricultural entomologists in Canada and the United States.


1931 ◽  
Vol 5 (6) ◽  
pp. 660-664 ◽  
Author(s):  
L. E. Kirk ◽  
T. M. Stevenson

The chief determining factor in spontaneous self-fertilization in white sweet clover (Melilotus alba) appears to be the distribution of pollen within the unopened flowers. This in turn depends on (1) length of stamens, (2) length of style, (3) amount of pollen, and (4) size of cavity within the upper part of the keel. When the flower structure and quantity of pollen is such as to insure the deposition of pollen grains on the stigma before the blossom is likely to be disturbed by insects, the plant will be normally self-fertilized. In the yellow flowered species of sweet clover (Melilotus officinalis) spontaneous self-fertilization is effectively prevented, except in certain varieties, by a characteristic of the stigma which makes it unreceptive. Scarification of the stigmatic surface appears to be necessary before fertilization can take place. Variation occurs also, as in M. alba, in the length of stamens and style, size of keel cavity, and the amount of pollen.There is a high correlation in M. alba between the percentage of flowers which are naturally self-pollinated and the percentage of flowers which produce pods when the plants are caged to exclude insects. Selection of plants which are normally self-fertilized can be made by examining the early flowers, thus obviating the necessity of bagging or caging plants which do not possess this character.A strain of M. alba which is normally self-fertilized was found to produce almost twice as much seed as another strain which is normally cross-pollinated under comparable conditions in the field.


Author(s):  
Margo M. Burgess ◽  
Scott Wilkie ◽  
Rick Doblanko ◽  
Ibrahim Konuk

The Norman Wells pipeline is an 869 km long, small diameter, buried, ambient temperature, oil pipeline operated by Enbridge Pipeline (NW) Inc. in the discontinuous permafrost zone of northwestern Canada. Since operation began in 1985, average oil temperatures entering the line have been maintained slightly below 0°C, initially through constant chilling year round and since 1993 through a seasonal cycling of temperatures through a range from −4 to +9°C. At one location, 5 km from the inlet at Norman Wells, on level terrain in an area of widespread permafrost, uplift of a 20 m segment of line was observed in the early 1990s. The uplift gradually increased and by 1997 the pipe was exposed 0.5 m above the ground surface. Detailed studies at the site have included field investigations of terrain and thermal conditions, repeated pipe and ground surface elevation surveys, and annual Geopig surveys. The field work has revealed that the section of line was buried in low density soils, thawed to depths of 4 m on-right-of-way, and not subjected to complete refreezing in winter. The thaw depths are related to surface or near-surface flows from a nearby natural spring, as well as to the development of a thaw bulb around the pipe in the cleared right-of-way. Icings indicative of perennial water flow occur commonly at this location in the winter. The pipe experienced annual cycles of heave and settlement (on the order of 0.5 m) due to seasonal freezing and thawing within the surrounding low density soils. The pipe reached its highest elevation at the end of each winter freezing season, and its lowest elevation at the end of the summer thaw period. Superimposed on this heave/settlement cycle was an additional step-like cycle of increasing pipe strain related to thermal expansion and contraction of the pipe. A remedial program was initiated in the winter of 1997–98 in order to curtail the cumulative uplift of the pipe, reduce the increasing maximum annual pipe strain and ensure pipe safety. A 0.5 m cover of sandbags and coarse rock was placed over the exposed pipe segment. Continued pipe elevation monitoring and annual Geopig surveys have indicated that both seasonal heave/settlement and strains have been reduced subsequent to the remedial loading. Introduction of a gravel berm has also altered both the surrounding hydrologic and ground thermal regimes.


1976 ◽  
Vol 12 (3) ◽  
pp. 257-265 ◽  
Author(s):  
A.G.L. Wilson

In experiments conducted in the Ord River Valley, North Western Australia, the extent of egg laying, larval numbers and grain damage from Heliothis armigera was studied with three sorghum varieties of different head densities. Total numbers of eggs laid were similar for each variety, larval infestation was highest on a very dense-headed variety Pickett 932045 and similar in the semi-dense headed RS610 and the open-headed E57 varieties. Greater losses per larva were estimated with varieties E57 and Pickett 932045 than for RS610, where lesser susceptibility was associated with ability to compensate, mainly by increased grain size, for grain loss. This paper reports the results of experiments at Kimberley Research Station to measure infestation and damage caused by H. armigera on three varieties of sorghum with head types ranging from dense to open, and the effectiveness of biological and chemical control practices are also discussed.


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