Differences in Survival of the Wheat Stem Sawfly, Cephus cinctus Nort. (Hymenoptera: Cephidae), from Two Geographic Areas in Varieties of Spring Wheat

1957 ◽  
Vol 89 (6) ◽  
pp. 272-275 ◽  
Author(s):  
N. D. Holmes ◽  
L. K. Peterson ◽  
A. J. McGinnis

The larva of the wheat stem sawfly, Cephus cinctus Nort., lives inside the host stem, cuts it off at ground level in late summer, and spends the winter inside the stub below ground level. This insect can be controlled by the use of resistant spring wheats such as Rescue and Golden Ball. The possibility of the existence of a strain of C. cinctus to which these varieties are not resistant is of major importance.Platt, Farstad, and Callenbach (1948) found that the average percentages of Rescue stems cut by C. cinctus for five years were 36 at Regina, Saskatchewan, and two at Lethbridge. They suggested that this difference may have resulted from the effects of the environments in two areas, or from genetic variations between the sawflies at the two stations.

1960 ◽  
Vol 40 (1) ◽  
pp. 7-20 ◽  
Author(s):  
D. W. A. Roberts

Quantitative data obtained in field experiments showed that the resistance of wheat to attack by the wheat stem sawfly (Cephus cinctus Nort.) depended on the stage of development of the plants at the time of oviposition. Wheat plants were usually most heavily infested for a part or all of the period from 1 week before shot blade to 1 week after the flowering stage. Rescue, H46146, H4191, Golden Ball, and Melanopus lost their resistance to the development of the eggs and first-instar larvae some time between shot blade and flowering. Thatcher and Red Bobs did not show this type of resistance. The mortality of the older larvae increased in plants infested toward maturity. The time at which this increase began depended on the variety involved and ranged from just before shot blade to just after flowering.


1975 ◽  
Vol 107 (4) ◽  
pp. 391-401 ◽  
Author(s):  
N. D. Holmes

AbstractUntil mid- or late July, most larvae of the wheat stem sawfly generally move into the upper internodes of the host stems. Then, as the stems mature, the larvae migrate down to the basal internodes and cut the stems at about ground level.The migration is initiated in response to the visible and infrared light transmitted through the ripening stems. The direction of the migration, toward the basal internodes, results from the orientation of the larvae to the vertical axis of the stems reinforced by a positive larval response to gravity.The larvae cut the stems at ground level because they are shielded there by the soil from visible and infrared radiation. The location of cutting is also influenced by the preference of the larvae for drier sites in which to cut.The date of cutting is directly related to the loss of moisture from the stems, but not to a precise level of stem moisture. The larvae may form their cocoons in response to desiccation.


1957 ◽  
Vol 37 (3) ◽  
pp. 292-299 ◽  
Author(s):  
D. W. A. Roberts

The resistance of seven varieties of wheat to the wheat stem sawfly (Cephus cinctus Nort.) was tested in the greenhouse and on irrigated plots. In five of the seven varieties tested, namely, Rescue, H46146, Golden Ball, Red Bobs and Thatcher, the percentage of infested stems that were cut by sawflies was significantly higher in plants grown in the greenhouse in either summer or winter than in plants grown under irrigation in the field. In the other two varieties, H4191 and Melanopus, results were similar but the differences were not significant. This lower resistance of plants grown in the greenhouse was associated with a decrease in the percentage of tunnelled stems in which the older larvae had died. In percentage of infested stems cut, no significant differences were found between the varieties grown in the outdoor soil bins and those on adjacent irrigated land. In other 2-year tests on irrigated land, the variable resistance of wheat was apparently associated with variations in percentage of tunnelled stems in which the older larvae had died. Although stem solidness is usually associated with resistance on dry land, it appears that this characteristic alone cannot be relied on as a measure of sawfly resistance in a given variety when grown in diverse environments.


2007 ◽  
Vol 42 (2) ◽  
pp. 133-138 ◽  
Author(s):  
H.B. Goosey ◽  
A.W. Lenssen ◽  
G.D. Johnson ◽  
S.L. Blodgett ◽  
G. R. Carlson ◽  
...  

The wheat stem sawfly, Cephus cinctus Norton, is the primary arthropod pest of wheat, Triticum aestivum Thell, in the Northern Great Plains. Yet, information is unavailable on wheat stem sawfly infestation potential of currently grown spring durum cultivars. Field trials were conducted in 1998 and 1999 to determine wheat stem sawfly susceptibility of 13 spring durum cultivars and one hard red spring wheat. Preharvest infestations ranged from 2–55%. Postharvest larval infestations of stubble ranged from 1–9.5%. Three durum cultivars ‘Lloyd’, ‘Plenty’, and ‘Sceptre’ appear to offer potential, as a rotational crop, for management of wheat stem sawfly.


1965 ◽  
Vol 45 (6) ◽  
pp. 583-589 ◽  
Author(s):  
Hugh McKenzie

Inheritance of reaction to the wheat stem sawfly, Cephus cinctus Nort., was studied in populations of F3 and B2 lines from the cross Red Bobs × C.T. 715 (Triticum aestivum L.), and the respective backcrosses. The data supported the hypothesis that the varieties differed by three genes for sawfly reaction. A major influence was attributable to one gene. Its allele for susceptibility when homozygous was epistatic to the other two genes. Its allele for resistance was twice as effective as either of the other genes in conditioning resistance. The other two genes lacked dominance and were equal in their influence on sawfly reaction.Correlation coefficients showed that sawfly reaction was not associated with reaction to race T-2 of Tilletia caries (DC.) Tul., heading date, or awnedness. Sawfly susceptibility was weakly correlated with height.


1952 ◽  
Vol 84 (3) ◽  
pp. 90-92 ◽  
Author(s):  
L. A. Jacobson ◽  
C. W. Farstad

In 1945 a field experiment was designed at the Lethbridge laboratory to augment data on the effect of the time of seeding on infestation by the wheat stem sawfly, Cephus cinctus Nort. At that time one of the recommendations for the control of this insect was to delay seeding wheat until after May 15. The resulting crop escaped infestation because of the retarded plant during the period of the sawfly flight.


Diversity ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 482
Author(s):  
Huon L. Clark ◽  
Bruno A. Buzatto ◽  
Stuart A. Halse

Knowledge of subterranean fauna has mostly been derived from caves and streambeds, which are relatively easily accessed. In contrast, subterranean fauna inhabiting regional groundwater aquifers or the vadose zone (between surface soil layers and the watertable) is difficult to sample. Here we provide species lists for a globally significant subterranean fauna hotspot in the Robe Valley of the Pilbara region, Western Australia. This fauna was collected from up to 50 m below ground level using mining exploration drill holes and monitoring wells. Altogether, 123 subterranean species were collected over a distance of 17 km, comprising 65 troglofauna and 58 stygofauna species. Of these, 61 species were troglobionts and 48 stygobionts. The troglofauna occurs in small voids and fissures in mesas comprised mostly of an iron ore formation, while the stygofauna occurs in the alluvium of a river floodplain. The richness of the Robe Valley is not a localized aberration, but rather reflects the richness of the arid Pilbara region. While legislation in Western Australia has recognized the importance of subterranean fauna, mining is occurring in the Robe Valley hotspot with conditions of environmental approval that are designed to ensure species persistence.


Author(s):  
Darren M Cockrell ◽  
Terri Randolph ◽  
Erika Peirce ◽  
Frank B Peairs

Abstract From 2012 through 2020, a survey of wheat stem sawfly, Cephus cinctus Norton, was conducted in wheat (Triticum aestivum L.) fields in Eastern Colorado. In 2013, results showed sawfly infestations concentrated in the northern part of the state with only a few highly infested sites, with 38 of the 94 sampled sites having any infestation (five of which had >50% infestation levels). By 2020 sawfly had been found in all eastern counties sampled, and 72 of the 106 sites sampled were found to contain sawfly (11 of which had >50% infestation levels). The spread of this pest across the Colorado wheat-growing region will have lasting economic effects. The information gathered from this and future surveys will inform wheat variety development and aid in management decisions made by growers across the state.


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