DEVELOPMENT AND SURVIVAL OF PODISUS MACULIVENTRIS (SAY) AND PODISUS SAGITTA (FAB.) (HETEROPTERA: PENTATOMIDAE) AT VARIOUS CONSTANT TEMPERATURES

1992 ◽  
Vol 124 (1) ◽  
pp. 125-133 ◽  
Author(s):  
P. De Clercq ◽  
D. Degheele

AbstractDevelopment and survival of the predatory pentatomids Podisus maculiventris (Say) and Podisus sagitta (Fab.) were studied at six constant temperatures ranging from 19 to 35 °C. Time required for development from egg to adult ranged from 48.9 days (19 °C) to 18.9 days (30 °C) for P. maculiventris and from 51.9 days (19 °C) to 16.9 days (33 °C) for P. sagitta. At 33 °C, eggs of P. maculiventris did not hatch and development of nymphs that had emerged at 23 °C was retarded; none of the first-instar nymphs incubated at 35 °C survived the next moult. A constant temperature of 35 °C was fatal to P. sagitta eggs and extended the developmental period of nymphs from 23 °C. Egg hatch ranged from 47% (19 °C) to 57% (27 °C) for P. maculiventris and from 54% (33 °C) to 71% (27 °C) for P. sagitta. Nymphal survival was high at moderate temperatures, with 63–78% and 65–82% of the first-instar nymphs of the respective species reaching adulthood. Mortality during the nymphal stage was significantly increased at high temperatures, but was considerably lower for P. sagitta than for P. maculiventris. Lower threshold temperatures for egg and nymphal development were estimated to be 10.7 and 11.7 °C for P. maculiventris, and 13.3 and 12.2 °C for P. sagitta. Thermal requirements for these stages were 78.2 and 275.5 degree-days, and 60.9 and 265.5 degree-days, respectively. These observations suggest that P. sagitta is somewhat better adapted to high temperatures than is P. maculiventris.

1981 ◽  
Vol 113 (7) ◽  
pp. 569-574 ◽  
Author(s):  
A. B. Stevenson

AbstractThe effect of temperature on development of the carrot rust fly, Psila rosae (F.), was determined at constant temperatures in the laboratory. The relationship between rate of development and temperature was essentially linear from 10° to 17.5°C but began to diverge from linearity between 17.5° and 20°C. Estimated threshold temperatures (t) and thermal constants (K) for development of overwintered pupae were 2.3°C and 319 degree-days (dd) for first emergence and 1.8°C and 368 dd for 50% emergence. For laboratory-reared stages, t and K values were 4.1°C and 102 dd for egg hatch, 2.0°C and 642 dd for development from egg to mature larvae, and 3.0°C and 107 dd for pupation. Development in the laboratory from egg (less than 24 h old) to adult was completed in 59, 70, and 81 days at 20°, 17.5°, and 15°C respectively; no threshold or thermal constant was estimated because few or no individuals completed development to adult at 12.5° or 10°C within expected times, presumably because diapause was induced at these temperatures.


2012 ◽  
Vol 34 (1) ◽  
pp. 15-23 ◽  
Author(s):  
Heloísa Ferro Constâncio Mendonça ◽  
Eunice Oliveira Calvete ◽  
Alexandre Augusto Nienow ◽  
Rosiani Castoldi da Costa ◽  
Lucas Zerbielli ◽  
...  

The phyllochron is defined as the time required for the appearance of successive leaves on a plant; this characterises plant growth, development and adaptation to the environment. To check the growth and adaptation in cultivars of strawberry grown intercropped with fig trees, it was estimated the phyllochron in these production systems and in the monocrop. The experiment was conducted in greenhouses at the University of Passo Fundo (28º15'41'' S, 52º24'45'' W and 709 m) from June 8th to September 4th, 2009; this comprised the period of transplant until the 2nd flowering. The cultivars Aromas, Camino Real, Albion, Camarosa and Ventana, which seedlings were originated from the Agrícola LLahuen Nursery in Chile, as well as Festival, Camino Real and Earlibrite, originated from the Viansa S.A. Nursery in Argentina, were grown in white polyethylene bags filled with commercial substrate (Tecnomax®) and evaluated. The treatments were arranged in a randomised block design and four replicates were performed. A linear regression was realized between the leaf number (LN) in the main crown and the accumulated thermal time (ATT). The phyllochron (degree-day leaf-1) was estimated as the inverse of the angular coefficient of the linear regression. The data were submitted to ANOVA, and when significance was observed, the means were compared using the Tukey test (p < 0.05). The mean and standard deviation of phyllochrons of strawberry cultivars intercropped with fig trees varied from 149.35ºC day leaf-1 ± 31.29 in the Albion cultivar to 86.34ºC day leaf-1 ± 34.74 in the Ventana cultivar. Significant differences were observed among cultivars produced in a soilless environment with higher values recorded for Albion (199.96ºC day leaf-1 ± 29.7), which required more degree-days to produce a leaf, while cv. Ventana (85.76ºC day leaf-1 ± 11.51) exhibited a lower phyllochron mean value. Based on these results, Albion requires more degree-days to issue a leaf as compared to cv. Ventana. It was conclude that strawberry cultivars can be grown intercropped with fig trees (cv. Roxo de Valinhos).


2017 ◽  
Vol 48 (1) ◽  
Author(s):  
Taciana Melissa de Azevedo Kuhn ◽  
Alci Enimar Loeck ◽  
Marcos Botton

ABSTRACT: The thermal threshold and thermal requirements of Neopamera bilobata were determined, and the number of generations that this species may produce in the main strawberry-producing regions of Brazil was estimated. In a climate chamber (70±10% RH and 12h photophase) at 16, 19, 22, 25, 28, or 30±1°C, the development of 120 eggs was monitored until the adult stage, at each temperature. Nymphs were maintained in individual cages and fed on strawberry fruits of the cultivar Aromas. The mean duration and viability of the egg and nymph stages were calculated by estimating the lower and upper developmental thresholds and the thermal constant, and this information was used to estimate the number of generations per year in different strawberry-producing regions of Brazil. The egg-to-adult duration decreased as temperatures increased, up to 28°C (93.4, 83.2, 43.9, and 31.4 days at 19, 22, 25, and 28°C, respectively). Viability of nymphs was highest between 22 and 28°C. At 30°C, the egg-to-adult duration increased (36 days), while the viability decreased (11.11%). The lower egg-to-adult developmental threshold was 15.2°C and the thermal constant was 418.4 degree-days. Calculating the number of generations indicated that the largest number (5.1 generations yr-1) was obtained for the municipality of Jaboti, Paraná, and the smallest for Caxias do Sul, Rio Grande do Sul (1.9 generations yr-1). Our findings demonstrated that important strawberry-producing regions in Brazil are suitable for the development of N. bilobata.


2012 ◽  
Vol 13 (1) ◽  
pp. 2 ◽  
Author(s):  
Katherine L. Kamminga ◽  
Thomas P. Kuhar ◽  
Adam Wimer ◽  
D. Ames Herbert

The brown marmorated stink bug (BMSB), Halyomorpha halys (Stål), is an invasive pest from China that causes economic damage to field crops, vegetables, and tree fruit. Due to its destructive potential, applications of broad-spectrum insecticides have escalated. Researchers are trying to identify options for controlling BMSB that have less of a negative impact on non-target species. Chitin biosynthesis inhibitors are more selective than the commonly used pyrethroids and organophosphates. They are active on the larval stage of the insect and are reported as having sublethal effects such as reducing adult fecundity. In our studies, bioassays were completed with chitin biosynthesis inhibitors novaluron and diflubenzuron to evaluate the effectiveness of these insecticides on adult mortality, nymphal growth, adult fecundity, and egg hatch. Our data indicate that treatments of novaluron at 362.2 g ai/ha or diflubenzuron at 280.2 g ai/ha effectively controlled BMSB nymphs. However, the insecticides were not effective at reducing egg hatch, adult fecundity, or adult life span. If novaluron or diflubenzuron are used in agriculture for BMSB control, then the nymphal stage should be targeted. Accepted for publication 9 November 2012. Published 12 December 2012.


2005 ◽  
Vol 137 (6) ◽  
pp. 728-738 ◽  
Author(s):  
A.L. Knight ◽  
D.M. Light

AbstractThe use of the timing of moth catch in traps to predict the start of egg hatch by first-generation codling moth, Cydia pomonella (L.), in apple, Malus domestica Borkh. (Rosaceae), was evaluated with ethyl (E,Z)-2,4-decadienoate (pear ester) and (E,E)-8,10-dodecadien-1-ol (codlemone) lures. Two sets of paired traps baited with either lure were placed in each of seven orchards and checked daily during the spring flight in 2000 and 2001. Rearing of field-collected eggs and sampling of fruit for injury were used to estimate the date of first egg hatch. Moth catch in traps baited with codlemone and pear ester occurred approximately 144 and 105 degree-days prior to the start of egg hatch, respectively. The effectiveness of using the timing of sustained moth catch in traps baited with these lures as a biological reference point (Biofix) to predict the start of egg hatch when traps were checked every 3–4 d was evaluated in 11 orchards from 2000 to 2002. The calendar date for the start of sustained moth catch in traps baited with either lure varied widely among orchards and years. Significant differences in mean cumulative degree-days from first sustained moth catch until egg hatch were found among male moth catch in codlemone-baited traps and total and female moth catch in pear ester-baited traps. Adjusting the Biofix based on daily temperature thresholds significantly changed the cumulative degree-days required until egg hatch only for female moth catch. No significant differences were found in the accuracy of predicting the date of egg hatch using either the codlemone or pear ester lure or by adjusting the Biofix date using daily temperature thresholds. The cumulative degree-day totals required from Biofix until egg hatch had the lowest variability when the Biofix was (i) based on the sustained catch of female moths in a pear ester-baited trap and (ii) adjusted with a temperature threshold for moth activity.


1991 ◽  
Vol 123 (6) ◽  
pp. 1183-1197 ◽  
Author(s):  
A.W. Schaafsma ◽  
G.H. Whitfield ◽  
C.R. Ellis

AbstractDevelopmental rates of post-diapause eggs of Diabrotica virgifera virgifera LeConte were compared in the laboratory at six constant temperatures, 12, 16, 20, 24, 28, and 32°C. Linear and nonlinear models were fitted to temperature versus developmental data and were used to predict egg hatch in the field. A four-parameter model fitted to median developmental rates (r2 = 0.99) indicated that development was linear between 16 and 28°C, optimal at 28°C, and decreased at 32°C. The lower development threshold (± SE) (10.5 ± 0.1°C) was determined by linear regression and the x-intercept method. Completion of post-diapause egg development required 258 ± 3 degree-days (± SE) above the base temperature. This compared well with the mean degree-days accumulated to 50% hatch (± SE) of 265 ± 24 which we observed in the field at several locations over 3 years using a degree-day model incorporating an 11°C developmental threshold and soil temperatures at 5- and 10-cm depths. A stochastic simulation model, incorporating a nonlinear developmental function dependant on soil temperatures taken every 2 h also predicted 50% hatch within 2 days. This model was validated in the field with 19 independent records of soil temperatures for several locations at two depths in the soil over 3 years. The simulation model accurately predicted time of 5 and 95% hatch, which indicates that this model has broad application in predicting the pattern of egg hatch for pest management.


1980 ◽  
Vol 70 (4) ◽  
pp. 635-647 ◽  
Author(s):  
K. G. Wardhaugh

AbstractPhotoperiod was shown to be the principal factor regulating the induction of a facultative egg-diapause in Chortoicetes terminifera(Wlk.). All developmental stages from first-instar nymphs to immature adults were sensitive to photoperiod. At constant photophases, the insect exhibited a short-day—long-day response, with the upper and lower critical photo-periods for induction approximating to LD 15·5: 8·5 and 11:13, respectively. These correspond to the range of photoperiods experienced by the insect under natural conditions. The maximum inductive response occurred at about the mid-point of this range, i.e. LD 13·5: 10·5. In experiments in which insects experienced a change in photophase at the end of the nymphal stage, the incidence of diapause varied with the direction of change (long to short or short to long) and indicated that diapause induction was prevented by an increase in photophase but enhanced when the photophase was reduced. The size of the inductive response associated with a decrease in photophase appeared to depend less on the size of the decrease than on its position within the inductive range, such that the maximum effects were observed when the sequence of light regimes were close to or spanned the most inductive constant photophase. Temperature was also important in determining the induction of diapause. In the upper portion of the inductive range (15·5 to 12·5 h light), insects subjected to high temperatures or to an increase in temperature during development showed a lower incidence of diapause than those subjected to low temperatures or to a decrease in temperature. In the lower portion of the inductive range, the effects of temperature were reversed, with high temperature or an increase in temperature being more inductive than low temperature or a decrease in temperature.


1987 ◽  
Vol 119 (7-8) ◽  
pp. 653-661 ◽  
Author(s):  
William P. Kemp ◽  
Norma E. Sánchez

AbstractA study was conducted to examine the springtime hatching characteristics of Melanoplus sanguinipes (F.) and Aulocara elliotti (Thomas) eggs on rangeland. Laboratory experiments showed that eggs of M. sanguinipes required fewer accumulated degree days (DD) to complete post-diapause development than those of A. elliotti at a constant temperature of 23.3°C. Springtime field observations revealed that A. elliotti nymphs emerged prior to or concurrent with M. sanguinipes. Additionally, results suggest that A. elliotti nymphs emerge over a shorter interval than M. sanguinipes. Much of the variation in springtime emergence could be attributed to species-specific oviposition sites, pod depth, and pod orientation that resulted in A. elliotti eggs accumulating heat more rapidly than M. sanguinipes eggs. Results help explain some of the variation found in egg hatching of these two grasshopper species on rangeland.


1964 ◽  
Vol 96 (3) ◽  
pp. 541-549 ◽  
Author(s):  
R. D. McMullen

AbstractIn laboratory experiments wettable and emulsifiable malathion and Perthane were most toxic to adult T. vaporariorum and progressively less so to the larval stages in order of development. Eggs were not killed. Perthane was most toxic at low temperatures, malathion at high temperatures. Malathion was more toxic than Perthane and the emulsifiable formulations of both more toxic than the wettable formulations. Against first-instar larvae, at the LD50, level, 70% maneb and 50% Perthane wettable powders were equally toxic but 65% zineb wettable powder was less toxic. Against adults, 70% maneb and 65% zineb wettable powders were one-half and one-third as toxic as 50% Perthane wettable powder at the LD50, level. Tests of spray mixtures against larvae with either 25% malathion or 50% Perthane wettable powders added to either 70% maneb or 65% zineb wettable powders showed neither synergistic nor antagonistic effects.


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