scholarly journals Biology of Hyphantria cunea DRURY (Lepidoptera : Arctiidae) in Japan : VI. Effect of Temperature on Development of Immature Stages

1968 ◽  
Vol 3 (4) ◽  
pp. 163-175 ◽  
Author(s):  
Yosiaki ITO ◽  
Kazuyoshi MIYASHITA ◽  
Hideo YAMADA
1991 ◽  
Vol 39 (2) ◽  
pp. 191 ◽  
Author(s):  
JG Hamilton ◽  
MP Zalucki

C. plebejana were reared from egg to adult at a range of constant temperatures. At 10-degrees-C no immature stages survived. Development rates increased over the temperature range 14-34-degrees-C; these were simulated with a non-linear model. Females emerged before males. Fecundity decreased with increased rearing temperature as a direct result of reduced adult female weight. At 34-degrees-C development rate and survival were reduced and all eggs laid were infertile. Optimum temperature for population increase was 28-degrees-C. Validation of a non-linear model for development rate shows that the species of host-plant affects mean development rates of tipworm. Although 5.3 tipworm generations are possible on cotton annually, only one occurs; reasons for this are suggested.


1961 ◽  
Vol 9 (2) ◽  
pp. 173 ◽  
Author(s):  
DA Maelzer

The distribution and abundance of the univoltine species A. tasmaniae in the lower south-east of South Australia appears to be related to annual rainfall. The effects of moisture on the mortality rates of the immature stages were consequently studied and observations were made of the effects of variations in moisture in the field. Laboratory experiments and field observations suggested that variations in soil moisture have little effect on the eggs and the diapausing prepupae in the field. Eggs absorbed water and hatched normally within a pF range of 2.50-3.75 in a sand and in a clay loam. At pF 4.0 in both soils, eggs lost weight and did not hatch. The adults, however, tend to lay the eggs well within the pF range in which the eggs can develop, and soil samples suggested that eggs would develop with little mortality in the kinds of places in which they are usually laid. When prepupae enter diapause they have a water content of c. 77%. When desiccated in the laboratory, few prepupae died until their water content fell below 62%. The mortality rate then increased sharply, and it was estimated that 50% of the prepupae died when their water content dropped to 57%. Droughts of sufficient duration and intensity to kill 50% of the prepupae have never been recorded from the study area, and field observations suggested that few prepupae died of desiccation in summer. Unlike the two stages above, the first and third instar larvae may be markedly affected by variations in moisture in the field. The first instar larvae, after hatching, do not move to the surface of the soil and do not feed much until the soil is saturated with rain. As rainfall is variable at this time of the year, the larvae may be in dry soil for many weeks before they are stimulated to extend their burrows to the surface and search for food. Many larvae may die of starvation during this time, and the mortality rate of the larvae was related empirically to the length of the autumn "drought". Third instar larvae may be affected, on the other hand, by excessive water. In wet winters, vast numbers of larvae are drowned when extensive flooding occurs on the poorly-drained soils, and on well-drained soils a large proportion of larvae are killed by the entomophagous fungus Cordyceps aphodii. The above data have suggested that moisture is one of the major factors affecting the distribution and abundance of the species. Temperature has little effect on the rate of increase of the species.


2014 ◽  
Vol 14 (1) ◽  
Author(s):  
Fatemeh Soltani Orang ◽  
Hossein Ranjbar Aghdam ◽  
Habib Abbasipour ◽  
Alireza Askarianzadeh

1970 ◽  
Vol 15 ◽  
pp. 41-46 ◽  
Author(s):  
MM Rahman ◽  
W Islam ◽  
KN Ahmed

Xylocoris flavipes (Reuter) is one of the dominant predators of many stored product insect pest including Cryptolestes pusillus. The influence of temperature on predator development, survival and some selected life history parameters was determined. Eggs laid/female (27.27±2.52) and egg hatching rate (%) (88.25±2.19) were highest at 30°C and lowest at 20°C (5.43±1.19 and 30.79±4.63%) respectively but no eggs laid at 15°C. Mortality among immature stages (%) was highest (51.71±1.48) at 35°C and lowest (24.25c±1.14) at 25°C. Developmental times decreasing with the increasing of temperature. Maximum numbers of progeny/female/day (3.55±0.76) were produced at 25°C and minimum (0.83±0.04) were at 20°C.The sex ratios (% female) of X. flavipes were 47.04, 56.68, 51.66 and 50.07 for 20, 25, 30 and 35°C respectively. Survivorship of ovipositing females was highest at 25°C but lowest at 35°C respectively. Key words: Xylocoris flavipes, Cryptolestes pusillus, life history, temperature, developmental time   doi: 10.3329/jbs.v15i0.2201 J. bio-sci. 15: 41-46, 2007


1961 ◽  
Vol 38 (2) ◽  
pp. 277-290 ◽  
Author(s):  
J. W. L. BEAMENT

1. The permeability to water of the cuticles of a number of aquatic insects has been measured under conditions of evaporation. The range of rates of evaporation amongst these animals is very great; some adult aquatic beetles are quite as waterproof as more permeable terrestrial insects (caterpillars for example), whereas their larvae would seem to be without specific mechanism for restricting the passage of water. 2. Two methods are described, whereby local differences in permeability may be detected, and from one of these methods it is possible to calculate the permeability/ temperature characteristics of different areas of cuticle of an intact insect. 3. The more impermeable insects have uniform permeability over their entire surfaces; these include adult beetles, and both mature and immature stages of Hemiptera. Larvae of mayflies and of some beetles, which are very permeable to water, likewise show no local differences in permeability. 4. The gills of all the species examined are very permeable to water; those of zygopteran dragonflies are more permeable than the rest of the cuticle at lower temperatures, those of Sialis are much more permeable at all temperatures. 5. The effect of temperature upon permeability has been measured. The more waterproof insects reveal transition phenomena characteristic of organized monolayers of lipid, such as are found in terrestrial insects, but by comparison with them the temperatures at which transition occurs are very low. In particular, the temperature at which adults of Dytiscus and Gyrinus become suddenly more permeable (ca. 25°C.) could obtain in natural circumstances, and the evidence suggests that these animals die through osmotic invasion of water when placed at higher temperatures. Other beetles and aquatic Hemiptera, with higher transition temperatures, survive temperatures above 25°C. These ecological implications are discussed. 6. A transition phenomenon occurs in organized lipid over the main cuticle of Sialis, whereas the more permeable gill shows no evidence of this. There is no evidence for organized lipid on the main cuticle of zygopteran larvae, but the temperature/ permeability relations of the general cuticle and of the gill are very different. 7. The absolute permeability, and the shape of the permeability/temperature function, of the cuticle of those insects which have very hydrofuge areas of surface suggest that their waterproofing system consists of only one monolayer of organized lipid, which may be either grease or wax.


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