Development and larval diapause in the southern African dung beetle Onitis caffer Boheman (Coleoptera: Scarabaeidae)

1986 ◽  
Vol 76 (1) ◽  
pp. 109-117 ◽  
Author(s):  
Penelope B. Edwards
Keyword(s):  
Adult Development ◽  
Development Time ◽  
Larval Instar ◽  
Summer Rainfall ◽  
Dry Weight ◽  
Dung Beetle ◽  
Cattle Dung ◽  
Winter Rainfall ◽  
The Third ◽  
Larval Diapause

AbstractThe development of Onitis caffer Boheman in cattle dung was studied in the laboratory. The larvae feed on the dung in which the eggs are laid. Egg to adult development at 25°C was completed in 24·7 weeks by a strain from a winter rainfall (WR) area of South Africa and 29·4 weeks by a strain from a summer rainfall (SR) area, and occurred without diapause. Maximum larval dry weight was achieved mid-way through the third larval instar, after which the larva emptied much of its gut to form a protective faecal shell, in which pupation occurred. At 20°C, 20% of WR larvae developed without diapause and the adults emerged after 33·5 weeks, whereas the remaining 80% of adults emerged after 80·1 weeks. In the SR strain, 70% emerged after 37·1 weeks without having entered diapause, while the remaining 30% emerged after 83·8 weeks. Thus, the period of diapause for both strains was 47 weeks and occurred in the third larval instar. At 15°C, 74% of WR larvae had pupated by 153 weeks, with a mean development time of 121·8 weeks. Zero development temperatures were 10·4°C (WR) and 10·1°C (SR), and day-degree requirements for development without diapause at 20°C were 2251 (WR) and 2571 (SR).

Phenology and field biology of the dung beetle onitis caffer Boheman (Coleoptera: Scarabaeidae) in southern Africa

1986 ◽  
Vol 76 (3) ◽  
pp. 433-446 ◽  
Author(s):  
Penelope B. Edwards
Keyword(s):  
Late Summer ◽  
Summer Rainfall ◽  
Dung Beetle ◽  
Immature Stages ◽  
Average Depth ◽  
Winter Rainfall ◽  
The Third ◽  
Field Biology ◽  
June July ◽  
Third Instar Larvae

AbstractThe biology and development of immature stages of summer (SR) and winter rainfall (WR) strains of Onitis caffer Boheman were studied in South Africa in a summer rainfall area (Pretoria). A pair of adult beetles buried up to 650 ml of dung from one dung pad, and females laid an average of 1 egg for every 62 ml of dung buried. Broods were buried at an average depth of 50 cm in watered soil and 24 cm in unwatered soil. Eggs laid in June (winter) hatched 10 weeks later. The third instar was reached by late October. WR larvae suffered higher mortality (82%) with the onset of summer rains than did SR larvae (53%). By the following June, 6% of surviving WR individuals had emerged as adults, 12% were adults in faecal shells and 82% were diapausing third-instar larvae. Of the SR individuals, 67% emerged by June and 33% were diapausing third-instar larvae. In a second experiment, two groups of broods of the SR strain of O. caffer of different ages were set out in the field in June. One group, equivalent to broods produced early in the season (March), entered diapause as third-instar larvae, and adults emerged the following autumn. The second group represented broods produced later in the season (May); the majority did not diapause, but adults also emerged the following autumn. A field population of SR adults of O. caffer was sampled for two years. Adults were first recorded at the end of February (late summer), and newly-emerged specimens were caught up until the end of April. Maximum numbers were recorded in late March to early April (autumn), and activity ceased in June-July (winter).

WEIGHT AND DEVELOPMENT TIME OF DIFFERENT STADIA OF MOSQUITOES REARED AT VARIOUS CONSTANT TEMPERATURES

1967 ◽  
Vol 99 (9) ◽  
pp. 986-993 ◽  
Author(s):  
R. A. Brust
Keyword(s):  
Weight Gain ◽  
Development Time ◽  
Adult Stage ◽  
Larval Instar ◽  
Dry Weight ◽  
Specific Weight ◽  
Fourth Instar ◽  
Rearing Temperature ◽  
Males And Females ◽  
Culiseta Inornata

AbstractDevelopment time decreased with each increase in rearing temperature in Aedes vexans, A. nigromaculis, and Culiseta inornata until the optimum survival temperature was reached. The optimum survival temperature for A. vexans was 26.5 °C, for A. nigromaculis 21 °C, and for C. inornata 21 °C. Dry weight gain per hour in female larvae was greater than in male larvae in all three species, at all temperatures. There was a significant reduction in weight in each larval instar, pupal, and adult stage, with each 5.5 °C increase in rearing temperature. Times to larval–pupal ecdysis and pupal–adult ecdysis were the same for males and females of A. nigromaculis at all developmental temperatures tested. Time to larval–pupal ecdysis and pupal–adult ecdysis in A. vexans and C. inornata occurred 1 to several days later in females, depending upon the developmental temperature. In all three species the duration of the fourth instar was longest and the specific weight gain greatest.

A comparison of two types of trap for sampling dung beetle populations (Coleoptera: Scarabaeidae)

1990 ◽  
Vol 80 (3) ◽  
pp. 259-263 ◽  
Author(s):  
Bernard M. Doube ◽  
Paul S. Giller
Keyword(s):  
South Africa ◽  
Summer Rainfall ◽  
Dung Beetle ◽  
Direct Access ◽  
Cattle Dung ◽  
Pitfall Traps ◽  
Significant Difference ◽  
Immigration And Emigration ◽  
Rank Abundance

AbstractThe effectiveness of pitfall traps baited with cattle dung enclosed in a gauze bag and pads of cattle dung on soil as methods for sampling dung beetle populations was assessed in the summer-rainfall regions of South Africa using 17 species of nocturnal/crepuscular tunnelling beetles. Pitfall traps accumulated the catch and prevented both access to and emigration from the dung bait. In contrast, beetles had direct access to dung pads on soil which allowed colonists to modify the bait and to emigrate. The number of beetles collected was therefore the net result of immigration and emigration. On each of five occasions in November–December 1985, 40 pitfall traps and 40 dung pads were set out in the evening and the trapped beetles recovered the following morning. Overall, 3774 individuals were trapped. For most species there was no significant difference between trap types in the numbers caught but two species were significantly more numerous in pitfall traps and one species was more numerous in the dung pads. However, both methods produced similar patterns of rank abundance of species (r=0.95). There was no evidence that beetles were more evenly distributed between dung pad baits than between pitfall traps.

Bush fly, Musca vetustissima Walker (Diptera: Muscidae), control in relation to seasonal abundance of scarabaeine dung beetles (Coleoptera: Scarabaeidae) in south-western Australia

1988 ◽  
Vol 78 (4) ◽  
pp. 633-639 ◽  
Author(s):  
T. J. Ridsdill-Smith ◽  
J. N. Matthiessen
Keyword(s):  
Western Australia ◽  
Dry Weight ◽  
Dung Beetle ◽  
Early Summer ◽  
Dung Beetles ◽  
Seasonal Abundance ◽  
Adult Survival ◽  
Cattle Dung ◽  
Beetle Species ◽  
Additional Species

AbstractSeasonal patterns of abundance of Musca vetustissima Walker and scarabaeine dung beetles were measured at Busselton in south-western Australia for two years before and three years after, the introduction and establishment of two species of summer-active dung beetles, Oniticellus pallipes (F.) and Onthophagus binodis (Thunberg). Previously, only a single winter-active native dung beetle species, O. ferox Harold, occurred in this area. The mean dry weight of dung beetles trapped in December (early summer) was unaffected by the establishment of the additional species, and fly populations remained high. In January, however, dung beetle dry weight increased more than 60-fold and M. vetustissima abundance fell to 12% of its previous value, essentially halving the duration of major fly problems in the area. Virtually no flies emerged from cattle dung after December, when dung beetle activity reduced egg-adult survival of M. vetustissima to only 0·5%. It is proposed that better M. vetustissima control could be achieved in much of south-western Australia by introducing additional dung beetle species that are abundant in November and December.

The study of important agronomic traits by multivariate analysis in winter rapeseed cultivars

2014 ◽  
Vol 1 (1) ◽  
pp. 20-24
Author(s):  
Gader Ghaffari ◽  
Farhad Baghbani ◽  
Behnam Tahmasebpour
Keyword(s):  
Water Potential ◽  
Water Deficit ◽  
Leaf Water Potential ◽  
Seed Weight ◽  
Dry Weight ◽  
Total Variance ◽  
Water Deficit Stress ◽  
The Third ◽  
High Eigenvalue ◽  
Winter Rapeseed

In order to group winter rapeseed cultivars according to evaluated traits, an experiment was conducted in the Research Greenhouse of Agriculture Faculty, University of Tabriz - IRAN. In the experiment were included 12 cultivars of winter rapeseed and 3 levels of water deficit stress. Gypsum blocks were used to monitor soil moisture. Water deficit stress was imposed from stem elongation to physiological maturity. According to the principal component analysis, five principal components were chosen with greater eigenvalue (more than 0.7) that are including 81.34% of the primeval variance of variables. The first component that explained the 48.02% of total variance had the high eigenvalue. The second component could justify about 13.64% of total variance and had positive association with leaf water potential and proline content and had negative relationship with leaf stomatal conductivity. The third, fourth and fifth components expressed around, 10.18, 4.83 and 4.68% of the total variance respectively. The third component had the high eigenvalue for plant dry weight. The fourth component put 1000-seed weight, seed yield, Silique per Plant and root dry weight against plant dry weight, chlorophyll fluorescence and leaf water potential. The fifth component had the high eigenvalue for root dry weight, root volume and 1000-seed weight.

BOTANICAL COMPOSITION AND PRODUCTIVITY OF PERENNIAL GRASSES AGROPHYTOCENOSES WITH TETRAPLOID MEADOW CLOVER

1970 ◽  
pp. 59-62
Author(s):  
N. I. Kasatkina ◽  
Zh. S. Nelyubina
Keyword(s):  
Dry Weight ◽  
Single Species ◽  
Lotus Corniculatus ◽  
Specific Weight ◽  
Biological Properties ◽  
Phleum Pratense ◽  
Perennial Grasses ◽  
High Yield ◽  
Botanical Composition ◽  
The Third

The biological properties of plants, their mutual relations under different growth conditions and at different periods of their life, must be known for obtaining highly productive agrophytocenoses with participation of a meadow clover (Trifolium pratense L.). Botanical composition and fodder productivity of perennial grasses in agrocenoses with participation of meadow tetraploid clover Kudesnik were studied in 2014-2017. It was revealed that in the first and second years of use the agrophytocenosis, the yield of green mass was formed due to meadow tetraploid clover, the share of its participation in the first mowing was at level of 71-87% and 64-97% respectively. Specific weight of clover in multispecies agrocenoses considerably decreased by the third year of use: in the first mowing up to 32-68%, in the second - up to 8-52%. At the same time, the percentage of long-term herbaceous grasses increased: meadow timothy (Phleum pratense L.) - up to 34-54%, eastern galega (Galéga orientális Lam.) - up to 33%, changeable alfalfa (Medicago x varia Martyn) - up to 22-54%, lotus corniculatus (Lotus corniculatus L.) - up to 14-19%. The proportion of weed admixture in single-species clover planting was 12%, in agrocenoses - 2-14%. The grass mixtures clover + timothy and clover + alfalfa + timothy were less infested by weeds. High yield of dry weight of single-species sowing of meadow tetraploid clover was obtained in the first two years of use - 7.8 and 6.5 tons / ha, respectively. By the third year of use, the productivity of clover has decreased to 2.9 t / ha. On average, for three years of use, the highest yield (6.2-6.3 t / ha) was formed by agrocenoses meadow tetraploid clover + meadow timothy and meadow tetraploid clover + changeable alfalfa + meadow timothy.

scholarly journals Does exposure of maleDrosophila melanogasterto acute gamma radiation influence egg to adult development time and longevity of F1-F3offspring?

2014 ◽  
Vol 18 (3) ◽  
pp. 368-376 ◽  
Author(s):  
P. Mohamed Shameer ◽  
K. Sowmithra ◽  
B. P. Harini ◽  
R. C. Chaubey ◽  
S. K. Jha ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Adult Development ◽  
Development Time

The Relation of Oxygen Consumption to Body Size and to Temperature in the Larvae of Chironomus Riparius Meigen

1958 ◽  
Vol 35 (2) ◽  
pp. 383-395
Author(s):  
R. W. EDWARDS
Keyword(s):  
Oxygen Consumption ◽  
Body Size ◽  
Dry Matter ◽  
Larval Instar ◽  
Weight Ratio ◽  
Dry Weight ◽  
Chironomus Riparius ◽  
Consumption Rates ◽  
Rate Of Oxygen Consumption ◽  
Wet Weight

1. The oxygen consumption rates of 3rd- and 4th-instar larvae of Chironomus riparius have been measured at 10 and 20° C. using a constant-volume respirometer. 2. The oxygen consumption is approximately proportional to the 0.7 power of the dry weight: it is not proportional to the estimated surface area. 3. This relationship between oxygen consumption and dry weight is the same at 10 and at 20° C.. 4. The rate of oxygen consumption at 20° C. is greater than at 10° C. by a factor of 2.6. 5. During growth the percentage of dry matter of 4th-instar larvae increases from 10 to 16 and the specific gravity from 1.030 to 1.043. 6. The change in the dry weight/wet weight ratio during the 4 larval instar supports the theory of heterauxesis. 7. At 20° C., ‘summer’ larvae respire faster than ‘winter’ larvae.

The Post-embryonic Development of the Tracheal System in Drosophila melanogaster

1957 ◽  
Vol s3-98 (41) ◽  
pp. 123-150
Author(s):  
JOAN M. WHITTEN
Keyword(s):  
Drosophila Melanogaster ◽  
Adult Stage ◽  
Larval Instar ◽  
Pupal Stage ◽  
Tracheal System ◽  
True Nature ◽  
The Third ◽  
Air Sacs ◽  
Abdominal Region ◽  
Pupal Cuticle

The fate of the tracheal system is traced from the first larval instar to the adult stage. The basic larval pattern conforms to that shown for other Diptera Cyclorrhapha (Whitten, 1955), and is identical in all three instars. According to previous accounts the adult system directly replaces the larval: the larval system is partly shed, partly histolysed, and the adult system arises from imaginal cell clusters independently of the preceding larval system. In contrast, it is shown here that in the cephalic, thoracic, and anterior abdominal region there is a definite continuity in the tracheal system, from larval, through pupal to the adult stage, whereas in the posterior abdominal region the larval system is histolysed, and the adult system is independent of it in origin. Moreover, in the pupal stage this region is tracheated by tracheae arising from the anterior abdominal region and belonging to a distinct pupal system. Moulting of the tracheal linings is complete at the first and second larval ecdyses, but incomplete at the third larval-pupal and pupal-adult ecdyses. In consequence, in both pupal and adult systems there are tracheae which are secreted around preexisting tracheae, others formed as new ‘branch’ tracheae, and those which have been carried over from the previous instar. In the adult the newly formed tracheae of the posterior abdominal region fall into a fourth category. Most of the adult thoracic air sacs correspond to new ‘branch’ tracheae of other instars. The pre-pupal moult and instar are discussed with reference to the tracheal system and tentative suggestions are made concerning the true nature of the pre-pupal cuticle. There is no pre-pupal tracheal system. Events traced for Drosophila would seem to be general for Cyclorrhapha, both Acalypterae and Calypterae. The separate fates of the anterior and posterior abdom inal systems, in contrast with the straightforward development in Dipterc Nematocera, would appear to mark a distinct step in the evolution of the system in Diptera.

scholarly journals Production of germ-free mosquitoes via transient colonisation allows stage-specific investigation of host-microbiota interactions

2019 ◽  
Author(s):  
Ottavia Romoli ◽  
Johan Claes Schönbeck ◽  
Siegfried Hapfelmeier ◽  
Mathilde Gendrin
Keyword(s):  
Larval Development ◽  
Emerging Adults ◽  
Larval Instar ◽  
Bacterial Colonisation ◽  
Germ Free ◽  
Functional Studies ◽  
The Third ◽  
Novel Approach ◽  
Folate Biosynthesis ◽  
Vector Borne

AbstractThe mosquito microbiota impacts the physiology of its host and is essential for normal larval development, thereby influencing transmission of vector-borne pathogens. Germ-free mosquitoes generated with current methods show larval stunting and developmental deficits. Therefore, functional studies of the mosquito microbiota have so far mostly been limited to antibiotic treatments of emerging adults. In this study, we developed a novel approach to produce germ-free Aedes aegypti mosquitoes. It is based on reversible colonisation with bacteria genetically modified to allow complete decolonisation at any developmental stage. We show that, unlike germ-free mosquitoes previously produced using sterile diets, reversibly colonised mosquitoes show no developmental retardation and reach the same size as control adults. This allowed us to uncouple the study of the microbiota in larvae and adults. In adults, we detected no impact of bacterial colonisation on mosquito fecundity or longevity. In larvae, we performed a transcriptome analysis and diet supplementation experiments following decolonisation during the third larval instar. Our data suggest that bacteria support larval development by contributing to folate biosynthesis and by enhancing energy storage. Our study establishes a novel tool to study the microbiota in insects and deepens our knowledge on the metabolic contribution of bacteria to mosquito development.

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