Effects of Food on the Longevity, Fecundity, and Development of Adult Coccinellids (Coleoptera: Coccinellidae)

1965 ◽  
Vol 97 (9) ◽  
pp. 910-919 ◽  
Author(s):  
B. C. Smith

AbstractAccess to drinking water increased the longevity of Coccinella trifasciata perplexa Muls. by about 35%. The water content of field-collected insects was 70% and of laboratory-fed insects 64%. Rate of loss of water increased, and longevity decreased when protein was absent from the food.Anatis mali Auct. lived more than 1000 days and Coleomegilla maculata lengi Timberlake lived more than 400 days when fed on various synthetic foods. Seven of 13 species tested kid eggs when fed on these foods. A diet containing desiccated liver was the best non-prey food supplement for reproduction, and adults of three generations of C. maculata were kept on this food.A. mali preferred dry powdered pea aphids, Acyrthosiphon pisum (Harr.), to either bean aphids. Aphis fabae Scop., or corn aphids, Rhopalosiphum maidis (Fitch), whereas C. maculata preferred corn pollen to aphids and A. pisum and R. maidis to A. fabae. Previous feeding did not affect the preference of either A. mali or C. maculata for dry aphids or pollen. C. maculata produced six eggs per mg. of food while feeding on A. pisum and four on R. maidis. Young adults ate more than older adults.The rate of food intake was highest in A. mali during the first two weeks and in C. maculata during the first eight days after emergence. The living weight and dry weight of feeding C. maculata adults increased for eight days and then did not vary, whereas the water content decreased in this period. The index of relative growth was about 0.10 mg. per day per mg. of adult weight and food efficiency was about 0.18 mg. per mg. of food.

1965 ◽  
Vol 97 (7) ◽  
pp. 760-768 ◽  
Author(s):  
B. C. Smith

AbstractTen species of predatory coccinellids representing seven genera were reared from the first-instar larva to the adult stage on dry powdered aphids. Dry pea aphids, Acyrthosiphon pisum (Harr.), and corn aphids, Rhopalosiphum maidis (Fitch), were both superior to bean aphids, Aphis fabae Scop., for growing coccinellid larvae. Though Anatis mali Auct. grew equally well on A. pisum and R. maidis, the larvae generally lived longer when starved after feeding on R. maidis. Dry aphids were as good as living aphids for growing A. mali and Coleomegilla maculata lengi Timberlake. C. maculata grew as well in darkness as in light, and an aphid–pollen mixture was superior to either component alone. Three generations of C. maculata were reared on a yeast diet and this diet is the most promising food for use to supplement natural foods in the field. An arrangement of coccinellid species on the basis of their food specificity does not correspond to the current phylogenetic arrangement, as the taxonomically primitive tribe Coccinellini contains both generalized and selective feeders.


1992 ◽  
Vol 124 (1) ◽  
pp. 87-95 ◽  
Author(s):  
K.L. Kouamé ◽  
M. Mackauer

AbstractThe influence of nutrient stress on growth, development, and reproduction in apterous virginoparae of the pea aphid, Acyrthosiphon pisum (Harris), was investigated in the laboratory. We tested the hypothesis that species with a high reproductive investment have low resistance to starvation. Aphids in two groups were starved daily from birth for 4 h and 6 h, respectively, and compared with feeding counterparts reared on leaves of broad beans, Vicia faba L. Aphid wet weight increased as an exponential function of age in all groups. Starved aphids had lower adult weight and required longer from birth to parturition than feeding aphids. These effects increased with the length of daily starvation. The number of offspring produced was correlated with adult dry weight. Aphids were unable to compensate, or to compensate completely, for water and nutrient loss resulting from starvation. It is suggested that pea aphids allocate resources first to maintenance and then to reproduction when deprived of food.


2020 ◽  
Vol 31 (1) ◽  
pp. 95-106
Author(s):  
Mahadev Bista

A survey was conducted to explore the aphid pests’ diversity in Kanchanpur district, far-western, Nepal from April 2018 to March 2019. A total of 15 aphid pests were collected and identified, viz. Acyrthosiphon pisum (Harris), Aphis craccivora (Koch), Aphis gossypii (Glover), Aphis fabae (Scopoli), Aphis nerii Boyer de Fonscolombe, Brevicoryne brassicae (Linnaeus), Lipaphis erysmi (Kaltenbach), Macrosiphum euphorbiae (Thomas), Macrosiphum rosae (Linnaeus), Myzus persicae (Sulzer), Rhopalosiphum maidis (Fitch), Rhopalosiphum padi (Linnaeus), Rhopalosiphum rufiadominale (Sasaki), Uroleucon compositae (Theobald), and the guava aphid. Exploration of aphid pests showed that they caused serious damages to agricultural crops by attacking different parts of plants.


1965 ◽  
Vol 97 (11) ◽  
pp. 1159-1166 ◽  
Author(s):  
B. C. Smith

AbstractCapacity to adjust to variable resources of food is a useful criterion for assessing the regulatory influence of predators on the population of prey. Anatis mali Auct. was better adapted than Coleomegilla maculata lengi Timberlake to tolerate a shortage of food. When the food supply was increased, survival and adult weight increased in both species – adult weight to a much greater extent in A. mali than in C. maculata, and developmental time decreased in A. mali, but was unchanged in C. maculata. C. maculata was better able to withstand regularly occurring periods of intermittent feeding than a shortage near the end of its development.The conversion ratio of third-instar A. mali larvae and the growth rate of C. maculata larvae were higher when individuals were fed on Acyrthosiphon pisum (Harr.) than on Rhopalosiphum maidis (Fitch). Between the minimum food requirement and the maximum quantity eaten, the conversion ratio of A. mali decreased whereas that of C. maculata remained constant except at the highest quantities of food where the rate of intake increased and the ratio decreased. Relative food intake rate is an accurate criterion for comparing stages and species of predators that are fed on various foods.


1986 ◽  
Vol 64 (10) ◽  
pp. 2362-2367 ◽  
Author(s):  
C. D. B. Hawkins ◽  
M. I. Whitecross ◽  
M. J. Aston

The effects of cowpea aphids (Aphis craccivora Koch) and pea aphids (Acyrthosiphon pisum (Harris)), both Homptera: Aphididae, on nitrogen (N) and phosphorus (P) uptake by and growth of cowpea (Vigna unguiculata (L.) Walp. cv. Caloona), broad bean (Vicia faba L. cv. Aquadulce), and garden pea (Pisum sativum L. cv. Victory Freezer) seedlings were investigated. After 10 days of aphid infestation, all leaf areas were significantly lower in infested plants, and plant dry weight, mean relative growth rate, and unit leaf rate were significantly lower in all plant–aphid combinations except for pea – pea aphids. The mean leaf area ratio was the same for infested and control plants indicating that infested plants did not reallocate their assimilate resources in response to aphid feeding. The accumulation of N and P as a percentage of plant dry weight did not differ between control and infested plants and was specific to the species examined. However, control plants all had greater absolute amounts of N and P after 10 days. Even though the responses of the plants to aphid feeding were similar, the accumulation of N and P appears to be a plant species specific phenomenon.


1972 ◽  
Vol 104 (11) ◽  
pp. 1717-1722 ◽  
Author(s):  
B. D. Frazer

AbstractLife tables were prepared from daily fecundity and survival data on 69 apterous black bean aphids, Aphis fabae Scopoli, and 47 apterous pea aphids, Acyrthosiphon pisum (Harris). Both were on broad beans in 20° ± 0.5 °C, 70–80% R.H., and 16 hr light per day. The intrinsic rates of natural increase (rm) computed from the life tables were 0.359 ♀/♀ day for the bean aphid and 0.404 ♀/♀ day for the pea aphid. Mortality was not important in determining the rates of increase because very few aphids died during their reproductive periods. Only 5 of 116 reproducing aphids died, all from inability to extrude nymphs which had died before bursting their embryonic membranes. These nymphs became covered with a discharge from the mother which cemented them in place and prevented the birth of succeeding nymphs. The resulting engorged females died in 3–4 days.An analysis of and comparison with life tables of two other aphid species in addition to those produced here showed that the differences in rm were due almost entirely to differences in fecundity. Two fecundity patterns, correlated with aphid phylogeny, were recognized.


Author(s):  
Songquan Sun ◽  
Richard D. Leapman

Analyses of ultrathin cryosections are generally performed after freeze-drying because the presence of water renders the specimens highly susceptible to radiation damage. The water content of a subcellular compartment is an important quantity that must be known, for example, to convert the dry weight concentrations of ions to the physiologically more relevant molar concentrations. Water content can be determined indirectly from dark-field mass measurements provided that there is no differential shrinkage between compartments and that there exists a suitable internal standard. The potential advantage of a more direct method for measuring water has led us to explore the use of electron energy loss spectroscopy (EELS) for characterizing biological specimens in their frozen hydrated state.We have obtained preliminary EELS measurements from pure amorphous ice and from cryosectioned frozen protein solutions. The specimens were cryotransfered into a VG-HB501 field-emission STEM equipped with a 666 Gatan parallel-detection spectrometer and analyzed at approximately −160 C.


Author(s):  
R.D. Leapman ◽  
S.Q. Sun ◽  
S-L. Shi ◽  
R.A. Buchanan ◽  
S.B. Andrews

Recent advances in rapid-freezing and cryosectioning techniques coupled with use of the quantitative signals available in the scanning transmission electron microscope (STEM) can provide us with new methods for determining the water distributions of subcellular compartments. The water content is an important physiological quantity that reflects how fluid and electrolytes are regulated in the cell; it is also required to convert dry weight concentrations of ions obtained from x-ray microanalysis into the more relevant molar ionic concentrations. Here we compare the information about water concentrations from both elastic (annular dark-field) and inelastic (electron energy loss) scattering measurements.In order to utilize the elastic signal it is first necessary to increase contrast by removing the water from the cryosection. After dehydration the tissue can be digitally imaged under low-dose conditions, in the same way that STEM mass mapping of macromolecules is performed. The resulting pixel intensities are then converted into dry mass fractions by using an internal standard, e.g., the mean intensity of the whole image may be taken as representative of the bulk water content of the tissue.


2005 ◽  
Vol 37 (5) ◽  
pp. 425-432 ◽  
Author(s):  
Ana PINTADO ◽  
Leopoldo G. SANCHO ◽  
T. G. Allan GREEN ◽  
José Manuel BLANQUER ◽  
Roberto LÁZARO

The Tabernas badlands in semiarid south-east Spain is one of the driest regions in Europe with a mean annual precipitation of c. 240 mm. The landscape is deeply dissected, with canyons, ramblas and sparsely vegetated eroded badland slopes. The vegetation is predominantly a biological soil crust consisting of different types of lichen-rich communities, one of the more conspicuous being dominated by Diploschistes diacapsis (Ach.) Lumbsch. This lichen is mainly restricted to the north- facing slopes, where it forms extensive whitish carpets and probably plays an important role in preventing erosion of the slopes and allowing plant colonization. South-facing slopes are much more eroded and generally lack vegetation. %The photosynthetic performance of north (shade) and south-facing (sun) populations of D. diacapsis was studied to determine if these different populations showed any adaptations to the microclimatic conditions of their individual habitats. The response of CO2 exchange to light intensity, temperature and water content was measured under controlled conditions in the laboratory. Dry weight-based net photosynthetic rates were higher in the southern-exposed population but quantum efficiency, and light compensation points were similar. Thallus weight per unit area (LMA) was considerably higher for shade specimens but maximum water content and optimal water content were very similar and chlorophyll content on a dry weight basis was also similar. Chlorophyll content on an area basis was higher in the northern-exposed population and always much larger than those reported in other studies on the same species (up to 8 times larger) with the result that NP values on a chlorophyll basis were relatively low. The larger LMA meant that shade thalli stored more water per unit area which should ensure longer active periods than sun thalli. The results support a strategy pair of high NP and short active time versus low NP and long active time, both having been reported for other soil crust species. However, the visibly larger biomass of the shade D. diacapsis suggests that the lichen is at the limit of its adaptability in these habitats.


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