The Super-Cooling Point of the Spiralling Whitefly, Aleurodicus dispersus Russell

2014 ◽  
Vol 1010-1012 ◽  
pp. 1175-1180
Author(s):  
Jun Yu Chen ◽  
Guang Chang Ma ◽  
Yue Guan Fu
Keyword(s):  
Cold Hardiness ◽  
Laboratory Experiments ◽  
Instar Nymph ◽  
Male Adult ◽  
Aleurodicus Dispersus ◽  
Different Seasons ◽  
Egg Stages

Laboratory experiments were conducted to the super-cooling point (SCP) for Aleurodicus dispersus Russell. The results showed that the SCP of A. dispersus was varied in different seasons. The SCP of eggs was-23.21°C in spring, which was lowest than others. The SCP of male adult was-11.10°C in winter, which was highest. For individuals, the lowest SCP was 1th instar nymph, the highest was male adults. The sequence of SCP from low to high is eggs <the 1st instar nymph <2nd instar <3rd instar <4th instar <adults. The SCP of eggs and 1st instar nymph were lowest in every season, which lower than adults significantly (P<0.01). The results revealed stronger cold hardiness in egg stages than adults.

scholarly journals Reproductive performance of spiralling whitefly on guava and impact of weather parameters on its immature stages

2018 ◽  
Vol 15 (2) ◽  
pp. 207-214
Author(s):  
I Hossain ◽  
MMH Khan ◽  
SMH Jahan
Keyword(s):  
Relative Humidity ◽  
Negative Correlation ◽  
Reproductive Performance ◽  
Significant Positive Correlation ◽  
Instar Nymph ◽  
Maximum Temperature ◽  
Immature Stages ◽  
Positive Correlation ◽  
Aleurodicus Dispersus ◽  
Weather Parameters

The study was conducted to know the reproductive performance of spiralling whitefly on guava. Number of colony, eggs, 1st instar, 2nd instar, 3rd instar and 4th instar nymphs per five leaves ranged from 6 to 15, 8 to 32, 0 to 44, 0 to 22, 0 to 45 and 0 to 28, respectively. Maximum number of adults and nymphs were found in the month of January. Highest longevity of Aleurodicus dispersus (21.5 days) was recorded in adult while the lowest was in 2nd instar nymph (6.4 days). The number of colony/leaf and number of 3rd and 4th instar nymphs of A. dispersus had significant positive correlation with minimum and maximum temperature while non-significant positive correlation is observed between the number of egg/colony, the number 1st and 2nd instar nymphs with minimum and maximum temperature. A. dispersus showed nonsignificant positive correlation with minimum and maximum relative humidity regarding number of colony/leaf, 2nd instar nymph while nonsignificant negative correlation with 4th instar nymph.SAARC J. Agri., 15(2): 207-214 (2017)

Inoculative freezing promotes winter survival in hatchling diamondback terrapin, Malaclemys terrapin

2006 ◽  
Vol 84 (1) ◽  
pp. 116-124 ◽  
Author(s):  
P J Baker ◽  
J P Costanzo ◽  
R Herlands ◽  
R C Wood ◽  
R E Lee, Jr.
Keyword(s):  
Cold Hardiness ◽  
Laboratory Experiments ◽  
Freeze Tolerance ◽  
Winter Survival ◽  
Diamondback Terrapin ◽  
Malaclemys Terrapin ◽  
High Susceptibility ◽  
Freeze Avoidance ◽  
Inoculative Freezing ◽  
Diamondback Terrapins

We investigated the hibernation ecology and cold hardiness of hatchling diamondback terrapins, Malaclemys terrapin (Schoepf, 1793), an estuarine species that reaches 42°N along the Atlantic Ocean. During 3 years of study, about 50% of the nests we monitored harboured hatchlings during winter, and the majority (87%) of these individuals survived despite being intermittently exposed to subfreezing temperatures. Most such exposures were brief (ca. 12 h) and mild (minimum temperature: ca. –1.2 °C); however, turtles were occasionally subjected to longer chilling episodes and lower temperatures. In laboratory experiments, hatchlings supercooled extensively, attaining ca. –15 °C before spontaneously freezing. However, they were highly susceptible to inoculative freezing through contact with external ice and (or) ice-nucleating agents, which occur in nesting soil. Therefore, freeze avoidance through supercooling does not appear to be a viable cold-hardiness strategy in these turtles. Hatchlings subjected to experimental freezing survived exposure to temperatures as low as –3.0 °C, suggesting that freeze tolerance may account for the high winter survival observed in natural nests. We conclude that freeze tolerance in hatchling M. terrapin is promoted by high susceptibility to inoculation, which is known to moderate freezing, allowing cells time to adapt to the attendant physical and osmotic stresses.

Winter survival of nuisance fly parasitoids (Hymenoptera: Pteromalidae) in Canada and Denmark

2004 ◽  
Vol 94 (4) ◽  
pp. 331-340 ◽  
Author(s):  
K.D. Floate ◽  
H. Skovgård
Keyword(s):  
Air Temperature ◽  
Cold Hardiness ◽  
Ambient Air ◽  
House Fly ◽  
Winter Survival ◽  
Nasonia Vitripennis ◽  
Mean Values ◽  
Southern Alberta ◽  
Similar Survival ◽  
Egg Stages

AbstractIndependent studies were performed in Canada and in Denmark to assess the survival of parasitic wasps (Hymenoptera: Pteromalidae) wintering in puparia of house fly, Musca domestica Linnaeus (Diptera: Muscidae). Data in Canada were collected for Muscidifurax raptorGirault & Saunders, M. raptorellus Kogan & Legner, M. zaraptor Kogan & Legner, Nasonia vitripennis(Walker), Spalangia cameroniPerkins, Trichomalopsis sarcophagae (Gahan) and Urolepis rufipes (Ashmead) in three microsites at an outdoor cattle facility in southern Alberta. Survival was highest for N. vitripennis, T. sarcophagaeand U. rufipes, ranging from near zero to c. 7%. No survival was observed for S. cameroni. Daily mean values for ambient air temperature (DMAT) averaged about −3.5°C during exposure periods. Data for Denmark were collected for M. raptor, S. cameroniand U. rufipes in a dairy barn and in a swine barn. Survival of M. raptorand U. rufipes was higher than that of S. cameroniin the dairy barn (DMAT = 8.6°C), with the three species having similar survival in the swine barn (DMAT = 15.4°C). In both studies, parasitoids in egg stages were least likely to survive. These results identify the potential for T. sarcophagae and U. rufipes to be commercialized for use in northern climates as biocontrol agents for nuisance flies, compare directly the cold-hardiness of commercialized species (i.e. all of the above species excluding T. sarcophagae and U. rufipes), and document the importance of microsite on winter survival.

Experimental evidence of the fundamental feeding niche in Cenocorixa (Hemiptera: Corixidae)

1987 ◽  
Vol 65 (4) ◽  
pp. 967-973 ◽  
Author(s):  
J. D. Reynolds ◽  
G. G. E. Scudder
Keyword(s):  
Laboratory Experiments ◽  
Salinity Range ◽  
Dietary Overlap ◽  
Chironomid Larvae ◽  
Larval Instars ◽  
Food Acceptance ◽  
Low Salinity ◽  
Feeding Niche ◽  
Different Seasons ◽  
Competition For Food

The fundamental feeding niche of Cenocorixa bifida hungerfordi Lansbury and Cenocorixa expleta (Uhler) from saline lakes (500–20 000 μS cm−1 at 25 °C) was determined in laboratory experiments. Each species was offered a variety of potential foods, to determine potential dietary overlap. No significant differences in food acceptance were seen between corixids collected from different lakes or at different seasons. The species were both carnivorous and predaceous, showing little propensity to feed on plant material. Adults of both species attacked and fed on chironomid larvae most frequently; larval instars were less specific. Cenocorixa expleta adults and larval instars of both C. expleta and C. bifida fed more on dead than living food organisms. When offered mixed live Zooplankton, C. bifida chose more Ceriodaphnia than Diaptomus, whereas C. expleta showed no such selection; these differences were not seen with dead Zooplankton. Cenocorixa bifida and C. expleta coexist at moderate salinities, and appear physiologically capable of inhabiting the entire salinity range encountered. Their fundamental feeding niches, although not identical, overlap considerably and could result in competition for food. This could lead to the exclusion of C. expleta from low salinity lakes.

scholarly journals Enzyme Activity, Cold Hardiness, and Supercooling Point in Developmental Stages of Acrosternum arabicum (Hemiptera: Pentatomidae)

2016 ◽  
Vol 16 (1) ◽  
Author(s):  
Mozhgan Mohammadzadeh ◽  
Hamzeh Izadi
Keyword(s):  
Cold Hardiness ◽  
Developmental Stages ◽  
Instar Nymph ◽  
Amylolytic Activity ◽  
Supercooling Point ◽  
Optimal Activity ◽  
Adult Females ◽  
First Instar ◽  
The Mean ◽  
Optimal Ph

Abstract Several species of pentatomid bugs feed on pistachio fruits in Iran. Acrosternum arabicum Wagner (Hemiptera: Pentatomidae) is one of the most important pests of pistachio in Rafsanjan, Iran. This study was carried out to investigate the carbohydrase activities, supercooling points, and cold hardiness profiles of different developmental stages of A. arabicum under laboratory conditions. The midgut amylolytic of A. arabicum showed an optimal pH at 7.0. The highest amylolytic activity was found in the female adults (35.41 ± 0.90 nmol/min/gut). The mean amylolytic activity measured in first instar nymph was 6.75 ± 0.54 nmol/min/gut. Midgut α- and β-glucosidase showed an optimal activity at pH 5 and 7, respectively. These activities increased from first (83 ± 5 and 54 ± 5 nmol/min, respectively) to fifth (881 ± 17 and 237 ± 14 nmol/min, respectively) instar nymphs. The enzyme activities increased in the adults. Midgut α- and β-galactosidase showed an optimal activity at pH 5. α- and β-galactosidase activities were low in the first instar nymphs (73 ± 5 and 21 ± 3 nmol/min, respectively). The level of α- and β-galactosidase activities in the female adults (533 ± 18 and 246 ± 6 nmol/min, respectively) was higher than the nymphs. The lowest super cooling points (−19 and −18.2 °C, respectively) and the highest cold hardiness (22 and 18% following 24 h exposure at − 20 °C, respectively) were recorded for the eggs and adult females.

SOME FACTORS ASSOCIATED WITH INJURY TO ALFALFA DURING THE 1977–78 WINTER AT BEAVERLODGE, ALBERTA

1980 ◽  
Vol 60 (1) ◽  
pp. 103-112 ◽  
Author(s):  
J. S. McKENZIE ◽  
G. E. McLEAN
Keyword(s):  
Cold Hardiness ◽  
Laboratory Experiments ◽  
Severely Injured ◽  
Factors Associated ◽  
Air Temperatures ◽  
Soil Temperatures ◽  
Cutting Management ◽  
Food Reserves ◽  
Perennial Legumes ◽  
Northern Alberta

During the 1977–78 winter, many perennial legumes were severely injured in northern Alberta and British Columbia. The winter was characterized by an early killing frost on 1 Sept. 1977. Air temperatures were −28 °C in late November and −43 °C in early December prior to any appreciable ground snow cover. This caused soil temperatures at 5 cm to drop to −19 °C. Field and laboratory experiments are described in which cold hardiness measurements (LT40), etiolated regrowth weight measurements of root food reserves and visual percent stand estimates were determined on various cultivars of Medicago sativa, M. media and M. falcata prior to, during and/or following the 1977–78 winter. Injury was first observed in plants collected from the field following the low soil temperatures in November and December. Fall cutting management studies indicated that alfalfa harvested during August or early September in 1977 suffered the most severe injury the following spring. In June 1978, first-cut yields of these plots were up to 50% lower than the yields from single-cut control plots or plots harvested after mid-September. M. sativa, M. media and M. falcata cultivars left for seed showed little evidence of winter injury. The results suggest that low fall food reserves which resulted from harvesting during August or early September and low soil temperatures in December and January were two primary factors associated with winter injury. M. sativa stands cut twice in 1977 were more severely injured than stands of M. media or M. falcata. Three-year-old stands of M. media were more severely injured than 2-yr-old stands.

Neoperlops vietnamellus, a rare stonefly from Vietnam (Plecoptera: Perlidae)

Zootaxa ◽  
2008 ◽  
Vol 1968 (1) ◽  
pp. 33-38 ◽  
Author(s):  
THI KIM THU CAO ◽  
YEON JAE BAE
Keyword(s):  
Female Adult ◽  
Male Adult ◽  
Male And Female ◽  
Sensilla Basiconica ◽  
Subgenital Plate ◽  
Unique Distribution ◽  
Egg Stages ◽  
Ventral Edge ◽  
Key Characters

A rare perlid stonefly, Neoperlops vietnamellus, sp. nov., is described from Vietnam. Descriptions and figures of key characters are provided for the male and female adult, nymph, and egg stages. The male adult of N. vietnamellus can be distinguished from other congeners by its unique distribution of patches of sensilla basiconica posteromesally on the abdominal terga VII–IX, by the absence of sensilla basiconica on the anterior processes of the hemiterga, and by the absence of prominent spines along ventral edge of the hemiterga. The female adult has a slightly protruding subgenital plate on the abdominal sternum VIII as a strongly sclerotized mesal tab. The nymphs can be distinguished by the distinct M-line marking on the head, relatively long cerci, and a lack of dense swimming hairs on cerci. The egg chorion surface is completely smooth, and the anchor features a number of long filaments.

Cold hardiness of tree-hole mosquitoes in the Great Lakes region of the United States

1990 ◽  
Vol 68 (6) ◽  
pp. 1307-1314 ◽  
Author(s):  
Robert S. Copeland ◽  
George B. Craig Jr.
Keyword(s):  
Cold Hardiness ◽  
Laboratory Experiments ◽  
The United States ◽  
Great Lakes Region ◽  
Aquatic Animal ◽  
Larval Stages ◽  
Tree Hole ◽  
Reproductive Capability ◽  
Freeze Tolerant ◽  
Cold Hardy

We examined cold hardiness of the overwintering stages of five species of North American tree-hole mosquitoes through laboratory experiments and field observations. Among the species that overwinter as larvae, fall-collected individuals were freeze tolerant, whereas all summer-collected larvae were killed by freezing. Cold hardiness varied among species and among larval stages within species. The order of diminishing cold tolerance was Orthopodmyia alba, Anopheles barberi, and Orthopodomyia signifera. Some O. alba larvae survived freezing at −25 °C, the lowest temperature reported to be survived by an aquatic animal in ice. Prolonged (up to 16 days) and multiple (four) exposures to −15 °C had no effect on survival of O. alba third-instar larvae, but increased mortality of second instars of O. alba and A. barberi. Species were more tolerant of cold when frozen in rot-hole water in which they are commonly found in nature than in "pan" water in which they rarely occur. Both photoperiodically induced dormancy and prefreezing exposure to low temperature were necessary for the establishment of cold hardiness in laboratory-reared A. barberi. Eggs of Aedes triseriatus and Aedes hendersoni were more cold hardy than larvae of Orthopodomyia and Anopheles. Neither preconditioning to cold nor dormancy was necessary for survival at −15 °C for 24 h. Females that had survived temperatures to −25 °C as eggs showed no impairment of reproductive capability.

Nymphal antennae and antennal sensilla in Aleurodicus dispersus (Hemiptera: Aleyrodidae)

2014 ◽  
Vol 104 (5) ◽  
pp. 622-630 ◽  
Author(s):  
L.X. Zheng ◽  
W.J. Wu ◽  
G.W. Liang ◽  
Y.G. Fu
Keyword(s):  
Host Plants ◽  
Structural Changes ◽  
Morphological Structure ◽  
Instar Nymph ◽  
Fourth Instar ◽  
Distributional Pattern ◽  
Antennal Sensilla ◽  
Nymphal Stage ◽  
First Instar ◽  
Aleurodicus Dispersus

AbstractWhiteflies have distinct nymphal stages: their first stage is mobile, whereas the later immature stages are sessile. The developmental and structural changes of antennae and antennal sensilla in whiteflies during these stages have rarely been investigated. This paper describes the morphology of antennae and antennal sensilla in four nymphal stages of Aleurodicus dispersus based on scanning electron microscopy. There were significant differences found in shape and length of the antennae, and differences in type, number, morphological structure and distributional pattern of antennal sensilla in the four nymphal stages of A. dispersus. We found two types of sensilla on the antennae of first-instar nymph, three types on the third-instar nymphal antennae, four types on the second-instar and seven types on the fourth-instar nymphal antennae. Sensilla trichoidea (ST) and elevated sensilla placodea were found on the antennae of each nymphal stage, sensilla chaetica only occurred on the antennae of fourth-instar nymph. Sensilla furcatea occurred on the antennae of second- and third-instar nymphs, and sensilla basiconica were found on the antennae of second- and fourth-instar nymphs. In addition, there were sensilla campaniform and sensilla coeloconica found only on the antennae of fourth-instar nymph, whereas the ST of fourth-instar nymphs included sensilla trichoidea 1 and sensilla trichoidea 2. The possible functions of antennal sensilla are discussed. Our results contribute to a better understanding of the development of the olfactory system of whitefly nymphal stages, and provide a basis for further exploration of chemical communication mechanisms between whiteflies and host plants.

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