scholarly journals Performance ofTomicus yunnanensisandTomicus minor(Col., Scolytinae) onPinus yunnanensisandPinus armandiiin Yunnan, Southwestern China

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Tao Zhao ◽  
Bo Långström
Keyword(s):  
Sex Ratio ◽  
Host Species ◽  
Developmental Period ◽  
Host Material ◽  
Southwestern China ◽  
Pinus Yunnanensis ◽  
Attack Phase ◽  
Tomicus Minor ◽  
Pine Shoot Beetles

Pine shoot beetles,Tomicus yunnanensisKirkendall and Faccoli andTomicus minorHartig (Col., Scolytinae), have been causing substantial mortality to Yunnan pine (Pinus yunnanensisFranch) in Yunnan, southwestern China, whereas only a few Armand pine (Pinus armandiiFranch) were attacked by the beetles. In order to evaluate the suitability ofP. armandiias host material for the twoTomicus, adults of bothTomicuswere caged on living branches and felled logs of the two pines during shoot feeding and trunk attack phase, respectively. More beetles survived on the living branches ofP. yunnanensisthan onP. armandii.Tomicus yunnanensisandT. minorproduced similar progeny in the logs of the two pines. The sex ratio and developmental period were not affected by host species, but the brood beetles emerging from Armand pine weighed less than those from Yunnan pine, suggesting thatP. armandiiare less suitable to be host ofT. yunnanensisandT. minor.

TWO NEW SPECIES OF PISSODES (COLEOPTERA: CURCULIONIDAE) FROM CHINA

1999 ◽  
Vol 131 (5) ◽  
pp. 593-603 ◽  
Author(s):  
David W. Langor ◽  
Ying-X Situ ◽  
Runzhi Zhang
Keyword(s):  
New Species ◽  
Southwestern China ◽  
Pinus Yunnanensis ◽  
Two New Species

AbstractPissodes punctatussp.nov. and Pissodes yunnanensissp.nov., reared from Pinus armandii Franchet and Pinus yunnanensis Franchet (Pinaceae) in southwestern China, are described and illustrated. Both species attack the upper portions of the stems of young trees, and larvae feed in the phloem and cambium.

Intraspecific and interspecific attraction of threeTomicusbeetle species during the shoot-feeding phase

2015 ◽  
Vol 105 (2) ◽  
pp. 225-233 ◽  
Author(s):  
J. Wang ◽  
Z. Zhang ◽  
X. Kong ◽  
H. Wang ◽  
S. Zhang
Keyword(s):  
Sampling Method ◽  
Beetle Species ◽  
Dynamic Headspace ◽  
Headspace Volatiles ◽  
Interspecific Attraction ◽  
Host Trees ◽  
Pinus Yunnanensis ◽  
Dynamic Headspace Sampling ◽  
Ecological Relationship ◽  
Tomicus Minor

AbstractThe shoot beetlesTomicus minor, Tomicus yunnanensis, andTomicus brevipilosushave been decimatingPinus yunnanensistrees for more than 30 years in Southwestern China. To understand the chemical ecological relationship between pines andTomicus, and among the three beetle species, we compared the attraction of these beetles to damaged shoots, extracts from damaged shoots, and volatiles from damaged shoots collected by the dynamic headspace sampling method. Experiments were performed using a modified open-arena olfactometer. The maleT. minorand both sexes ofT. brevipilosuswere more strongly attracted to damaged shoots than to undamaged shoots and they showed attraction to shoots damaged by the same species. FemaleT. minorand both sexes ofT. yunnanensiswere attracted to shoots damaged by femaleT. brevipilosus. The three beetle species were attracted to shoot extracts and dynamic headspace volatiles from shoots damaged by the same species and sex. FemaleT. minorand maleT. yunnanensiswere also attracted to dynamic headspace volatiles from shoots damaged by both sexes ofT. brevipilosus. The results suggested that specific semiochemicals that are induced or produced byT. brevipilosusalso attractT. minorandT. yunnanensis. The semiochemicals in damaged shoots affect the attraction of the three beetle species and play an important chemical communication role in weakening the host trees during the beetles’ shoot-feeding phase.

Host Preference, Longevity, Developmental Period and Sex Ratio of Aphelinus asychis1 with Three Sorghum-Fed Species of Aphids2 Held at Controlled Temperatures3

1971 ◽  
Vol 64 (1) ◽  
pp. 169-176 ◽  
Author(s):  
Harley G. Raney ◽  
Leon W. Coles ◽  
R. D. Eikenbary ◽  
Robert D. Morrison ◽  
Kennth J. Starks
Keyword(s):  
Sex Ratio ◽  
Host Preference ◽  
Developmental Period

Host species critical for offspring fitness and sex ratio for an oligophagous parasitoid: implications for host coexistence

2010 ◽  
Vol 100 (6) ◽  
pp. 735-740 ◽  
Author(s):  
J.A. Stenberg ◽  
P.A. Hambäck
Keyword(s):  
Body Size ◽  
Sex Ratio ◽  
Host Species ◽  
Resource Competition ◽  
Apparent Competition ◽  
Future Studies ◽  
Offspring Fitness ◽  
Female Body Size ◽  
Differential Outcomes ◽  
Strong Asymmetry

AbstractIn theory, inferior apparent competitors sharing a natural enemy with superior apparent competitors should be excluded in the absence of stabilising factors. Nevertheless, plentiful examples of coexisting apparent competitors exist. In this paper, we show that parasitoid resource competition within hosts affects both parasitoid sex ratio and female body size, with implication for population growth and apparent competition between the two closely related hosts experiencing a strong asymmetry in their interaction. While the superior competitor delivers parasitoids with higher fitness to the shared parasitoid pool, the inferior competitor delivers a higher proportion of female parasitoids. Hence, the inferior host experience an inflow of fit parasitoids from the superior competitor, which should increase the risk of exclusion, but also an outflow of parasitoid females, which should reduce the risk of exclusion and increase stability. We conclude that differential outcomes of parasitoid resource competition in different host species may have profound effects on shared parasitoid populations and should be included in future studies of apparent competition between hosts.

Observations on the biology of Lycts Brunneus (Steph.)

1953 ◽  
Vol 1 (1) ◽  
pp. 102 ◽  
Author(s):  
FJ Gay
Keyword(s):  
Heat Treatment ◽  
Life Cycle ◽  
Relative Humidity ◽  
Sex Ratio ◽  
Moisture Content ◽  
Incubation Period ◽  
Developmental Period ◽  
Wood Moisture Content ◽  
Optimal Conditions ◽  
Wood Moisture

An account is given of certain aspects of the biology of Lyctus brunneus (Steph.). Female beetles are able to oviposit within 24 hr. after emerging from infested timber and deposit an average of more than 70 eggs per female over a period of 1-2 weeks. Eggs are deposited at depths of 1.0-6.5 mm. in the wood vessels, preferentially from a transverse surface, but also through radial and tangential faces. The incubation period of the eggs ranges from about 1 week at 26�C, to 3 weeks at 15�C. The egg-adult developmental period ranges from 4 months at 26�C. to 16 months or more at 15�C. Under optimal conditions of temperature, relative humidity (and hence wood moisture content), and nutrition, the life cycle may be as short as 2 months. The sex ratio of L. brunneus is 1 : 1 and the adult beetles live from 2.5 to 7 weeks, depending upon the temperature, females being somewhat longer-lived than males. The larvae of L. brunneus are somewhat more resistant to heat treatment than are the eggs, but one 1/2hr. exposure to 50�C. is completely lethal to both stages.

scholarly journals Horizontal transfer of parasitic sex ratio distorters between crustacean hosts

Parasitology ◽  
1998 ◽  
Vol 117 (1) ◽  
pp. 15-19 ◽  
Author(s):  
A. M. DUNN ◽  
T. RIGAUD
Keyword(s):  
Sex Ratio ◽  
Sex Determination ◽  
Host Specificity ◽  
Host Species ◽  
Horizontal Transfer ◽  
Parasite Infection ◽  
Parasite Transmission ◽  
Ratio Distortion ◽  
Sex Ratio Distortion ◽  
Crustacean Host

Parasitic sex ratio distorters were artificially transferred within and between crustacean host species in order to study the effects of parasitism on host fitness and sex determination and to investigate parasite–host specificity. Implantation of Nosema sp. to uninfected strains of its Gammarus duebeni host resulted in an active parasite infection in the gonad of recipient females and subsequent transovarial parasite transmission. The young of artificially infected females were feminized by the parasite, demonstrating that Nosema sp. is a cause of sex ratio distortion in its host. In contrast, we were unable to cross-infect Armadillidium vulgare with the feminizing microsporidian from G. duebeni or to cross-infect G. duebeni with the feminizing bacterium Wolbachia sp. from A. vulgare.

scholarly journals A solitary mud-daubing wasp, Brachymenes dyscherus (Hymenoptera: Vespidae) fron Brazil with evidence of a life-cyde polyphenism

2015 ◽  
pp. 949-958
Author(s):  
Evandro Camillo
Keyword(s):  
Life Cycle ◽  
Sex Ratio ◽  
Life Table ◽  
Total Population ◽  
Total Duration ◽  
Sao Paulo ◽  
Developmental Period ◽  
Immature Stages ◽  
São Paulo ◽  
Interior Walls

Nests ( n=60 ) of a solitary mud-daubing wasp, Brachymenes dyscherus were conected at Fazenda Santa Carlota, Cajuru, Sao Paulo, Brazil ín 1995 and 1996 . The multi-celled mud nests were constructed on the interior walls of abandoned houses in dry and shaded places. Nests were composed of 1 to 4 layers with cens constructed in two paralle! series. The number of cens per nest ranged from 3 to 62. Cells containing prey (larvae of Lepidoptera) numbered fram 4 to 29. B. dyscherus is a uniyoltíne species. Adults emerge from September to December, and nesting talces place at the beginning of the following year; however, the developmental period for some immatures with proloFlged diapause l3.Sted up to 596 days. The total duration of immature stages n nests collected in 1996 was less for males than for females. The sex ratio for the total populatíon was 1 . 5 males: 1 female with males emerging earher than females. A life table was constructed, and details of lhe life cycle of the wasps and parasitoids are presented. The mos! common mOl1ality factors were either endogenous or due 10 Melittobia sp. (Eulophidae) .

scholarly journals Electrophysiological and behavioral responses of Tomicus minor (Coleoptera: Scolytidae) to host volatiles

2015 ◽  
Vol 26 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Yang Hua ◽  
Wang Hong-Wei ◽  
Yang Wei ◽  
Yang Chun-Ping
Keyword(s):  
Behavioral Responses ◽  
Gas Chromatography Mass Spectrometry ◽  
Forest Pest ◽  
Behavioral Tests ◽  
Host Volatiles ◽  
Male And Female ◽  
Pinus Yunnanensis ◽  
Pine Shoot Beetle ◽  
Tomicus Minor ◽  
Plant Compounds

To screen for host volatiles that effectively attract the lesser pine shoot beetle, Tomicus minor (Coleoptera: Scolytidae), an important forest pest, water vapor distillation extraction and gas chromatography-mass spectrometry were combined to analyze volatiles emitted from uninfested and infested shoots of Pinus yunnanensis (Pinaceae). Electroantennography and Y-tube olfactometer behavioral tests were used to compare and analyze the responses of male and female beetles to each of selected eight compounds. The spectrometry results showed that monoterpenes are the primary chemicals emitted by P. yunnanensis. The electroantennogram responses of adult T. minor to six of the plant compounds peaked at 10 μg/μL; the exceptions were terpinolene and myrcene, which had maxima above 100 μg/μL. (+)-α-Pinene and β-phellandrene were strongly attractiveto the male and female adults.

scholarly journals Are we underestimating the diversity and incidence of insect bacterial symbionts? A case study in ladybird beetles

2007 ◽  
Vol 3 (6) ◽  
pp. 678-681 ◽  
Author(s):  
Lucy A Weinert ◽  
Matthew C Tinsley ◽  
Matilda Temperley ◽  
Francis M Jiggins
Keyword(s):  
Sex Ratio ◽  
Host Species ◽  
Small Proportion ◽  
Small Samples ◽  
Bacterial Symbionts ◽  
True Incidence ◽  
Bacterial Genus ◽  
Large Samples ◽  
Ladybird Beetles

Vertically transmitted bacterial symbionts are common in arthropods. However, estimates of their incidence and diversity are based on studies that test for a single bacterial genus and often only include small samples of each host species. Focussing on ladybird beetles, we collected large samples from 21 species and tested them for four different bacterial symbionts. Over half the species were infected, and there were often multiple symbionts in the same population. In most cases, more females than males were infected, suggesting that the symbionts may be sex ratio distorters. Many of these infections would have been missed in previous studies as they only infect a small proportion of the population. Furthermore, 11 out of the 17 symbionts discovered by us were either in the genus Rickettsia or Spiroplasma , which are rarely sampled. Our results suggest that the true incidence and diversity of bacterial symbionts in insects may be far greater than previously thought.

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