Biology of Pissodes yunnanensis (Coleoptera: Curculionidae), a pest of Yunnan pine in southwestern China

2004 ◽  
Vol 136 (5) ◽  
pp. 719-726 ◽  
Author(s):  
Hongrui Zhang ◽  
Hui Ye ◽  
Robert A. Haack ◽  
David W. Langor
Keyword(s):  
Yunnan Province ◽  
Tree Mortality ◽  
Fourth Instar ◽  
Southwestern China ◽  
Old Growth ◽  
Optimal Development ◽  
Pinus Yunnanensis ◽  
First Instar ◽  
Pine Trees ◽  
Lateral Branches

AbstractPissodes yunnanensis Langor et Zhang, a pest of Yunnan pine, Pinus yunnanensis Franchet, in southwestern China, occurs at elevations of 2200–2800 m. These weevils infest Yunnan pine trees less than 20 years old but prefer trees 8–10 years old. Oviposition occurs mainly along the upper trunk on current-year and 1-year-old growth and occasionally on the upper lateral branches. Weevil feeding often kills the leader, which results in stem forking and crooking. At times, after 2–3 years of consecutive severe infestation, tree mortality occurs. In southwestern Yunnan Province, adults of this univoltine weevil emerge from infested stems from mid-April to mid-July. Eggs appear in late June, first-instar larvae in early July, and fourth-instar larvae in late March of the next year. First- and second-instar larvae feed in the phloem, and third-instar larvae move to the sapwood or pith, where they overwinter. In March, larvae resume feeding and development. Fourth-instar larvae excavate pupal chambers (chip cocoons) in the outer sapwood or pith, and pupation occurs from late March to late May. Optimal development of eggs and pupae occurs at 25 °C in the laboratory. Parasitism is the main cause of mortality in P. yunnanensis, accounting for 2%–25% of mortality among third- and fourth-instar larvae and 5%–10% among pupae.

scholarly journals Coexistence and Competition betweenTomicus yunnanensisandT. minor(Coleoptera: Scolytinae) in Yunnan Pine

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Rong Chun Lu ◽  
Hong Bin Wang ◽  
Zhen Zhang ◽  
John A. Byers ◽  
You Ju Jin ◽  
...  
Keyword(s):  
Thin Layer ◽  
Bark Beetles ◽  
Yunnan Province ◽  
Southwest China ◽  
Lower Trunk ◽  
Competition And Cooperation ◽  
Pinus Yunnanensis ◽  
Pine Trees ◽  
Tomicus Minor ◽  
Intensity Of Competition

Competition and cooperation between bark beetles,Tomicus yunnanensisKirkendall and Faccoli andTomicus minor(Hartig) (Coleoptera: Scolytinae) were examined when they coexisted together in living Yunnan pine trees (Pinus yunnanensisFranchet) in Yunnan province in Southwest China.T. yunnanensisbark beetles were observed to initiate dispersal from pine shoots to trunks in November, while the majority ofT. minorbegins to transfer in December.T. yunnanensismainly attacks the top and middle parts of the trunk, whereasT. minormainly resides in the lower and middle parts of the trunk. The patterns of attack densities of these two species were similar, but withT. yunnanensiscolonizing the upper section of the trunk andT. minorthe lower trunk. The highest attack density ofT. Yunnanensiswas 297 egg galleries/m2, and the highest attack density ofT. minorwas 305 egg galleries/m2. Although there was significant overlap for the same bark areas, the two species generally colonize different areas of the tree, which reduces the intensity of competition for the relatively thin layer of phloem-cambium tissues where the beetles feed and reside.

Variation in canopy gap formation among developmental stages of northern hardwood stands

1996 ◽  
Vol 26 (10) ◽  
pp. 1875-1892 ◽  
Author(s):  
Sally E. Dahir ◽  
Craig G. Lorimer
Keyword(s):  
Sugar Maple ◽  
Tree Mortality ◽  
Developmental Stages ◽  
Turnover Time ◽  
Gap Formation ◽  
Old Growth ◽  
Northern Hardwood ◽  
Hardwood Species ◽  
Shade Tolerant Species ◽  
Mature Stands

Trends in gap dynamics among pole, mature, and old-growth northern hardwood stands were investigated on eight sites in the Porcupine Mountains of western upper Michigan. Recent gaps (created between 1981 and 1992) were identified using permanent plot records of tree mortality, while older gaps (1940–1981) were identified using stand reconstruction techniques. Although canopy gaps were somewhat more numerous in pole and mature stands, gaps were <25% as large as those in old-growth stands because of smaller gap-maker size, and the proportion of stand area turned over in gaps was only about half as large. Gap makers in younger stands generally had mean relative diameters (ratio of gap-maker DBH to mean DBH of canopy trees) <1.0 and were disproportionately from minor species such as eastern hophornbeam (Ostryavirginiana (Mill.) K. Koch). Gap makers in old-growth stands had mean relative diameters >1.5 and were predominantly from the dominant canopy species. Even in old-growth forests, most gaps were small (mean 44 m2) and created by single trees. Based on the identity of the tallest gap tree in each gap, nearly all shade-tolerant and midtolerant species have been successful in capturing gaps, but gap capture rates for some species were significantly different from their relative density in the upper canopy. The tallest gap trees of shade-tolerant species were often formerly overtopped trees, averaging more than 60% of the mean canopy height and having mean ages of 65–149 years. Canopy turnover times, based on gap formation rates over a 50-year period, were estimated to average 128 years for old-growth stands dominated by sugar maple (Acersaccharum Marsh.) and 192 years for old-growth stands dominated by hemlock (Tsugacanadensis (L.) Carrière). While these estimates of turnover time are substantially shorter than maximum tree ages observed on these sites, they agree closely with independent data on mean canopy residence time for trees that die at the average gap-maker size of 51 cm DBH. The data support previous hypothetical explanations of the apparent discrepancy between canopy turnover times of <130 years for hardwood species and the frequent occurrence of trees exceeding 250 years of age.

Two new species of the Rhopalopsole magnicerca group (Plecoptera: Leuctridae) from China

Zootaxa ◽  
2018 ◽  
Vol 4388 (3) ◽  
pp. 444
Author(s):  
RAORAO MO ◽  
GUOQUAN WANG ◽  
DING YANG ◽  
WEIHAI LI
Keyword(s):  
New Species ◽  
Yunnan Province ◽  
Southern China ◽  
Southwestern China ◽  
Autonomous Region ◽  
Two New Species

Two leuctrid species of the Rhopalopsole magnicerca group are described as new, R. brevicula sp. nov. and R. jizushana sp. nov. from the Guangxi Autonomous Region of southern China, bordering Vietnam and Yunnan Province of southwestern China, respectively. The new species are compared with related taxa. 

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.

scholarly journals Biologi Stenocranus pacificus Kirkaldy (Hemiptera: Delphacidae) pada tanaman jagung (Zea mays L.) di rumah kasa

2020 ◽  
Vol 17 (2) ◽  
pp. 104
Author(s):  
Dosma Ulina Simbolon ◽  
Maryani Cyccu Tobing ◽  
Darma Bakti
Keyword(s):  
Zea Mays ◽  
Life Cycle ◽  
Sex Ratio ◽  
Zea Mays L ◽  
Instar Nymph ◽  
Fourth Instar ◽  
The Third ◽  
First Instar ◽  
Corn Plants ◽  
North Sumatra

<p><em>Stenocranus pacificus </em>Kirkaldy (Hemiptera: Delphacidae) is destructive pest on corn plants in South Lampung and it has been reported to cause corn damages in North Sumatra. The  objective of this research was to study some aspects biology of <em>S. pacificus</em> on corn plants in screenhouse. The research was conducted by observing the biology of <em>S. pacificus</em> that was reared on corn plants in screenhouse.<em> </em>The results showed that life cycle of <em>S. pacificus </em>was 38–47 (41,60 ± 3,19) days: egg was 9–11 (10,20 ± 0,79) days, the first instar nymph was 3–4 (3,70 ± 0,48) days, the second instar nymph was 3–4 (3,90 ± 0,32) days, the third instar nymph was 3–4 (3,70 ± 0,48) days, the fourth instar nymph was 3–4 (3,80 ± 0,42) days, and the fifth instar nymph was 3–4 (3,60 ± 0,52) days. Age of female was 13–17 (15,30 ± 1,34) days. It was longer than age of male which was 8–12 (10,10 ± 1,20) days. Female could produce 181–214 (197,60 ± 11,64) eggs during its life. The sex ratio was 1:1,98.</p>

A remarkable new species of Nemoura (Plecoptera: Nemouridae) from Chuxiong Yi Autonomous Prefecture of Yunnan Province, China

Zootaxa ◽  
2018 ◽  
Vol 4375 (2) ◽  
pp. 281 ◽  
Author(s):  
YU-HAN QIAN ◽  
QIAN XIAO ◽  
ZHI-TENG CHEN ◽  
YU-ZHOU DU
Keyword(s):  
New Species ◽  
Yunnan Province ◽  
Southwestern China ◽  
A New Species

A new species of the genus Nemoura, N. latilongispina sp. nov. from Chuxiong Yi Autonomous Prefecture of Yunnan Province, southwestern China is described and illustrated. The new species is characterized by ventral sclerite of epiproct extended laterally, forming upcurved plates fringed with long spines along upper margin, and by the strongly sclerotized, fork-shaped cercus.  

Observations on an introduced bud scale, Physokermes hemicryphus (Homoptera: Coccidae), infesting Norway spruce in Idaho

2004 ◽  
Vol 34 (6) ◽  
pp. 1348-1352 ◽  
Author(s):  
Malcolm M Furniss
Keyword(s):  
North America ◽  
Picea Abies ◽  
Norway Spruce ◽  
First Instar ◽  
The Dead ◽  
Lateral Branches

An introduced bud scale on Norway spruce (Picea abies (L.) Karst. (Pinaceae)) in Idaho, formerly thought to be Physokermes piceae Schrank (Homoptera: Coccidae), is identified as Physokermes hemicryphus (Dalman). Secondary lateral branches of infested Norway spruce become pendent as a result of growing abnormally in length relative to diameter. The scale reproduces by parthenogenesis in North America; no male is known there. Mature females in situ resemble a branch bud. An average of 2.2 females occurred per infested node. They grew larger in late May, at which time they protruded visibly from beneath branch bud scales of the previous year and became immersed in their secreted honeydew. At maturity, females contained a prolific number of eggs (290–858). The eggs hatched into nymphs within the rigid exoskeleton of the dead female in late June. Nymphs emerged during July and migrated distally along a branch. They overwintered as second (final) instars attached to needles or beneath bud scales at the branch node from which the current-year terminal emanated. Four species of hymenopterous parasites were reared from adult scales. Of these, Americencyrtus sp. (Hymenoptera: Encyrtidae) was most abundant. It parasitized a majority of first instar nymphs but allowed them to develop to maturity the following spring before destroying their embryonic eggs and emerging in synchrony with appearance of nymphs of unparasitized females.

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