Characteristics of Attack of Coastal Timbers by Pselactus spadix (Herbst) (Col.: Curc.: Cossoninae) and an Investigation of its Life History

Holzforschung ◽  
2002 ◽  
Vol 56 (4) ◽  
pp. 335-359 ◽  
Author(s):  
P. Oevering ◽  
A.J. Pitman

Summary Pselactus spadix attack of marine timbers was characterised by circular emergence holes 1.48±0.05 mm in diameter and adult tunnels (1.49±0.34 mm) breaking through the wood surface. Larval tunnels measured 0.407–1.892 mm in diameter, initiated from adult tunnels and increased in diameter away from the adult tunnel terminating in frass free pupal chambers (1.6±0.3 mm × 3.5±0.7 mm). Observations of larval tunnel locations indicated oviposition occurred inside the adult tunnels. P. spadix life history was investigated in Scots pine (Pinus sylvestris) heartwood at 22±2 °C and 99±1% r.h. Mean adult longevity was 11.5±6.5 months, with mean post-mating longevity for males (11.7±2.9 months) significantly longer than for females (6.3±1.1 months). Adults of at least 2–3 months old were found mating in galleries, which, with observations of the larval tunnel pattern, indicated P. spadix can complete its life cycle without emerging from wood. Five larval instars were identified by measurement of 1722 head capsule widths and application of Dyar's law. Mean development time from 2nd instar to adult emergence was 70.5±6.9 weeks and pupation took 14.6±5.8 days. Development from 2nd instar to reproductive adult took between 17–20 months, with life cycle approximating 24 months at 22±2 °C and 99±1%

1965 ◽  
Vol 97 (9) ◽  
pp. 962-969
Author(s):  
Louis F. Wilson

AbstractThe pine gall weevil has a 3-year life cycle on red pine (Pinus resinosa Ait.) in Michigan. Adults oviposit from June to August, depositing 1 to 10 eggs in a niche chewed in the bark of a branch internode. Larvae first emerge in August, feed as a group toward the cambium, and then radiate out along the xylem. Head capsule measurements from 1585 larvae indicate that there are three larval instars. Gall development begins in June of the second year, shortly after the larvae begin the second instar. The third instar commences in June of the third year. Pupation occurs in May of the fourth season; adult emergence follows in June. Overwintering occurs in the egg stage or in the three larval instars. Adults do not overwinter, and apparently three distinct broods occur in Michigan.


Author(s):  
Alec R. Lackmann ◽  
Malcolm G. Butler

Except for one unconfirmed case, chironomid larvae have been reported to pass through four larval instars between egg and pupal stages. We have observed a fifth larval instar to be a standard life-cycle feature of the podonomine Trichotanypus alaskensis Brundin 1966 in tundra ponds on the Arctic Coastal Plain near Barrow, Alaska. T. alaskensis has a one-year life cycle in these arctic ponds. Adults emerge in June ~2-3 weeks after pond thaw, then mate and oviposit; most newly-hatched larvae reach instar IV by October when pond sediments freeze. Overwintering larvae complete instar IV within a few days of thaw, then molt again to a fifth larval instar. Imaginal discs, normally seen only during instar IV in Chironomidae, develop across both instars IV & V prior to pupation and adult emergence. While monitoring larval development post-thaw in 2014, we noticed freshly-molted T. alaskensis larval exuviae a week or more prior to any pupation by that species. In 2015-16 we reared overwintering instar IV larvae from single pond sources, individually with daily monitoring, through molts to instar V, pupa, and adult. Some overwintering instar II and III larvae were reared as well, but were few in number. During 2016 we also reared T. alaskensis progeny (from eggs) through instar II, thus documenting head capsule size ranges for all five instars in a single pond’s population. Without individual rearings, the fifth larval instar was not readily apparent for two reasons: 1) The molt itself occurs immediately after thaw and is so synchronous it is difficult to discern in daily field samples. 2) The head capsule size increment between instars IV-V is much lower than the ratio predicted by the Brooks-Dyar Rule. Up through instar IV, the Brooks-Dyar ratio for T. alaskensis ranged 1.30-1.61, but during the IV-V molt head capsule dimensions (sexes pooled) increased by a ratio of 1.09 – comparable to the magnitude of sexual dimorphism in head capsule size within each of the final two larval instars. Individual rearings coupled with 2014-2016 field surveys in nine other ponds suggest that five larval instars is an obligatory trait of this species at this location. As this is the first confirmed case of five larval instars in a chironomid, the phylogenetic uniqueness of this trait needs further investigation.


2019 ◽  
Vol 112 (6) ◽  
pp. 505-510 ◽  
Author(s):  
Brittny M Jones ◽  
Jeffery K Tomberlin

Abstract The black soldier fly, Hermetia illucens (L.), is economically important due to its use in waste management and as an alternative protein source for livestock, poultry, and aquaculture. While industry promotes mass production of the black soldier fly, little is known about the impact of larval competition on development time, resulting immature and adult weight, or adult longevity. The goal of this research was to examine the life-history traits of black soldier flies when reared at four densities (500, 1,000, 1,500, and 2,000 larvae/4-liter container) provided 54-g Gainesville diet at 70% moisture (feed rates of 0.027, 0.036, 0.054, and 0.108 g) every other day. Results were as expected with the lowest larval density (500) producing heavier individuals (by 26%) than the greatest larval density (2,000) across all life stages. In addition to weights, larvae reared at the lowest density developed 63% faster than those reared at the greatest density. In regard to pupal development time, those reared at the lowest larval density developed 3% slower than the greatest density. A 21% difference between the two extreme densities was found in survivorship to prepupal stage, with the lowest larval density having the greatest survivorship (92%) compared with the greatest larval density (70%). All densities displayed over 90% adult emergence rates. Such information is vital for optimization of the process of converting waste products to protein at an industrial scale with the black soldier fly.


Zoosymposia ◽  
2011 ◽  
Vol 5 (1) ◽  
pp. 401-407
Author(s):  
SYLVESTER OGBOGU ◽  
WILLIAMS ADU

The life history and density of Cheumatopsyche digitata Mosely (Trichoptera: Hydropsychidae) were examined below Opa Reservoir in Ile-Ife, southwestern Nigeria. This caddisfly is the only species that occurs immediately below the impoundment auxiliary spillway where it closely associates with an aquatic bryophyte, Fontinalis sp. We collected larvae every month between July 2004 and June 2005 as long as larvae were available in the study site. The instar growth ratio was fairly constant and ranged from 1.198 to 1.402 (mean ± standard error = 1.285 ± 0.073) but mean head capsule width increased with larval development. The frequency distribution of head capsule width of larvae clustered into 5 size classes, suggesting 5 larval instars for C. digitata in the study site. Density of larvae ranged from 1,100 to 11,150 inds.m-2 (mean ± SE = 6739  inds.m-2 ± 3904.70), the highest densities occurring in October 2004 during the bloom of Fontinalis. The first larval instar appeared in July 2004. Adult emergence occurred mainly in December 2004 through January 2005 at the onset of reservoir draw-down and death of Fontinalis. These patterns indicate that C. digitata tended to show a univoltine life cycle in the study site.


1958 ◽  
Vol 90 (10) ◽  
pp. 627-631 ◽  
Author(s):  
Peter Harris

Ocnerostoma piniariella Zell. is an unimportant pest of Scots pine, Pinus sylvestris L., in Europe. A variety, copiosella Frey, is found in the Swiss Alps attacking a white pine, Pinus cembra L., and sometimes occurs in sufficient numbers to reduce growth. Both European forms have a life-history similar to that described here for British Columbia.In North America, specimens identified as O. piniariella were collected in 1882 at Ithaca, New York (Forbes, 1924). The first Canadian record was for 1922 at Abbotsford, British Columbia, from white pine (Felt, 1922). The species has since been found in British Columbia at Vancouver, Victoria, Langley, and Aldergrove. Dr. T. N. Freeman (in litt.), Entomology Division, Ottawa, has collected it at Constance Bay, South March, Ottawa, and Bells Corners, Ontario.


1968 ◽  
Vol 100 (2) ◽  
pp. 202-206 ◽  
Author(s):  
Louis F. Wilson

AbstractThe willow beaked gall midge, Mayetiola rigidae (Osten Sacken), is univoltine in Michigan. Adults emerge from bud galls on Salix discolor Mühl. and other willows on mornings of warm days in early April. Eggs are laid singly on or near the buds of the host. Head capsule measurements indicate three larval instars. The last two instars each possess a spatula. The first-instar larva emerges in late April and penetrates the soft bud tissues. The gall begins to develop at the beginning of the second instar in mid-May. The third instar appears in early July and continues to enlarge the gall until fall. Prior to overwintering, the larva lines the inner chamber of the gall with silk and constructs one to seven silken septa across the passageway. Pupation occurs in mid-March. The gall deforms the stem and occasionally a galled branch dies or breaks off.


1982 ◽  
Vol 114 (6) ◽  
pp. 535-537 ◽  
Author(s):  
Michael T. Smith ◽  
Richard A. Goyer

AbstractThe life cycle of Corticeus glaber (LeConte) was investigated at 25 °C and 60% R.H. The developmental time from egg to adult for C. glaber ranged from 30 to 41 days and five larval instars were determined from head capsule measurements. The mature larva is described.


1987 ◽  
Vol 22 (3) ◽  
pp. 237-244 ◽  
Author(s):  
W. Davis Martin ◽  
G. A. Herzog

The life history of the tobacco flea beetle, Epitrix hirtipennis (Melsheimer) (= Epitrix parvula Fab.) was studied under the controlled conditions of 27 ± 2.8°C, 80 ± 6% and a 14L:10D photophase. Eggs matured in ca. 4 days, the larval stage, including 3 instars, developed in 13 days, prepupal development took 3 days and the pupal stage lasted approximately 5 days. There was a 24 day interval between oviposition and adult emergence. Females laid 3.1 eggs/day with a 13 day period between adult emergence and first oviposition. The mean number of total eggs/female was 138.6 ± 14.7. Female oviposition continued until a few days before death and adult longevity was approximately 70 days. A visual means of distinguishing between male and female beetles was also developed.


1998 ◽  
Vol 130 (4) ◽  
pp. 387-397 ◽  
Author(s):  
David W. Langor ◽  
Daryl J.M. Williams

AbstractThe seasonal life history and mortality of the lodgepole terminal weevil, Pissodes terminalis Hopping (Coleoptera: Curculionidae), were investigated in young lodgepole pine, Pinus contorta Douglas var. latifolia Engelmann (Pinaceae), at three sites in west-central Alberta. Flight was monitored with traps. Development and mortality of all stages were investigated by dissecting infested leaders biweekly from late spring to early fall. Two years were required for P. terminalis to complete its life cycle, and generations overlapped. Overwintered adults emerged from the duff and commenced flight in late May, with a peak in mid-June. Eggs were present from mid-June to late July. There were four larval instars. The first two instars fed only in the phloem. Third and fourth larval instars eventually entered the pith to continue feeding, overwinter, and complete development the following spring. The new generation of adults emerged between mid-July and early August, fed on new shoots for several weeks, and overwintered in the duff. Adults have an obligatory diapause and did not reproduce until after winter. Fourth larval instars suffered the highest mortality. The major attributable cause of mortality was resinosis among eggs and young larvae and cold temperatures during the winter among mature larvae. Pathogens caused little mortality. Six species of parasitoids were collected.


1976 ◽  
Vol 54 (2) ◽  
pp. 266-284 ◽  
Author(s):  
G. Pritchard

Collections of all stages of the crane fly, Tipula sacra have been made over a period of years from a series of abandoned beaver ponds in the Kananaskis Valley, Alberta. The growth of larvae was followed by head-capsule measurements and weights. Eggs hatch within a month; first-instar larvae grow rapidly and enter the second instar after a few weeks. The second instar may last for 3 months and the third instar usually lasts for 6 months, including the first winter. Most larvae spend almost a full year in the fourth instar and overwinter for a second time. However, there was much variation in growth rate within the population. Adult emergence curves were consistent in form in 4 years. Each spanned a period of just over 2 months, although individual adults lived for only a few days. These curves snowed two peaks, the second of which contained 15–20% of the year's emergents. These two groups may represent different cohorts that have grown at different rates, suggesting that the life history may be semivoltine or univoltine. The sex ratio changes from about 1:1 in the third instar to 2:1 in favor of males in the late fourth instar, pupa, and adult.


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