REPRODUCTIVE BEHAVIOUR OF THE DOUGLAS-FIR CONE GALL MIDGE, CONTARINIA OREGONENSIS (DIPTERA: CECIDOMYIIDAE)

1984 ◽  
Vol 116 (4) ◽  
pp. 607-618 ◽  
Author(s):  
G. E. Miller ◽  
J. H. Borden

AbstractThe reproductive behaviour of the Douglas-fir cone gall midge, Contarinia oregonensis Foote, was studied in the laboratory and in cages outdoors. Adult emergence began in mid-April outdoors and lasted about 2 weeks. Emergence began outdoors at 0600–0700 h Pacific Standard Time, peaked at 1100 h and continued until 1900 h; females dominated emergence early in the day. Mating occurred on or near the duff from which females emerged. Virgin females appeared to “call” males by extending their ovipositors and waving them back and forth, and this behaviour was followed by mating. Laboratory bioassay s using rinses of female abdomens gave further evidence that virgin females produce a sex pheromone. Oviposition behaviour on already infested conelets differed from that on uninfested conelets and suggested the presence of an oviposition deterrent. The mean number of eggs developed by the females was 254, 93% of which were usually laid during the life of the females.

1986 ◽  
Vol 118 (12) ◽  
pp. 1297-1306 ◽  
Author(s):  
G.E. Miller

AbstractDamage at cone harvest by the Douglas-fir cone gall midge, Contarinia oregonensis Foote, was positively correlated with the number of egg-infested scales per conelet in the spring. Reducing the average number of galled seeds per cone by 1.5 increased the average number of filled seeds per cone by 1.0 in insecticide trials. Optimum sample sizes for estimating average densities of egg-infested scales were calculated to be one conelet per tree and 150 trees per orchard. The mean crowding variable was linearly related to average density so a sequential sampling technique relative to a critical density, using Iwao’s procedure, was developed for determining the need of control actions.


2017 ◽  
Vol 42 (3) ◽  
pp. 503-508
Author(s):  
MMH Khan

Experiments were conducted to observe mating and oviposition behabiour as well as biology of hog-plum beetle. Results revealed that the average mating frequency, mating duration and mating interval were 11.2, 30.5 hours and 60.3 hours, respectively. The highest number of eggs per clusters was on leaf rachis followed by young stem. The mean number of eggs per cluster was 15.70 while the length and breadth of an egg was 1.95 mm and 0.60 mm, respectively. The mean duration of 1st, 2nd, 3rd and 4th instar larvae were 3.80, 3.40, 3.70 and 3.00 days, respectively. The mean pupal period was 22.74 days. The female beetle lived longer (48.30 days) than the male (45.10 days). The size of female beetle was larger (15.30 mm) than male (11.96 mm). The mean length of antennae was 7.42 mm. The length of fore, mid and hind legs were 9.20, 9.50 and 11.70 mm, respectively. Hind wings were larger (16.10 mm length and 7.85 mm breadth) than fore wings (12.38 mm length and 5.30 mm breadth).Bangladesh J. Agril. Res. 42(3): 503-508, September 2017


2011 ◽  
Vol 46 (6) ◽  
pp. 669-671 ◽  
Author(s):  
Adrise Medeiros Nunes ◽  
Dori Edson Nava ◽  
Fernanda Appel Müller ◽  
Rafael da Silva Gonçalves ◽  
Mauro Silveira Garcia

The objective of this work was to study the biology and parasitic potential of Doryctobracon areolatus on larvae of Anastrepha fraterculus. The egg-adult period, the sex ratio, the longevity, the pupal viability, and the parasitism rate of D. areolatus were determined in laboratory, using A. fraterculus as host. The parasitoid development from oviposition to adult emergence required 25.00±1.70 days, the sex ratio was 0.62±0.09, and the mean longevity was 16.36±3.62 days for males and 10.24±1.71 days for females. The mean parasitism rate was 53.50±8.93%, varying from 41.60 to 68.60%, which shows the potential of this parasitoid for biological control of A. fraterculus.


1989 ◽  
Vol 19 (10) ◽  
pp. 1322-1329 ◽  
Author(s):  
G. H. Mohammed ◽  
K. R. Patel ◽  
W. E. Vidaver

Rooting percentage and root number in tissue-cultured Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) were influenced by the rooting substrate, the concentration of sucrose and boron in the rooting medium, shoot height, and shoot generation. Peat–perlite was a better substrate than agar, producing 70% compared with 0% rooted shoots, respectively. On peat–perlite, cell divisions were organized and were associated with tracheid nests, whereas on agar proliferation was unorganized and not restricted to the nests. A sucrose concentration of 4% was optimal for the production of nodular or rooted shoots. At 4% sucrose and 3 mg •L−1 boric acid, 100% of the shoots rooted, and the mean root number was 11. Rooting percentage and root number were significantly higher with shoots that were 3 cm tall than 2 or 1 cm tall shoots. Finally, it was found that shoot responses were more rapid in third and fourth generation shoots than in second generation shoots. At least 80% were rooted or nodular after 4 weeks, compared with only 36% from the second generation.


2008 ◽  
Vol 54 (No. 7) ◽  
pp. 321-332 ◽  
Author(s):  
P. Kantor

: The study evaluates production parameters (height, diameter at breast height, volume) of Douglas fir (<I>Pseudotsuga menziesii</I> [Mirb.] Franco) at mesotrophic sites of the Křtiny Training Forest Enterprise in mature stands. In total, 29 mixed stands were assessed with the registered proportion of Douglas fir at an age of 85 to 136 years. Comparing the 10 largest Douglas firs with the 10 largest spruces or larches higher, and as a rule markedly higher, production potential of introduced Douglas fir was found in all assessed stands. There were also groups of trees where the volume of Douglas fir was twice to 3 times higher than the volume of spruce or larch (see Tabs. 5 to 10). For example, in stand 177B11, the mean volume of 9.12 m<sup>3</sup> was recorded in the 10 largest Douglas fir trees but the volume of spruce reached only 3.17 m<sup>3</sup> and the volume of larch was 3.70 m<sup>3</sup>. Differences in mensurational parameters of Douglas fir found on the one hand and of Norway spruce (<I>Picea abies</I> [L.] Karst.) or European larch (<I>Larix decidua</I> Mill.) on the other hand compared by ANOVA tests were statistically highly significant. Annual ring analyses have shown that at present the volume increment of particular Douglas fir trees ranges from 0.12 to 0.16 m<sup>3</sup> per year in mature stands (i.e. about 1.5 m<sup>3</sup> every 10 years).


1985 ◽  
Vol 15 (6) ◽  
pp. 1092-1098 ◽  
Author(s):  
Joseph E. Means ◽  
Kermit Cromack Jr ◽  
Paul C. MacMillan

Logs of Pseudotsugamenziesii (Mirb.) Franco that had been on the ground for up to 313 years were grouped into five decay classes that ranged from 1, essentially undecayed, to 5, soft and incorporated into the forest floor but still identifiable. The mean residence times on the forest floor were 7, 17, 33, 82, and 219 years for decay classes 1 through 5, respectively. The single-exponential model of litter decomposition was fitted to the density of these logs. The summation-exponential model was constructed by summing single-exponential models fitted to lignin, cellulose, and the acid detergent soluble fraction. Both models gave virtually identical, statistically significant fits to the data. Wood density of these Douglas-fir logs decreased more slowly than that of most species other researchers have studied. The single-exponential model gave mineralization rates (k) of 0.0063 and 0.0070 year−1 when residence time and decay class age (mean residence time of the decay class), respectively, were used as the independent variable. Lignin decayed more slowly than cellulose or the fraction soluble in hot acid detergent, both of which decayed at rates that were not significantly different; thus, the summation-exponential model is recommended when these constituents are of interest.


2019 ◽  
pp. 1025-1030
Author(s):  
Almerinda Amélia Rodrigues Araújo ◽  
Raimunda Nonata Santos Lemos ◽  
José Ribamar Gusmão Araújo ◽  
Paulo Roberto Ramalho Silva ◽  
Solange Maria França ◽  
...  

Fruit flies (Diptera: Tephritidae) are considered important pests of fruticulture due to considerable losses to production and limitation to free transit of fresh fruits. A generalist species is cresature that can live or feed on a wide variety of environemnts or host plants. Although, Anastrepha is a generalist species but infests a small range of plants. The specificity of this species with host plants is a peculiar characteristic of genus Anastrepha. Therefore, it is important to understand the host species and its feeding behaviour on host plants. This way, we will better know its ecology, biology and evolution for rational control ways and measures. Therefore, this study aimed at understanding the biology of Anastrepha alveata Stone (Diptera: Tephritidae). A study was carried out under controlled laboratory conditions (27 ± 2°C temperature, 70 ± 5% RH, photoperiod 12 hours) during the period from November/2015 to October/2017. Anastrepha alveata adults were obtained from wild plum fruits Ximenia americana L. (Olacaceae), collected from Savanna area in two fructification periods. One-hundred and fifty Anastrepha alveata adults were collected (60 females and 90 males) to determine sexual maturity, mating behavior, fecundity and longevity. The sexual maturity for Anastrepha alveata was 8-13 days after emergence for females. At this age they emitted signal of acceptance for mating and copulation. For males, 5-7 days after emergence this mating signals was given, which was characterized by the protrusion of the lateral abdominal pleural glands. The mating rhythm of Anastrepha alveata was crepuscular/nocturnal, beginning around 6 p.m. and extending to/after 9 p.m. Anastrepha alveata females did not mate with more than one male but mated more than once. The number of males did not affect significantly the mating time, the number of eggs and the longevity of Anastrepha alveata. The mean pupal period for Anastrepha alveata was 17.5 days. Two preferential peaks for adult emergence were observed at 10:00 am and 03:00 pm. The longevity of the adult insects was greater than 300 days, surviving until the fructification of its host (wild plum) in the following year. Therefore, A. alveata has a strictly monophagous food habit associated with the Ximenia americana host.


2017 ◽  
Vol 67 (1) ◽  
pp. 41-52 ◽  
Author(s):  
L. Arellano ◽  
C. Castillo-Guevara ◽  
C. Huerta ◽  
A. Germán-García ◽  
C. Lara

Obtaining knowledge about a species’ life history and reproductive behaviour is fundamental for understanding its biology, ecology, and potential role in ecosystem services. Here, we focused on the dung beetle species Onthophagus lecontei. Adults were collected in the field and then confined to terrariums, where they were supplied with semi-fresh domestic goat dung (Capra aegagrus Erxleben, 1777). After being paired (26 pairs), the nesting behavior of beetles was observed under laboratory conditions and the preimaginal development of individuals obtained from mating (from the deposition of the egg until the emergence of the adult) was described. Their nesting behavior was found to be characteristic of what is known as pattern I, which comprises building of brood masses, oviposition of a single egg in each brood mass, development of three larval instars, construction of a pupation chamber, pupal stage and adult emergence. Both sexes were involved in the handling of dung, tunnel construction, and mass nest elaboration. Pairs built from one to seven brood masses. The pre-nesting period (feeding) lasted 16 days; the egg stage two days, the larval period 22 days; the pupal period 11 days and the imagoes four days, after which the adults emerged. Our results are discussed and compared with other species in the genus. However, our knowledge of this dung beetle is still limited, and further studies are required in all areas of its biology.


1966 ◽  
Vol 42 (1) ◽  
pp. 76-82 ◽  
Author(s):  
A. F. Hedlin

Cone-bearing Douglas-fir trees in three localities on Vancouver Island were sprayed with the systemic insecticides Bidrin (0.35 and 0.75%), dimethoate, Sumithion, Meta-Systox-R, and SD 9129 (1.0 and 2.0%) when cones had reached the pendent stage of development. With the exception of Sumithion, all materials gave varying degrees of control over important insect pests of cones in this area, i.e. the gall midge, Contarinia oregonensis Foote, the cone moth, Barbara colfaxiana (Kft.), the seed chalcid, Megastigmus spermotrophus Wachtl, and the scale midge, C. washingtonensis Johnson.


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