HOST FINDING BEHAVIOR OF COELOIDES BRUNNERI (HYMENOPTERA: BRACONIDAE)

1972 ◽  
Vol 104 (8) ◽  
pp. 1235-1250 ◽  
Author(s):  
J. V. Richerson ◽  
John H. Borden
Keyword(s):  
Ponderosa Pine ◽  
Random Search ◽  
Host Finding ◽  
Douglas Fir ◽  
Search Pattern ◽  
Dendroctonus Pseudotsugae ◽  
Straight Path ◽  
Search Patterns ◽  
Plastic Cylinder ◽  
Host Finding Behavior

AbstractThe host-finding search patterns of Coeloides brunneri Viereck, a braconid parasite of Douglas-fir beetle larvae, were studied by visual observations and from tracings of the parasite’s path on a plastic cylinder wrapped around a beetle-infested log on which the parasite was searching. The female parasite locates its host, lying under approximately.6 cm of bark, through four distinct phases of host finding: random search, nonrandom search, oviposition, and nonsearch (resting and cleaning). Random search is characterized by large areas of bark being examined in a relatively straight path. Nonrandom search is a highly intensified examination of a small bark area and numerous turns of greater than 70°. Nonrandom search is initiated only at the end of a bark beetle gallery. Ovipositional probes are the culmination of successful host finding, in which the parasite paralyzes the host and deposits an egg. C. brunneri searched effectively on both Dendroctonus pseudotsugae Hopkins in Douglas-fir and D. ponderosae Hopkins in ponderosa pine, although there was a slightly more efficient search on D. pseudotsugae. The percentage of time spent in each search pattern was identical in 90-minute and 24-hour tests. A stimulus associated with the end of a larval gallery was concluded to be the key stimulus by which the parasite recognizes its host. Amputation experiments showed that the antennae are the principal receptor organs used in host finding. Various experiments and observations produced no evidence that sound or vibrations produced by the host, sound produced by the parasite (sonar), magnetism or odor of the host, or its host tree are used in host finding.

scholarly journals Adaptive switch to sexually dimorphic movements by partner-seeking termites

2018 ◽  
Author(s):  
Nobuaki Mizumoto ◽  
Shigeto Dobata
Keyword(s):  
Random Search ◽  
Search Pattern ◽  
Sexually Dimorphic ◽  
Tandem Running ◽  
Exact Location ◽  
Nest Sites ◽  
Mate Search ◽  
Search Patterns ◽  
Straight Lines ◽  
Search Modes

AbstractWhen searching for targets whose location is not known, animals should benefit by adopting movement patterns that promote random encounters. During mate search, theory predicts that the optimal search pattern depends on the expected distance to potential partners. A key question is whether actual males and females update their mate search patterns to increase encounter probability when conditions change. Here we show that two termite species, Reticulitermes speratus and Coptoterines formosanus, adaptively alternate between sexually monomorphic and dimorphic movements during mate search. After leaving their nests in a synchronized manner, termites begin to search for a mate. The resulting pairs perform tandem runs toward potential nest sites. We found that both sexes moved faster and in straight lines before finding partners, which is known to improve encounter rates when targets have completely unpredictable positions. In stark contrast, when pairs were accidentally separated during tandem running, they showed distinct sexually dimorphic movements, where females paused for long periods while males paused only briefly and moved actively. Data-based simulations demonstrated that such sexually dimorphic movements are advantageous when a mate is located nearby but its exact location is unknown. These results emphasize the importance of biological details to evaluate the efficiency of random search in animals. By extending the concept of mutual search beyond the context of mating, the dimorphic movements between partners represent a remarkable convergence between termites and other animals including humans.Significance StatementHow should females and males move to search for partners whose exact location is unknown? Theory predicts that the answer depends on what they know about where targets can be found, indicating that the question doesn’t make sense until the searching context is clarified. We demonstrated that termites adaptively switch their search modes depending on the potential distance to their partners. When the location of potential mates was completely unpredictable, both sexes moved in straight lines to explore widely. In contrast, when the stray partner was at least nearby, males moved while females paused. Simulations confirmed that these movements increase the rate of successful encounters. The context-dependent switch of search modes is a key to enhance random encounters in animals.

Laboratory and Field Methods for Assaying Olfactory Responses of the Douglas-fir Beetle, Dendroctonus pseudotsugae Hopkins

1965 ◽  
Vol 97 (9) ◽  
pp. 935-941 ◽  
Author(s):  
O. K. Jantz ◽  
J. A. Rudinsky
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Field Tests ◽  
Douglas Fir ◽  
Pinus Monticola ◽  
White Pine ◽  
Larix Occidentalis ◽  
Dendroctonus Pseudotsugae ◽  
Field Methods ◽  
Olfactory Responses

AbstractLaboratory tests revealed that female Douglas-fir beetles, Dendroctonus pseudotsugae Hopkins, boring in logs of both host and non-host species produce a volatile substance that both attracts and arrests adult beetles. Male arrestment provided a reliable method for laboratory bioassay of volatile substances. Field tests were devised to show the attack, the attraction produced, and the broad development in six tree species: Douglas-fir, Pseudotsuga menziesii (Mirb.) Franco; western larch, Larix occidentalis Nutt.; ponderosa pine, Pinus ponderosa Laws.; western hemlock, Tsuga heteropbylla (Raf.) Sarg.; western white pine, Pinus monticola Dougl.; and grand fir, Abies grandis (Dougl.) Lindl.

3-Methylcyclohex-2-en-1-one and the Douglas-fir beetle (Coleoptera: Curculionidae): history of successful bark beetle pheromone treatments

2020 ◽  
Vol 153 (1) ◽  
pp. 62-78
Author(s):  
Darrell W. Ross
Keyword(s):  
Bark Beetle ◽  
Douglas Fir ◽  
Future Research ◽  
Beetle Species ◽  
Successful Management ◽  
Dendroctonus Pseudotsugae ◽  
Successful Development ◽  
History Of ◽  
Antiaggregation Pheromone

AbstractThis paper reviews the literature on the identification of 3-methylcyclohex-2-en-1-one (MCH) as the antiaggregation pheromone of the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) (Coleoptera: Curculionidae) and the development of successful management applications using the pheromone. Previously unpublished data from two studies on novel uses of MCH are included. The successful development of antiaggregation pheromone-based treatments for the Douglas-fir beetle is discussed in relation to efforts to develop similar treatments for other bark beetle species, and opportunities for future research on MCH and the Douglas-fir beetle are suggested.

scholarly journals Douglas Fir and Ponderosa Pine Seed Dormancy as Regulated by Grassland Seedbed Conditions

2004 ◽  
Vol 57 (6) ◽  
pp. 661 ◽  
Author(s):  
Yuguang Bai ◽  
Don Thompson ◽  
Klaas Broersma
Keyword(s):  
Seed Dormancy ◽  
Ponderosa Pine ◽  
Douglas Fir

Dendroctonus pseudotsugae. [Distribution map].

2004 ◽  
Author(s):  
Keyword(s):  
British Columbia ◽  
New Mexico ◽  
North America ◽  
Geographical Distribution ◽  
Pseudotsuga Menziesii ◽  
Douglas Fir ◽  
Distribution Map ◽  
Dendroctonus Pseudotsugae ◽  
New Distribution

Abstract A new distribution map is provided for Dendroctonus pseudotsugae Hopkins Coleoptera: Scolytidae Hosts: Mainly Douglas fir (Pseudotsuga menziesii), also other Pseudotsuga spp. Information is given on the geographical distribution in NORTH AMERICA, Canada, Alberta, British Columbia, Mexico, USA, Arizona, California, Colorado, Idaho, Montana, Nevada, New Mexico, Oregon, Texas, Utah, Washington, Wyoming.

A field experiment informs expected patterns of conifer regeneration after disturbance under changing climate conditions

2015 ◽  
Vol 45 (11) ◽  
pp. 1607-1616 ◽  
Author(s):  
Monica T. Rother ◽  
Thomas T. Veblen ◽  
Luke G. Furman
Keyword(s):  
Field Experiment ◽  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Douglas Fir ◽  
Tree Regeneration ◽  
Colorado Front Range ◽  
Front Range ◽  
Average Growth ◽  
Growth And Survival ◽  
Treatment Type

Climate change may inhibit tree regeneration following disturbances such as wildfire, altering post-disturbance vegetation trajectories. We implemented a field experiment to examine the effects of manipulations of temperature and water on ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) and Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seedlings planted in a low-elevation, recently disturbed setting of the Colorado Front Range. We implemented four treatments: warmed only (Wm), watered only (Wt), warmed and watered (WmWt), and control (Co). We found that measures of growth and survival varied significantly by treatment type. Average growth and survival was highest in the Wt plots, followed by the Co, WmWt, and Wm plots, respectively. This general trend was observed for both conifer species, although average growth and survival was generally higher in ponderosa pine than in Douglas-fir. Our findings suggest that warming temperatures and associated drought are likely to inhibit post-disturbance regeneration of ponderosa pine and Douglas-fir in low-elevation forests of the Colorado Front Range and that future vegetation composition and structure may differ notably from historic patterns in some areas. Our findings are relevant to other forested ecosystems in which a warming climate may similarly inhibit regeneration by dominant tree species.

Failure of ovarian development in the Douglas-fir bark beetle, Dendroctonus pseudotsugae; an analysis of gut proteases and female-specific proteins

1971 ◽  
Vol 49 (7) ◽  
pp. 1021-1024 ◽  
Author(s):  
T. S. Sahota
Keyword(s):  
High Activity ◽  
Bark Beetle ◽  
Methyl Ether ◽  
Bark Beetles ◽  
Ovarian Development ◽  
Proteolytic Enzymes ◽  
Douglas Fir ◽  
Dendroctonus Pseudotsugae ◽  
Specific Proteins ◽  
Female Specific

The failure of ovarian development in Douglas-fir bark beetles denied of their natural gallery environment and maintained on host bark chips was investigated. Such insects possessed a high activity of proteolytic enzymes in their guts but relatively small amounts of female-specific proteins both in haemolymph and the oocytes. Topical application of farnesyl methyl ether did not increase the activity of gut proteases but resulted in increased amounts of female-specific proteins in haemolymph and ovaries. Thus it appears that the Douglas-fir bark beetles maintained on bark chips do not suffer from an inability to break down the ingested proteins, but synthesize and transfer less than normal amounts of female-specific proteins to the developing oocytes.

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