桔褐天牛和桑粒肩天牛幼虫声行为的研究

对寄主木段中的桔褐天牛Nadezhdiella cantori(Hope)幼虫、桑粒肩天牛Apriona germari(Hope)幼虫的声行为进行了研究。天牛幼虫在寄主内可因取食、爬行活动而产生沿寄主传导的固体声。与爬行声相比,幼虫取食声的振幅大、持续时间短(约60ms)、间歇发出,振动频率可达700Hz;爬行声的振幅小、持续时问可达数百毫秒、可连续发出,振动频率低于300Hz。取食声信号因天牛幼虫的种类和寄主的种类不同而有明显差别。桔褐天牛幼虫取食声功率谱为准谐型,谱带2(B_2)为主能量带,其主峰频率(MPF=424±43Hz)约为B_1的MPF的1.8倍频。桑粒肩天牛幼虫取食声功率谱多为非谐型,大多数被测信号多以谱带1为主能量带(81％),不同木段中幼虫取食声谱带1的MPF分别为359±23Hz和293±26Hz。     

Response of bat species to sylvo-pastoral abandonment

We assessed the effect of abandonment of sylvo-pastoral practices in chestnut orchards (Castanea sativa) on bats in southern Switzerland to determine practical recommendations for bat conservation. We compared bat species richness and foraging activities between traditionally managed and unmanaged chestnut orchards, testing the hypothesis that managed orchards provide better foraging opportunities and harbour more bat species. Echolocation calls of foraging bats were sampled simultaneously at paired sites of managed and unmanaged orchards using custom made recorders. Vegetation structure and aerial insect availability were sampled at the recording sites and used as explanatory variables in the model. In a paired sampling design, we found twice the number of bat species (12) and five times higher total foraging activity in the managed chestnut orchards compared to the unmanaged ones. Bat species with low flight manoeuvrability were 14 times more common in managed orchards, whereas bats with medium to high manoeuvrability were only 5 times more common than in abandoned orchards. The vegetation structure was less dense in managed orchards. However, management did not affect relative insect abundance. Bats primarily visited the most open orchards, free of undergrowth. As a result of restricted access into the overgrown forests, the abandonment of chestnut orchards leads to a decline in bat species richness and foraging activities. Continued management of chestnut orchards to maintain an open structure is important for the conservation of endangered bat species in the southern Swiss Alps.     

红棕象甲幼虫声音室内探测

根据红棕象甲幼虫蛀食、爬行时发出的声音,运用AED-2000L便携式声音探测仪对不同虫口密度幼虫的树段、树段的不同测试位点、不同温度条件下的幼虫、不同发育阶段的幼虫进行室内声音探测.结果表明:①随着虫口密度的增大,测量值(Total Hits和Total counts)随之增大,说明一定密度虫口范围内,虫口密度越大,声音探测效果越明显;②测试位点的选取对探测效果有较大影响,随着测试位点与幼虫距离的增大,测量值(Total Hits和Total counts)随之减小;③温度对幼虫活动声音的探测值(Tota) Hits)也有较大的影响,在(28±1)℃条件下,幼虫声音平均探测值(Total Hits)最大,其次(24±1)℃、(32±1)℃条件下幼虫声音平均探测值(TotalHits),但三者没有显著差异;④随着幼虫日龄的增加,测量值(Total Hits和Total counts)随之增大,但到末龄幼虫(接近预蛹期)时,测量值(Total Hits和Total counts)开始明显下降.     

Development of external and neutrally buoyant acoustic transmitters for juvenile salmon turbine passage evaluation

Fish can sustain injury or mortality when they pass through hydroelectric facilities. To develop a method to monitor the passage and survival of juvenile salmonids without bias through turbines within the Federal Columbia River Power System, we developed and fabricated two designs of neutrally buoyant transmitters: Type A (sutured to the dorsal musculature of the fish anterior to the dorsal fin) and Type B (two-part design attached with wire pushed through the dorsal musculature, ventral to the dorsal fin). To determine the efficacy of the two designs under non-turbine passage-related conditions, fish had one of the tags attached and were held for 14 days to determine any potential effects of the tags on growth, survival and tissue damage. We also evaluated the attachment method by monitoring tag retention. These two neutrally buoyant tag designs were compared to nontagged individuals and those surgically implanted with current Juvenile Salmon Acoustic Telemetry System (JSATS) transmitters and passive integrated responder (PIT) tags. In addition, two suture materials (Monocryl and Vicryl Rapide) were tested for attachment of Type A tags. When compared with non-tagged individuals, fish tagged with Type A tags did not differ significantly with respect to growth or mortality over a 14-d holding period. However, fish tagged with Type B transmitters had lower growth rates than the nontagged controls or other tag treatments. The efficacy of two designs was also compared to nontagged individuals under shear exposure. Fish were exposed to a submerged, 6.35-cm-diameter water jet at velocities ranging from 3.0 to 12.2 m/s in a water flume to simulate turbine conditions within the Columbia River basin. Throughout the shear exposure study, no mortalities or tag loss were observed. There was also no significant difference in the rates of shear injury between untagged fish and fish tagged with Type A or Type B tags. When tissue damage was assessed for tagged individuals exposed to shear forces, those tagged with Type A tags showed lower rates and severity of injury when compared to Type B-tagged fish. Overall, Type A tags may be a viable tag design for juvenile Chinook salmon passing through hydropower facilities.     

Relationship between tissue firmness and optical properties of ‘Royal Gala’ apples from 400 to 1050 nm

Absorption and reduced scattering coefficients were measured between 400 and 1050 nm for ‘Royal Gala’ apples using the inverse adding-doubling technique. Relationships between penetrometer, acoustic firmness and the optical properties are identified. Carotenoid (400–500 nm), and to a lesser extent chlorophyll-a (680 nm), absorptions were found to correlate with penetrometer firmness, with correlation coefficients equal to −0.69 and 0.52 respectively. The reduced scattering coefficient across all wavelengths increased as fruit softened. An average correlation coefficient of −0.68 was found between the reduced scattering coefficient (550–900 nm) and penetrometer firmness. No correlation was found between the AWETA acoustic firmness and either of the optical properties. A correction was developed to improve the correlation between penetrometer firmness and carotenoid absorption. This compensated for errors introduced by light loss in the inverse adding-doubling system and improved the correlation from −0.68 to −0.78.