苏云金芽孢杆菌YJ-2000菌株对家蚕主要生物学特性影响的研究

苏云金芽孢杆菌YJ 2 0 0 0菌株对多种鳞翅目害虫具明显杀虫活性而对家蚕蚁蚕表现低毒性。以对家蚕蚁蚕表现高毒性的苏云金芽孢杆菌CRY1Ab和YJ 1999菌株为对照 ,研究了苏云金芽孢杆菌YJ 2 0 0 0菌株对家蚕的生物学安全性。YJ 2 0 0 0菌株除导致 1龄幼虫历期延长 11 1%、取食量减少 0～ 6 0 0 %及体重降低 5 2 3%～ 6 2 5 %外 ,对 2龄及其以后各龄幼虫的存活率、发育历期、取食量、眠蚕体重、化蛹率、蛹期、全茧量、蛹重、茧层量、羽化率和产卵量等均无显著影响。相比之下 ,CRY1Ab和YJ 1999菌株则不同 ,高浓度会导致全部蚁蚕死亡 ,呈现高急性毒性 ;低浓度虽不能使幼虫全部死亡 ,但对幸存幼虫的取食、生长发育、结茧和产卵等大多呈现明显的不良影响。综合分析认为 :YJ 2 0 0 0菌株对家蚕不仅低毒 ,而且对其生长发育、结茧和生殖力等均无明显的不良影响。     

催青温度对家蚕二化性品种丙酮酸脱氢酶激酶基因(BmPDK)表达的影响

丙酮酸脱氢酶激酶(PDK)在生物体的新陈代谢中具有重要的生理功能。为了探讨家蚕(Bombyx mori)PDK基因的表达特性,用蛾区半分法将二化性家蚕品种的活化越年卵(丙2期)分别以常温(25℃)光照和低温(15℃)黑暗催青,通过实时荧光定量PCR技术检测分析2种温度催青处理后家蚕不同发育阶段和不同组织的BmPDK表达水平。常温光照催青区BmP-DK的表达水平表现出发育时期和组织差异:胚胎发育阶段BmPDK在己4期的表达水平最高,其次是戊2、己3和己5期;幼虫发育阶段BmPDK的表达水平在蚁蚕期极显著高于其它龄期,5龄期在卵巢和精巢的表达水平高于其它组织;蛹期BmPDK的表达水平比其它发育时期低;成虫期的表达水平与胚胎发育末期相当,其中雌蛾的脂肪体和卵巢中BmPDK的表达水平较高。推测BmPDK在家蚕胚胎发育末期及产卵过程中有重要作用。催青温度影响BmPDK在家蚕各发育时期及卵巢组织中的表达水平:胚胎发育阶段戊2期BmPDK的表达水平为常温催青区显著高于低温催青区,己3～己5期常温催青区BmPDK的表达呈低-高-低的趋势,而低温催青区则呈上升趋势;蚁蚕期BmPDK表达水平为低温催青区极显著低于常温催青区;蛹期和成虫期卵巢中,常温催青区BmPDK的表达水平极显著高于低温催青区。催青温度对二化性家蚕BmPDK的表达的影响主要出现在胚胎戊2期、胚胎己3期～蚁蚕期、蛹期、成虫期。     

In vitro acaricidal effect of plant extract of neem seed oil (Azadirachta indica) on egg, immature, and adult stages of Hyalomma anatolicum excavatum (Ixodoidea: Ixodidae)

Effects of the plant extract of neem seed (Azadirachta indica) on eggs, immature, and adult stages of Hyalomma anatolicum excavatum was studied at concentrations of 1.6, 3.2, 6.4, and 12.8%. The extract was found to have a significant effect on the hatching rate of eggs. It significantly increased the hatching rate during the first 7 days post-treatment (DPT) giving incompletely developed and dead larvae; however, it cause hatching failure at DPT 15. Neem Azal F induced a significant increased in mortality rates of newly hatched larvae, unfed larvae, and unfed adults reaching 100% on 15th, 3rd, and 15th DPT, respectively. The mortality rates increased with the extract concentrations. Although, it had no significant effect on the moulting rates of fed nymphs, it caused malformation or deformities in 4% of adults moulted. It was concluded that the concentration of Neem Azal F which may be used for commercial control of this tick species were 1.6 and 3.2%.     

Early development of artificially spawned southern mullet,Liza richardsonii (Smith, 1846)

The embryonic development of artificially spawned southern mullet, Liza richardsonii, eggs and the development of the larvae to 46 days are described and illustrated using drawings and photographs. The floating eggs hatched in sea water at 18–24°C after 46–60 h. Newly stripped eggs usually had more than one oil droplet (up to 16) which merged during development. Free embryos averaged 2,36 mm at hatching and had distinct yellow pigment.     

Effect of luteinizing hormone on the right regressing ovary of newly hatched chicks treated during embryonic development

We studied the histologic and stereological changes induced in the right ovary of newly hatched chicks treated with LH during their embryonic development. Results indicate that LH administration causes a diminution in size and total volume (P < 0.01) of the right ovary, as well as a decrease in the total volume of lacunar channels, blood vessels, and interstitium. Other changes obtained after LH treatment were a reduction (P < 0.001) in the number of germ cells, as well as an increase in the total volume of interstitial cell cords (P < 0.01). This expansion is due to the increase of cellular volume of interstitial cells (P < 0.001) and not to their number, which decrease in the LH-treated right ovary. All these modifications were similar to those occurring in the regressing right ovary during development. The findings suggest that the right ovary of the newly hatched chick is able to respond to LH treatment during embryonic development, inducing marked histologic changes that accelerate its regression.     

Rearing of Culicoides nubeculosus (Diptera: Ceratopogonidae) by natural or artificial feeding in the laboratory

A technique for the mass rearing of Culicoides nubeculosus in the laboratory is described. Female midges were fed either on fresh or deep-frozen, defibrinated cattle blood (-70 degrees C) through latex membranes, or on anesthetized white mice. Feeding rates of up to 90% were obtained on the latex membrane, whereas only 41% of the midges fed on mice. The best oviposition rates of greater than 50% were achieved after feeding either on the latex membrane with fresh cattle blood or on mice. An average of greater than 100 eggs per female were deposited. The highest larval hatching rate was observed after feeding with fresh blood; about half of the larvae developed to the adult stage. A reproduction index was defined for the colony based on the feeding rate, oviposition rate, larval hatching rate and development to the adult stage. The highest reproduction index was obtained when the midges were fed on fresh cattle blood through the membrane.     

Biology of hippobosca longipennis (fabricus, 1805) in Egypt (Dipteria: Hippoboscidae)

Emergence of the adult flies took place mainly between 7 and 9 a.m. The feeding mechanim was described. The prefeeding period varied from several seconds to 30 minutes. The duration of a complete blood meal took, on average, 8 minutes, and adults had to take a blood meal at least every 6 hours. The weight of the blood meal taken by newly emerged flies was 2.56 mg and 3.35 mg in males and females, respectively. The flies starvation more easily in moist than in dry atmosphere, and newly emerged flies in the laboratory were more tolerant to starvation that were flies collected in the field. Female flies were less affected by starvation than males. Male and female flies reached sexual maturity after 8 and 5.40 days, respectively, and sex ratio was 43.96% males and 56.04% females. The act of mating was described. The duration was 12 minutes. The period epapsing between two successive larvipositions was determined during August (3.6 days), November (4.1 days), February (6.4 days) and May (3.9 days). The third larval stage was described. The mean adult longevity in August was 41 and 45,6 days in males and females, respectively, whereas in February it was 56.6 and 64.9. The number of larvae laid per female was 8.2 in August and 8.7 in February.The external morphology of the pupa was described. The effect of adult food on the pupal size and weight was tested. The maximum pupal period under insectary conditions was of the larvae laid during the 4th week of November (142 days) and the minimum was for the larvae laid during the fourth week of June of the second week of July (19 days). The effect of temperature on the pupal duration was described. The shortest duration (18.8 days) occured at 32°C, while the longest (130.1 days) was at 20°C. No emergence occured at temperatures above 32°C. Study of the effect of relative humidity on the pupal duration revealed that 40% humidity was the optimum for pual development. The mean duration of pupal produced by flies reared on guinea pigs was slightly longer (20.54 days) than those obtained from flies reared on dogs (20.08 days).     

Efficiency of entomopathogenic fungi in the control of eggs and larvae of the horn fly Haematobia irritans (Diptera: Muscidae)

The present study assessed the pathogenic effect of isolates E9, IBCB425 and IBCB159 of the Metarhizium anisopliae fungus, JAB06, JAB07 and AM09 of Beauveria bassiana, IBCB133 and CB75 of Isaria fumosorosea (=Paecilomyces fumosoroseus) and CG189 and CG195 of Isaria farinosa (=Paecilomyces farinosus) against eggs and larvae of the horn fly Haematobia irritans. Eggs were inoculated with suspensions containing 10⁶, 10⁷ and 10⁸ conidia ml⁻¹ of the fungal isolates and observed after 48 h to determine viability. In the larvae study, eggs were allowed to hatch into fresh bovine feces that had been treated with 10⁸, 10⁷ or 10⁶ conidia mg feces⁻¹. In both studies, 5 days after initial procedures, all formed pupae were transferred to an incubator at 27 ± 0.5 °C until the emergence of the adult flies was complete. The M. anisopliae isolates did not cause the death of H. irritans eggs, but they did promote the death of larvae that hatched from treated eggs, and therefore increased the total mortality. Isolate E9 promoted 100% mortality of treated larvae at a concentration of 10⁸ conidia ml⁻¹. For the B. bassiana isolates, no activity was observed against insect eggs or larvae. Both I. fumosorosea isolates promoted significant mortality (p < 0.05) of eggs at every concentration of conidia. Isolate CG195 of I. farinosa increased the mortality of larvae and pupae that hatched from treated eggs and promoted significant total mortality (p < 0.05) of the insect at every concentration of conidia.     

桑天牛卵啮小蜂Aprostocetus prolixus的寄生生物学研究

桑天牛卵啮小蜂 (Aprostocetusprolixus)是一个新种 ,对桑天牛有较高的寄生率。观察发现该寄生蜂 1年 2～ 3代 ,老熟幼虫以休眠状态越冬。 6月下旬越冬代的成虫开始羽化 ;第 1代成虫 7月下旬开始羽化 ,8月上中旬为盛期 ;第 2代幼虫一部分以老熟幼虫直接越冬 ;第 2代成虫 8月下旬至 9月中旬羽化 ,8月底与 9月初为盛期 ,所产小蜂幼虫从 9月中下旬开始陆续以老熟幼虫在寄主体内越冬。探明了该寄生蜂的羽化时间、交配、产卵、寄生等行为习性。     

Embryonic and larval development of garpike from the Adriatic Sea

Although information about embryonic and larval development of garpike, Belone belone (Linnaeus, 1761), is present in the published literature, the bulk of research concerns garpike from the northeastern Atlantic Ocean and the Baltic Sea. The present work describes the embryonic and larval development of garpike, Belone belone, from the Adriatic Sea, and methods used for incubation of fertilized eggs in aquarium conditions. Because garpike is, as suggested by some authors, divided into subspecies, we conclude that some differences in embryonic development could also be expected. In the present study, eggs were fertilized using the dry fertilization method and were incubated in a tank equipped with aeration and constant sea water flow. Salinity and content of dissolved oxygen were constant, and the temperature varied between 19.4 and 22.3°C. Eggs were spherical, measuring 3071.9 ± 75.73 μm in diameter. Yolk sacs were homogeneous and did not contain oil globules. The first larvae hatched 329 h and 47 min after fertilization. Absorption of the yolk sac occurred 17 h – 48 h after hatching and the total length of newly hatched larvae was 9.78 mm. The peculiarities observed in the embryonic and early larval development are evidence of an exceptional plasticity and adaptive potential, which could be considered as helpful features in extending the natural range of occurrence of this species.     

家蚕人工饲料育的小蚕饲育技术研究

从收蚁方法、饲料形状、光照条件等方面研究家蚕人工饲料育的小蚕饲育技术。结果表明 :不带卵壳收蚁其疏毛率、起蚕率、生长发育进度优于带壳卵收蚁 ;收蚁用饲料以平板状为好 ,有利于蚕的取食和疏毛 ,2龄以后用片状饲料饲育较适宜 ;光线不仅影响蚕的生长发育 ,而且影响饲料价值。为便于实际操作 ,防止饲料变质和污染 ,保持饲料水分等以黑暗封闭饲育为宜     

Arteria maxillaris of the donkey (Equus asinus)

Gross anatomical examination of the organization of the maxillary artery was carried out in 10 formalin embalmed, latex injected adult donkeys. The results indicate that although there are variations from other domestic animals, the distribution of this artery in the donkey is similar to that of the horse.     

柞树害虫栎粉舟蛾的初步研究

栎粉舟蛾Femtoma ocypete(Bremer)是柞树的重要害虫之一。此虫在辽宁一年发生一代,以蛹在土中越冬。翌年7月中旬开始羽化,持续到8月中旬。羽化后即可交配产卵。7月下旬到8月下旬均有幼虫孵出。幼虫经6个龄期,于9月中、下旬入土化蛹。防治方法:8月中旬往柞树上喷洒0.025％浓度的“杀虫灵”农药,能杀死各龄幼虫,防治效果为90％左右,七天后养蚕无害。     

Acaricidal activity of limonene, limonene oxide and beta-amino alcohol derivatives on Rhipicephalus (Boophilus) microplus

Limonene, limonene oxide and eight beta-amino alcohol derivatives obtained by synthesis were investigated for the effect on egg hatchability and mortality rates of newly hatched larvae of the cattle tick Rhipicephalus (Boophilus) microplus. At the doses between 10mug/ml and 2.5mug/ml all the compounds were highly lethal to the larvae and some of them showed activity at lower concentrations. The effect on the eggs hatchability was observed in all the treatments.     

Larval biology of rhipicephalus (Boophilus) decoloratus (Acarina: Ixodidae) in Free State Province, South Africa

The objective of this study was to determine certain aspects of the biology of Rhipicephalus (Boophilus) decoloratus larvae under laboratory and field conditions. Larvae allowed 48 h to select a vertical questing substrate preferred 90 cm rods in length to those of 60 or 30 cm, while in a separate experiment migration from rods 5 cm or 25 cm in length to rods 45 cm in length continued between 48 h and 72 h after larval release. Hatching of the larval progeny of engorged female ticks exposed to ambient field temperatures during the period June to August, occurred synchronously during the third or fourth week of November. With a single exception, larvae that hatched during November and between April and July survived for 38 days or longer, while those that hatched from December to March survived for 31 days or less. Questing larvae were present on vegetation throughout the year, with most being recovered during January and February. Parasitic larvae were present on cattle from October to May with most being collected during January and February.     

Evaluation of the prophylactic effect and curative efficacy of fipronil 1% pour on (Topline) on post-castration scrotal myiasis caused by Cochliomyia hominivorax in cattle

A field trial was carried out during a summer-fall period on a commercial beef cattle farm in Minas Gerais State, located in the Southeast of Brazil. In order to evaluate the prophylactic effect and the curative efficacy of fipronil in a 1% solution, 200 Zebu crossbred bulls, with ages varying from 20 to 30 months and weights from 233 to 362 kg, were selected. The bulls were assigned by ranked pair to an untreated control group (A) or to a treated group (B), resulting in 100 animals per group. All experimental animals were surgically castrated on day 0, following routine procedures. After castration all animals in the group B were treated with 10 mg/kg bw of a 1% fipronil solution, topically on the dorsal mid-line. The wounds were individually inspected on days: 2, 4, 7, 10, 14, 17, 21, 28 and 35. After castration the animals were naturally exposed to Cochliomyia hominivorax and remained in the same pasture throughout the trial. Among the animals in the control group, 83 were observed to harbor C. hominivorax eggs, with a total of 97 ovipositions, and among those 73 animals had active myiasis. In group B (fipronil 1%), 66 animals showed C. hominivorax eggs, with 92 ovipositions and five animals with active myiasis. Most ovipositions and active myiasis were detected until seven days post-castration for both groups. Wound parasite infestation evidenced bleeding, serous purulent exudation and presence of active C. hominivorax larvae. Treatment with fipronil 1% had a prophylactic effect on scrotal wounds against the development of C. hominivorax larvae in more than 95% of the treated animals for up to 17 days after castration. The treatment showed partial protection of 66% and 50% on days 21 and 28 post-treatment (pt), respectively. Three animals from the control group and one from the treated group showed active screwworms on day 21 pt, and one animal from the treated group and two from the control group also presented C. hominivorax larvae on scrotal wounds on day 28 pt. By the end of the observation period (day 35 pt), the castration wound had healed in all animals. All experimental animals presenting scrotal wounds infested with C. hominivorax larvae were treated with a 1% pour-on formulation of fipronil, on the same day that infestation was observed. Active C. hominivorax larvae were not seen during the monitoring period immediately after treatment. The curative efficacy of fipronil 1% against C. hominivorax larvae infestation in castration wounds was 100%.     

Cross-transmission studies with Hypoderma lineatum de Vill. (Diptera: Oestridae): attempted infestation of goats (Capra hircus)

The potential for cross-transmission of Hypoderma lineatum from cattle to domestic goats (Capra hircus) was examined using artificial infestation techniques. Two routes of infestation, subcutaneous injection and dermal penetration, were used to expose goats to newly hatched first instars. Presence of antibodies and appearance of circulating antigen (hypodermin C) were evaluated at selected intervals for up to 40 weeks post-infestation. In addition, immunoblots against H. lineatum first-instar proteins were conducted using sera taken at 10 weeks post-infestation. Goats were palpated for the presence of developing larvae at sub-dermal sites beginning at week 30 pi. No developing larvae were palpated at any time, regardless of the route of infestation nor was circulating antigen detected in any infested goats. Antibodies were present at weeks 6 and 10 and week 27 pi in both infested groups. Immunoblots indicated all infested goats produced antibodies to first instar H. lineatum antigens. H. lineatum appears to be incapable of completing development in domestic goats although the transient appearance of ELISA detectable antibodies and the presence of bands on immunoblots suggests that at least some larvae survive long-enough to engender a humoural response. The host specificity of H. lineatum is discussed in light of the general concepts of host-parasite relationships of oestrids.     

Acaricidal activity of Calea serrata (Asteraceae) on Boophilus microplus and Rhipicephalus sanguineus

Calea serrata (Asteraceae) is an endemic Southern Brazilian plant species used for religious and medicinal purposes. Previous study revealed the presence of chromenes, a class of natural compounds that possess insecticidal properties. This study reports the effect of the hexane extract from the aerial parts of this plant on egg hatchability, egg production and mortality rates of newly hatched larvae of the cattle tick Boophilus microplus. Larvae of Rhipicephalus sanguineus, the brown dog tick, received the same treatment. The extract was toxic to the eggs of B. microplus and to the larvae of both B. microplus and R. sanguineus.     

家蚕种质资源对无桑人工饲料的摄食性调查

对 38 6个家蚕保存品种进行无桑人工饲料的摄食性调查 ,蚁蚕 48h摄食率平均为 1 74%,最高为83 98%。蚁蚕 48h疏毛率平均为 0 5 7%,最高为 6 6 4 8%。家蚕种质资源的不同品种对无桑人工饲料的摄食性 ,以中系一化为最好 ,多化最差。 48h疏毛率与摄食率呈高度正相关 (r =0 85 9)。不同品种对无桑人工饲料和有桑人工饲料摄食性的相关系数为 0 0 86 9,未达到显著水平。     

Further evidence on the internal life cycle of Przhevalskiana silenus (Diptera, Oestridae)

Knowledge of the internal life cycle of goat warble fly infestation is scarce despite ample data available on the aetiology, epidemiology, immunodiagnosis and treatment of such infestations. This study was carried out at the slaughterhouse of Rossano Calabro (Cosenza, southern Italy) on 154 animals from 10 months to 6 years of age from May 1997 to June 1998. 1206 Przhevalskiana silenus larvae were collected during the trial period from the subcutaneous tissue of the slaughtered animals. The larval stage average size ranged from 4.7 mm, for first instar larvae (May), to 16.6 mm, for third instar larvae (February), in the first cycle of infestation. No larvae were found in March-April, coinciding with the pupation period. Small first instar larvae were found at the beginning of the second cycle of infestation (May-June). Necroscopic examinations were also carried out on internal organs and no larvae were found. The results pointed out that the internal life cycle of P. silenus is exclusively subcutaneous and there is no internal migration of the larvae.