Feedback control of juvenile hormone synthesis in cockroaches: possible role for ecdysterone

Inactive female corpora allata implanted into adult males become active and continue to synthesize juvenile hormone at high rates. However, when an ovary is implanted together with the corpora allata, rates of juvenile hormone synthesis decline as the oocytes complete maturation. Injections of ecdysterone mimic the effect of an implanted ovary.     

Canopy orientation: a new kind of orientation in ants

Celestial cues, such as the sun or patterns of polarized sky light, appear to have no detectable effect in the precise homing orientation of foragers of Paltothyreus tarsatus. Field and laboratory experiments reveal that canopy patterns are a major influence in the home range orientation of this ponerine ant, a common species in African forests. Canopy orientation appears to be well suited to the restrictive lighting conditions of tropical forests.     

Natural and synthetic allatotoxins: suicide substrates for juvenile hormone biosynthesis

Cytotoxic agents with antijuvenile hormone activity in insects have been discovered. Their mechanism of action may involve an oxidative bioactivation into a reactive quinone methide.     

A new approach in integrated control: insect juvenile hormone plus a hymenopteran parasite against the stable fly

Two insect juvenile hormone analogs, 4[(6,7-epoxy-3-ethyl-7-methyl-2-nonenyl)oxy] benzene and 6,7-epoxy-1-(p-ethylphenoxy)-3,7-dimethyl-2-octene, when applied topically to pupae of the stable fly, Stomoxys calcitrans (L.), were morphogenetically effective against the metamorphosing pupae but did not affect oviposition and development of the hymenopteran parasite, Muscidifurax raptor Girault and Sanders, in the treated pupae. Also, reproductivity of the parent generation of parasites was not affected.     

Juvocimenes: potent juvenile hormone mimics from sweet basil

Two compounds with highly potent juvenile hormone activity were isolated and identified from the oil of sweet basil, Ocimum basilicum L., Labiatae.     

Insect juvenile hormone: activity of selected terpenoid compounds

A nuimber of compounds with terpenoid skeletons attached to various functional groups were prepared and tested for their effects as a juvenile hormone in the yellow mealworm Tenebrio molitor. Several of these compounds showed high activity.     

Treehoppers transfer parental care to ants: a new benefit of mutualism

Female treehoppers (Publilia reticulata Van Duzee) modify their parental care behavior in the presence of ants. Females with untended young remain with their original brood, but females from ant-tended colonies readily desert their first brood and produce additional clutches. Care by female treehoppers, in the absence of ants, increases the probability that a colony will produce some survivors, but ant attendance greatly increases the number of surviving nymphs.     

Growth hormone: important role in muscular exercise in adults

Measurement by radio-immunoassay of growth hormone in the plasma of adults showed consistently low concentrations in subjects in bed in the morning. Exercise caused marked increases except when the subjects ingested carbohydrate during the exercise.     

Transition state analogs as ligands for affinity purification of juvenile hormone esterase

Insect juvenile hormones are metabolized in numerous species of caterpillars by low abundance, highly specific esterases. Because of their role in regulating and possibly disrupting juvenile hormone titer and thus insect metamorphosis, they are of interest to developmental biologists as well as scientists interested in selective insect control. However, the enzymes have defied attempts to purify and characterize them. Juvenile hormone esterase activity can be inhibited by a variety of 3-substituted 1,1,1-trifluoropropanone sulfides. These apparent transition state analogs were used as ligands and eluting agents to purify juvenile hormone esterase from four insect species from 500-fold to over 1000-fold in high yield. After elution from the affinity column, the enzymes were radiolabeled with paraoxon and analyzed by electrophoresis, and the results demonstrate a high degree of purity. Transition state analogs may be useful for the affinity purification of other enzymes.     

Cuticle deposition in imaginal disks: effects of juvenile hormone and fat body in vitro

Wing disks from the last larval instar of the Indian meal moth, Plodia interpunctella (Hübner), were successfully cultured in modified Grace's medium. 20-Hydroxyecdysone induced cuticle deposition in these disks in vitro. This response was enhanced by treating the medium with larval fat body and was inhibited by application of juvenile hormone.     

Juvenile hormone: evidence of its role in the reproduction of ticks

Ovarian dlevelopmnent, vitellogenesis, andt etnbrvogenesis in recently matedlce fiemnales of tlhe sofi tick Ornithodoros parkeri Coolev were prevented by topical application of the insect antiallatotropin precocene 2. ThCe blockage was relieved by topical application of jtivenile hormonoe. Cancellation of the anti-juvenile hormnone jJects of precocene 2 and the reestablishment of oogenesis (and oviposition in one specimen) bv a naturally occurring insect juvenile hormone argues strongly for a physiological role of juvenile hormone in acarine reproduction.     

一种新的肉及肉制品酸价测定方法

建立了一种新的肉及肉制品酸价测定方法。该法的相对标准偏差RSD和回收率分别为0.56%～4.28%、99.64%～100.89%,与国标法测定结果无显著差异,且该法与国标法的测定结果在0.01水平上显著相关。与国标法相比,该法具有操作简便、耗时短、有机溶剂和样品用量少、试验成本低等优点。     

Involvement of juvenile hormone in the regulation of pheromone release activities in a moth

Juvenile hormone has been implicated in the mediation of several reproduction-related events in adult insects, but had previously been found to play no role in the regulation of sex pheromone production and release behavior ("calling") in moths. In females of the true armyworm moth, Pseudaletia unipuncta, juvenile hormone is shown to be essential to the initiation of both calling behavior and pheromone production. Females without corpora allata, the source of juvenile hormone, do not call and do not produce pheromone, but injection of juvenile hormone into allatectomized females restored these activities. The armyworm's control system has likely evolved in response to the adults' migratory behavior which may necessitate that mating be restricted to the period following migration.     

海南兴隆地区黑水虻的人工繁育技术研究初报

2009年12月至2011年5月,在海南省兴隆热带植物园进行黑水虻的人工饲养技术试验,探索热带季风气候条件下,黑水虻的人工繁育系统建立方法及饲养技术要点。结果显示,虫卵孵化需要2～6 d,幼虫经20～23 d进入预蛹期,8～11 d后开始羽化,成虫置于蚊帐中每天都可交配产卵。产卵量的多少随气候条件的变化有较大差异,冬季低温和连续阴天是导致卵量变少的重要原因。     

仲胺量测定的新方法

本文提出一种快速测定仲胺的新方法:氨水-氨荒酸铜盐分光光度法。仲胺在氨水等试剂存在下,可以和二硫化碳、硫酸铜发生反应,生成黄色的氨荒酸铜盐,在室温下1分钟内反应完全,生成物可用分光光度法定量测定。用本法对麻黄碱进行分光光度测定,相对误差0.12％,平均误差0.04％,可检测最低浓度为1μg·cm~(-3)。