Firm coupling of genitalia is critical for copulation in most groups of insects. To counter female resistance that usually breaks off genital connection, male scorpionflies (Mecoptera: Panorpidae) usually provide nuptial gifts for the female and seize their mates with grasping devices. The notal organ, a modified clamp on tergum III of male scorpionflies, plays a significant role in seizing the female wings and helping maintain mating position during copulation. The mating behaviour remains unknown for the scorpionfly Furcatopanorpa longihypovalva (Hua and Cai, 2009) whose male lacks a notal organ. In this paper, we first attempt to study the mating behaviour of F. longihypovalva. The results show that the male provides liquid salivary secretion through a mouth-to-mouth mode for the female, and maintains copulation mainly by continuous provision of salivary secretion rather than by seizing the female with grasping devices. Thus the male copulates with the female in an atypical O-shaped position, with only their mouthparts and genitalia connected to each other. The salivary glands exhibit remarkable sexual dimorphism: short and bifurcated in the female, but well-developed and multi-furcated in the male. The extremely developed salivary glands of the male lay a structural foundation for the male to continuously provide liquid salivary secretion, and to help the male to mediate female resistance, being likely to serve as a compensation to his absence of the notal organ. We also investigated the functional morphology and copulatory mechanism of the male and female genitalia.
Cantharidin (CTD), a terpenoid defensive toxin mainly produced by blister beetles, is widely known by its toxicity to both cancer cells and pests. However, little information is known about its biosynthesis in blister beetles. In this study, first we determined the CTD content in various tissues of adult blister beetles on different days after mating, and then detected the temporal and spatial expression patterns of genes related to CTD biosynthesis in Epicauta chinensis. Results revealed that the accessory gland is the source of the highest CTD production. The second highest level was in the fat body in male blister beetles after mating. In females, the highest CTD content was in the reproductive system except the ovary after mating. As revealed by messenger RNA expression level analysis, the highest levels of 3-hydroxy-3-methylglutary-CoA reductase (HMGR) and juvenile hormone epoxide hydrolase (JHEH) transcripts of E. chinensis were observed in the fat body in males after mating. However, the highest transcript level of EcHMGR was in the ovary and EcJHEH was maintained at a nearly similar level in females. The transcript level of methyl-farnesoate epoxide was significantly higher in the head and that of CYP4BM1 in the midgut in both male and female E. chinensis. We speculate that the fat body may play a more important role than other tissues on the CTD biosynthesis in male E. chinensis after mating. There may be multiple tissues involved in the process of CTD biosynthesis. These four genes probably play regulatory roles in different tissues in males.
Using an asymmetric tetradentate ligand N-((6-(1H-pyrazol-1-yl)pyridin-2-yl)methylene)benzohydrazide (pypzbeyz), two high-coordinate 3d transition metal compounds [CoII(pypzbeyz)(NO3)2] (1) and [FeII(pypzbeyz)2](BF4)2(CH3CN) (2) have been synthesized and characterized by structural and magnetic measurements. X-ray crystallographic analyses revealed that compound 1 is seven-coordinate with a distorted pentagonal bipyramidal geometry (pseudo-D5h) and compound 2 is eight-coordinate with a triangular dodecahedral geometry (pseudo-D2d). Direct current (dc) magnetic susceptibilities revealed that compound 1 shows easy-plane magnetic anisotropy (D = +29.9 cm-1, E = 0.31 cm-1) and 2 shows easy-axis magnetic anisotropy (D = -6.6 cm-1, E = 0.02 cm-1). Alternating current (ac) magnetic measurements indicate that both compounds exhibit field-induced slow magnetic relaxation behavior. Furthermore, ab initio calculations also demonstrate that compound 1 presents a strong easy-plane magnetic anisotropy and 2 presents an easy-axis magnetic anisotropy, which are further identified by the calculated orientations of the local magnetic axes. These results demonstrate an effective way to achieve the targeted synthesis of high-coordinate 3d SIMs.
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