0000000000042524
AUTHOR
E. Sehn
Testis differentiation in the glowworm,Lampyris noctiluca, with special reference to the apical tissue
The gonads of Lampyris noctiluca are sexually undifferentiated during the first larval instars. They consist of many gonadal follicles that include the germ stem cells enclosed by the somatic cells of the follicle wall. Follicle wall cells are more numerous at the follicle apices than at the distal parts, but different cell types cannot be distinguished. In male larvae, the appearance of apical follicle tissue, derived from follicle wall cells, marks the onset of testis differentiation. When maximally expressed, the apical tissue occupies about the upper half of the testis follicles and can be observed in larvae of the fifth and sixth instar. The apical tissue is characterized by its “light…
Effects of a new IGR-ovicide on a heteropteran (Oncopeltus fasciatusDallas) and lepidopteran (Manduca sextaJohansen) insect
A new insect ovicide (Ov. 165049), 4-methoxy-benzoic acid propargylester, synthesized by BASF (Ludwigshafen) was tested on Oncopeltus fasciatus and Manduca sexta. In the case of O. fasciatus also the effects on last-instar larvae and adult bugs were studied. Topical application of 40 μg/larva dissolved in acetone caused a mortality exceeding 50% at day 1 after treatment. The few animals which developed into imagines did not reproduce. A treatment with 4 μg/larva had no severe impact on metamorphosis and reproduction. Adult O. fasciatus received doses of 40 μg, 20 μg and 4 μg per animal. The high dose caused mortality of 50% at day 1 as in larvae. Mating and egg deposition did not occur in s…
Ergastoplasmic paracrystalline inclusion bodies in the adipose gonadal envelope and fat body of the glow worm, Lampyris noctiluca (Insecta, Coleoptera).
Abstract The gonads of glow worm larvae are enveloped by adipose tissue which represents a specialized fat body. The adipose gonadal envelope, and also to a lesser extent the fat body cells, contain tubular paracrystalline inclusion bodies (PIBs). Cells of other tissues are devoid of such inclusions. The PIBs form in the cisternae of rough ER. In young larvae PIB formation is sparse, but at advanced larval stages PIBs often occur as bundles in stacks of ergastoplasm. Typically, a PIB within a cisterna consists of four to seven parallel tubules. The outer diameter of a tubule is ca 28.8 nm and the width of the tubule lumen ca 12.2 nm. The “wall” of a tubule contains globular protein subunits…