The Effect of Juvenile Hormone Mimics on Development of the Mud Crab, Rhithropanopeus harrisii (Gould)

1977 ◽  
pp. 439-457 ◽  
Author(s):  
J.D. COSTLOW
Keyword(s):  
Juvenile Hormone ◽  
Mud Crab ◽  
Rhithropanopeus Harrisii ◽  
Juvenile Hormone Mimics

Insect juvenile hormone mimics: A structural basis for gonadotropic activity in a cockroach and a moth

1975 ◽  
Vol 21 (2) ◽  
pp. 463-469 ◽  
Author(s):  
Paul Sroka ◽  
Robert H. Barth ◽  
Lawrence I. Gilbert ◽  
Gerardus B. Staal
Keyword(s):  
Juvenile Hormone ◽  
Structural Basis ◽  
Gonadotropic Activity ◽  
Juvenile Hormone Mimics

Effects of juvenile hormone mimics on the codling moth Cydia Pomonella (L.) (Lep., Olethreutidae)

1973 ◽  
Vol 63 (1) ◽  
pp. 7-16 ◽  
Author(s):  
I. Gelbič ◽  
F. Sehnal
Keyword(s):  
Juvenile Hormone ◽  
Laboratory Experiments ◽  
Cydia Pomonella ◽  
Codling Moth ◽  
The Other ◽  
Wide Range ◽  
Juvenile Hormone Analogues ◽  
Juvenile Hormone Mimics

AbstractLaboratory experiments with juvenile hormone analogues on Cydia pomonella (L.) showed that Cecropia C17 juvenile hormone (methyl 10,ll-epoxy-3,7,ll-trimethyl-2,6-dodecadienoate) was the most active of the 28 compounds tested. When applied to four-hour-old eggs at 0.1 μg/egg, the hormone caused 100% failure in embryogenesis, while the other compounds were at least five times less effective. Depending on the time since ecdysis and the dose, juvenile hormone mimics applied to last-instar larvae resulted in a wide range of intermediate forms. Against three-day-old last-instar larvae, the Cecropia C17 hormone gave 100% inhibition of development at a dose of 1 μg/larva, while three other compounds (methyl 10,11-epoxy-3,7,11-trimethyl-2,6-dodecadienoate, ethyl 11-chloro-3,7,11-trimethyl-2-dodecenoate and ethyl 3,7,11-tri-methyl-2,4-dodecadienoate) gave the same effect at 2–5 μg/larva. Against newly emerged adults, the last two compounds at 10–50 μg/insect reduced fecundity and fertility to 0–81% and 0–50%, respectively, of their normal levels.

Assessment of Crab Limb Regeneration as an Assay for Developmental Toxicity

1992 ◽  
Vol 49 (6) ◽  
pp. 1268-1273 ◽  
Author(s):  
Anthony S. Clare ◽  
John D. Costlow ◽  
Hassan M. Bedair ◽  
George Lumb
Keyword(s):  
Developmental Toxicity ◽  
Limb Regeneration ◽  
Optimal Conditions ◽  
Mud Crab ◽  
Rhithropanopeus Harrisii ◽  
Full Size ◽  
Juvenile Crab ◽  
Sublethal Concentrations ◽  
Crab Stage ◽  
Duration Of Development

The regeneration of a cheliped that is autotomised at the final larval stage, the megalopa, of the mud crab Rhithropanopeus harrisii (Gould) forms the basis of an assay for developmental toxicity. Cheliped regeneration is followed through to the third juvenile crab stage; a regenerate that is approximately two thirds full size normally emerges at the moult to the second crab, and full size is attained at crab 3. The absence of a regenerate at crab 2, or a regenerate that is smaller than normal and/or malformed, is scored as abnormal regeneration. Other parameters examined in this assay include survival and duration of development. The assay is of comparatively short duration (approximately 2 wk), and survival is high following autotomy under optimal conditions. Four insecticides and a herbicide have been tested in the assay at lethal and sublethal concentrations. Of these compounds, methomyl, carbofuran, and alachlor induced abnormal regeneration whereas cypermethrin and RH 5849 did not affect regeneration at the concentrations tested. Although reproducibility of results needs improvement, crab limb regeneration is otherwise a practical assay for developmental toxicity.

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