We describe the development and appearance of Follicle Resorption Bodies (FRBs) and Oocyte Resorption Bodies (ORBs) in the grasshopper Romalea microptera (= guttata), and demonstrate that these structures can be used to determine the past ovipositional and environmental history of females. In R. microptera, one resorption body is deposited at the base of each ovariole following each gonotropic cycle. These structures are semi-permanent, and remain distinct for at least 8 wks and two additional ovipositions. Ovarioles that ovulate a mature, healthy oocyte, produce a cream-colored FRB. Ovarioles that resorb their oocyte, produce an orange-colored ORB. The number of FRBs equals the number of eggs laid, and the number of ORBs equals the number of oocytes resorbed. Healthy, well-fed R. microptera resorbed about a quarter of their developing oocytes. Starvation or other environmental or physiological stress increased the rate of oocyte resorption and thus increased the number of ORBs. By counting the n... Résumé Nous décrivons l'apparition et le développement des follicules de résorption ovocytaire (trace de ponte)(FRB) et des corps de régression ovocytaire (ORB) chez le criquet Romalea microptera et nous démontrons que ces structures peuvent être utilisées pour reconstituer l'historique du fonctionnement ovarien et pour évaluer la qualité de l'environnement où les femelles avaient vécu. Chez Romalea microptera, il se forme à la base de chaque ovariole un corps de résorption (folliculaire ou ovocytaire) à la fin de chaque cycle gonotrophique. Ces structures semi-permanentes sont discernables pendant au moins 8 semaines et après 3 pontes. Les ovarioles ayant ovulé un ovocyte sain et mûr, produisent une trace de ponte de couleur blanc crème (FRB) alors que les ovarioles ayant résorbé un ovocyte, produisent un corps de régression de couleur jaune orangé. Le nombre de traces de ponte est égal au nombre d'oeufs pondus et le nombre de corps de régression au nombre d'ovocytes ayant régressé. Les R. microptera en ...

Cantharidin (CTD) is a toxic monoterpene produced by blister beetles (Fam. Meloidae) as a chemical defense against predators. Although CTD is highly poisonous to many predator species, some have evolved the ability to feed on poisonous Meloidae, or otherwise beneficially use blister beetles. Great Bustards, Otis tarda, eat CTD-containing Berberomeloe majalis blister beetles, and it has been hypothesized that beetle consumption by these birds reduces parasite load (a case of self-medication). We examined this hypothesis by testing diverse organisms against CTD and extracts of B. majalis hemolymph and bodies. Our results show that all three preparations (CTD and extracts of B. majalis) were toxic to a protozoan (Trichomonas vaginalis), a nematode (Meloidogyne javanica), two insects (Myzus persicae and Rhopalosiphum padi) and a tick (Hyalomma lusitanicum). This not only supports the anti-parasitic hypothesis for beetle consumption, but suggests potential new roles for CTD, under certain conditions.

Comparing closely related species from disparate habitats can uncover habitat-specific adaptations. We compared 32 environment and oviposition characteristics in two closely related grasshoppers from opposite environments: Romalea microptera from the Florida Everglades wetlands vs Taeniopoda eques from the Chihuahuan Desert. These closely related species can interbreed, but differ in oviposition characteristics. Desert T. eques deposited long, straight, deep pods containing more eggs, and tended to lay within vegetation where they were shaded and hidden from predators. They did not oviposit in the early morning, late afternoon or evening, and males did not mate-guard. In contrast, wetlands-inhabiting R. microptera laid smaller pods closer to the soil surface, and often laid exposed to full sunlight on elevated ground away from water and nearby vegetation, in the morning or even after dark, and were usually mate-guarded. Oviposition phenology also differed, with R. microptera ovipositing in the su...

Background: The Apicomplexa are a diverse group of obligate protozoan parasites infesting a wide range of invertebrate and vertebrate hosts including humans. These parasites are notoriously difficult to control and many species continue to evolve resistance to commercial antibiotics. In this study, we sought to find an effective chemotherapeutic treatment against arthropod gregarines (Apicomplexa), and to identify candidate compounds for testing against other groups of protozoan parasites. Methods: We tested eleven commercial antibiotics against a gregarine parasite of Romalea microptera grasshoppers. Infected insects were fed daily, lettuce containing known amounts of specific antibiotics. On Days 15 or 20, we measured the number of gregarines remaining in the digestive tract of each grasshopper. Results: Treatment with metronidazole and griseofulvin in host insects significantly reduced gregarine counts, whereas, gregarine counts of insects fed, albendazole, ampicillin, chloramphenicol, fumagillin, quinine, streptomycin, sulfadimethoxine, thiabendazole or tetracycline, were not significantly different from the controls. However, albendazole produced a strong, but non-significant reduction in gregarine count, and streptomycin exhibited a non-significant antagonistic trend. Conclusion: Our results confirm that gregarine infections are difficult to control and suggest the possibility that streptomycin might aggravate gregarine infection. In addition, the insect system described here, provides a simple, inexpensive, and effective method for screening antibiotics.

In the laboratory, we measured the nonfeeding periods that precede and follow molting and hatching in the lubber grasshopper, Romalea microptera. New hatchlings first fed ~ 16 h after egg eclosion. A similar ~ 12-h nonfeeding period was observed after each molt. In contrast, the premolt nonfeeding period increased from 25 h for the 1st molt, to 64 h for the adult molt. In total, hatch- and molt-related nonfeeding periods comprised ~ 272 h, or 21% of the total 54-d nymphal development period. Scientists need to be aware of molt-related nonfeeding periods in arthropods, because they could influence nutrition, growth, physiology, feeding ecology, predator exposure, and life history. They may also hamper pest control, because short-lived poison baits or ingestion-dependent insecticides will not harm individuals that are not feeding. In this study, grasshoppers tended to molt near the beginning of the photophase. Early morning molting might have nutritional, thermal, humidity, or antipredator benefits...