Histopathology and Ultrastructure of Nosema pyrgomorphae n.sp.(Microspora, Nosematidae) Parasite of Pyrgomorpha conica tereticornis (Orthoptera, Pyrgomorphidae)

NOSEMATIDAE AND OTHER PROTOZOA AS AGENTS FOR CONTROL OF GRASSHOPPERS AND LOCUSTS: CURRENT STATUS AND PROSPECTS

Protozoa known to infect Acrididae include certain Amoebida (Phylum Rhizopoda), Eugregarinida, Neogregarinida (Phylum Apicomplexa) and at least one species from the Phylum Ciliophora, but are mainly Microsporida (Phylum Microspora). Among the Microsporida, Nosema locustae Canning has been the most common subject of large-scale field testing as a potential microbial control of grasshoppers and locusts. Although there have been demonstrations of significant impacts of Protozoa such as Nosema spp. on survival, development, reproduction and feeding of grasshoppers and locusts, these candidates have not met the requirements for fast-acting control of Acrididae. However, recently discovered and as yet undiscovered Microspora and other Protozoa may offer reliable non-chemical control of grasshoppers and locusts. Research on candidates such as Nosema locustae has not been wasted effort; at a minimum, research invested toward development of methods of formulation, application, assessment and ecological fate of these potential microbial control agents has provided useful information needed to prepare for the eventuality of discovery of more fast-acting protozoa, and has contributed to development of field methods required for testing of other microbial agents. With improvements in understanding of insect behavioral and physiological responses, satisfactory short-term efficacy (perhaps resulting from combined formulations with behavioral modifiers or stressors) may allow N. locustae, N. cuneatum Henry, N. acridophagus Henry or Johenrea locustae Lange et al. to also serve a role in limiting acridid abundance and activity, either as an agent of biological control in sites requiring special care, or within a rangeland IPM context.

Development, ultrastructure, natural occurrence, and molecular characterization of Liebermannia patagonica n. g., n. sp., a microsporidian parasite of the grasshopper Tristira magellanica (Orthoptera: Tristiridae)

A new microsporidium, Liebermannia patagonica n. gen., n. sp., is described from midgut and gastric caecum epithelial cells of Tristira magellanica, an apterous grasshopper species of southern Patagonia, Argentina. L.patagonica is diplokaryotic, apansporoblastic, homosporous, and polysporoblastic. Transitional (from merogony to sporogony) stages and sporonts of L. patagonica were surrounded by host rough endoplasmic reticulum. The ovocylindrical spores measured 2.9 +/- 0.09 x 1.2 +/- 0.04 microm (fresh, n = 50), and they had an isofilar polar filament of only three coils and a cluster of tubules instead of a classical posterior vacuole. Prevalence was high (up to 80.6%) at the type locality for the four years sampled . Maximum likelihood , neighbor joining, maximum parismony analyses of the small submit rDNA all placed L.patagonica(Accession No. DQ 239917) in one with Orthosomella operophterae.