Food and the spatial distribution of adult female pinworms parasitic in the hindgut of Periplaneta americana L.

Food and the spatial distribution of adult female pinworms parasitic in the hindgut of Periplaneta americana L. International Journal for Parasitology 4: 759–771. The spatial distribution of the two pinworms Hammerschmidtiella diesingi and Leidynema appendiculata in the adult cockroach Periplaneta americana was determined by examination of hind guts fixed by immersion in liquid air. The position of the mouths of the worms reveals that L. appendiculata favours a more anterior position and is more restricted in its distribution than H. diesingi. The position of each species in the colon is unaffected by the presence of the other species or by crowding. Moreover, the two species are segregated in terms of their radial distribution, with the mouth of H, diesingi being restricted to a position near the intima of the colon while that of L. appendiculata favours the lumen. The two nematodes differ in the structure of the stoma and pharynx which reflect a difference in their diet. The food of L. appendiculata consists of relatively large particles while that of H. diesingi is finely patticulate. The ability of these two species to coexist in the same host is explained by their longitudinal and radial distribution and by the different sources of their food.     

Protrellus dixoni n. sp. (Nematoda: Thelastomatidae) from the cockroach Drymaplaneta variegata

Abstract

In New Zealand, Protrellus dixoni n. sp. occurs in the hind gut of the introduced Australian cockroach Drymaplaneta variegata. It is distinguished from all other Protrellus species by its morphology. Females have a well developed muscular ovijector with a sphincter, and a conical tail with a filiform projection; males have four, not three, tail papillae. The taxonomic history of the genus is discussed and the generic diagnosis emended. New combinations include Protrellus eurycotesi, P. ischnopterae, P. ituana, and P. gurri. The population structure of P. dixoni in adult hosts is described: there are never more than one adult male, and usually few (one to three) adult females per host.     

Blatticola monandros n.sp. (Nematoda: Thelastomatidae) from the blattellid cockroach Parellipsidion pachycercum

Abstract

Blatticola monandros n.sp. occurs in the hind gut of nymphs and adults of the endemic New Zealand cockroach Parellipsidion pachycercum. It is distinguished from all other species of Blatticola in morphology — both sexes are smaller, the oesophagus is proportionately longer, and the spicule is shorter. The size of the nematode increases with the size of the host.     

New species of rhigonematid and thelastomatid nematodes from indigenous New Zealand millipedes

Abstract

Seven new species of nematode are described from the hind-gut of several different millipedes indigenous to New Zealand: Heth hamatus n. sp. from Spirobollelus antipodarus and Icosidemus hochstetteri from Auckland, Erythrodemus echinopogon from Seddonville, and Eumasligonus sp. from Aickens, and Avenue Scenic Reserve; Thelastoma moko n. sp. from coastal specimens of Eumastigonus sp.; Thelastoma rigo n. sp. from montane specimens of Eumastigonus sp.; Dudekemia prolifica n. sp. from Spirobellelus antipodarus; Dudekemia alpinensis n. sp. from the montane Eumastigonus sp.; Dudekemia kaorinus n. sp. from Eumastigonus kaorinus from Hardys Creek; and Dudekemia hirsutus n. sp. from Erythrodemus echinopogon from Seddonville.

The family Rhigonematidae is reviewed.     

Population regulation in parasitic nematodes (Thelastomatidae) of cockroaches

Abstract

Populations of four species of thelastomatid nematode in six species of cockroach were regulated by a density- and sex-dependent mechanism. Regulation resulted in an underdispersed (regular) or random distribution of parasites. No cockroach contained more than one adult or juvenile male and rarely more than two adult females, and monogamy was common. Juvenile males were rare whereas juvenile females were relatively common, suggesting that males developed rapidly and were eliminated rapidly from hosts (leaving one). Prevalence of infection varied markedly between cockroach species.