Structure of the male reproductive accessory glands of Pterostichus nigrita (Coleoptera: Carabidae), their role in spermatophore formation

Accessory gland secretions of male insects have many important functions including the formation of spermatophores. We used light and electron microscopy to investigate the structure of the accessory glands and posterior vasa deferentia of the carabid beetle Pterostichus nigrita to try to determine where spermatophore material is produced. Each accessory gland and posterior vas deferens had an outer layer of longitudinal muscle, beneath which was a layer of connective tissue and a thin band of circular muscle, all of which surrounded a layer of epithelial cells lining the lumen of the ducts. Based on the ultrastructure of the epithelial cells, and their secretory products, we identified two epithelial cell types in each region (distal and proximal) of the accessory glands and four types in the posterior vas deferens. Most secretory products, which stained positively for proteins and some mucins, were released into the lumen of the ducts by apocrine secretion. The accessory glands produced one type of secretory product whereas in posterior vasa deferentia, four types of secretory products were found layered in the lumen. Our results suggest that most of the structural material used to construct a spermatophore is produced by the cells of the posterior vasa deferentia.     

Prevalence of ixodid ticks on cattle in Mazandaran province, Iran

A survey was carried out to investigate the prevalence of hard tick species (Acari: Ixodidae) on cattle in Mazandaran province, Iran. A total of 953 ticks were collected from 86 infested cattle during activating seasons of ticks during 2004-2005. Nine species were identified: Boophilus annulatus (51.3%), Rhipicephalus bursa (16.8%), Haemaphysalis punctata (6.3%), Ixodes ricinus (6.8%), Hyalomma marginatum (12.5%), Hyalomma anatolicum excavatum (5.2%), Hyalomma asiaticum (0.6%), Hyalomma detritum (0.2 %), and Dermacentor spp. (0.1%). The results show that Boophilus annulatus, Rhipicephalus bursa, and Hyalomma species are dominant tick species in the surveyed area.     

Mating effort function of the spermatophore in the bushcricket Poecilimon veluchianus (Orthoptera, Phanero[pteridae): support from a comparison of the mating behaviour of two subspecies.

To analyse spcrmatophore function, various aspects of the mating behaviour (e.g. spermatophore mass, duration of sperm transfer, mating frequency) were compared in two subspecies of the bushcricket P. veluchianus. Body mass was significantly different in both subspecies and had a strong effect on spermatophore mass, resulting in a large difference in absolute and relative (percentage of male body mass) spermatophore mass in both subspecies. After copulation the small P. v. minor spermatophores were consumed much faster by the female than the larger ones of P. v. veluchianus. The time necessary for sperm transfer from the spermatophore to the female spermatheca was much shorter in the subspecies with small spermatophores than in that with large spermatophores, and in both subspecies similar to the time required to consume the spermatophores. Mating frequency varied also between the subspecies and was murh higher in P. v. minor than in P. v. veluchianus. Differences in body mass between the two subspecies therefore resulted in changes in several aspects of mating behaviour. However, despite large differences in the mass of the spermatophore, its main function seems to be to ensure sperm transfer. This can be concluded from the similarity between the duration of sperm transfer and the time period necessary for spermatophore consumption in each of the subspecies. The spermatophore is thus considered to be male mating effort.     

Hard ticks (Acari,Ixodidae) of Croatia

The present paper is based on original and literature data. In Croatia the first studies on the occurrence of ixodid species were made about 80 years ago. The number of tick species recorded in Croatia considerably increased during the 1950s, 60s, 70s and 80s of the past century. A total of 21 species of hard tick belonging to 5 genera have been recorded in Croatia. Ixodes is the best represented genus, with seven species recorded. Haemaphysalis is represented by six species, followed by Rhipicephalus with four species. Dermacentor and Hyalomma are represented by two species each. The ticks were collected on 47 different host species. Eleven tick species were collected on Bos taurus and Ovis aries, followed by Capra hircus and Equus caballus with 8 species and Canis lupus familiaris with 6 species. On the remaining 42 host species one, two or three tick species were collected. The most widespread tick is Ixodes ricinus which was found on 25 different host species.     

Long hyaline gland discharge and multiple spermatophore formation by the male grasshopper, Melanoplus sanguinipes

ABSTRACT. Discharge from the male accessory reproductive gland (ARG) by the male grasshopper, Melanoplus sanguinipes (Fabr.), has been studied by assay of a characterized product, a glycoprotein LHPI, and the rate of formation of spermatophores. LHPI is an exclusive long hyaline gland (a prominent ARG tubule type) product whose discharge is symmetrical from the bilaterally paired glands. LHPI forms 65% of a viscous secretion that is discharged concomitantly with the spermatophores. Though low ARG reserves in 5-day-old males limit both the number of spermatophores formed and LHPI discharged in copulations ≤6 h, this appears to be the result of shorter copulations. The number of spermarophores formed in 1 h was not impaired by general depletion of ARG protein (by repeated copulations) or by selective depletion of long hyaline gland protein (by unilateral and bilateral long hyaline gland removal), though these manipulations reduced LHPI discharge by 22%, 44% and 100%, respectively. However, 56% of spermatophores formed by males with the long hyaline gland bilaterally ablated failed to uncoil properly. These results indicate LHPI and/or other long hyaline gland proteins may act as lubricants. Unlike spermatophore formation and LHPI discharge, which increased steadily up to 90–120 min then levelled off, transfer of radiolabelled male ejaculate to the spermatheca was very variable. In 90 min copulations, only 1% of the total radioactivity (representing c. 5 μg protein) lost from the ARG complex was transferred to the spermatheca. The importance of male-derived protein in vitellogenesis is discussed.     

Structural changes in the spermatophore of the freshwater 'red claw' crayfish Cherax quadricarinatus (Von Martens, 1898) (Decapoda, Parastacidae)

López Greco, L.S. and Lo Nostro, F.L. 2007. Structural changes in the spermatophore of the freshwater ‘red claw’ crayfish Cherax quadricarinatus (Von Martens, 1898) (Decapoda, Parastacidae). —Acta Zoologica (Stockholm) 88 : 000–000 The structure of the spermatophore was studied in Cherax quadricarinatus. Pieces of the distal vas deferens and transferred spermatophore from the females were fixed, cut and stained. Within the distal vas deferens, the primary layer and the secondary layer of the spermatophore were distinguishable. In the latter, two components were detected: cytoplasmic droplets and a homogeneous matrix. During the first 10 minutes post‐extrusion the cytoplasmic droplets drastically changed from looking like ‘empty droplets’; at this time the spermatophore changed from a liquid stage to a sticky one. One hour after extrusion the spermatophore began to harden and within the first 24–48 h post‐mating it was a solid and intense white structure tightly attached to the female; after 72 h it acquired a softer aspect, completely dehiscing between 96 and 120 h post‐mating. Histologically, the primary layer maintained its integrity surrounding the spermatozoa while the secondary layer lost the cytoplasmic droplets. The spermatophore began to hydrate between 24 and 48 h and by 72–96 h many sections of the sperm cord began to coalesce. From 48 h post‐mating some fissures appeared within the matrix that enlarged between 72 and 120 h. We propose that both manipulation by the female and hydration are the mechanisms involved in the release of the spermatozoa from the spermatophore.     

A review of the types of parasite-host relations in ixodid ticks

In the first type of mutual relationships the ixodid ticks expose an evident pathogenicity to vertebrate hosts (tick toxicoses) and in the second type the hosts expose a resistance on a base of organism immune system activisation in a response to blood sucking. In the third type of relationships an interaction between the ticks and hosts have a dynamic character (tolerability of host). The first type of relationships leading to a selective elimination of hosts according to our opinion means a comparatively youth of relationships. The third type represent ancient and long term relationships. The second type probably having been widely spread in a historical past occupies an intermediate position. Depending upon areal the ticks of the same type expose different degree of the pathogenicity. Even an acquired resistance of the host does exist in natural conditions, it is a transient phenomenon.     

Effects of saline intake on spermatophore and sperm ejaculation in the male swallowtail butterfly Papilio xuthus (Lepidoptera: Papilionidae)

Although sodium ions induce puddling behavior in males of some butterfly species, the role of sodium ions in male life history is unclear. Newly emerged laboratory‐reared males of the swallowtail butterfly Papilio xuthus were allocated to five adult diets: water (as a control) and 0.001, 0.01, 0.1 or 1 mol/L saline solution. Males preferred to take 0.1 mol/L saline solution. We attempted to hand‐pair males after two days of intake. Males on all diets, except those taking 1 mol/L saline solution, were likely to couple. Males taking 0.01 mol/L saline solution produced the largest spermatophore, although there were no significant differences in the number of eupyrene sperm bundles and apyrene spermatozoa between saline‐taking males and control males. Salt accumulation in the male body also had little effect on the number of both types of spermatozoon in the spermatophore.     

Female ixodid ticks grow endocuticle during the rapid phase of engorgement

Lees (Proc Zool Soc Lond 121:759–772, 1952) concluded that the ixodid tick Ixodes ricinus grows endocuticle during the slow but not during the rapid, phase of engorgement, a conclusion supported by Andersen and Roepstorff (Insect Biochem Mol Biol 35:1181–1188, 2005) for the same species. In this study analysis of dimensional data and cuticle weight measurements from female ixodid ticks (Amblyomma hebraeum) were used to test this hypothesis. Both approaches showed that endocuticle growth continues during the rapid phase, tapering to zero at a fed/unfed weight ratio of ~60. Of the total mass of cuticle in the engorged tick 32–43% was formed during the rapid phase. We demonstrate that if cuticle growth stopped at the end of the slow phase, there would not be sufficient cuticle to account for the thickness of cuticle observed at the end of engorgement. This finding is consistent with prior studies of Rhipicephalus (Boophilus) microplus, and with a dimensional analysis of the cuticle thickness data of Lees for I. ricinus, in contradiction to his conclusion from an analysis of tick cuticle weight measurements. An examination of cuticle weight measurements for I. ricinus by Andersen and Roepstorff similarly supports the finding of cuticle growth during the rapid phase. All ixodid ticks undergo major body expansion, typically tenfold or more, during a rapid phase of engorgement and require sufficient cuticle at the end of that process to contain their body. The fact that cuticle grows during the rapid phase of engorgement in three species suggests that this is a general characteristic of the family Ixodidae.     

Phenology of ixodid ticks of the genus Dermacentor in the Central Ciscaucasia

In Stavropol Territory, ixodid ticks of the genus Dermacentor are represented by three species: D. marginatus, D. reticulatus, and D. niveus. D. marginatus is the most widespread species, constituting 14.8% of all the ticks in the region; D. reticulatus and D. niveus are found less frequently, constituting 2.8% and 0.01%, respectively. D. marginatus and D. reticulatus are spread mostly in the forest-steppe and steppe zones of Stavropol Territory. D. niveus is represented by solitary specimens in arid and semidesert zones. The main hosts of adult D. marginatus in Stavropol Territory are cattle (88.4%) and sheep and goats (5.3%). The hosts of D. reticulatus are also cattle (72.3%) and sheep and goats (4%). D. marginatus activates at an average monthly temperature of +2.07°C and average monthly rainfall of 47.2 mm. The peak of parasitizing on hosts was observed at an average monthly temperature of +7.8°C and average monthly rainfall of 56.2 mm. The autumnal activation was recorded at an average monthly temperature of +15.3°C and average monthly rainfall of 58.2 mm.     

Survival of six species of African ticks in relation to saturation deficits

The survival of unfed males and females of six species of African ticks was monitored at five different saturation deficits at constant temperature (25°C). The survivorship curves for each species comprised a pre-mortality period, prior to when ticks started to die and a mortality period corresponding to a rapid increase in the mortality rate. Longevity was defined as pre-mortality plus mortality. A negative correlation between the longevity of the ticks and the saturation deficits was found with ticks surviving longer at lower deficits. The survival of males and females was similar. At low saturation deficits (2–4 mmHg) Amblyomma hebraeum survived the longest periods (74 weeks). Some correlation was found between the tick survival under dehydrating conditions and habitat associations. Rhipicephalus appendiculatus and Haemaphysalis leachii, the most mesic in distribution, had the shortest longevity (21 and 13 weeks, respectively) at high saturation deficits (7–21 mmHg). Hyalomma marginatum rufipes, the most xerophilic in distribution, had the longest survival (39.3±10.5 weeks) at high saturation deficits. Other factors apart from the adult survival should be taken into account when accounting for the tick distribution, in particular the tolerance of earlier developmental stages to desiccation.     

Argulus japonicus: Sperm transfer by means of a spermatophore on Carassius auratus (L)

The process of sperm transfer is somewhat enigmatic in Argulus, even though copulation has been witnessed. A breeding colony of Argulus japonicus was kept under laboratory conditions in order to study reproduction in the species. Pairs in copula were removed and studied with histology and scanning electron microscopy to describe the mechanism of sperm transfer. Sections of copulating pairs revealed sperm on the accessory copulatory structures of the male’s swimming legs; and scanning electron microscopy showed that sperm transfer occurs in three phases which can be differentiated to 10 different stages. Sperm transfer occurs via a spermatophore which is extruded from the genital aperture of the male and is then transferred to the socket on the third pair of legs of the male, before being transferred into the spermathecae of the female via the spermathecal spines. This is the first observation of a spermatophore in Argulus.     

Control of Karoo paralysis ticks through vegetation management

Abstract. Karoo paralysis, caused by feeding Ixodes rubicundus females, is a major disease of small stock in South Africa. Control methods currently practised are almost exclusively chemical based. To limit overdependance on chemicals, vegetation management was investigated as a possible method for control, to be incorporated in an integrated tick management system. Laboratory and field experiments were conducted to determine, firstly, the extent of vertical migration and survival of ticks on long and short copper rods which simulated grasses as questing substrates; secondly, the infestation burdens of sheep exposed to similar tick challenges in pens with long and short grass; and thirdly, the effect of trimming the lower crown line of wild olive trees, simulating the browsing effect of goats, on tick density in the immediate environment of the trees. When ticks were exposed to optimal (>45 cm) and sub-optimal (<10 cm) length rods on which to quest, the extent of vertical migration over extended periods of time (up to 87 days) was significantly higher ( P < 0.001) for the ticks exposed to long rods. Also, almost 3 times as many ticks exposed to long rods survived compared to those exposed to short rods. Sheep exposed to long grass were infested by twice as many ticks compared to those exposed to short grass. Tick density at modified wild olive trees ( Olea europaea africana ) (0.027 ticks/m²) differed significantly ( P < 0.05) from that at control trees (0.088 ticks/m²). It is recommended that coarse grazers such as cattle and horses should be used to graze down long grasses before sheep are introduced into camps known to be infested with I. rubicundus. Similarly, domestic goats can, through their browsing effect on shrubs and trees, modify the vegetation and as such play an important role in an integrated tick management system.     

Correlation of the relative population count of ixodid ticks with various recording methods

Data are given on the relative abundance ratio of 3 species of ixodid ticks obtained by different counting methods.     

New species of ixodid ticks (Ixodidae) for the fauna of Armenia

Two species of ixodids , Ixodes arboricola Schulze et Schlottke and I. frontalis ( Panzer ), new for the fauna of Armenia are given. Larvae and nymphs of these ticks were found on birds in the forest zone and gardens.     

Habitat and occurrence of ixodid ticks in the Liguria region,northwest Italy

Questing ticks were collected during monthly dragging sessions (March–August 2011) in three provinces of the Liguria region, north-western Italy, to evaluate the species occurrence, spatial distribution and relative abundance. A total of 1,464 specimens were collected in 94 dragging sites. Ixodes ricinus was the most abundant species (81.3 % of collected ticks), followed by Haemaphysalis punctata (10.9 %), Dermacentor marginatus (5.5 %), Ixodes frontalis (1.3 %), and Rhipicephalus spp. (0.9 %). Ixodes frontalis is reported for the first time in Liguria. An aggregation of I. ricinus positive sites was observed in inland areas characterized by dense forests dominated by deciduous trees (Castanetum and Fagetum phytoclimatic zones), especially in the west of the region where the differences in the Normalized Difference Vegetation Index (NDVI) were higher between inland and coastal sites. Negative binomial regression for repeated measures was used to model the associations of NDVI and season with counts of host-seeking I. ricinus nymphs. The NDVI was a good predictor of I. ricinus nymphs abundance, and confirmed its utility in discriminating habitat suitability for this vector in north-western coastal Italy, where dry habitat conditions may limit the distribution of this species.     

Ultrastructural study of the internal organs of ixodid ticks in the scanning electron microscope

The structure of the surfaces of midgut and salivary glands in hungry and engorged females of Hyalomma asiaticum was studied by means of scanning electron microscopy. Preparations were fixed in glutaraldehyde osmium and then dehydrated by the critical point method and gold or platinum coating Different periods of fixation at room temperature or at 4 degrees C did not affect the condition of surface structures of gut and salivary glands.