Adverse responses of Cabera pusaria caterpillars to high dietary manganese concentration

The adaptation of insects to environmental changes can constitute a crucial factor in their development and activity. The response of Cabera pusaria L. (Lepidoptera: Geometridae) caterpillars to high manganese (Mn) concentrations in the diet was studied. Birch leaves were treated by dipping in MnCl₂·4H₂O solutions, thereby achieving Mn contents of 370 (T0), 695 (T1), 3 198 (T2), and 6 302 mg kg⁻¹ (T3). The reactions were determined by observing caterpillar mortality, development time, food consumption, and pupal weight. Manganese concentrations in larval excrement, pupae, and food were determined. Manganese in the diet at unnaturally increased concentrations caused great stress for caterpillars. All individuals in the treatment with the highest Mn concentration (T3) died during rearing and successful pupation occurred in only four individuals in T2. Even in the case of caterpillars from T1 (twofold higher than T0) a negative reaction (increased food consumption and prolonged development) was recorded. We also determined significantly increased Mn concentration in pupae from T1 (T2 and T3 were not included in this evaluation due to mortality) and excrement (T1‒T3) compared with T0 having a natural Mn concentration. Caterpillars were seen to eliminate negatively acting dietary Mn by its translocation to excrement. However, the highest mortality rate in T2 and T3 and negative reactions of individuals in T1 very likely demonstrate energy insufficiency and the high energy requirements of Mn elimination mechanisms.     

A simple topographical model to predict Golden Eagle Aquila chrysaetos space use during dispersal

Many large raptors exploit or rely on anabatic and orographic winds which provide vertical lift, to supplement or provide the energy fuelling flight. Airspace is therefore a critical habitat for such large raptors and its use is subject to the underlying terrestrial topography, because particular topographical features are more likely to provide wind-energetic lift. Accordingly, ridges and/or ‘rugged topography’ are common preferred features in habitat use by large raptors. Our study aimed to provide a simple model of space use for a large raptor, the Golden Eagle Aquila chrysaetos, based on thousands of GPS telemetry records during juvenile dispersal of 92 birds tagged as nestlings between 2007 and 2016 across upland Scotland. Model development was based on the hypothesis that four topographical variables would be influential: slope, aspect, altitude and distance from ridge. The telemetry dataset was divided into training and two testing components. The first testing set was derived by a temporal split resulting in approximately equal sample size on records and some temporal overlap in individuals’ records with training data. The second testing set involved no individuals from the training set. Aspect was removed early in training model development because it was not influential. The model found that young Golden Eagles preferred, or used according to availability, space above slopes greater than 10°, at an altitude of ≥ 300 m, and within 300 m of a ridge. The test data were highly correlated with those from the training data in the model variables, and performance as regard to expected preferences from the model was improved in both test datasets, indicating the model was robust. Given the apparent universal nature of large raptor dependence on topography, that topography is relatively immutable according to time and use, and that topographical data are readily available, we commend our approach to other habitat preference studies of Golden Eagles and other large raptors elsewhere.     

Bioactivity of Piper guineense Schum. & Thonn seed and Moringa oleifera Lam. leaf powder against Trogoderma granarium Everts (Coleoptera: Dermestidae)

Laboratory studies were carried out to investigate bioactivity of Piper guineense seeds and Moringa oleifera leaf powders applied singly or in a mixture against larvae and adult Trogoderma granarium Everts in airtight containers. Three levels (0.0 g, 0.5 g, and 1.0 g/20 g groundnut seeds) of the plant powders were used and pirimiphos-methyl was applied at 0.01 g/20 g seeds (recommended dose). Another control consisting of untreated seeds with aerated lids was included in the bioassay. Both larvae and adults were not killed in control with aerated lids throughout the experimental period and larvae were also tolerant to airtight storage conditions. Adults were more susceptible to plant powders than larvae and adult mortality recorded in P. guineense at 1.0 g, 0.5 g and M. oleifera at 1.0 g/20 g seeds were not significantly different from the mortality observed with the recommended dose of Pirimiphos methyl at five days after treatment (DAT). Larval mortality observed in a mixture of both plants (1:1; w/w) caused significantly higher mortality (77.5%) than other treatments at 5 DAT. All treatments (P. guineense and M. oleifera applied singly or in a mixture) were repellant to larvae T. granarium with 60% repellency recorded in the mixture of plants, 50% repellency in P. guineense and 30% repellency in M. oleifera slurry. The water absorption capacity of treated seeds was not affected by treatment with plant powders and ranged from 31.98% to 37.59%.     

In vitro nemato-toxic potential of some leaf extracts on Juvenile mortality of Meloidogyne incognita race-3

Abstract

Aqueous leaf extracts of four commonly growing weeds namely Ageratum conyzoides, Elephantopus scaber, Lantana camara and Xanthium strumarium were used to evaluate their nematicidal activity on second stage juvenile of Meloidogyne incognita race-3. The juveniles were exposed to various concentration of leaf extract namely 250, 500, 1000 and 2000?ppm for 12, 24 and 48?h, respectively. All leaf extracts showed the nematicidal property in concentration and time-dependent manner. The maximum juvenile mortality was recorded in E. scaber throughout the incubation period followed by X. strumarium, L. camara and A. conyzoides. The regression and correlation of regression revealed the best concentration-dependent effect of aqueous leaf extracts on nematode mortality in E. scaber (R²?=?.751) followed by X. strumarium (R²?=?.749), A. conyzoides (R²?=?.687) and L. camara (R²?=?.756). Aqueous leaves extracts of these aforementioned weeds showed nematicidal properties, therefore, may be used as a key component of integrated disease management programme.     

Post-construction avian mortality monitoring at Project West Wind

Abstract

Post-construction avifauna investigations were undertaken at Project West Wind, Meridian Energy Limited's 62-turbine wind farm on the Wellington south coast. These investigations were required in accordance with the resource consent conditions to quantify the level of avian mortalities occurring at the wind farm, particularly in regard to New Zealand falcon (Falco novaeseelandiae), kākā (Nestor meridionalis) and kererū (Hemiphaga novaeseelandiae). This is the first comprehensive study at a New Zealand operating wind farm. The methods included three field components necessary to calculate annual estimates of mortalities across the wind farm site: routine turbine searches; carcass detection trials; and carcass removal trials. Results from years 1 and 2 of a three-year programme are presented. To date, mortalities have been recorded for 17 taxa at 18 of the 24 study turbines. There have been no recorded mortalities of falcon, kākā or kererū. Australasian harrier (Circus approximans) has been the species for which the most mortalities have been recorded. Overall estimated annual mortality rates for years 1 and 2 were calculated to be approximately six and five birds per turbine respectively.     

Physical size,condition, and demography of chamois (Rupicapra rupicapra L.) in the Avoca River region,Canterbury, New Zealand

Abstract

The physical and demographic characteristics of chamois in the Avoca region are evaluated from 306 animals shot and autopsied between 1975 and 1978. These data are compared with published and unpublished information for chamois populations in Westland and Canterbury. Avoca chamois were large-framed, but weighed less than Westland chamois. The weight difference suggests better habitat condition and food resources for Westland animals, but the large skeletal size of Avoca chamois is unexplained.

High rates of juvenile mortality were caused by acute bacterial-pneumonia infections (Pasteurella). These deaths and other losses by natural causes were offset by the good breeding success of adult females so that stable population numbers were maintained.     

Protein production in components of the accessory gland complex of male Melanoplus sanguinipes (Insecta: Orthoptera)

Protein production during sexual maturation or after allatectomy (followed by juvenile hormone replacement therapy) has been examined in the long hyaline glands, short hyaline glands, white glands, and seminal vesicles, which make up the accessory gland complex of male Melanoplus sanguinipes. During maturation, the amount of protein in the long hyaline glands increases about 14-fold, and in each of the other components between 5- and 6-fold. Most protein accumulates between days 3 and 5, and this is reflected in high levels of incorporation of radiolabelled leucine in this period.

The components show differential sensitivity to the effects of allatectomy. After this operation, the protein content of, and incorporation of radiolabel into, the long hyaline glands remain near the day 0 level. In the white glands and short hyaline glands, allatectomy also has a marked, though less severe, effect on protein synthesis and accumulation. The seminal vesicles are least affected by allatectomy and continue to accumulate protein (though more slowly) to about 60% of the normal level by day 10. Juvenile hormone compounds applied topically to allatectomized insects on day 2 restored the ability of the gland components to accumulate proteins, though to differing degrees. JHI is the most effective compound, stimulating synthesis and accumulation of protein to near normal levels by day 10, whereas application of JHIII or Stauffer's synthetic JH led to only partial restoration of protein synthesis in the glands.     

The effect of salinity on larval survival and development in the sea urchin Echinometra lucunter

Summary

Reductions in salinity can have adverse effects on larval development and larval survival in some invertebrate taxa but not others. Salinity tolerance of larvae may be particularly important in echinoderms because they are both poor ion regulators and stenohaline. I examined the effect of six levels of salinity (15, 18, 21, 24, 27 and 33 PSU) on survival and rate of development of larvae in the subtropical sea urchin Echinometra lucunter. In the short-term, mortality rate was significantly lower in 33 PSU than in all other salinities except 27 PSU, and it was significantly greater in 15 and 18 PSU than in all higher salinities. In the long-term, daily and cumulative mortality were significantly greater in 15 PSU than in most other salinities over 11 days of development (except for cumulative mortality in 18 PSU). They were significantly greater in 18 PSU than in 21 PSU or 33 PSU over a period of 13 days. Furthermore, daily mortality was significantly greater in 18 PSU than in 24 PSU or 27 PSU at 13 d after fertilization. Daily and cumulative mortality were significantly lower in 33 PSU than in 21, 24 or 27 PSU over a period of 17 days. Although in the control (33 PSU) 75% of larvae completed development to the 8-arm stage at 35 d, no larvae developed further than the 4-arm stage in 18, 21, 24 or 27 PSU; in 15 PSU, ~60% of larvae did not develop further than swimming blastulae. Since prolonged exposure to salinities as high as 27 PSU (frequently recorded in the adult habitat) can result in great larval losses, adaptive behaviours that prevent larvae from entering water layers of low salinity will enhance their chance for survival.     

Energy storage during the transition from endogenous to exogenous feeding in Australian redclaw crayfish Cherax quadricarinatus (Von Martens, 1898)

Summary

The Australian redclaw crayfish Cherax quadricarinatus hatches at an advanced stage. Two post-hatching stages rely on yolk reserves before the organism becomes a juvenile. After a juvenile appears, the yolk is depleted and young crayfish might spend a few days among female pleopods before starting to feed independently. During this phase, the juvenile organism needs alternative energy sources. Offspring from three females were analyzed with histological and histochemical techniques, from hatching until reaching the 2-week juvenile stage, to trace digestive system development and internal organ lipid and glycogen accumulation. Neutral lipids are stored in specialized cells of the hepatopancreatic tissue until the juvenile stage is reached. An increasing rate of accumulation was found. Glycogen was stored in hepatopancreas and tail muscle cells until post-embryo II, and no increasing or decreasing rate was found in storage functions.     

EFFECT OF ECDYSTERONE ON VITELLOGENIN CONCENTRATION IN HAEMOLYMPH OF MALE AND FEMALE SARCOPHAGA BULLATA

Using Polyacrylamide gel electrophoresis, cycloheximide, incorporation of ³H-labelled amino acids and immunological methods, we have demonstrated that injection of ecdy- sterone induces de novo synthesis and release of vitellogenin in both sexes of Sarcophaga bullata. Vitellogenin concentrations were measured by the Mancini-radial immunodiffusion technique. In males a dose as low as 1 ng always makes vitellogenin appear in the haemolymph but very reproducible results are only obtained when doses varying from 10 to 250 ng were injected. In this range, the dose-response curve was linear on a semi- logarithmic scale.

In females, vitellogenin concentration remained low until a few hours after liver feeding and thereafter it rose sharply and reached its maximum about 24 h after the protein meal. 100 μg 6-hydroxydopamine HCl, injected before liver feeding in 4-day-old females, inhibited vitellogenin synthesis and yolk deposition, probably by interfering with the release of a brain hormone. This inhibitory effect on vitellogenin synthesis, but not that on yolk deposition, could be overruled by injection of ecdysterone. Juvenile hormone was ineffective on both. Females, ovariectomized on day 2 or 3, accumulated vitellogenin in their haemolymph, indicating that the continuous presence of the ovaries was not required for vitellogenin synthesis. The possible relation between the gonadotrophs hormone from the brain, vitellogenin synthesis and moulting hormone metabolism is discussed.