Spatiotemporal Distribution of Two Euschistus spp. Stink Bugs (Hemiptera: Pentatomidae) in Southeastern Farmscapes

Stink bugs (Hemiptera: Pentatomidae) are ubiquitous, cryptic, phytophagous pests that are found in many crops. In agroecosystems, individuals disperse from adjacent noncrop hosts and tend to aggregate or cluster within fields. In this study, we characterized the distribution of Euschistus servus (Say) and Euschistus tristigmus (Say) (Hemiptera: Pentatomidae) over 2 yr at three southeastern United States farmscapes. Stink bugs were captured in pheromone-baited traps, and Spatial Analysis by Distance Indices (SADIE) used to identify the location of significant aggregations by habitat type and season. Euschistus servus adults were more likely to be captured in pecan orchards, cotton, other crops, or unmanaged habitats than in woodland habitats. Significant aggregations of E. servus were detected in a variety of habitats including pecan, corn, cotton, peanut, and tobacco, as well as fallow and hay fields, pastures, and hedgerows. Fewer adult E. tristigmus were captured than E. servus adults, and E. tristigmus adults were typically trapped and aggregated in woodland habitats. The resulting data provide an important understanding regarding the seasonal movement and relative abundance levels of stink bug populations, which are critical to the development of integrated pest management strategies.     

Ram management for northeastern flocks

The ram is an important member of the flock, particularly in smaller, intensively managed flocks such as are found in the Northeast. An infertile ram can spell reproductive and financial failure for the producer. A highly fertile ram can settle more ewes in a shorter time, produce more twins, and confer valuable traits on his offspring. These include wool type, rate of gain and higher sperm production and ovulation rates. Details of the breeding soundness examination, including semen evaluation are discussed. Ram management techniques appropriate for Northeastern sheep producers are presented.     

The use of isozyme genetic markers to estimate the rate of outcrossing in a Sitka spruce (Picea sitchensis (Bong.) Carr.) seed orchard in Scotland

Effects of genotype, collection date, auxin treatment, crown position and artificial chilling on rooting and subsequent vegetative growth of Cupressus sempervirens L. softwood cuttings taken from 13-year-old plants were evaluated. Three different clones (318, 296 and 22) previously selected for resistance to cypress cortical cancer caused by Seiridium cardinale were used. In all these clones, both the IBA treated and the untreated cuttings showed seasonal periodicity of rooting. Untreated cuttings rooted best when collected in April (up to 49% for the best clone, i.e. 296) and rooted very poorly in July and October. Auxin treatments appeared unable to overcome this periodicity, as the cuttings taken in July and October did not respond to IBA stimulation. However, in January and April, IBA treatments enhanced adventitious root formation of poorly rooting clones (318 and 22), as well as of clone 296, which performed best (89%) when cuttings were treated in April with 1.5% IBA. Cuttings of each clone collected in the lower third of the crown of the donor trees showed a significantly higher rooting percentage, when compared with those from the upper third. A 4-week post-severance chilling treatment (4°C) significantly enhanced the rooting capacity of cuttings taken in January, while a longer chilling treatment (8 weeks) had a negative effect. The subsequent growth of the rooted cuttings was not affected by either the crown position of the severed cuttings, or the genotype.     

Allometric analysis of ciprofloxacin and enrofloxacin pharmacokinetics across species

The purpose of this study was to examine the allometric analysis of ciprofloxacin and enrofloxacin using pharmacokinetic data from the literature. The pharmacokinetic parameters used were half-life, clearance and volume of distribution. Relationships between body weight and the pharmacokinetic parameter were based on the empirical formula Y = aW(b), where Y is half-life, clearance or volume of distribution, W the body weight and a is an allometric coefficient (intercept) that is constant for a given drug. The exponential term b is a proportionality constant that describes the relationship between the pharmacokinetic parameter of interest and body weight. A total of 21 different species of animals were studied. Results of the allometric analyses indicated similarity between clearance and volume of distribution as they related to body weight for both drugs. Results of the current analyses indicate it is possible to use allometry to predict pharmacokinetic variables of enrofloxacin or ciprofloxacin based on body size of species. This could provide information on appropriate doses of ciprofloxacin and enrofloxacin for all species.     

Compensatory feeding during early gestation for sows with a high weight loss after a summer lactation increased piglet birth weight but reduced litter size

Sows mated in summer produce a greater proportion of born-light piglets (<1.1 kg) which contributes to increased carcass fatness in the progeny population. The reasons for the low birth weight of these piglets remain unclear, and there have been few successful mitigation strategies identified. We hypothesized that: 1) the low birth weight of progeny born to sows mated in summer may be associated with weight loss during the previous summer lactation; and 2) increasing early gestation feed allowance for the sows with high lactational weight loss in summer can help weight recovery and improve progeny birth weight. Sows were classified as having either low (av. 1%) or high (av. 7%) lactational weight loss in their summer lactation. All the sows with low lactational weight loss (LLStd) and half of the sows with high lactational weight loss received a standard gestation feeding regime (HLStd) (2.6 kg/d; day 0–30 gestation), whereas the rest of the sows with high lactational weight loss received a compensatory feed allowance (HLComp) (3.5 kg/d; day 0–30 gestation). A comparison of LLStd (n = 75) versus HLStd sows (n = 78) showed that this magnitude of weight loss over summer lactation did not affect the average piglet or litter birth weight, but such results may be influenced by the higher litter size (P = 0.030) observed in LLStd sows. A comparison of HLStd versus HLComp (n = 81) sows showed that the compensatory feeding increased (P = 0.021) weight gain of gestating sows by 6 kg, increased (P = 0.009) average piglet birth weight by 0.12 kg, tended to reduce (P = 0.054) the percentage of born-light piglets from 23.5% to 17.1% but reduced the litter size by 1.4 (P = 0.014). A subgroup of progeny stratified as born-light (0.8–1.1 kg) or -normal (1.3–1.7 kg) from each sow treatment were monitored for growth performance from weaning until 100 kg weight. The growth performance and carcass backfat of progeny were not affected by sow treatments. Born-light progeny had lower feed intake, lower growth rate, higher G:F, and higher carcass backfat than born-normal progeny (all P < 0.05). In summary, compensatory feeding from day 0 to 30 gestation in the sows with high weight loss during summer lactation reduced the percentage of born-light progeny at the cost of a lower litter size, which should improve growth rate and carcass leanness in the progeny population born to sows with high lactational weight loss.     

In vitro response to noradrenaline of small intestine taken from normal and grass sickness-affected horses

Small intestine was taken from the caudal flexure of the duodenum and the terminal ileum proximal to the ileocaecal fold of 25 horses, 9 with acute grass sickness (AGS), 12 with subacute grass sickness (SAGS) and 12 with chronic grass sickness (CGS). The motility in the samples was measured isometrically either within 1 h of death or after storage for 24 h at 4°C.In control tissue, noradrenaline produced contractions of muscle strips which did not involve a muscarinic cholinergic mechanism and which were unaffected by the 1 antagonist prazosin but were blocked by the 2 antagonist yohimbine. Pretreatment with the antagonist phentolamine prevented the contractile response to noradrenaline and the background contractions either continued at a reduced rate and amplitude or were abolished after a few minutes. Thus, following blockade, noradrenaline reduced the background contraction rate by an effect on inhibitory adrenoceptors. The rate of background contractions in duodenal preparations was significantly greater than that in control ileal preparations.Although cold storage for 24 h caused a reduction in the background contraction rates of the control preparations, there was no effect on the contractile responses to noradrenaline, the associated pharmacology being similar to that of fresh tissue. This suggests that noradrenaline-evoked contraction was not dependent on enteric neural elements.The response to noradrenaline by grass sickness-affected tissue was generally similar to that of tissue from control horses, with an immediate contraction which was 2 sensitive. The contractile response to noradrenaline after propranolol was significantly reduced in the CGS group and there were significant differences between the AGS, CGS and control groups. There was a significant difference between the ileal preparations from the control and SAGS groups in their response to noradrenaline following pretreatment with propranolol.