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Brainstem gliomas comprise 10-20% of all pediatric central nervous system (CNS) tumors and diffuse intrinsic pontine gliomas (DIPGs) account for the majority of these lesions. DIPG is a rapidly progressive disease with almost universally fatal outcomes and a median survival less than 12 months. Current standard-of-care treatment for DIPG includes radiation therapy, but its long-term survival effects are still under debate. Clinical trials investigating the efficacy of systemic administration of various therapeutic agents have been associated with disappointing outcomes. Recent efforts have focused on improvements in chemotherapeutic agents employed and in methods of localized and targeted drug delivery. This review provides an update on current preclinical and clinical studies investigating treatment options for brainstem gliomas.

Colony collapse disorder (CCD), a syndrome whose defining trait is the rapid loss of adult worker honey bees, Apis mellifera L., is thought to be responsible for a minority of the large overwintering losses experienced by U.S. beekeepers since the winter 2006-2007. Using the same data set developed to perform a monofactorial analysis (PloS ONE 4: e6481, 2009), we conducted a classification and regression tree (CART) analysis in an attempt to better understand the relative importance and interrelations among different risk variables in explaining CCD. Fifty-five exploratory variables were used to construct two CART models: one model with and one model without a cost of misclassifying a CCD-diagnosed colony as a non-CCD colony. The resulting model tree that permitted for misclassification had a sensitivity and specificity of 85 and 74%, respectively. Although factors measuring colony stress (e.g., adult bee physiological measures, such as fluctuating asymmetry or mass of head) were important discriminating values, six of the 19 variables having the greatest discriminatory value were pesticide levels in different hive matrices. Notably, coumaphos levels in brood (a miticide commonly used by beekeepers) had the highest discriminatory value and were highest in control (healthy) colonies. Our CART analysis provides evidence that CCD is probably the result of several factors acting in concert, making afflicted colonies more susceptible to disease. This analysis highlights several areas that warrant further attention, including the effect of sublethal pesticide exposure on pathogen prevalence and the role of variability in bee tolerance to pesticides on colony survivorship.

Fractionated radiotherapy (FRT) and gamma knife stereotactic radiosurgery (GKSRS) are used as adjuvant therapies to surgical resection for functional and non-functional pituitary adenomas, although their optimum role in the treatment algorithm, as well as long-term safety and efficacy, still awaits further study. We report a single center experience with 33 patients with non-functional (16 patients), ACTH- (five patients), GH- (four patients), or prolactin-secreting (eight patients) tumors treated with FRT or SRS. The median tumor diameter was 1.9 cm, and the median follow-up was 36 months. For GKSRS, the median dosage was 16 Gy for non-functional adenomas and 23 Gy for hormone-secreting tumors. The median total dose for FRT was 50.4 Gy over 28 fractions (median). Two patients (6%) demonstrated radiographic evidence of tumor progression, three patients (9%) demonstrated radiation-induced visual field deficits on neuro-ophthalmic evaluation, and two patients (6%) suffered from radiation-induced hypopituitarism. Biochemical control, defined as normalized hormone values in the absence of medical therapy, was achieved in five out of eight prolactinoma patients and two out of five patients with Cushing's disease, but none of the four patients with acromegaly. These results are presented with a review of the relevant literature on the differential characteristics of FRT versus SRS in the treatment of functional and non-functional pituitary adenomas and validate postoperative irradiation as a potentially safe and effective means for tumor control.

Disseminated intravascular coagulation (DIC) as a complication of surgery for ventriculoperitoneal (VP) shunts is extremely rare, and only one case has been documented in the literature. The authors present the case of a 9-year-old girl with shunted hydrocephalus who presented with a 3-day history of headaches and vomiting. A head CT showed enlarged ventricles compared with baseline. An emergent VP shunt revision was performed, during which an obstructed proximal catheter was found. Immediately after extubation, the patient became apneic and progressed to cardiopulmonary arrest. A breathing tube was reinserted followed by resuscitation attempts that led to extracorporeal membrane oxygenation. Soon after reintubation, bloody drainage was noted in the endotracheal tube, and subsequent laboratory studies were consistent with DIC. The patient died on postoperative Day 1, and autopsy findings confirmed DIC. Note that DIC is a recognized complication of trauma, particularly with brain injury, but it is rare with neurosurgical procedures. Disseminated intravascular coagulation should be considered if excessive bleeding occurs after any brain insult.

Background Low-grade gliomas have been documented to undergo transformation into high-grade astrocytomas, and the time interval of this transformation has been reported to generally occur within 5 years in about 50% of patients harboring these low-grade lesions. Several studies have investigated the evolution of low-grade gliomas into malignant gliomas by CT and MRI characteristics, but many have not documented the timing of these transformation processes. Case Description The authors discuss the cases of 2 patients with histopathologically confirmed grade II astrocytomas after craniotomies that underwent rapid evolution into malignant gliomas within 13 weeks. Interestingly, both low-grade astrocytomas were positive with immunostaining for the epidermal growth factor receptor, in which its amplification has been implicated as a molecular marker of malignant gliomas. In addition, the grade II astrocytomas were negative for p53 in both patients but were found to be positive upon transformation into malignant gliomas. Conclusions To our knowledge, this is the first report of rapid malignant transformation of low-grade gliomas, which were proven by histology, within 13 weeks. There may be patients with a subtype of low-grade astrocytomas that may warrant molecular characterization to determine if aggressive adjuvant therapy would be of benefit.

Diffuse intrinsic pontine gliomas constitute ~ 60–75% of tumors found within the pediatric brainstem. These malignant lesions present with rapidly progressive symptoms such as cranial nerve, long tract, or cerebellar dysfunctions. Magnetic resonance imaging is usually sufficient to establish the diagnosis and obviates the need for surgical biopsy in most cases. The prognosis of the disease is dismal, and the median survival is < 12 months. Resection is not a viable option. Standard therapy involves radiotherapy, which produces transient neurological improvement with a progression-free survival benefit, but provides no improvement in overall survival. Clinical trials have been conducted to assess the efficacy of chemotherapeutic and biological agents in the treatment of diffuse pontine gliomas. In this review, the authors discuss recent studies in which systemic therapy was administered prior to, concomitantly with, or after radiotherapy. For future perspective, the discussion includes a rationale for stereotactic biopsies as well as possible therapeutic options of local chemotherapy in these lesions.

Hypothalamic hamartomas are rare congenital malformations located in the region of the tuber cinereum and third ventricle. Patients may be asymptomatic, but the usual presentation is gelastic seizures, precocious puberty, and/or developmental delay. Without surgical intervention, the gelastic seizures, which are typically present in childhood, may progress to other seizure types, including generalized epilepsy, and are generally refractory to antiepileptic drugs. This review will discuss the clinical and electrophysiologic aspects of these lesions, as well as treatment options, including surgery, endoscopy, and radiosurgery.

Sellar and parasellar lesions in the pediatric population have traditionally been approached through either a transsphenoidal hypophysectomy or craniotomy or a combination of the two, with the surgical approach being dictated by the anatomical location and extent of the pathology. The introduction and evolution of the endonasal endoscopic technique has provided a minimally invasive method alone or in combination with the operative microscope for removal of these lesions in the pediatric population. The authors have implemented in their practice the use of endonasal endoscopic-assisted microsurgery in the pediatric population harboring sellar and/or lesions extending to the suprasellar space and report our experience in nine patients. Five craniopharyngiomas, one Rathke’s cleft cyst, and two pituitary tumors were treated via endonasal endoscopic-assisted microsurgery. Histopathologic examination revealed lymphocytic hypophysitis in one patient with an enhancing lesion in the pituitary stalk. The approach utilized by the authors is performed through one nostril without any resection of the nasal turbinates or nasal septum. The middle turbinate is displaced laterally, while the nasal septum is moved medially. Gross total, near-total, and subtotal resections and a diagnostic biopsy were obtained in six, one, one, and one patients, respectively. The authors were able to safely perform this procedure in nine pediatric patients, and the lack of turbinate or septum resection minimized postoperative discomfort.

Object.Leukocyte—endothelial cell interactions may play a role in the development of cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH) because the extravasation of circulating leukocytes into the periadventitial space within 24 hours after the hemorrhage appears to be a critical event in this process. Ibuprofen is an antiinflammatory agent that inhibits the expression of specific cell adhesion molecules and, consequently, disrupts leukocyte—endothelial cell interactions. The authors investigated the efficacy of ibuprofen delivered locally from controlled-release polymers in the rabbit basilar artery (BA) model of cerebral vasospasm.Methods.Ibuprofen was incorporated into controlled-release ethylene—vinyl acetate copolymer (EVAc) constituting 45% of the resulting polymer by weight. Fifty-four New Zealand White rabbits were randomized to 10 groups: sham operation (seven animals); SAH only (seven animals); and SAH plus either empty EVAc or ibuprofen—EVAc polymer at 30 minutes or 6, 12, or 24 hours (five animals per group; 40 total). The rabbits were killed 72 hours after induction of SAH, at the time of maximal vasospasm. The efficacy of ibuprofen in preventing vasospasm was assessed by measuring lumen patency of the rabbit's BAs. The intracranial controlled release of ibuprofen resulted in a significant inhibition of vasospasm when treatment was initiated at 30 minutes (patency 92.3 ± 5.1% compared with 52.1 ± 5.1% in animals given empty EVAc; p < 0.001) and 6 hours (patency 69.5 ± 3.5% compared with 47.2 ± 1.5% in animals given empty EVAc; p < 0.03) after blood deposition compared with treatment with empty EVAc. No effect was observed when treatment was begun at either 12 or 24 hours.Conclusions.Local intracranial delivery of ibuprofen accomplished using controlled-release polymers prevents vasospasm in the rabbit BA model of vasospasm when administered within 6 hours after blood exposure.

Object.Implantation of controlled-release polymers into the subarachnoid space to deliver drugs for treatment of vasospasm after subarachnoid hemorrhage (SAH) is currently of interest. Among the issues regarding local delivery of drugs in the subarachnoid space, however, are the extent of diffusion and the rate of release of the loaded agents. In this study Evans blue dye (EBD) was loaded into controlled-release polymers and its pharmacokinetic properties were determined in vitro and in vivo by using a rabbit model of SAH.Methods.Ethylene—vinyl acetate copolymer (EVAc) was loaded 40% (w:w) with EBD and its pharmacokinetics were spectrophotometrically determined in vitro by examining three EBD—EVAc polymers. Additional polymers were implanted either into the frontal lobe or into the cisterna magna of 16 New Zealand White rabbits. Subarachnoid hemorrhage was induced in eight of the animals by an injection of 1.5 ml of arterial blood into the cisterna magna. The animals were killed 3 or 14 days postoperatively, their brains and spinal cords were harvested, and samples of each were placed in formamide for dye extraction and quantification. Specimens were examined macroscopically and the concentrations of EBD were determined with the aid of a spectrophotometer.The EBD—EVAc polymers continuously released EBD over a 133-day period. The controlled release of the dye into the subarachnoid space in either location resulted in staining of the entire central nervous system (CNS) in rabbits when the polymers were placed either on the frontal lobe or in the cisterna magna. The EBD diffusion covered a distance of at least 40 cm. The presence of blood in the subarachnoid space did not interfere with the diffusion.Conclusions.In this study the authors define the rate and extent of diffusion of EBD from controlled-release polymers placed in the subarachnoid space under conditions of SAH. Evans blue dye diffused through the entire rabbit CNS, covering a distance greater than that of the longest dimension of the hemicircumference of the subarachnoid space around the human brain. The pharmacokinetic properties of EBD—EVAc polymers are comparable to those of antivasospasm agents that are successfully used in animal models of SAH.

Minocycline, a tetracycline derivative, has been shown to inhibit tumor angiogenesis through inhibitory effects on matrix metalloproteinases. Previous studies have shown this agent to be effective against a rodent brain tumor model when delivered intracranially and to potentiate the efficacy of standard chemotherapeutic agents. In the present study, the in vivo efficacy of intracranial minocycline delivered by a biodegradable controlled-release polymer against rat intracranial 9L gliosarcoma was investigated to determine whether it potentiates the effects of systemic 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU). Minocycline was incorporated into the biodegradable polymer polyanhydride poly[bis(p-carboxyphenoxy)propane-sebacic acid] (pCPP:SA) at a ratio of 50:50 by weight. The release kinetics of minocycline from the polymer were assessed. For the efficacy studies, female Fischer 344 rats were implanted with 9L glioma. Treatment with minocycline delivered by the pCPP:SA polymer at the time of tumor implantation resulted in 100% survival in contrast to untreated control animals that died within 21 days. Treatment with the minocycline-polymer 5 days after tumor implantation provided only modest increases in survival. The combination of intracranial minocycline and systemic BCNU extended median survival by 82% compared to BCNU alone (p < 0.0001) and 200% compared to no treatment (p < 0.004). We conclude that local intracranial delivery of minocycline from biodegradable controlled-release polymers inhibits tumor growth and may have clinical utility when combined with a chemotherapeutic agent.

Dr. Fumio Matsumura's legacy embraced a passion for exploring environmental impacts of agrochemicals on non-target species such as bees. Why most formulations are more toxic to bees than respective active ingredients and how pesticides interact to cause pollinator decline cannot be answered without understanding the prevailing environmental chemical background to which bees are exposed. Modern pesticide formulations and seed treatments, particularly when multiple active ingredients are blended, require proprietary adjuvants and inert ingredients to achieve high efficacy for targeted pests. Although we have found over 130 different pesticides and metabolites in beehive samples, no individual pesticide or amount correlates with recent bee declines. Recently we have shown that honey bees are sensitive to organosilicone surfactants, nonylphenol polyethoxylates and the solvent N-methyl-2-pyrrolidone (NMP), widespread co-formulants used in agrochemicals and frequent pollutants within the beehive. Effects include learning impairment for adult bees and chronic toxicity in larval feeding bioassays. Multi-billion pounds of formulation ingredients like NMP are used and released into US environments. These synthetic organic chemicals are generally recognized as safe, have no mandated tolerances, and residues remain largely unmonitored. In contrast to finding about 70% of the pesticide active ingredients searched for in our pesticide analysis of beehive samples, we have found 100% of the other formulation ingredients targeted for analysis. These ‘inerts’ overwhelm the chemical burden from active pesticide, drug and personal care ingredients with which they are formulated. Honey bees serve as an optimal terrestrial bioindicator to determine if ‘the formulation and not just the dose makes the poison’.

Isolated Whipple disease of the central nervous system is a rare occurrence. Migratory arthralgias and gastrointestinal problems, including malabsorption, abdominal pain, diarrhea, and weight loss, are common presenting symptoms.For those patients with systemic signs and symptoms of Whipple disease, 6% to 43% will have clinically manifested CNS involvement that may include alterations in personality, ataxia, and dementia. We report our experience with a patient, who was successfully treated for Whipple disease 12 years prior to presentation and had a magnetic resonance image of the brain that revealed two solitary lesions resembling a tumor upon presentation.

Disseminated intravascular coagulation (DIC) as a complication of surgery for ventriculoperitoneal (VP) shunts is extremely rare, and only one case has been documented in the literature. The authors present the case of a 9-year-old girl with shunted hydrocephalus who presented with a 3-day history of headaches and vomiting. A head CT showed enlarged ventricles compared with baseline. An emergent VP shunt revision was performed, during which an obstructed proximal catheter was found. Immediately after extubation, the patient became apneic and progressed to cardiopulmonary arrest. A breathing tube was reinserted followed by resuscitation attempts that led to extracorporeal membrane oxygenation. Soon after reintubation, bloody drainage was noted in the endotracheal tube, and subsequent laboratory studies were consistent with DIC. The patient died on postoperative Day 1, and autopsy findings confirmed DIC. Note that DIC is a recognized complication of trauma, particularly with brain injury, but it is rare with neurosurgical procedures. Disseminated intravascular coagulation should be considered if excessive bleeding occurs after any brain insult.

This article provides a broad overview of the data, including laboratory and clinical studies, currently available on the combination of immunotherapy and chemotherapy for treating cancer. The various forms of immunotherapy combined with chemotherapy include monoclonal antibodies, adoptive lymphocyte transfer, or active specific immunotherapy, such as tumor proteins, irradiated tumor cells, tumor cell lysates, dendritic cells pulsed with peptides or lysates, or tumor antigens expressed in plasmids or viral vectors. This discussion is not limited to malignant brain tumors, because many of the studies have been conducted on various cancer types, thereby providing a comprehensive perspective that may encourage further studies that combine chemotherapy and immunotherapy for treating brain tumors.

Purpose: The objective of this study was to report our experience with stereotactic radiosurgery performed with the Gamma Knife (GK) in the treatment of patients with brain metastases and to compare survival for those treated with radiosurgery alone with survival for those treated with radiosurgery and whole-brain radiotherapy. Methods and Materials: Prospectively collected demographic and clinical characteristics and treatment and survival data on 237 patients with intracranial metastases who underwent radiosurgery with the GK between 2003 and 2007 were reviewed. Kaplan-Meier and Cox proportional hazards regression analyses were used to compare survival by demographic and clinical characteristics and treatment. Results: The mean age of the patient population was 56 years. The most common tumor histologies were non-small-cell lung carcinoma (34.2%) and breast cancer (13.9%). The median overall survival time was 8.5 months from the time of treatment. The median survival times for patients with one, two/three, and four or more brain metastases were 8.5, 9.4, and 6.7 months, respectively. Patients aged 65 years or greater and those aged less than 65 years had median survival times of 7.8 and 9 months, respectively (p = 0.008). The Karnofsky Performance Score (KPS) at the time of treatment was a significant predictor ofmore » survival: those patients with a KPS of 70 or less had a median survival of 2.9 months compared with 10.3 months (p = 0.034) for those with a KPS of 80 or greater. There was no statistically significant difference in survival between patients treated with radiosurgery alone and those treated with radiosurgery plus whole-brain radiotherapy. Conclusions: Radiosurgery with the GK is an efficacious treatment modality for brain metastases. A KPS greater than 70, histology of breast cancer, smaller tumor volume, and age less than 65 years were associated with a longer median survival in our study.« less

Spinal meningoceles are protrusions or expansions of one or more layers of the thecal sac through a canal or foramen of the spinal column in which there is a defect. They are frequently found in a posterior location with the dysraphic vertebrae over the thoracolumbar region. Spinal meningoceles are most commonly observed at birth and constitute approximately 10% of all patients with spina bifida [1, 2]. Although non-dysraphic anterior, lateral, and anterolateral meningoceles in the cervical, thoracic, and lumbar spine are very rare and frequently characterized by the absence of a congenital defect of the vertebrae, they are usually associated with neurofibromatosis 1 (NF-1) or Marfan’s syndrome [1, 2, 3, 4, 5, 6, 7, 8]. However, anterior lumbosacral meningoceles are a rare form of spinal dysraphism because of a bony defect. Their embryologic origin remains unclear, although there are several hypotheses [2]. Thoracic and/or lumbosacral spinal levels are the most common, with cervical localization being very rare [5, 6, 7, 9, 10, 11].

✓ Brain abscesses occur infrequently but continue to be problematic for the pediatric neurosurgical community. The incidence of brain abscesses in children has not changed much, although individual reports may show an increase or decrease in the number of reported cases depending on the patient population studied. An increase could be attributed to earlier detection due to advancements in imaging modalities and/or to an increase in the number of children with immunodeficient states caused by AIDS, chemotherapy for malignant lesions, and immunosuppressive therapy for organ transplantation. A decrease in the incidence of brain abscesses could be attributed to practices such as antibiotic treatment for otitis media, sinusitis, and/or prophylactic antimicrobial treatment for congenital heart disease in children. The morbidity and mortality rates associated with brain abscesses have not changed dramatically in the antibiotic and imaging era, and their preferred management can vary among healthcare providers. These lesions have been successfully treated by neurosurgeons. The causes of brain abscesses are highly variable in children, which is also the case in adults, but the predisposing factors in the pediatric population differ in prevalence. Cyanotic congenital heart disease, hematogenous dissemination, contiguous infection, and penetrating traumatic injuries are the most common causes of brain abscesses in children. In this review, the authors discuss the causes and medical and surgical management of brain abscesses in children.

Minocycline, a tetracycline derivative, has been shown to inhibit tumor angiogenesis through inhibitory effects on matrix metalloproteinases. Previous studies have shown this agent to be effective against a rodent brain tumor model when delivered intracranially and to potentiate the efficacy of standard chemotherapeutic agents. In the present study, the in vivo efficacy of intracranial minocycline delivered by a biodegradable controlled-release polymer against rat intracranial 9L gliosarcoma was investigated to determine whether it potentiates the effects of systemic 1,3-bis (2-chloroethyl)-1-nitrosourea (BCNU). Minocycline was incorporated into the biodegradable polymer polyanhydride poly[bis(p-carboxyphenoxy)propane-sebacic acid] (pCPP:SA) at a ratio of 50:50 by weight. The release kinetics of minocycline from the polymer were assessed. For the efficacy studies, female Fischer 344 rats were implanted with 9L glioma. Treatment with minocycline delivered by the pCPP:SA polymer at the time of tumor implantation resulted in 100% survival in contrast to untreated control animals that died within 21 days. Treatment with the minocycline-polymer 5 days after tumor implantation provided only modest increases in survival. The combination of intracranial minocycline and systemic BCNU extended median survival by 82% compared to BCNU alone (p0.0001) and 200% compared to no treatment (p0.004). We conclude that local intracranial delivery of minocycline from biodegradable controlled-release polymers inhibits tumor growth and may have clinical utility when combined with a chemotherapeutic agent.

In East Africa, honey bees (Apis mellifera) provide critical pollination services and income for small-holder farmers and rural families. While honey bee populations in North America and Europe are in decline, little is known about the status of honey bee populations in Africa. We initiated a nationwide survey encompassing 24 locations across Kenya in 2010 to evaluate the numbers and sizes of honey bee colonies, assess the presence of parasites (Varroa mites and Nosema microsporidia) and viruses, identify and quantify pesticide contaminants in hives, and assay for levels of hygienic behavior. Varroa mites were present throughout Kenya, except in the remote north. Levels of Varroa were positively correlated with elevation, suggesting that environmental factors may play a role in honey bee host-parasite interactions. Levels of Varroa were negatively correlated with levels of hygienic behavior: however, while Varroa infestation dramatically reduces honey bee colony survival in the US and Europe, in Kenya Varroa presence alone does not appear to impact colony size. Nosema apis was found at three sites along the coast and one interior site. Only a small number of pesticides at low concentrations were found. Of the seven common US/European honey bee viruses, only three were identified but, like Varroa, were absent from northern Kenya. The number of viruses present was positively correlated with Varroa levels, but was not correlated with colony size or hygienic behavior. Our results suggest that Varroa, the three viruses, and Nosema have been relatively recently introduced into Kenya, but these factors do not yet appear to be impacting Kenyan bee populations. Thus chemical control for Varroa and Nosema are not necessary for Kenyan bees at this time. This study provides baseline data for future analyses of the possible mechanisms underlying resistance to and the long-term impacts of these factors on African bee populations.

Placement of a ventriculoperitoneal (VP) shunt is the most common form of treatment for hydrocephalus. Thoracic complications with VP shunts are rare, but we present the second documented case of the distal migration of the distal catheter of a VP shunt into the heart.A 14-year-old boy, who underwent placement of a right occipital VP shunt at another institution after closed-head injury, presented with hypertension. Plain chest x-rays and computed tomography revealed the distal catheter to be in the right ventricle of the heart.A joint surgical procedure was performed with the cardiac surgery team. The cardiac surgeons created a pericardial window through a subxyphoid incision. Simultaneously, a right occipital incision was made to access the distal catheter, which was then slowly pulled out with the pericardium under direct visualization. No hemorrhage or change in the pericardium was observed, and, therefore, the need for a thoracotomy was eliminated. A new distal catheter was placed into the peritoneal cavity.The migration of the distal catheter probably occurred during the initial VP shunt placement. The internal jugular vein probably was perforated by the tunneler during the creation of the distal catheter tract. Slow venous flow and negative inspiratory pressure may have gradually pulled the catheter up into the right atria and ventricle. As demonstrated by our case report, the catheter can be extracted safely in a joint procedure with cardiac surgeons, and a thoracotomy is not always necessary. The patient did not experience postoperative complications, and his hypertension was alleviated.

Sensilla on the labial tip of the tarnished plant bug, Lygus lineolaris, were examined with scanning and transmission electron microscopy in order to provide morphological evidence indicative of their function. The tripartate apex of the labium consists of 2 lateral lobes and an apical plate. Each lateral lobe possesses a field of 11 thick-walled, uniporous peg sensilla, 5–6 μm long and a thick-walled, nonporous hair sensillum, 18–22 μm long. The uniporous peg sensilla are innervated by 3 or 5 bipolar neurons. The nonporous hair sensillum has no dendrites within its lumen. The apical plate is a noninnervated structure which possesses terminal cuticular projections 5–8 μm long. Morphological evidence supports previously reported physiological evidence that the uniporous peg sensilla have a chemosensory function.

Scanning electron microscopy of the antennal clubs of the clover head weevil, Hypera meles (F.), revealed a dense receptor field composed of sensilla trichodea (Types I and II), sensilla basiconica (Types I, II, and III), and sensilla styloconica. Club circumference is divided equally by 6 trichodea Type I, arranged radially around the perimeter of each segment. Trichodea Type II and basiconica Type I occur on the entire receptor field of each club segment, while basiconica Type II and styloconica occur in bands along the distal edges of the dorsal surface of segments II and III, respectively. Basiconica Type III were found only at the extreme distal tip of the antennal club on segment IV. Significantly greater ( p = 0.05) numbers of sensilla trichodea Type II and basiconica Type II, found on the ventral surfaces of male and female antennal clubs, suggest that these sensilla are utilized in host reception during weevil antennal tapping.

Antennae of the 4 nymphal instars and the alate and apterous virginoparous adults of pea aphid ( Acyrthosiphon pisum (Harris)) were studied. Differences in antennal morphology as well as distribution and description of antennal sensilla are given. The first 2 nymphal instars possess 5 antennal segments, the others have 6. Total number of sensilla remains constant from second nymphal instar through adult. Scanning electron micrographs of sunken uniporous pegs of primary sensoria on segment 6 and openings to “rhinariellae” on segment 2 are presented for the first time. Comparisons are made of adult antennal characteristics of 17 species of aphids from 5 subfamilies. Microtrichia are absent from secondary sensoria, except in Drepanosiphinae and in 2 species of Aphidinae. Microtrichia are present around primary sensoria except in subfamilies Chaitophorinae and Lachninae. Thick walled hairs with enlarged tips are found in Drepanosiphinae and in the tribe Macrosiphini of Aphidinae. A new multiporous sensillum is described from members of the subfamily Drepanosiphinae. It is suggested that some of these antennal characters may aid in tracing phylogenetic relationships.

1. 1. Whole-body homogenate and hemolymph enzyme profiles of normal and γ-irradiated boll weevils were compared. 2. 2. The specific activity of homogenate lactic dehydrogenase (LDH) in treated males was significantly lower than that in normal males ( 73 ± 3 vs 104 ± 3 mU/mg protein ). 3. 3. The specific activity of homogenate acid phosphatase (AP) in treated females was significantly lower than that observed in normal females ( 89 ± 5 vs 109 ± 5 mU/mg protein ). 4. 4. Hemolymph LDH and AP showed a comparable activity pattern to homogenate LDH and AP activities. 5. 5. The homogenate LDH activity in normal males correlated well with egg production and egg hatching by females after mating with normal males. 6. 6. Low LDH activity corresponded with very low egg production and no egg hatching in irradiated males. 7. 7. LDH and AP may be monitored to assess the sterility of the boll weevil after γ-irradiation.

A model study of the reaction of muzigadial antifeedant with L -cysteine methyl ester indicates that muzigadial probably interacts with an insect chemoreceptive site via pyrrole formation with an NH2 group rather than Michael-addition with a SH group.

Steam distilled volatiles from flower buds of white clover, Trifolium repens, attracted significantly greater numbers of female clover head weevils, Hypera meles, than males, in laboratory bioassays. Persian clover, T. resupinatum, bud extract, which attracted significantly more females than either small hop clover, T. dubium or red clover, T. pratense, also displayed qualitative and quantitative differences in the gas chromatographic profile of its bud volatiles. The strong attraction of normal females to Persian clover in laboratory bioassays was abolished by antennectomy, suggesting that attraction is regulated by olfactory receptors located on weevil antennal clubs. Weevils demonstrated a similar attraction to Persian clover in the field, indicating the possibility of developing a lure made from the flower bud extract of this clover to trap weevils for control or population monitoring purposes.

1. 1. The specific activities of lactic dehydrogenase, α-hydroxybutyric dehydrogenase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase, and acid phosphatase were monitored in adult male and female boll weevil homogenates for eleven days post emergence. 2. 2. The above enzymes, plus β-glucuronidase, were monitored in adult male and female boll weevil hemolymph for 10 days post emergence.

Scanning electron microscopy revealed 2 types of sensilla trichodea, 4 types of sensilla basiconica, and one type of sensilla styloconica on the antennal club of the pecan weevil, Curculio caryae. All receptor types are found on both male and female weevils and their distribution is similar. The total number of sensilla on the antennal club of the male is estimated to be 1467 and on the female 1491. Significant differences in numbers of basiconica type I exist for dorsal and ventral surfaces on the male but not on the female. A significant difference in number exists between the sexes for trichodea type I and for dorsal/ventral surfaces on the female. Significant differences exist in length between the sexes for trichodea type I on segments 2 and 3 and trichodea type II on all 3 segments. The porous surface present on basiconica type I sensilla indicates a possible olfactory function.

Field-collected adults of Loxosceles reclusa were examined for weight loss, longevity, and body water content at death under the influence of food, water, sex, RH, ambient water vapor pressure, vapor pressure deficit, and temperature. Data were statistically analyzed and fitted with models. The amount of water left in the body at the time of death was independent of environmental factors, consisting of 28.77–42.68% of the original body weight. The natural logarithm of longevity varied linearly with vapor pressure, but temperature had a nonlinear effect. Spiders engorged in the field prior to tests generally survived longer (124–222 days) than those field-collected, starved, and subsequently fed on water (55–94 days). Percentage weight loss per day was exponentially related to longevity and was influenced primarily by temperature and vapor pressure deficit. Original weight, RH, and sex did not significantly influence longevity, weight loss, or the amount of body water content at death. Physiological adaptations of the spider to its natural habitat are discussed with reference to its water relations.

Acid phosphatases from boll weevils, Anthonomus grandis have a pH optimum of 4.6 and a temperature optimum of 37°C in 0.09 M citrate buffer. Enzyme activity is inhibited by 0.02 M fluoride (80%), arsenate (67%), and azide (24%), while activation by calcium and magnesium (5%) was considered nonsignificant. Activity of whole body homogenates is greater for females (31.8 μm/hr/mg protein) than for males (28.3 μm/hr/mg) and varies with adult age. Activity in supernatant and pellet fractions of ovaries was 53.4 and 50.0 μm/hr/mg, respectively, while corresponding activity for testes was 68.0 and 60.6 μm/hr/mg.

Plant-feeding insects have evolved an array of subtle discrimination capabilities involving their chemical senses. During the last 25 years an extensive list of plant chemicals that are detected by the contact and olfactory chemical senses of insects has accumulated. This list together with some 25–30 species of insects for which we have electrophysiological data on their chemical senses form the basis for our understanding of the chemical control of feeding. Many additional experiments at the behavioral level leave little doubt that the feeding of insects is regulated by some “umwelt” of plant chemicals, but the unique messages offered by host and nonhost plants have yet to be discovered (Dethier and Crnjar, 1982). The dynamic aspects of plant chemistry, as well as the many plant surface compounds that may have behavioral significance add to the complexity of this task (Fobes et al., 1985; Berenbaum, 1985; Gibson and Pickett, 1983; Woodhead, 1983). In addition, several types of physiological feedbacks that are important in regulating feeding have many details yet to be resolved (Shirahashi and Yano, 1984; Bernays and Simpson, 1982). These limitations in our understanding of the regulation of insect feeding come sharply into focus when we attempt to understand the importance of plant allelochemicals that inhibit feeding.

The elegant behavioral experiments of Dethier (1955) on the chemosensory control of feeding in the blow fly set the stage for the first recordings of individual cell responses by Hodgson et al. (1955). The animals clearly accepted some substances and rejected others, leading Dethier to infer that one chemosensory cell coded for acceptance and another for rejection. When electrophysiological techniques became available, the resulting data indicated that more than one sensory cell mediates each of these behaviors. Further electrophysiological experimentation led to the elucidation of how salt-, sugar-, and water-sensitive cells can interact to regulate feeding behavior (Dethier, 1976). Since then many investigators have incorporated electrophysiology as an invaluable tool in conjunction with behavioral experiments for elucidating the chemosensory basis of behavior.