Preoperative word-finding difficulties in children with posterior fossa tumours: a European cross-sectional study.

PURPOSE: Posterior fossa tumour surgery in children entails a high risk for severe speech and language impairments, but few studies have investigated the effect of the tumour on language prior to surgery. The current crosslinguistic study addresses this gap. We investigated the prevalence of preoperative word-finding difficulties, examined associations with medical and demographic characteristics, and analysed lexical errors. METHODS: We included 148 children aged 5-17 years with a posterior fossa tumour. Word-finding ability was assessed by means of a picture-naming test, Wordrace, and difficulties in accuracy and speed were identified by cut-off values. A norm-based subanalysis evaluated performance in a Swedish subsample. We compared the demographic and medical characteristics of children with slow, inaccurate, or combined slow and inaccurate word finding to the characteristics of children without word-finding difficulties and conducted a lexical error analysis. RESULTS: Thirty-seven percent (n = 55) presented with slow word finding, 24% (n = 35) with inaccurate word finding, and 16% (n = 23) with both slow and inaccurate word finding. Children with posterior fossa tumours were twice as slow as children in the norming sample. Right-hemisphere and brainstem location posed a higher risk for preoperative word-finding difficulties, relative to left-hemisphere location, and difficulties were more prevalent in boys than in girls. The most frequent errors were lack of response and semantically related sideordinated words. CONCLUSION: Word-finding difficulties are frequent in children with posterior fossa tumours, especially in boys and in children with right-hemisphere and brainstem tumours. Errors resemble those observed in typical development and children with word-finding difficulties.

Risk factors associated with nausea and vomiting in children with cancer receiving chemotherapy.

INTRODUCTION: Despite treatment with antiemetic medications, nausea remains uncontrolled for many children receiving chemotherapy. One reason is that risk factors for nausea in children remain poorly explored. The purpose of this study was to identify risk factors for chemotherapy-induced nausea (CIN) in children. METHODS: Prospective, observational study including 101 children (median age 6.4 years, range 0.8-17.9) with cancer receiving moderately or highly emetogenic chemotherapy. Primary endpoints were complete control of acute and delayed CIN, defined as no nausea in the acute phase 0-24 h after chemotherapy and in the delayed phase starting after the acute phase and ending 5 days later. Multivariable analyses included age, sex, cancer type, susceptibility to motion sickness, chemotherapy duration, numbers of antiemetics, co-administration with opioids or tricyclic antidepressants, and previously uncontrolled nausea or vomiting. RESULTS: Acute CIN was associated with susceptibility to motion sickness (odds ratio [OR] 5.73, 95% confidence interval [CI] 1.36-33.7) and older age (OR 4.19, 95% CI 1.30-14.7), comparing age group 8-18 years with 0-3 years. Delayed CIN was associated with uncontrolled acute nausea or vomiting (OR 10.3, 95% CI 2.65-50.9), highly emetogenic chemotherapy (OR 8.26, 95% CI 1.17-76.8), and having a hematologic cancer type (OR 7.81, 95% CI 1.05-79.2). CONCLUSIONS: Susceptibility to motion sickness and age can influence the risk of acute CIN. More research is needed on how best to integrate risk information in preventive antiemetic strategies. Sufficient acute nausea and vomiting control are crucial to prevent delayed CIN.

Postoperative speech impairment and cranial nerve deficits after secondary surgery of posterior fossa tumours in childhood: a prospective European multicentre study.

PURPOSE: Brain tumours constitute 25% of childhood neoplasms, and half of them are in the posterior fossa. Surgery is a fundamental component of therapy, because gross total resection is associated with a higher progression-free survival. Patients with residual tumour, progression of residual tumour or disease recurrence commonly require secondary surgery. We prospectively investigated the risk of postoperative speech impairment (POSI) and cranial nerve dysfunction (CND) following primary and secondary resection for posterior cranial fossa tumours. METHODS: In the Nordic-European study of the cerebellar mutism syndrome, we prospectively included children undergoing posterior fossa tumour resection or open biopsy in one of the 26 participating European centres. Neurological status was assessed preoperatively, and surgical details were noted post-operatively. Patients were followed up 2 weeks, 2 months and 1 year postoperatively. Here, we analyse the risk of postoperative speech impairment (POSI), defined as either mutism or reduced speech, and cranial nerve dysfunction (CND) following secondary, as compared to primary, surgery. RESULTS: We analysed 426 children undergoing primary and 78 undergoing secondary surgery between 2014 and 2020. The incidence of POSI was significantly lower after secondary (12%) compared with primary (28%, p = 0.0084) surgery. In a multivariate analysis adjusting for tumour histology, the odds ratio for developing POSI after secondary surgery was 0.23, compared with primary surgery (95% confidence interval: 0.08-0.65, p = 0.006). The frequency of postoperative CND did not differ significantly after primary vs. secondary surgery (p = 0.21). CONCLUSION: Children have a lower risk of POSI after secondary than after primary surgery for posterior fossa tumours but remain at significant risk of both POSI and CND. The present findings should be taken in account when weighing risks and benefits of secondary surgery for posterior fossa tumours.

Risk of impaired cognition after prenatal exposure to psychotropic drugs.

OBJECTIVE: Prenatal exposure to psychotropic drugs may affect the trajectories of brain development. In a register study, we investigated whether such exposure is associated with long-term impaired cognitive abilities. METHOD: Individuals born in Denmark in 1995-2008 were included. As proxies for cognitive impairment, requiring special needs education, attending special needs school, diagnoses of neurological/mental disorder, missed final examinations, and low school grade average were used. We accounted for maternal confounders. RESULTS: We identified 868 159 individuals of whom 13 983 (1.6%) were prenatally exposed. The adjusted odds ratio (OR) was 0.97[0.92-1.02] for requiring special needs education, 1.28[1.14-1.43] for attending special needs school, 1.32[1.20-1.46] for a neurological/mental disorder diagnosis, 1.37[1.22-1.54] for missing the final examinations, and 1.13[0.82-1.55] for obtaining a low school grade average. Exposure to psycholeptics (primarily antipsychotics and sedatives) was correlated with significantly increased risk for four outcomes. The highest was the risk of missing the primary school examinations (OR: 1.51[1.29-1.76]). The overall highest risk concerned the presence of a neurological/mental disorder after prenatal exposure to psychoanaleptics (primarily antidepressants) (OR: 1.86[1.24-2.78). CONCLUSION: Prenatal exposure to psychotropic drugs affects proxy outcomes of cognitive disabilities at school age. Exposure to psycholeptics carries the largest risk. The role of psychoanaleptics is currently unclear.

First Report of White Fir Dwarf Mistletoe (Arceuthobium abietinum f. sp. concoloris) on Durango Fir (Abies durangensis) from Durango, Mexico.

White fir dwarf mistletoe (Arceuthobium abietinum Engelm. ex Munz f. sp. concoloris Hawksw. & Wiens, Viscaceae) is a common parasite of grand fir (Abies grandis (Dougl. ex D. Don) Lindl.) in the Cascade Range and of Sierra white fir (Abies lowiana (Gord. & Glend.) A. Murray) in the Sierra Nevada Mountains (1). It also occurs in isolated populations on Rocky Mountain white fir (Abies concolor (Gord. & Glend.) Hildebr.) in Nevada, Utah, and Arizona (1). In addition, there are two widely separated known populations of white fir dwarf mistletoe on Durango fir (Abies durangensis Mart.) from Chihuahua, Mexico (1,2). The southernmost range of these Mexican populations extends to Cerro Mohinora near Guadalupe y Calvo close to the border with Durango and Sinaloa. In July 2012, white fir dwarf mistletoe was found infecting Durango fir on Cerro Gordo, the highest peak in the state of Durango (Latitude: 23° 12' 37″ N; Longitude: 104° 56″ 23″ W; elevation 3,060 m). Although there are many populations of Durango fir in Durango between Cerro Gordo and Cerro Mohinora, white fir dwarf mistletoe has never been reported from any of those populations (1). More than 70% of the trees were infected in the stand where the mistletoe was observed on Cerro Gordo, but little mortality of Durango fir was observed (4 trees). The infected Durango firs were growing in a mixed conifer forest of Durango fir, Douglas fir (Pseudotsuga menziesii (Mirb.) Franco), Cooper pine (Pinus cooperi Blanco), Mexican white pine (P. ayacahuite Ehrenb. ex Schltdl.), Durango pine (Pinus durangensis Mart.), and aspen (Populus tremuloides Michx.). There were no pure stands of Durango fir in the area. Infection by white fir dwarf mistletoe was only observed on Durango fir and infection was characterized by the formation of witches' brooms and branch swellings. Mistletoe plants collected from Durango fir on Cerro Gordo were identical to white fir dwarf mistletoe plants found on Cerro Mohinora when compared using morphological characters such as plant height (mean approximately 8 cm), plant color (yellow-green, green, green-brown, and rarely red-brown), mean diameter of flowers (2.8 mm), and mean fruit dimensions (5.0 × 3.0 mm) (2). White fir dwarf mistletoe is relatively host-specific and is the only dwarf mistletoe that has been reported to parasitize Durango fir in Mexico (1). Specimens of white fir dwarf mistletoe from Cerro Gordo were collected and deposited at the Hebario (CIIDIR), Instituto Politecnico Nacional, Durango, Mexico (Accession #40190). To our knowledge, this is the first report of white fir dwarf mistletoe from Durango, Mexico, and extends the known southern range of this mistletoe by approximately 370 km (1). References: (1) F. Hawksworth and D. Wiens. USDA For. Serv. Agric. Handb. 709, 1996. (2) R. Mathiasen. Plant Dis. 94:635, 2010.

First Report of Arceuthobium blumeri on Pinus ayacahuite and A. globosum subsp. globosum on P. durangensis from Sinaloa, Mexico.

Arceuthobium blumeri A. Nelson (Blumer's dwarf mistletoe, Viscaceae) is a parasite of Pinus ayacahuite Ehrenberg ex Schlechtendahl (Mexican white pine) and P. strobiformis Engelm. (southwestern white pine) in the Sierra Madre Occidental of northern Mexico (3). It is widely distributed in Chihuahua and Durango and is known from one location in Sonora (3,4). A. globosum Hawksworth & Wiens subsp. globosum (rounded dwarf mistletoe) parasitizes several pine species in the same areas of Mexico, but extends as far south as northern Jalisco (3). In July 2005, S. Quiñonez Barraza observed both of these dwarf mistletoes in Ejido San José del Barranco, Municipio de Badiraguato, Sinaloa, Mexico. A. blumeri was observed parasitizing P. ayacahuite at two locations: Paraje Faldeo Rancho del Oso (25°39'18″N, 107°01'27″W, elevation 2,600 m) and Paraje La Tableta (25°40'14″N, 107°01'33″W, elevation 2,520 m). The host at these two locations was identified by cone and needle morphology (1). Because the mistletoe plants were gray to straw in color and larger than 6 cm, they were clearly A. blumeri and not A. apachecum Hawksworth & Wiens, another dwarf mistletoe that parasitizes P. strobiformis in Arizona, New Mexico, and Coahuila, Mexico (3). A. globosum subsp. globosum was observed parasitizing P. durangensis Martínez at Paraje Puerto del Alacrán (25°39'52″N, 107°00'57″W, elevation 2,650 m). Infection of the pine hosts was severe at all three locations in Sinaloa and many trees were rated as class 5 and 6 by the 6-class dwarf mistletoe rating system (2). Large witches' brooms were formed on P. ayacahuite infected with A. blumeri, but no witches' brooms were formed on infected P. durangensis. Typically, A. globosum does not induce witches' brooms on infected pines (3). Specimens of A. blumeri and A. globosum subsp. globosum were collected and deposited at the Herbario CIIDIR, Instituto Politecnico Nacional, Durango, Dgo., 34220 Mexico. To our knowledge, this is the first report of A. blumeri and A. globosum subsp. globosum from Sinaloa, Mexico. References: (1) A. Farjon and B. T. Styles. Flora Neotrop. Monogr. 75. 1997. (2) F. G. Hawksworth. USDA For. Serv. Gen. Tech. Rep. RM-78, 1977. (3) F. G. Hawksworth and D. Wiens. USDA For. Serv. Agric. Handb. 709, 1996. (4) R. Mathiasen et al. Madroño 55:161, 2008.

First Report of Limber Pine Dwarf Mistletoe (Arceuthobium cyanocarpum) on Sugar Pine (Pinus lambertiana) from California.

Limber pine dwarf mistletoe (Arceuthobium cyanocarpum (A. Nelson ex Rydberg) Coulter & Nelson; Viscaceae) severely parasitizes limber pine (Pinus flexilis James) and several other white pines, including western white pine (P. monticola Dougl. ex D. Don) and whitebark pine (P. albicaulis Engelm.), over an extensive geographic range in the western United States (1). However, limber pine dwarf mistletoe has not been previously reported on sugar pine (P. lambertiana Dougl.), another white pine found within the range of limber pine dwarf mistletoe (1). In August 2009, we found a sugar pine infected with limber pine dwarf mistletoe approximately 0.8 km northeast of Tahquitz Peak in the San Jacinto Mountains, California (33°45'24''N, 116°40'24''W; elevation 2,640 m). The infected sugar pine was 13 inches (33 cm) in diameter and had 13 infections on five of its lower branches. Ten of the infections were producing mature male and female mistletoe plants with open flowers or developing fruits, respectively. Two of the infected branches were forming witches' brooms in response to infection by limber pine dwarf mistletoe. The infected sugar pine was growing within 3 m of four limber pines severely infected with limber pine dwarf mistletoe. The male and female plants produced on the infected sugar pine were morphologically identical to those growing on the infected limber pines. Limber pine dwarf mistletoe can be distinguished from sugar pine dwarf mistletoe (A. californicum Hawksw. & Wiens), the principal dwarf mistletoe parasitizing sugar pine in California, by its smaller plants (mean height 3 cm versus 8 cm) and flowering period (August to September versus June to July). In an attempt to determine the relative susceptibility of sugar pine to limber pine dwarf mistletoe, we conducted a survey of the infested limber pine stand. Because there were no additional sugar pines growing in the area, it was impossible to assess the general susceptibility of sugar pine to limber pine dwarf mistletoe, but the production of many mature plants from 10 of the infections on the sugar pine suggests this tree species may be highly susceptible. However, this is currently the only known location where sugar pine co-occurs with limber pine dwarf mistletoe (1), so assessing the susceptibility of sugar pine to this dwarf mistletoe will depend on locating additional sites where they co-occur. It should be noted also that previous surveys in the San Jacinto Mountains failed to detect infection by limber pine dwarf mistletoe on sugar pine (1). Specimens of limber pine dwarf mistletoe on sugar pine were collected and deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession No. 92697). To our knowledge, this is the first report of limber pine dwarf mistletoe parasitizing sugar pine. References: (1) F. G. Hawksworth and D. Wiens. USDA For. Serv. Agric. Handb. 709, 1996.

First Report of White Fir Dwarf Mistletoe (Arceuthobium abietinum f. sp. concoloris) on Mexican Spruce (Picea mexicana) in Northern Mexico.

White fir dwarf mistletoe (Arceuthobium abietinum Engelmann ex Munz f. sp. concoloris Hawksw. & Wiens, Viscaceae) severely parasitizes true firs (Abies spp.) from southern Washington to southern California (1). It also occurs in widely isolated populations on white fir (Abies concolor (Gord. & Glend.) Hildebr.) in Nevada, Utah, and Arizona (1). In addition, the two known populations of dwarf mistletoe on Durango fir (Abies durangensis Martínez) in Chihuahua, Mexico (near Yahuirachi and on Cerro Mohinora) have been classified as white fir dwarf mistletoe (1). Although a subspecies of fir dwarf mistletoe (A. abietinum Engelm. ex Munz subsp. wiensii Mathiasen & C. Daugherty) severely parasitizes Brewer spruce (Picea breweriana S. Watson) in northern California and southern Oregon (2), Engelmann spruce (P. engelmannii (Parry) Engelmann), blue spruce (P. pungens Engelm.), and Chihuahua spruce (P. chihuahuana Mart.) have been reported to be immune to infection by white fir dwarf mistletoe in the southwest and Mexico (1). However, in September 2009, white fir dwarf mistletoe was found to be infecting the rare Mexican spruce (P. mexicana Mart.) on Cerro Mohinora in southern Chihuahua, Mexico (25°57'42″N, 107°02'28″W, elevation 3,040 m). Infected Mexican spruces were growing among severely infected Durango firs in a mixed conifer forest of Durango fir, Mexican spruce, Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and Mexican white pine (Pinus ayacahuite Ehrenb.). White fir dwarf mistletoe was the only mistletoe present in the forest with the infected Mexican spruces. Only five infected spruces were observed, but some trees had as many as 20 infections. No mortality of Mexican spruce associated with mistletoe infection was observed. Some of the infected spruce branches were producing mature male and female plants with flowers and fruits, respectively. Mistletoe plants collected from Durango fir and Mexican spruce were identical when compared using morphological characters such as plant height (mean 8.4 cm), plant color (yellow-green, green, green-brown, and rarely red-brown), mean diameter of flowers (2.8 mm), and fruit dimensions (5.0 × 3.0 mm). It should be noted that although the dwarf mistletoe parasitizing Durango fir on Cerro Mohinora had been classified as white fir dwarf mistletoe (1), the morphological characters above are slightly different than those reported previously for this mistletoe (1,2). On the basis of the number of infected trees and the light to moderate level of infection observed, Mexican spruce should be tentatively classified as an occasional host of white fir dwarf mistletoe using the host susceptibility classification system proposed by Hawksworth and Wiens (1). Specimens of white fir dwarf mistletoe on Mexican spruce were collected and deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession No. 93827). To my knowledge, this is the first report of white fir dwarf mistletoe parasitizing Mexican spruce and the only know instance of white fir dwarf mistletoe parasitizing a species of spruce found in Mexico (1). References: (1) F. Hawksworth and D. Wiens. USDA For. Serv. Agric. Handb. 709, 1996. (2) R. Mathiasen and C. Daugherty. Madroño 56:120, 2009.

First Report of Mountain Hemlock Dwarf Mistletoe (Arceuthobium tsugense subsp. mertensianae) on Sugar Pine (Pinus lambertiana) from Oregon.

Mountain hemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahl) G.N. Jones subsp. mertensianae Hawksw. & Nickrent, Viscaceae) commonly parasitizes mountain hemlock (Tsuga mertensiana (Bong.) Carr.) from the central Sierra Nevada Mountains to the southern Cascades in Oregon (1,3). It has also been reported to commonly parasitize whitebark pine (Pinus albicaulis Engelm.) and occasionally western white pine (P. monticola Dougl. ex D. Don) (1,4). In September of 2008, we found mountain hemlock dwarf mistletoe infecting two sugar pines (P. lambertiana Dougl.) 4.5 km north of Windigo Pass, Oregon (42°24'40″N, 123°35'26″W, elevation 2,710 m). One of the sugar pines was 63.5 cm (25 inches) in diameter and had three infections. The other tree was 22.4 cm (9 inches) in diameter, but had 17 infections, many with mistletoe plants that allowed identification of the mistletoe using published descriptions (1,2). Mountain hemlock dwarf mistletoe can be distinguished from sugar pine dwarf mistletoe (A. californicum Hawksw. & Wiens) by its smaller plant size (mean height 5 cm versus 8 cm) and plant color (green-brown versus green to yellow) (1,2). An area (site) of approximately 1 ha around the infected sugar pines was examined and none of the other sugar pines we observed (33 trees) were found to be infected. Because mountain hemlock dwarf mistletoe also occurs in the principal range of sugar pine in the Sierra Nevada Mountains, it may also parasitize this tree there. However, our observations in several mountain hemlock stands infested with mountain hemlock dwarf mistletoe in California have failed to uncover infection of sugar pine by this mistletoe. Therefore, we would tentatively classify sugar pine as a rare host of mountain hemlock dwarf mistletoe (1). Specimens of mountain hemlock dwarf mistletoe on sugar pine were collected and deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession No. 87122). To our knowledge, this is the first report of mountain hemlock dwarf mistletoe parasitizing sugar pine. References: (1) F. G. Hawksworth and D. Wiens. USDA For. Serv. Agric. Handb. 709, 1996. (2) F. G. Hawksworth et al. Novon 2:204, 1992. (3) R. L. Mathiasen and C. M. Daugherty. Novon 17:222, 2007. (4) R. L. Mathiasen and F. G. Hawksworth. For. Sci. 34:429, 1988.

First Report of Durangan Dwarf Mistletoe, Arceuthobium vaginatum subsp. durangense, on Pinus cooperi and P. engelmannii in Mexico.

The Durangan dwarf mistletoe (Arceuthobium vaginatum subsp. durangense Hawksw. & Wiens, Viscaceae) parasitizes several species of pines (Pinus spp., Pinaceae) in the Mexican states of Durango, Sinaloa, and Jalisco (1,3). This mistletoe has primarily been reported from the western edge of the Sierra Madre Occidental in eastern Sinaloa and western Durango, but its distribution there is not well documented (3). In March 2007, I found Durangan dwarf mistletoe parasitizing Pinus engelmannii Carr., approximately 25 km north of Mexico Route 40 (24°00'51″N, 105°26'48″W, elevation 2,200 m), and on P. cooperi Blanco approximately 90 km north of Route 40 (24°24'40″N, 105°35'26″W, elevation 2,710 m) along the road to San Miguel de las Cruces, Durango. These populations are approximately 50 and 80 km northeast of the closest known population of Durangan dwarf mistletoe west of Buenos Aires along Route 40 in extreme western Durango. Infection of P. engelmannii was severe on 25 trees, but only severe on two trees of P. cooperi. No mortality associated with infection by Durangan dwarf mistletoe was observed at either location. Infection caused large, nonsystemic witches' brooms on P. engelmannii, but no brooms were observed on infected P. cooperi. To my knowledge, this is the first report of Durangan dwarf mistletoe on P. cooperi and P. engelmannii, and the first report of this mistletoe from the central Sierra Madre Occidental (3). Although Hawksworth and Wiens (2,3) treated Durangan dwarf mistletoe as a species (A. durangense Hawksw. & Wiens), I use the earlier classification of Durangan dwarf mistletoe as a subspecies of Mexican dwarf mistletoe (A. vaginatum (Willd.) Presl subsp. vaginatum) (1) because of recent molecular evidence (4) and morphological similarities with Mexican dwarf mistletoe. The principal difference between these mistletoes is that plants of Durangan dwarf mistletoe are bright orange while those of Mexican dwarf mistletoe are dark brown to black (1-3). Specimens of Durangan dwarf mistletoe on Pinus engelmannii and P. cooperi have been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession Nos. 76455 and 76456, respectively). References: (1) F. G. Hawksworth and D. Wiens, Brittonia 17:213, 1965. (2) F. G. Hawksworth and D. Wiens. Phytologia 66:3, 1989. (3) F. G. Hawksworth and D. Wiens. USDA For. Serv. Agric. Handb. 709, 1996. (4) D. L. Nickrent et al. Am. J. Bot. 91:125, 2004.

First Report of Arceuthobium aureum subsp. aureum in Mexico.

The golden dwarf mistletoe (Arceuthobium aureum Hawksw. & Wiens subsp. aureum, Viscaceae) parasitizes several pines (Pinus spp., Pinaceae) in central Guatemala (1). In September 2006, we observed golden dwarf mistletoe parasitizing Pinus maximinoi H.E. Moore in southern Chiapas, Mexico; 1 km west of El Rosario along Mexico Route 211 (15°19'23″N, 92°17'45″W, elevation 1,720m). Golden dwarf mistletoe can be distinguished from the closely related Peterson's dwarf mistletoe (A. aureum Hawksw. & Wiens subsp. petersonii Hawksw. & Wiens) by its smaller shoots, occurrence below 2,200 m in elevation, and flowering period (1). The shoots of the dwarf mistletoe at the El Rosario location were less than 20 cm high and male plants were not flowering. Male plants of Peterson's dwarf mistletoe observed at the type locality and other locations in Chiapas during September were in full flower. Although only 29 trees were infected at this location, infection was severe on 11 trees, but no mortality associated with dwarf mistletoe infection was observed. Mistletoe infection did not induce the formation of witches'-brooms near El Rosario, but infection by golden dwarf mistletoe on P. maximinoi does induce witches'-brooms on older trees in Guatemala (2). The golden dwarf mistletoe population near El Rosario is approximately 150 km west of the nearest known population of this species in Guatemala (1). To our knowledge, this is the first report of golden dwarf mistletoe in Mexico. Specimens of golden dwarf mistletoe from Chiapas, Mexico were deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 83122). References: (1) F. Hawksworth and D. Wiens. Dwarf Mistletoes: Biology, Systematics, and Pathology. USDA For. Serv. Agric. Handb. 709, 1996. 2) R. Mathiasen et al. Madrono 23:122, 2004.

First Report of Arceuthobium hondurense and Sruthanthus deppeanus in Nicaragua.

The Honduran dwarf mistletoe, Arceuthobium hondurense Hawksw. & Wiens (Viscaceae), is one of the rarest dwarf mistletoes known in Central America (1,2). It is only known from four general areas in Honduras, but has also been reported from three locations in southern Mexico (2,3). At one time, A. hondurense was thought to be in danger of extinction (1). During March 2006, we found three new populations of this rare dwarf mistletoe in the Cordillera Dipilto in northern Nicaragua (Department Nueva Segovia). One population was approximately 11 km northeast of San Fernando (13°44'55″N, 86°19'07″W; elevation 1,130 m), the second population was approximately 9 km north of Mozonte (13°44'09″N, 86°24'54″W; elevation 1,415 m), and the third population was approximately 6 km southwest of Depilto (13°42'51″N, 86°32'22″W; elevation 1,340 m). Honduran dwarf mistletoe was parasitizing Pinus tecunumanii Equiluz & J.P. Perry at each of these locations, and at the Mozonte population, it was also infecting P. oocarpa Schiede ex Schlecht. Only a few pines were infected at each of these localities and no pine mortality associated with dwarf mistletoe infection was observed. However, even lightly infected trees had large witches' brooms and some trees were severely broomed. These populations are 50 to 65 km southeast of the nearest population of Honduran dwarf mistletoe in Honduras and they represent the southern most populations of Arceuthobium spp. in the New World (1). The mistletoe, Struthanthus deppeanus (Cham. & Schlecht.) Bl. (Loranthaceae), also parasitizes pines in Central America and southern Mexico (3). We observed this mistletoe parasitizing P. tecunumanii at the San Fernando location described above, on P. oocarpa approximately 7 km north of Mozonte (13°43'57″N, 86°24'49″W; elevation 1,490 m), and on P. oocarpa approximately 3 km southwest of Dipilto (13°43'40″N, 86°31'56″W; elevation 1,170 m). Again, only a few pines were infected at each of these locations, and we did not observe pine mortality associated with infection by S. deppeanus. S. deppeanus does not cause the formation of witches' brooms on infected pines, but the mistletoe plants are often greater than 1 m long so they are easily observed. This mistletoe was most common southwest of Depilto. To our knowledge, this is the first report of A. hondurense and S. deppeanus in Nicaragua. Specimens of A. hondurense and S. deppeanus from Nicaragua have been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession Nos. 81561-81567). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996; (2) R. Mathiasen and J. Melgar, Plant Disease 90:685, 2006; (3) R. Mathiasen et al. Madrono 50:115, 2003.

First Report of Psittacanthus macrantherus on Pinus devoniana and Quercus castanea in Mexico.

The mistletoe Psittacanthus macrantherus Eichl. (Loranthaceae) is an important parasite of pines (Pinus spp., Pinaceae) in Mexico (1). It has been reported to parasitize Pinus engelmannii Carr., P. herrerai Mart., P. lawsonii Roezl ex Gord. & Glend., P. lumholtzii Robins & Fern., P. oocarpa Schiede, and P. pseudostrobus Lindl. (1). During July 2005, we found this mistletoe parasitizing P. devoniana Lindl. and Quercus castanea Nee near Route 40 in Sinaloa, Mexico approximately 12 km west of El Palmito (23°30'N, 105°07'W, elevation 1,900 m). The mistletoe was common in P. devoniana, and some trees were severely infected (>10 plants per tree). However, no mortality associated with mistletoe infection in P. devoniana was observed. Only one infected tree of Q. castanea was observed in this area and it was not severely infected. We also observed this mistletoe on P. douglasiana Mart. along Route 40 west and east of El Palmito, but no specimens were collected because plants were very high in the crowns of the infected trees. To our knowledge, this is the first report of this mistletoe parasitizing P. devoniana, P. douglasiana, and Q. castanea (1). Specimens of Psittacanthus macrantherus from P. devoniana and Q. castenea have been deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession Nos. 79534 and 79535). References: (1) B. Geils et al. Mistletoes of North American conifers. USDA For. Serv. Gen. Tech. Rep. RMRS-GTR-98, 2002.

First Report of Cladocolea cupulata on Pinus douglasiana and P. herrerai in Northern Mexico.

The mistletoe Cladocolea cupulata Kuijt (Loranthaceae) has previously been reported parasitizing pines (Pinus spp., Pinaceae) in central Mexico (3). As of today, reported pine hosts have been Pinus jaliscana Pérez de la Rosa and P. lumholtzii B.L. Rob. & Fernald from the state of Jalisco (1,2). During July 2005, we found this mistletoe parasitizing P. douglasiana Martinez and P. herrerai Martinez along Route 40 in Durango approximately 8 km east of El Palmito (23°35'54″N, 105°50'45″W, elevation 2,000 m). We also found the mistletoe on P. douglasiana along Route 40 at approximately 18 km west of El Palmito (23°27'51″N, 105°49'58″W, elevation 1,780 m) in the state of Sinaloa. Additional populations of this mistletoe were observed along the roadside of Route 40 in the Sinaloa-Durango border region. Infected trees had one to five mistletoe plants on them. Comparing infected hosts with neighboring noninfected hosts, the mistletoe appeared to have no effect on the growth of the infected trees. No mortality associated with mistletoe infection was observed for either of these mistletoe-host combinations. C. cupulata can be distinguished from its closest relatives, C. grahami Kuijt and C. pringlei Kuijt, by its longer, narrower, opposite leaves, parallel venation, and the saddle-like peduncles that hold four flowers (3). The other taxa have predominantly alternate leaves with pinnate venation and lack the saddle-like peduncle. To our knowledge, this is the first report of C.cupulata parasitizing P. douglasiana and P. herrerai and the first report of this mistletoe from the states of Durango and Sinaloa (2,3). Specimens of C. cupulata and host material were collected and have been deposited at the Deaver Herbarium (ASC), Northern Arizona University, Flagstaff (Accession Nos. 79532, 79533, and 79536). References: (1) B. Chazado. Biosphera 1:3, 1990. (2) B. Geils et al. USDA For. Serv. Gen. Tech. Rep. RMRS-GTR-98, 2002. (3) J. Kuijt. J. Arnold Arbor. Harv. Univ. 56:265, 1975.

First Report of Arceuthobium hondurense in Department El Paraiso, Honduras.

The Honduran dwarf mistletoe, Arceuthobium hondurense Hawksw. & Wiens (Viscaceae), has only been reported from three general areas in Honduras (2). During September 2005, we found a fourth location for this rare dwarf mistletoe south of San Lucas in Department El Paraiso (13°52'58″N, 86°58'04″W; elevation 1,350 m). The mistletoe was parasitizing Pinus oocarpa Schiede, and many trees were severely infected in this area. Several dead trees were also observed with evidence of past dwarf mistletoe infection (witches' brooms). Although this report only extends the distribution approximately 40 km to the southeast of populations of this mistletoe in Department Francisco Morazan, to our knowledge, this is the first report of A. hondurense in Department El Paraiso. At one time, A. hondurense was thought to be in danger of extinction (1), but it is now known from four separate locations in Honduras and has been discovered in a few locations in southern Mexico (2). Nevertheless, this dwarf mistletoe remains one of the rarest mistletoes known. Specimens of A. hondurense from El Paraiso have been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 80338). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996. (2) R. Mathiasen et al. Madrono 50:115, 2003.

First Report of Chihuahua Pine Dwarf Mistletoe (Arceuthobium gillii) on Apache Pine (Pinus engelmannii).

Arceuthobium gillii Hawksw. & Wiens (Viscaceae) is primarily distributed in the Sierra Madre Occidental of Mexico from central Durango and northern Sinaloa into Chihuahua and Sonora (3). In Mexico, it commonly parasitizes Pinus leiophylla Schiede & Deppe var. leiophylla and var. chihuahuana (Engelm.) G. R. Shaw, P. lumholtzii Robinson & Fern., and P. herrerai Martinez and rarely infects P. arizonica Engelm. and P. cooperi Blanco (3). This dwarf mistletoe also occurs in the Chiricahua, Huachuca, Santa Rita, Rincon, and Santa Catalina Mountains of southern Arizona and the Animas Mountains of southwestern New Mexico (1,3). In the United States, A. gillii has only been reported to parasitize P. leiophylla var. chihuahuana (1,2,3). The host range of A. gillii has consistently not included P. engelmannii Carr. (2,3). However, we have located a small population of P. engelmannii naturally infected by A. gillii in the South Fork of Cave Creek, Chiricahua Mountains, Arizona. The infected P. engelmannii occurred approximately 2.6 km west of the South Fork Cave Creek Picnic Area, Coronado National Forest, along Forest Trail 243 (31°50'53″N, 109°12'14″W, elevation 1,670 m). Only four P. engelmannii were infected: one tree had four infections as indicated by small, dense witches' brooms and branches with large, spindle-shaped swellings, and three trees had one infection each based on the presence of brooms. One branch was collected from the tree with four infections because observations of the branch with binoculars indicated it had dwarf mistletoe shoots. Only four male shoots of A. gillii were on the branch and they were consistent morphologically with other male plants of this dwarf mistletoe collected from nearby P. leiophylla var. chihuahuana. The infected P. engelmannii were all growing in close association with P. leiophylla var. chihuahuana severely infected with A. gillii. The only other dwarf mistletoe reported to infect P. engelmannii in the Chiricahua Mountains is A. vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens. This dwarf mistletoe was not present or anywhere near the Cave Creek population of P. engelmannii. In addition, plants of A. gillii can be easily distinguished morphologically from those of A. vaginatum subsp. cryptopodum by their color (2,3). Plants of A. gillii are consistently green to greenish brown, while plants of A. vaginatum subsp. cryptopodum are consistently orange to reddish brown. A specimen of A. gillii on P. engelmannii has been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 75392). To our knowledge, this is the first report of A. gillii on P. engelmannii. This host-dwarf mistletoe combination is evidently very rare because other investigators have reported that P. engelmannii was probably immune to A. gillii (2,3). References: (1) F. G. Hawksworth and M. Weiss. Southwest. Nat. 20:418, 1975. (2) F. G. Hawksworth and D. Wiens. Brittonia 16:54, 1964. (3) F. G. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996.

Southwestern Dwarf Mistletoe, Arceuthobium vaginatum subsp. cryptopodum, Found Parasitizing Picea pungens in Colorado.

Southwestern dwarf mistletoe (Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens, Viscaceae) severely parasitizes several species of pines (Pinus spp., family Pinaceae) in Colorado, Utah, Arizona, New Mexico, and northern Mexico, but it has not been reported to parasitize any species of spruce (Picea, family Pinaceae) (1). However, in June 2004, this dwarf mistletoe was observed parasitizing blue spruce (Picea pungens Engelm.) in the Black Forest north of Colorado Springs, CO (39°02.118'N, 104°36.028'W, elevation 2,250 m). The infected blue spruce was planted as an ornamental approximately 4 m from a 16-m-high ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) severely infected with southwestern dwarf mistletoe. Mature dwarf mistletoe shoots were produced on five infected branches of the blue spruce. These shoots were compared with a morphological description of southwestern dwarf mistletoe (1) and this was sufficient for a positive identification of the dwarf mistletoe. The other dwarf mistletoes reported to infect blue spruce are Arceuthobium microcarpum (Engelm.) Hawksw. & Wiens, A. americanum Nutt. ex Engelm., and A. douglasii Engelm.; these are all morphologically distinct from southwestern dwarf mistletoe (1). Three of the infected branches formed small (less than 0.3 m in diameter), nonsystemic witches' brooms. All of the infections on the 6-m-high blue spruce were higher than 1 m on the tree. Thus, it is likely that the spruce was infected after it was transplanted. Three other blue spruces were also located within 4 m of the infected ponderosa pine, but these trees were not infected. To our knowledge, this is the first report of southwestern dwarf mistletoe parasitizing blue spruce and the first report of this dwarf mistletoe on Picea spp. Voucher specimens have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 73959). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996.

First Report of Arceuthobium vaginatum subsp. vaginatum on Pinus pseudostrobus.

Arceuthobium vaginatum (Willd.) Presl subsp. vaginatum (family Viscaceae) is the most widespread and common dwarf mistletoe in Mexico (2). Although most dwarf mistletoes are considered to be relatively host-specific parasites, this species has the broadest host range found in the genus. It has been reported to infect 13 species of pines (Pinus spp., family Pinaceae) (2). Pinus pseudostrobus Lindl. is a common pine within the geographic range of A. vaginatum and has been reported as possibly being immune to this mistletoe (2). However, we have found a location in the Sierra Madre Oriental, Nuevo Leon, Mexico where A. vaginatum subsp. vaginatum is severely parasitizing P. pseudostrobus. The stand of infected P. pseudostrobus is located approximately 3 km east of Laguna de Sanchez(25°19'42″N, 100°15'45″W, elevation 1,950 m). Several hundred P. pseudostrobus are infected at this location; several trees in the stand have one or more dwarf mistletoe infections on nearly every branch and many trees have bole infections. P. pseudostrobus is the only pine growing at this locality, and the extent of infection on this pine clearly indicates it is highly susceptible to A. vaginatum subsp. vaginatum. Hawksworth and Wiens (2) based their tentative classification of P. pseudostrobus as immune to A. vaginatum subsp. vaginatum on observations of uninfected P. pseudostrobus growing near severely infected pines in central Mexico. The discrepancy between the susceptibility of P. pseudostrobus in central Mexico and in Nuevo Leon may be related to the different taxonomic classifications afforded these populations by different pine taxonomists. For example, Perry (3) considers the populations of P. pseudostrobus growing in Nuevo Leon to represent P. pseudostrobus forma megacarpa Loock, while Farjon and Styles (1) treat these populations as typical P. pseudostrobus. Whether the high level of susceptibility of the P. pseudostrobus population near Laguna de Sanchez indicates these populations are taxonomically distinct from typical P. pseudostrobus needs further study, but the severe infection we observed in Nuevo Leon clearly demonstrates that P. pseudostrobus should be reclassified as a principal host of A. vaginatum subsp. vaginatum in northeastern Mexico. Specimens of A. vaginatum subsp. vaginatum on P. pseudostrobus have been deposited at the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 76455). To our knowledge, this is the first report of A. vaginatum subsp. vaginatum on P. pseudostrobus. It should also be noted that the population of A. vaginatum subsp. vaginatum near Laguna de Sanchez is 150 m below the lower elevation limit previously reported for this dwarf mistletoe in Mexico (2). References: (1) A. Farjon and B. Styles. Pinus (Pinaceae). Flora Neotropica, Monogr. 75. NY Bot. Gard., 1997. (2) F. Hawksworth and D. Wiens. Dwarf mistletoes: Biology, pathology, and systematics. USDA For. Serv. Agric. Handb. 709, 1996. (3) J. P. Perry. The Pines of Mexico and Central America. Timber Press, Portland, OR, 1991.

First Report of Arceuthobium vaginatum subsp. cryptopodum on Pinus mugo.

Southwestern dwarf mistletoe (Arceuthobium vaginatum (Willd.) Presl subsp. cryptopodum (Engelm.) Hawksw. & Wiens, family Viscaceae) is a serious and common pathogen of ponderosa pine (Pinus ponderosa Douglas ex Lawson & C. Lawson) in Colorado, Utah, Arizona, New Mexico, and northern Mexico (1). In July 2002, this dwarf mistletoe was observed parasitizing a 1.4-m tall mugo pine (P. mugo Turra) in the Black Forest north of Colorado Springs, CO (39°02.118'N, 104°36.028'W, elevation 2,250 m). The infected mugo pine was planted as an ornamental approximately 6 m from a ponderosa pine infected with A vaginatum subsp. cryptopodum. Dwarf mistletoe shoots were produced on the only infected branch observed but this was sufficient for a positive identification of the dwarf mistletoe. Although J. Weir successfully inoculated mugo pine with western dwarf mistletoe (A. campylopodum Engelm.) and lodgepole pine dwarf mistletoe (A. americanum Nutt. ex Engelm.) (2), to our knowledge, this is the first report of a dwarf mistletoe occurring naturally on P. mugo, as well as the first report of A vaginatum subsp. cryptopodum on P. mugo (1). Specimens of A vaginatum subsp. cryptopodum from P. mugo have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff (Accession No. 73761). References: (1) F. Hawksworth and D. Wiens. Dwarf mistletoes: biology, pathology, and systematics. USDA Agric. Handb. 709, 1996. (2) J. Weir. Bot. Gaz. 56:1, 1918.

First Report of White Fir Dwarf Mistletoe on Mountain Hemlock.

White fir dwarf mistletoe (Arceuthobium abietinum Engelm. ex Munz f. sp. concoloris Hawksw. & Wiens) is a serious and common pathogen of white fir (Abies concolor (Gord. & Glend.) Hildebr.), grand fir (A. grandis (Dougl. ex D. Don) Lindl.), and Low's fir (A. lowiana (Gord.) A. Murr.) in the western United States (1). In August 2002, this dwarf mistletoe was observed parasitizing mountain hemlock (Tsuga mertensiana (Bong.) Carr.) growing among severely infected grand fir near the trailhead to Cabot Lake in the Mount Jefferson Wilderness Area, Oregon at 44°34'27″N, 121°43'43″W, elevation 1,340 m. Only 2 of 27 mountain hemlocks observed in this area were infected. One tree had four infections, and one tree had two infections. Several fully developed male plants were found on one of the infected branches of mountain hemlock and were morphologically similar to those growing on the nearby grand fir. Other dwarf mistletoes that commonly parasitize mountain hemlock (Arceuthobium tsugense subsp. mertensianae and Arceuthobium laricis) were not observed in the area. In addition, white fir dwarf mistletoe can be distinguished from these mistletoes by its larger, yellowish shoots (1). Specimens of the mistletoe from mountain hemlock have been deposited in the Deaver Herbarium, Northern Arizona University, Flagstaff. To my knowledge, this is the first report of white fir dwarf mistletoe on mountain hemlock (1). Reference: (1) F. Hawksworth, and D. Wiens. Dwarf mistletoes: biology, pathology, and systematics. USDA Agric. Handb. 709, 1996.