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This study provides an illustrated synoptic key and comparative morphology to the
38 known larvae of dryophthorine genera representing seven subtribes in four of the five tribes: Cactophagus LeConte, Cosmopolites Chevrolat, Cyrtotrachelus Schoenherr, Diathetes Pascoe, Diocalandra Faust, Dryophthoroides Roelofs, Dryophthorus Germar, Dynamis Chevrola...
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... Buprestid immatures are typically elongate and the dorsoventral flattening is more pronounced (e.g. emerald ash borer Agrilus planipennis, Chamorro et al. 2012) while Curculionids are compressed along the antero-posterior axis (Chamorro 2019). The thoracic legs of woodborer larvae are usually small or absent, but in the latter case locomotion can be aided by protuberances present on the abdomen or the thorax, called ambulatory ampullae. ...
The physiology and morphology of insects largely explain the immense adaptability of these organisms to forest ecosystems. This chapter presents an opportunity to review the basics of insect development, the morphology of the different stages and the organ systems that comprise them. The broad categories immature stages and developmental trajectories toward the adult are summarized. Important physiological systems involved in insect behavior such as sensory organs, the nervous system and locomotion are also reviewed. Concise reviews of digestion, immunity and reproduction provide the reader with a basic understanding of how insects interact with their hosts and pathogens and propagate. Together, these topics should convey the fundamental importance of insect form and function in forest entomology.
... The taxonomic identity of adult specimens associated with dead palm trees was corroborated with the keys of Chamorro [27] and Vásquez et al. [28]. The observations, photographs, and illustrations for the morphological descriptions were performed in the Laboratory of Entomology from the Ecuadorian National Plant Protection Organization (AGROCALIDAD), using the stereomicroscope Olympus SZX16 (Olympus, Center Valley, PA, USA) with double objectives for 3.5× to 100× zoom, associated with a reflection and transmission led lights, as well a high-resolution camera Olympus CellSens imaging software (version 1.12, Olympus, Tokyo, Japan). ...
Oil palm (Elaeis guineensis Jacquin) tree yields may be negatively affected by biotic factors such as Black weevil (Rhynchophorus palmarum L.; Coleoptera: Curculionidae) and Spear rot (Fusarium spp.). This study aimed to identify, model the temporal progress, and correlate Black weevil (BW) and Spear rot (SR) in the highly susceptible varieties INIAP-Tenera and IRHO, under field conditions in Ecuador between 2016 and 2020. Morphological analysis of BW and morphomolecular study of the causal agent of SR allowed us to identify Rhynchophorus palmarum and Fusarium solani, respectively, as biotic factors that affect oil palm trees in Ecuador. The number of adults increased in both genotypes over the years, but much more in INIAP-Tenera (in 2017 and 2019). The logistic model, having a smaller mean square of the residue, was the non-linear model that best explained the SR epidemic in both susceptible genotypes. The incidence of dead palms was higher in INIAP-Tenera trees compared to those of IRHO in the year 2020. Dead plants and the number of insects, and these with the fresh fruit bunches, were correlated significantly. To our knowledge, this is the first report on the positive correlation between dead plants (%) by SR and BW, and the study of both biotic factors in Ecuador
... The pupae were kept in 1.5 L multi plastic storage boxes (Home Collection, Cali, Colombia) until adults emerged, which were then stored in 96% ethanol. Both the adults collected from the stems and larvae collected in inflorescences were identified to species level following the keys of Wattanapongsiri (1966), Chamorro (2019), and direct examination of specimens as documented in Vásquez-Ordóñez et al. (2020). ...
Emergent and potentially invasive weevils are a permanent threat to the survival of palm plantations. Hence, understanding the role of emergent pests may be key for preventing future phytosanitary emergencies. In the present study, the role of Rhynchophorus palmarum L. and Dynamis borassi F. (both Coleoptera: Curculionidae) as main causative agents of the peach palm (Bactris gasipaes Kunth; Arecaceae) crown toppling problem were investigated, and the damage was described in 36 farms in the principal production areas of Colombia. A management strategy with the use of 2 pheromones (Rhynchophorol and Ferrolure) in 2 production areas also was evaluated. In total, 4,098 palms were examined from Nov 2017 to Feb 2019. Visible damage oscillated between 0 to 70% of palms affected and was highest on the Pacific coast. Larvae of D. borassi were found exclusively in the inflorescences suggesting that it initiates the damage. Meanwhile, adults of D. borassi and all stages of R. palmarum were recovered from stem damages. Also, new reports of damage were confirmed at the southern Pacific coast, the Andes, and the Amazon region. A total of 8,239 D. borassi and 2,886 R. palmarum were captured in pheromone traps for 14 mo on the Pacific coast. The traps baited with Fer-rolure + Rhynchophorol captured a greater number of D. borassi specimens. The data strongly confirm the central role of D. borassi in peach palm damage. Therefore, it is recommended strongly that pheromones be used to prevent further spread of this pest in other countries of this region and to protect palm industries.
Resumen Los picudos emergentes y potencialmente invasivos son una amenaza constante para la supervivencia de las plantaciones de palmas. Por lo tanto, el comprender el papel de las plagas emergentes puede ser clave para prevenir futuras emergencias fitosanitarias. En el presente estudio se inves-tigó el papel de Rhynchophorus palmarum L. y Dynamis borassi F. (ambos Coleoptera: Curculionidae) como principales causantes del problema de derribo de la corona de la palma de chontaduro (Bactris gasipaes Kunth; Arecaceae) y se describieron los daños en 36 fincas de las principales zonas de producción de Colombia. Además, se evaluó una estrategia de manejo con el uso de dos feromonas (Rhynchophorol y Ferrolure) en dos zonas de producción. En total, se examinaron 4,098 palmas entre noviembre de 2017 y febrero de 2019. Los daños visibles oscilaron entre el 0 a 70% de las palmas afectadas y fueron mayores en la costa del Pacífico. Las larvas de D. borassi se encontraron exclusivamente en las inflorescencias, lo que sugiere que es la causa del daño. Mientras tanto, los adultos de D. borassi y todos los estadios de R. palmarum se recuperaron de daños en los tallos. Se confirmaron nuevos reportes de presencia y daños en las regiones de la costa sur del Pacífico, los Andes, y del Amazonas. Un total de 8,239 D. bo-rassi y 2,886 R. palmarum fueron capturados en trampas de feromonas durante 14 meses en la costa del Pacífico. Las trampas cebadas con Ferrolure + Rhynchophorol capturaron un mayor número de especímenes de D. borassi. Los datos confirman firmemente el papel central de D. borassi en el daño de las palmas del chontaduro. Se recomienda el uso de feromonas como una intervención temprana para prevenir la distribución de esta plaga a otros países de la región y proteger así las diferentes industrias asociadas a las palmas.
... Marvaldi and Morrone (2000) recognized the monophyly of the subfamily and eight tribes following the classification by Kuschel (1995): Cryptodermatini, Dryophthorini, Orthognathini, Rhinostomini, Rhynchophorini, Sitophilini, Sphenophorini, and Stromboscerini; but this classification was later slightly modified by Alonso-Zarazaga and Lyal (1999). At the time, the group was treated as a family within the Curculionoidea, but their subfamily status is now widely accepted (Chamorro, 2019;Marvaldi et al., 2009;Oberprieler et al., 2007). It is among the few Curculionidae subfamilies for which natural limits are well understood (Marvaldi et al., 2002Mugu et al., 2018;Shin et al., 2017). ...
... Cosmopolites and Eucalandra and the newly described Stockwellius Anderson (2018) in Litosomina due to the shape of the scutellum and the presence of a premucro; however, until recently, Cosmopolites and Eucalandra were included in Sphenophorina (Alonso-Zarazaga & Lyal, 1999), mainly hinging on the presence of this unique type of femoral-tibial articulation (Kuschel, 1995 character space to provide more reliable adult and larval characters (Chamorro, 2019) to circumscribe the groups. ...
... Trigonotarsus, associated with Xanthorrhoea (Chamorro, 2019;May, 1994;Zimmerman, 1993), and the Afrotropical cycad-specialist ...
Dryophthorinae is an economically important, ecologically distinct, and ubiquitous monophyletic group of pantropical weevils with more than 1,200 species in 153 genera. This study provides the first comprehensive phylogeny of the group with the aim to provide insights into the process and timing of diversification of phytophagous insects, inform classification and facilitate predictions. The taxon sampling is the most extensive to date and includes representatives of all five dryophthorine tribes and all but one subtribe. The phylogeny is based on secondary structural alignment of 18S and 28S rRNA totaling 3,764 nucleotides analyzed under Bayesian and maximum likelihood inference. We used a fossil‐calibrated relaxed clock model with two approaches, node‐dating and fossilized birth‐death models, to estimate divergence times for the subfamily. All tribes except the species‐rich Rhynchophorini were found to be monophyletic, but higher support is required to ascertain the paraphyly of Rhynchophorini with more confidence. Nephius is closely related to Dryophthorini and Stromboscerini, and there is strong evidence for paraphyly of Sphenophorina. We find a large gap between the divergence of Dryophthorinae from their sister group Platypodinae in the Jurassic‐Cretaceous boundary and the diversification of extant species in the Cenozoic, highlighting the role of coevolution with angiosperms in this group.
... The taxonomic identity of the larval specimens and of their associated adults was corroborated with the keys of Wattanapongsiri (1966), Giblin-Davis et al. (2013) and Chamorro (2019). ...
... We also corroborate, as diagnostic of dryophthorines, that the first instar larva lacks the spiracles of abdominal segments I-VII, having only the thoracic and AVIII spiracles developed. The larvae of later instars of Dynamis and Rhynchophorus have the complete set of abdominal spiracles, and although those of AI to AVII are small, they are clearly functional (i.e., connected to tracheal system, see Fig. 7H); therefore, they are not absent as interpreted in the identification key by Chamorro (2019). The occurrence of egg-bursters in first instar larvae of Curculionoidea is less common, but also more poorly documented, than in their sister group Chrysomeloidea, where egg burster's features (e.g., position, shape) were found to be phylogenetic informative at both higher and lower taxonomic levels (Cox, 1988). ...
The morphology of the larvae of Dynamis borassi (Fabricius) and Rhynchophorus palmarum (Linnaeus) was compared, described and illustrated. A complete definition of subtribe Rhynchophorina at the larval stage was elaborated, based on mature and submature larvae, and characters of the first instar larvae are provided for the first time. Diagnostic characters to distinguish the larvae of D. borassi and R. palmarum are mainly from the epipharynx and maxillae, but the abdominal terminal plate also provides differential features that can aid in the identification. The characterization of both species at the larval stage is expected to be useful in the implementation of new control strategies in palm plantations in South America. For practical reasons, a comparative table is appended in Spanish to serve as a quick diagnostic guide for species identification.
... Of the more than 1,200 species and 153 genera classified in Dryophthorinae (Kuschel 1995;Alonso-Zarazaga and Lyal 1999;Anderson and Marvaldi 2014;Anderson 2018), only approximately 5% of dryophthorines, 80 species in 38 genera, representing seven subtribes within four of the five tribes, are known by both the adult and preimaginal stages. These treatments include detailed descriptions of only the larva or the larva and pupa (Stebbing 1914;Cotton 1924;Gardner 1934Gardner , 1938Anderson 1948;Wattanapongsiri 1966;May 1987May , 1994Chamorro et al. 2016) and/or through inclusion in identification keys (Anderson 1948;Zimmerman 1968;Chamorro 2019). The immature stages are unknown for one dryophthorine tribe, Cryptodermatini Bovie, 1908. ...
... May (1994) described the setae in question as "anterior pair of mes on margin between the 2 ams pairs". Furthermore, the recent comparative morphological study of 39 larval dryophthorines (Chamorro 2019) suggests plasticity within the subfamily in the placement of these setae. For example, genera such as Cactophagus LeConte, Temnoschoita Chevrolat, and Eucalandra Faust have anteriorly positioned mes3 adjacent to ams1, while in genera such as Cosmopolites and Polytus, these setae are located subapically, directed posterad, and closer and similar to mes1 and 2. Henceforth, the interpretation and count of what here is termed mes3 follows May (1994), Marvaldi (1998), Oberprieler et al. (2014, and Chamorro (2019). ...
Dryophthorinae includes some of the most economically important weevil pests. Feeding damage on host plant occurs
primarily during the endophytic larval stages. The immature stages of only approximately 5% of dryophthorine genera are
currently known. Traditional Ecological Knowledge of the Dawu People of the island of Lanyu led to the discovery of the
immature stages and host plant of the dryophthorine weevil genus Poteriophorus Schoenherr. The larva, pupa, and biology of
Poteriophorus uhlemanni (Schultze, 1922) are described for the first time. The newly discovered larva is compared to closely
related taxa, including two of the most economically important and commonly encountered genera in Sphenophorina: Metamasius
Horn, 1873 and Sphenophorus Schoenherr, 1838. Discovery of the associated larval and pupal stages of P. uhlemanni
provides suites of characters for morphologically based phylogenetic studies, insights into the larva’s functional morphology of
feeding, tunneling, and cocoon-making behavior, and the ability to accurately identify the species at all stages. Knowledge of host
preference will inform management strategies for poorly studied endemic species in the area.
Palm weevils, Rhynchophorus spp., are destructive pests of native, ornamental, and agricultural palm species. Of the 10 recognized species, two of the most injurious species, Rhynchophorus ferrugineus and Rhynchophorus palmarum, both of which have spread beyond their native range, are the best studied. Due to its greater global spread and damage to edible date industries in the Middle East, R. ferrugineus has received more research interest. Integrated pest management programs utilize traps baited with aggregation pheromone, removal of infested palms, and insecticides. However, weevil control is costly, development of resistance to insecticides is problematic, and program efficacy can be impaired because early detection of infestations is difficult. The genome of R. ferrugineus has been sequenced, and omics research is providing insight into pheromone communication and changes in volatile and metabolism profiles of weevil-infested palms. We outline how such developments could lead to new control strategies and early detection tools.
p> Sparganobasis subcruciata Marshall is a species of weevil occurring in Papua and eastern parts of Indonesia, which had been begun found to causes damage to oil palm in the Boven Digoel district. The research was carried out to investigate the symptoms of S. subcruciata attack and it’s damage level in one of oil palm plantation in Boven Digoel. The result shows that larvae of this weevil bore into the stem, particularly the lower part, giving rise to symptoms which are similar to symptoms of Ganoderma disease, specifically the occurrence of more than three leaves in the spear failing to open, hanging down and drying out and the ultimate death of the palm. The weevil has been detected in Boven Digoel, Papua, where significant numbers of oil palms appeared to be dead or dying in each of the plantation visited by us. We consider that this weevil constitutes a major threat to oil palm plantations in Papua and that it may in the future, if it is not already the case, be a threat to plantations in Eastern Indonesia. Early detection of the presence of the weevil is difficult and requires research, as do methods of control, which we suggest should focus on the development and use of pheromones.</p
