Hornworm Research Articles

Sex Differences in the Utilization of Essential and Non‐Essential Amino Acids in Lepidoptera

The different reproductive strategies of males and females have selected for differences in function and behavior that may translate into differences in resource use. Here we studied sexual differences in the utilization of essential and non‐essential amino acids by the Carolina sphinx moth (Manduca sexta: Sphingidae). We labeled two essential amino acids (leucine and phenylalanine) and one non‐essential amino acid (glycine) with an isotopically enriched first carbon (13C). These isotopically enriched amino acids were added either to the larval diet or to the adult nectar. We determined the allocation of these amino acids using a stable carbon isotope analyzer of the 13CO2 of the moth's breath as well as allocation to flight muscle and to the spermatophore. On day one after eclosion from the pupae, unfed male moths oxidized larval‐derived amino acids in higher ratios than unfed females, but this trend reversed after four days of starvation: females oxidized more amino acids than males. Males oxidized nectar‐derived essential amino acids more than females, whereas there was no difference between males and females in the oxidation of non‐essential amino acids. Males allocated significantly more nectar‐derived essential and non‐essential amino acids to flight muscle than did females. Last, males allocated relatively few nectar‐derived amino acids to their first spermataphore compared to a four‐fold increase to their second and third spermatophores. We conclude that males and females have fundamentally different allocation strategies of amino acids and that these allocation strategies differ for essential, compared to non‐essential, amino acids. We suggest that these differences in amino acid allocation strategies reflect the need of the males to maintain their ability to fly and find mates, a lower priority for females.Support or Funding InformationNSF grant IOS‐1053318 to GD

Two cases of bat pollination in Central America

Visits by bats of the family ,Phyllostomatidae (in the suborder Microchi­roptera) to the flowers of Durio zibethinus growing in Honduras and Mucuna andreana growing in Costa Rica are described and illustrated photographically. In Durio we have a case of flower-type which evolved in relation to visits from Megachiroptera in the Old World proving attractive to Microchiroptera which developed the flower-visiting habit in the New World. Hawkmoths also visit these flowers. Both kinds of visitor are capable of causing cross-pollination (which is necessary for fruit production by this species because it appears to be self-incompatible) . In Mucuna andreana , a native American vine demons­ trates a close adaptation to pollination by native bats; again a parallel to similar evolutionary development in the Old World.

Sex differences in the utilization of essential and non-essential amino acids in a Lepidoptera

The different reproductive strategies of males and females underlie differences in behavior that may also lead to differences in nutrient use between the two sexes. We studied sex differences in the utilization of two essential amino acids (EAAs) and one non-essential amino acid (NEAA) by the Carolina sphinx moth (Manduca sexta). On day one post-eclosion from the pupae, adult male moths oxidized greater amounts of larva-derived AAs than females, and more nectar-derived AAs after feeding. After 4days of starvation, the opposite pattern was observed: adult females oxidized more larva-derived AAs than males. Adult males allocated comparatively small amounts of nectar-derived AAs to their first spermatophore, but this allocation increased substantially in the second and third spermatophores. Males allocated significantly more adult-derived AAs to their flight muscle than females. These outcomes indicate that adult male and female moths employ different strategies for allocation and oxidation of dietary AAs.

Mitochondrial genome of the sweet potato hornworm, Agrius convolvuli (Lepidoptera: Sphingidae), and comparison with other Lepidoptera species.

In the present study, we sequenced the complete mitochondrial genome (mitogenome) of Agrius convolvuli (Lepidoptera: Sphingidae) and compared it with previously sequenced mitogenomes of lepidopteran species. The mitogenome was a circular molecule, 15 349 base pairs (bp) long, containing 37 genes. The order and orientation of genes in the A. convolvuli mitogenome were similar to those in sequenced mitogenomes of other lepidopterans. All 13 protein-coding genes (PCGs) were initiated by ATN codons, except for the cytochrome c oxidase subunit 1 (cox1) gene, which seemed to be initiated by the codon CGA, as observed in other lepidopterans. Three of the 13 PCGs had the incomplete termination codon T, while the remainder terminated with TAA. Additionally, the codon distributions of the 13 PCGs revealed that Asn, Ile, Leu2, Lys, Phe, and Tyr were the most frequently used codon families. All transfer RNAs were folded into the expected cloverleaf structure except for tRNASer(AGN), which lacked a stable dihydrouridine arm. The length of the adenine (A) + thymine (T)-rich region was 331 bp. This region included the motif ATAGA followed by a 19-bp poly-T stretch and a microsatellite-like (TA)8 element next to the motif ATTTA. Phylogenetic analyses (maximum likelihood and Bayesian methods) showed that A. convolvuli belongs to the family Sphingidae.

Deidamia inscriptum(Lettered Sphinx Moth) Caterpillars Feeding onOxydendrum arboreum(Sourwood) and Their Predation by Black Bears in Northeast Tennessee

Abstract An outbreak of Deidamia inscriptum (Lettered Sphinx Moth) caterpillars was noted in northeast Tennessee where Oxydendrum arboreum (Sourwood) trees were defoliated. Nearly all published literature and online resources list only plants in the grape family (Vitaceae) as larval food plants. Food-plant preference trials using fresh leaves of 3 woody plant species showed that Deidamia caterpillars from this region had a preference for Sourwood over Parthenocissus quinquefolia (Virginia Creeper), and rejected Acer rubrum (Red Maple), a non-host species. Ursus americanus (Black Bear) were feeding on the caterpillars as evidenced by bent and broken Sourwood saplings bearing claw marks and by abundant sphingid remains in bear scat.

Pollination ecology and fruiting behavior of Pavetta indica L. (Rubiaceae), a keystone shrub species in the southern Eastern Ghats forest, Andhra Pradesh, India

Pavetta indica is a massive bloomer for a brief period in May. The flowers are hermaphroditic, strikingly protandrous, self and cross-compatible, nectariferous and psychophilous. They possess secondary pollen presentation mechanism as a device to avoid autonomous autogamy but it does not prevent geitonogamy. The fruit set largely occurs through geitonogamy and xenogamy. Butterflies, especially papilionids, pierids, nymphalids, and sphingid hawk moth pollinate the flowers while collecting nectar. Honey bees and blue-banded digger bees feed on pollen and effect only accidental pollination. The nectar is sucrose-rich and contains essential and non-essential amino acids. Birds are seed dispersal agents. Seeds are non-dormant and germinate readily during rainy season but their continued growth and establishment is subject to the availability of soil moisture and nutrients. The plant is not able to populate itself in its natural area. The local uses of different parts of the plant have been found to be affecting its reproductive success and natural regeneration rate. Therefore, regulation of the uses of this plant is recommended for its survival and restoration of its population size in the natural areas due to its role as a keystone species for bees and butterflies during dry season.

Multifaceted biological insights from a draft genome sequence of the tobacco hornworm moth, Manduca sexta

Manduca sexta, known as the tobacco hornworm or Carolina sphinx moth, is a lepidopteran insect that is used extensively as a model system for research in insect biochemistry, physiology, neurobiology, development, and immunity. One important benefit of this species as an experimental model is its extremely large size, reaching more than 10 g in the larval stage. M. sexta larvae feed on solanaceous plants and thus must tolerate a substantial challenge from plant allelochemicals, including nicotine. We report the sequence and annotation of the M. sexta genome, and a survey of gene expression in various tissues and developmental stages. The Msex_1.0 genome assembly resulted in a total genome size of 419.4 Mbp. Repetitive sequences accounted for 25.8% of the assembled genome. The official gene set is comprised of 15,451 protein-coding genes, of which 2498 were manually curated. Extensive RNA-seq data from many tissues and developmental stages were used to improve gene models and for insights into gene expression patterns. Genome wide synteny analysis indicated a high level of macrosynteny in the Lepidoptera. Annotation and analyses were carried out for gene families involved in a wide spectrum of biological processes, including apoptosis, vacuole sorting, growth and development, structures of exoskeleton, egg shells, and muscle, vision, chemosensation, ion channels, signal transduction, neuropeptide signaling, neurotransmitter synthesis and transport, nicotine tolerance, lipid metabolism, and immunity. This genome sequence, annotation, and analysis provide an important new resource from a well-studied model insect species and will facilitate further biochemical and mechanistic experimental studies of many biological systems in insects.

Bernd Heinrich: Bumble Bees, Ravens, and the Boston Marathon

Bernd Heinrich is professor emeritus in the Department of Biology, University of Vermont, and is distinguished by his research in insect comparative physiology and behavioral ecology. His work illuminated new physiological mechanisms of temperature regulation in sphinx moths, bumble bees, dragonflies, dung beetles, and other insects. His groundbreaking discoveries on insect thermoregulation were published in Science a remarkable eight times. Heinrich is a prodigious author of books about biology, ecology, behavior, and personal reflections on natural history. His book Bumblebee Economics was a National Book Award in Science finalist. In addition to insects, he has published extensively on ornithology, including Ravens in Winter and Mind of the Raven , which won the John Burroughs Medal for Nature Writing. His Winter World: The Ingenuity of Animal Survival was a New York Times best seller. Heinrich was born 19 April 1940 near Danzig, Poland (now Gdansk, Germany). In January 1945, Heinrich's mother, his two sisters, and he began a five-month long escape across Poland and Germany from the invading Russian Red Army. They traveled by horse-drawn sleigh, German tank, cattle-car train, supply truck, Junker transport plane, and a stolen military car. Along their escape route, they connected with Heinrich's father, who was an officer in the German Luftwaffe. The family attempted to board a transport truck carrying refugees to an awaiting steamship on the Baltic coast, but when only Heinrich and his mother where able to squeeze onto the truck, his father, not wanting to separate the family, yanked them off. Later, it was learned, a Russian submarine torpedoed the ship and thousands drowned in the …

POSSIBILITIES FOR USING LIDAR AND PHOTOGRAMMETRIC DATA OBTAINED WITH AN UNMANNED AERIAL VEHICLE FOR LEVEE MONITORING

Abstract. This paper presents the possibilities for using an unmanned aerial system for evaluation of the condition of levees. The unmanned aerial system is equipped with two types of sensor. One is an ultra-light laser scanner, integrated with a GNSS receiver and an INS system; the other sensor is a digital camera that acquires data with stereoscopic coverage. Sensors have been mounted on the multirotor, unmanned platform the Hawk Moth, constructed by MSP company. LiDAR data and images of levees the length of several hundred metres were acquired during testing of the platform. Flights were performed in several variants. Control points measured with the use of the GNSS technique were considered as reference data. The obtained results are presented in this paper; the methodology of processing the acquired LiDAR data, which increase in accuracy when low accuracy of the navigation systems occurs as a result of systematic errors, is also discussed. The Iterative Closest Point (ICP) algorithm, as well as measurements of control points, were used to georeference the LiDAR data. Final accuracy in the order of centimetres was obtained for generation of the digital terrain model. The final products of the proposed UAV data processing are digital elevation models, an orthophotomap and colour point clouds. The authors conclude that such a platform offers wide possibilities for low-budget flights to deliver the data, which may compete with typical direct surveying measurements performed during monitoring of such objects. However, the biggest advantage is the density and continuity of data, which allows for detection of changes in objects being monitored.

POSSIBILITIES FOR USING LIDAR AND PHOTOGRAMMETRIC DATA OBTAINED WITH AN UNMANNED AERIAL VEHICLE FOR LEVEE MONITORING

This paper presents the possibilities for using an unmanned aerial system for evaluation of the condition of levees. The unmanned aerial system is equipped with two types of sensor. One is an ultra-light laser scanner, integrated with a GNSS receiver and an INS system; the other sensor is a digital camera that acquires data with stereoscopic coverage. Sensors have been mounted on the multirotor, unmanned platform the Hawk Moth, constructed by MSP company. LiDAR data and images of levees the length of several hundred metres were acquired during testing of the platform. Flights were performed in several variants. Control points measured with the use of the GNSS technique were considered as reference data. The obtained results are presented in this paper; the methodology of processing the acquired LiDAR data, which increase in accuracy when low accuracy of the navigation systems occurs as a result of systematic errors, is also discussed. The Iterative Closest Point (ICP) algorithm, as well as measurements of control points, were used to georeference the LiDAR data. Final accuracy in the order of centimetres was obtained for generation of the digital terrain model. The final products of the proposed UAV data processing are digital elevation models, an orthophotomap and colour point clouds. The authors conclude that such a platform offers wide possibilities for low-budget flights to deliver the data, which may compete with typical direct surveying measurements performed during monitoring of such objects. However, the biggest advantage is the density and continuity of data, which allows for detection of changes in objects being monitored.

Single-Component Pheromone Consisting of Bombykal in a Diurnal Hawk Moth, Neogurelca himachala sangaica.

Recent work has suggested that hawk moths share pheromone components but are sexually separated by qualitative and quantitative differences in their pheromone blends. During field assays on the sex pheromones of other species, a diurnal hawk moth, Neogurelca himachala sangaica (Lepidoptera: Sphingidae), was frequently captured, but the composition of the sex pheromone of this species was not known. Analysis of hexane extracts of the pheromone glands of calling female by gas chromatography (GC) using an electroantennographic detector (EAD) revealed two components that elicited EAD responses from male moth antennae. These components were identified by their mass spectra and retention indices on two GC columns as (10E,12Z)-10,12-hexadecadienal (E10,Z12-16:Ald) and a trace of its (10E,12E)-isomer (E10,E12-16:Ald) in 98:2 ratio. In field experiments, E10,Z12-16:Ald alone attracted male moths, and addition of E10,E12-16:Ald significantly reduced the attractiveness, even at the naturally-occurring ratio. Analysis of the data using a generalized linear mixed model showed that E10,Z12-16:Ald positively contributed to attractiveness, whereas E10,E12-16:Ald did so negatively, and it was concluded that the sex pheromone of N. himachala sangaica consists solely of E10,Z12-16:Ald, bombykal. The negative effect of E10,E12-16:Ald on attractiveness could promote the species-specificity of this single-component pheromone system.

Differential investment in visual and olfactory brain areas reflects behavioural choices in hawk moths.

Nervous tissue is one of the most metabolically expensive animal tissues, thus evolutionary investments that result in enlarged brain regions should also result in improved behavioural performance. Indeed, large-scale comparative studies in vertebrates and invertebrates have successfully linked differences in brain anatomy to differences in ecology and behaviour, but their precision can be limited by the detail of the anatomical measurements, or by only measuring behaviour indirectly. Therefore, detailed case studies are valuable complements to these investigations, and have provided important evidence linking brain structure to function in a range of higher-order behavioural traits, such as foraging experience or aggressive behaviour. Here, we show that differences in the size of both lower and higher-order sensory brain areas reflect differences in the relative importance of these senses in the foraging choices of hawk moths, as suggested by previous anatomical work in Lepidopterans. To this end we combined anatomical and behavioural quantifications of the relative importance of vision and olfaction in two closely related hawk moth species. We conclude that differences in sensory brain volume in these hawk moths can indeed be interpreted as differences in the importance of these senses for the animal’s behaviour.

Aerodynamic Model for Insect Flapping Wings with Induced Flow Effect

The aerodynamic characteristics of insect flight are investigated with the aim of developing an aerodynamic flapping-wing model for vertical and level forward flight. Models are sought that offer a compromise between physics and the rapidity of calculation. The insect prototype is the hawk moth. The wings have three degrees of freedom (pitching, weaving, and flapping) and are assumed as thin, rigid, flat plates. The aerodynamic forces and moments are determined via a quasi-steady-state model. This model is augmented with a design procedure to account for the unsteady flow due to the wake induced effects. Comparisons are shown with numerical simulations for the hover case and with experimental results for the forward-flight case. A heuristic optimization strategy (particle swarming optimization) is used to determine the set of optimal flight parameters over a range of forward speeds. It is demonstrated how this computational strategy is effective in reducing the power requirements. It is also demonstrated that the induced flow effects are strongest in the middle of the stroke. Finally, the aerodynamic effects of the wing shape are shown.

Flower-visitor selection on floral integration in three contrasting populations of Lonicera implexa.

Geographic differences in flower visitor assemblages might lead to among-population differences in the magnitude and pattern of floral integration. However, the role of current pollinator visitation in shaping the magnitude and pattern of floral trait correlations is still controversial. We used individual-level data on floral morphology, flower visitation, and fitness to assess if floral integration (at flower and floral-module level) and the covariance structure of floral traits varied among three populations of Lonicera implexa differing in the importance of long-tongue (hawk moths) and short-tongue (bees and small beetles) pollinators; and to assess whether this variation was related to the selection pressures exerted by flower visitors. Short-tongue pollinators preferentially visited plants with floral traits that enhanced flower accessibility; consequently, there was directional selection for accessibility (integration at floral-module level) in the populations where they dominated or codominated. In the population with both short- and long-tongue pollinators, disruptive selection on corolla width and directional selection against whole-flower integration was also found. Dominance by long-tongue pollinators (hawk moths) resulted in disruptive selection on whole-flower integration. Overall, the conflicting selection pressures that were found matched among-population differences in covariance structure: populations with short-tongue pollinators showed correlations between corolla-tube width and other floral traits that were absent in the population pollinated primarily by hawk moths. Conflicting selection on floral integration mediated by floral visitors can occur even in nearby populations of a species with restricted floral morphology.

Death's head hawk moth,Acherontia styxwestwood (Lepidoptera: Sphingidae)- Its taxonomy and biology

The death's head hawk moth, Acherontia styx Westwood from the subfamily Sphinginae is redescribed, with genitalic characters along with various parts such as labial palp, antenna, legs and wing venation. The total life cycle and morphometrics of life stages are also provided.

Fed males increase oviposition in female hawkmoths via non-nutritive direct benefits

Direct benefits provided by males have large effects on the fitness of females and their offspring in many species. Here, we examined whether mating or feeding experience of male Carolina sphinx moths, Manduca sexta (Sphingidae), affects the quality of direct benefits that males provide to their mates. We mated virgin females with fed and unfed, virgin and previously mated males. Feeding experience affected male mating success, spermatophore size and flight muscle size. In addition, females mated to fed males laid more eggs than females mated to unfed males, and females mated to virgin males laid more eggs than females mated to previously mated males. Using 13C-enriched glucose in the nectar of the fed males, we found that the second and third spermatophores of males were strongly labelled, but this labelled glucose was not present either in the female's fat body or in her eggs. Therefore, although fed males provided females direct benefits from the sugar in the nectar, the sugar was not used as a nutrient by females. We suggest that in short-lived species, where females mate singly and males mate multiply, and where nectar availability is highly variable, males may be selected to conserve their resources to maintain flight capability and to invest in sperm performance and, thus, provide only limited (non-nutritive) direct fitness benefits to their mates.

Complete nutrient content of three species of wild caught insects, pallid-winged grasshopper, rhinoceros beetles and white-lined sphinx moth

Insects serve as a major source of nutrients for many animal species, but complete nutritional information of wild insects is lacking. Wild pallid-winged grasshoppers, rhinoceros beetles and white-lined sphinx moths were caught in Rio Verde, Arizona, in the summer of 2013 (grasshoppers and beetle) or the spring of 2015 (moths). Pallid-winged grasshoppers, rhinoceros beetles and white-lined sphinx moths were analysed for moisture, crude protein, fat, ash, acid detergent fibre, minerals, amino acids, fatty acids and vitamins and values compared the nutrient requirements for both rats and poultry as reported by the National Research Council (NRC). The acid detergent fibre was also analysed for nitrogen. When compared to the nutrient requirements as established by the NRC for growing rats, grasshoppers were deficient in calcium, vitamin A, vitamin D, thiamine and vitamin B12, beetles were deficient in calcium, vitamin A, vitamin E, thiamine, pyridoxine and linoleic acid and moths were deficient in calcium, sodium, vitamin A, vitamin D, pyridoxine and vitamin B12. In contrast when compared to the nutrient requirements as established by the NRC for growing broiler chickens, grasshoppers were only deficient in calcium, manganese, and vitamin A, beetles were deficient in calcium, manganese, vitamin A, vitamin E, thiamine and linoleic acid and moths were deficient in calcium, sodium, manganese, vitamin A, vitamin D, and linoleic acid. These data show that Pallid-winged grasshoppers, Rhinoceros beetles and White-lined sphinx moths were good sources of most known nutrients including all essential amino acids, most minerals and most vitamins.

Manduca rustica(Lepidoptera: Sphingidae) Damage on Olive (Olea europaea; Lamiales: Oleaceae) trees in Florida

There is a growing interest in cultivating olives Olea europaea L. (Lamiales: Oleaceae) in Florida, USA. Although some parts of Florida seem well suited for olive production, the pests and diseases associ ated with cultivated olives in Florida are generally unknown. During a 2014 survey of olives being grown at the commercial and homeowner level, a novel pest was identified. A hornworm (Fig. 1), now known to be the larval stage of the rustic sphinx Manduca rustica (F.) (Lepidoptera: Sphingidae) (Wagner 2010; D. L. Wagner, personal communication), was reported as a pest of concern by growers from the Florida Panhandle in the north to Polk County in the south. Tuttle (2007) described M. rustica as a broadly distributed Neotropical species that breeds in the mid-Atlantic states as far north as Delaware, USA. In Florida, Heppner (2003) reported M. rustica ranges as far south as Miami-Dade County, but the species has not been reported from Monroe County (the Florida Keys).Worldwide, there are 49 recorded lepidopteran pests of O. europaea, 9 of which are in the family Sphingidae, but none is within the genus Manduca (Robinson et al. 2010). The primary concern of growers was the defoliation caused by larval feeding. One larva can quickly denude a 2-yr-old olive tree, causing problems for nursery producers and for growers with new plantings. Although trees can recover from this damage, olive trees are slow growing, and feeding damage can remain apparent for several months depending on the time of year. Manduca rustica is listed as having a host range that includes plants in the family Oleaceae (Kitching & Cadiou 2000; Tuttle 2007; Robinson et al. 2010); however, we were unable to find any report that it has been recorded as feeding on O. europaea. The rustic sphinx moth is recognized as a pollinator in the southeastern United States (Graham 2010). The only notable report of the rustic sphinx as a pest comes from Clavijo & Chacin (1992), who reported M. rustica as a pest of sesame in Venezuela. This is important to note for growers who are interested in using sesame as a cover crop or an attractant for beneficial insects near olive production areas in Florida. Initial reports from growers included photos of specimens collected from orchards and nurseries. Many growers elected to control mechani

Efficacy of Soil-Applied Systemic Insecticides Against Tobacco Pests, 2014

Efficacy of several soil-applied insecticides (Table 1) was tested against key tobacco pests: TFB, TBW, GPA, and tobacco/tomato hornworms (HW). Two identical experiments were conducted at the Upper Coastal Plain Research Station (UCPRS) in Rocky Mount, NC, and the Lower Coastal Plain Research Station (LCPRS) in Kinston, NC. In each experiment, four replicates of the six treatments, including an untreated check, were arranged an RCB design. Each 0.018-acre plot consisted of four, ca. 25 plant, rows. At LCPRS, pre-transplant greenhouse tray drench (GTD) insecticide applications were made on 7 May 2014 in 1 L water using a CO2-pressurized sprayer fitted a single flat-fan nozzle. Twice the application volume was used to wash the material into the root zone immediately following treatment. GTD treatments were applied as above at UCPRS on 28 Apr. The plants were transplanted on 5 May at UCPRS and 8 May at LCPRS, and in-furrow transplant water (TPW) treatments were applied in ca. 160 gal/A of water using four 5-gal mini-tanks affixed to the planter. Plants received no additional insecticide treatments for the …

Nectar Robbery and Thievery in the Hawk Moth (Lepidoptera: Sphingidae)-Pollinated Western Prairie Fringed OrchidPlatanthera praeclara

ABSTRACT Nectar larcenists target flowers with a long nectar spur. The western prairie fringed orchid, Platanthera praeclara Sheviak and Bowles (Orchidaceae), has a 50-mm-long spur and is pollinated by hawk moth (Lepidoptera: Sphingidae) species with tongues that are shorter than the spur.We placed net traps above inflorescences at P. praeclara sites in southeastern North Dakota to survey potential nectar larcenists, including hawk moth thieves (2004–2014) and bumble bee robbers (2007–2014).We captured two hawk moths, Manduca quinquemaculata (Haworth) and Agrius cingulata (F.), that have tongues over twice the length of P. praeclara's spur. Also captured were eight bumble bee species (genus Bombus), which may produce the holes discovered in P. praecala's spur. Holes triggered loss of the spur and its nectar. In 2007, 2013, and 2014, robbery was observed in 10, 60, and 37% flowers per plant, respectively. At the flower level, robbery had a positive effect on removal of pollinaria and no effect on pollen de...