New occurrence of the invasive alien leaf‐footed bug Leptoglossus gonagra (Hemiptera: Coreidae) in South Korea

The invasive alien leaf‐footed bug Leptoglossus gonagra (Fabricius 1775), native to the Americas, is herein recorded from South Korea for the first time. Forty nymphs and adults were collected on 22 September 2016 from arable lands of two separate sites. These individuals were identified based on the analysis of morphological characters and cytochrome oxidase c subunit 1 sequences. A neighbor‐joining tree indicated the existence of two clades: Group A from Brazil, and Group B from Asia and Oceania. Mean genetic distance between clades was 8.11%, range 7.60–8.57%. Within clades, mean genetic distance was 0.42% (0.17–0.83%) in Group A and, 0.45% (0.00–0.83%) in Group B. Colonies of 2nd‐final instar nymphs and adults were found, on top of leaves, flowers, fruits, and between the stems of pumpkins (Cucurbita moschata). Nymphs and adults damaged host plants by sucking their leaves, stems, fruits, and buds. After the first discovery in 2016, we were unable to find the bugs again (in 2017–2019). Therefore, the invasion of this species seems to have occurred only temporarily, during the warm season. We suggest that the species may have failed to overwinter as it is normally distributed in regions warmer than Korea. Nevertheless, possible appearances of this species must be continuously monitored as it is a potential pest of various plants cultivated in South Korea.     

Distribution analysis of Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) in South Korea using climate and host plant ensemble maps

Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) is a notorious pest that causes irreversible damage to coniferous forests in South Korea. However, an effective control strategy is still under development. In this study, we used CLIMEX to analyze the potential distribution of L. occidentalis in relation to climate and host plants in South Korea for the identification of effective control spots. The climate needs of L. occidentalis under current and future climate conditions were analyzed and projected on a map along with the distribution of coniferous forests. The CLIMEX model projected that the area of L. occidentalis distribution would decrease slightly in 2060 compared with that at present. However, it was projected that occurrence in mountainous regions would be sustained, suggesting continued damage to coniferous forests in South Korea.     

Life table for Leptoglossus occidentalis Heidemann (Heteroptera: Coreidae) and prediction of damage in lodgepole pine seed orchards

Abstract 1 Fecundity, egg hatch and nymphal survivorship of Leptoglossus occidentalis Heidemann were determined and used to develop a damage prediction formula for seed bugs in lodgepole pine seed orchards. 2 A single overwintered L. occidentalis female may lay up to 80 eggs during early and mid‐season cone development. 3 Up to 83.4% of eggs that were attached to branches with tape hatched successfully, compared with 53.5% of eggs attached to needles with wire. Egg parasitism was only observed in egg masses attached with wire. 4 Egg masses attached with wire suffered approximately 30% mortality from parasitism, primarily by Gryon pennsylvanicum (Ashmead). 5 Approximately 15.1 and 2.5% of first instars survived to adulthood in 2000 and 2001, respectively. Survival of caged nymphs that were protected from predators was 14.5 and 17.8%, respectively. 6 A composite survival table indicated that 9.3% of eggs laid by L. occidentalis are expected to survive to adulthood. 7 Based on previously determined damage estimates for each life stage of feeding during three periods of cone development, a hypothetical density of one seed bug per tree early in the season will result in an expected seed loss of approximately 310 seeds.     

Specific biochemical marker-based techniques for the identification of damage to Douglas-fir seed resulting from feeding by the western conifer seed bug, Leptoglossus occidentalis Heidemann (Hemiptera: Coreidae)

Specific biochemical marker-based techniques were tested for their ability to distinguish between seeds of Douglas-fir, Pseudotsuga menziesii (Mirbel) Franco, that were filled or unfilled (aborted) at maturity and those that were damaged or emptied by the western conifer seed bug, Leptoglossus occidentalis Heidemann. A polyclonal antibody raised against salivary gland extracts from L. occidentalis successfully identified residual salivary proteins on Western blots containing proteins from Douglas-fir seeds that had sustained various degrees of seed bug feeding damage. In a single blind experiment, the polyclonal antibody correctly identified 100% of undamaged control, 97% of unfilled control (aborted), and 98% of seed bug damaged seeds. Polyclonal antibodies raised against insoluble alfalfa crystalloid storage protein (11S globulin) detected the depletion of 11S globulin and the subsequent appearance of its hydrolyzed fragments in the soluble protein fraction of Douglas-fir seeds that were fed-upon by the seed bug. Feeding by L. occidentalis nymphs caused ca. 98% depletion of insoluble protein, but only ca. 53% reduction in the amount of soluble protein in seeds that appeared empty on radiographs. By comparison, unfilled (aborted) seeds contained significantly less insoluble and soluble protein than empty seeds that were fed-upon by L. occidentalis; moreover, no crystalloid (11S globulin) breakdown products were generated. The biochemical markers described in this study are reliable tools that can be used to identify conifer seeds that have sustained light to severe damage from L. occidentalis feeding.     

Morphology and chemical composition of metathoracic scent glands in Dolycoris baccarum (Linnaeus, 1758) (Heteroptera: Pentatomidae)

One of the general defining characters of the Heteroptera is the presence of metathoracic scent glands (MTG). Using scanning electron microscopy, the morphology of the MTG of Dolycoris baccarum (Linnaeus 1758) (Heteroptera: Pentatomidae) was studied. The MTG belong to the diastomian type. The two glandular pores located between the mesothoracic and metathoracic coxae are associated with 'mushroom-like' structures. The MTG are composed of a reservoir and a pair of lateral glands is connected to the reservoir by a duct. A groove-like structure extends downwards from the ostiole. While this structure is long and wide, its ostiole is oval. Extracts of the volatile fractions from male and female MTG secretions were analysed by capillary gas chromatography–mass spectrometry (GC-MS) and exhibited a typical pentatomid composition. Seventeen chemical compounds were detected in female secretions, whereas 13 chemical compounds were detected in the male secretions. Most chemical compounds were similar between the sexes but were different in their quantities. In this regard, the compounds identified were investigated and the biological functions of the glandular secretions were discussed. In the analyses of the MTG of females of D. baccarum , tridecane (50.97%) was a major odour component and (Z,Z)-4,16-octadecadien-1-ol acetate (0.02%) was a minor odour component. In males, tridecane (50.80%) was a major odour component and 1,2-benzenedicarboxylic acid (0.02%) was a minor odour component.     

Functional anatomy of the vagina muscles in the adult western conifer seed bug,Leptoglossus occidentalis (Heteroptera: Coreidae), and its implication for the egg laying behaviour in insects

The anatomy of the female reproductive tract and the nerve-evoked contractions of the vagina muscles and their association with the ovipositor in the western conifer seed bug, Leptoglossus occidentalis (Heidemann) are investigated for the first time. The reproductive tract consists of a set of paired telotrophic ovaries, each containing seven ovarioles, located in the anterior lateral regions of the abdomen. Each ovary is attached to a lateral oviduct which spans most of the abdomen to attach to a relatively short common oviduct that joins the vagina near the rear of the animal. The vagina is associated with a pair of bilaterally symmetrical muscles attached at their posterior ends to lateral extensions of sternite VIII, the valvifer of the Type II ovipositor. From this attachment site, the muscles fan out medially and anteriorly to converge along the dorsal midline of the vagina up to the base of the common oviduct. Vagina muscles respond to a single stimulation of their motor nerves by producing a smooth contraction lasting approximately 1 s. With increasing frequencies of stimulation, the muscle contractions summate to create a tetanic response. The muscles are fatigue resistant being able to maintain the same degree of tension for up to 10 min at 10 Hz stimulation. Visual observation shows that other muscles associated with the valves of the ovipositor behave in a similar fashion to that of the vagina muscles from which the tension recordings were obtained. Fatigue-resistant vagina muscles are discussed in relation to copulation, sperm transport and this insect's ability to deposit a series of eggs directly onto the surface of a conifer needle in a manner by which eight or more blunt-ended eggs are packed end-to-end in a single row.     

Males of the seed bug Togo hemipterus (Heteroptera: Lygaeidae) use accessory gland substances to inhibit remating by females

In species in which females mate repeatedly, males can adopt several strategies to reduce the risk of sperm competition with future males. The refractory period of females significantly increased as the mating duration increased in the seed bug Togo hemipterus (Heteroptera: Lygaeidae). To elucidate the mechanisms by which mated females are inhibited from remating, we investigated the effects of male-derived substances on the inhibition of mating receptivity of virgin females by injecting the substances into their abdomens. The length of time from injection to mating in virgin females was significantly longer for females injected with accessory gland B solution than for those injected with seminal vesicle, accessory gland A, or control solutions. This is the first report showing that heteropteran males inhibit female remating by using substances from an accessory gland. We discuss and consider the adoption and evolution of this strategy by T. hemipterus males by focusing on female genitalia structures, oviposition habit, and paternity and comparing these traits with those of other heteropterids.     

Mouthpart morphology and feeding behavior of the invasive kudzu bug,Megacopta cribraria (Hemiptera: Plataspidae)

The invasive kudzu bug, Megacopta cribraria, was first reported in North America in 2009 and has subsequently spread through most of the southeastern United States, causing yield loss in soybean. Since detection in the USA, research has focused mainly on managing this newly established pest, but many important characteristics of the pest's mouthpart morphology and feeding behavior are unknown. Qualitative and quantitative comparisons of nymph and adult mouthparts and sensilla were made through scanning electron microscopy and light microscopy, and feeding behavior was examined using electropenetrography (EPG) and paraffin histology. Morphologies observed were similar to what has previously been reported for other piercing–sucking hemipterans. The relationship between rostrum length and body size (pronotum width and dorsal length) exhibited negative allometry. Rostrum length exhibited an isometric relationship with interocular width. Adult females (n=9) probed soybean stems 1.3±0.8 times in 9 h, with an average probe time of 2.3±1.3 h. EPG waveforms were characterized and correlated with behavior. Salivary sheaths were shown to terminate in the vascular tissue; four of five sheaths terminated in the phloem. This is the first time that the feeding behavior of a member of the Plataspidae has been recorded using EPG. Results add to our current limited knowledge of plataspid mouthpart morphology and provide a baseline for further research on the feeding behaviors of M. cribraria and other soybean‐feeding hemipterans.     

First records of the western conifer seed bug Leptoglossus occidentalis Heid. (Heteroptera, Coreidae) from Russia and Ukraine, regularities in its distribution and possibilities of its range expansion in the palaearctic region

The paper presents the first records of the western conifer seed bug Leptoglossus occidentalis Heidemann, 1910 for the fauna of Russia (Rostov Province) and Ukraine (Crimea and Zaporizhia Province). The dependence of the spread of this species on positive and negative temperatures and the availability of food plants is considered. The forecast of further expansion of its range in the Palaearctic Region is given.     

Multiple male morphs in the leaf‐footed bug Mictis longicornis (Hemiptera: Coreidae)

Species within the coreid clade (Hemiptera: Coreidae) can often be observed competing in intrasexual competitions over access to mates and territories. Coreids that partake in these competitions typically possess sexually dimorphic hind legs that are used to strike and squeeze their rivals. In addition to their weaponized legs, some coreid species also possess sexually dimorphic abdominal tubercles, which are assumed to be sexually selected weapons. Still, much remains unknown about the morphology of these structures. Here, using the species Mictis longicornis Westwood, we investigate the frequency distribution and static allometry of abdominal thickness, a measure that includes tubercle length. Furthermore, we also investigate the morphological relationship between abdominal tubercles and weaponized hind legs. We find that male abdominal thickness is best explained by a bimodal distribution, thereby describing the first observed male polymorphism in the coreid clade; a phenomenon typically associated with alternative reproductive tactics. Additionally, we find that major males are characterized primarily by having large weaponized legs and abdominal tubercles, which further suggests that abdominal tubercles are used in male–male competition.     

Three groups of species in Petunia sensu Jussieu (Solanaceae) inferred from the intact seed

The intact seed surface morphology in 45 taxa of Petunia sensu Jussieu native to South America (Petunia sensu Wijsman plus Calibrachoa) was compared under scanning electron microscopy. The existence of three groups of species, differentiated in terms of seed morphology, was revealed as follows: (1) all species of Petunia sensu Wijsman, having coarse wavy middle lamellae and anticlinal walls; (2) Calibrachoa parviflora and C. pygmaea, having fine wavy middle lamellae embedded in straight anticlinal walls; and (3) the other species of Calibrachoa, having straight middle lamellae and anticlinal walls. Close relationships between seed morphology and the other characteristics observable in the groups of species are discussed.     

中华蚊蝎蛉成虫口器感器的超微结构

口器感器在昆虫取食活动中起着重要作用, 但蚊蝎蛉成虫口器上感器的种类和形态迄今未见报道。我们利用扫描电子显微镜, 观察了中华蚊蝎蛉Bittacus sinensis Walker成虫口器上的感器。结果显示: 中华蚊蝎蛉口器上共有8种感器, 分别为锥形、毛形、刺形、指形、掌状、钟形、柱状感器及Böhm氏鬃毛, 主要集中于内唇、 下颚须以及下唇须上。锥形感器和刺形感器数量最多; 毛形感器主要在下颚轴节、 茎节和下唇的亚颏和前颏有分布; 钟形感器和Böhm氏鬃毛只存在于下唇须和下颚须上。下颚须端节和下唇须端节的感器种类相同, 以锥形感器为主。高度骨化的上颚以及下颚内颚叶与外颚叶上未发现感器分布。简要讨论了口器感器在昆虫分类中的意义。     

Diurnal rhythm of male–male combat behavior in the bean bug Riptortus pedestris (Heteroptera: Alydidae)

In many insects, mating is affected by the day–night cycle, i.e., diurnal rhythm. Although there are many reports that mating and other reproductive behaviors are controlled by daily rhythms in various taxonomic insect species, little attention has been paid to the effect of daily rhythms on male fighting behavior. Here, we investigate whether the frequency and escalation of male–male aggressive interaction exhibit diurnal rhythms under a long‐day condition in the bean bug Riptortus pedestris. Despite the fact that male aggressive behaviors were most often observed in the middle of the later half of light periods, no interaction was found between escalation of fighting and the time period. The results, at least, suggest that male aggressive behaviors are influenced by diurnal rhythms like other reproductive behaviors in R. pedestris.     

Emendation of the Genus Paurodontella Husain &Khan, 1968 and Description of P. auriculata n. sp. from Western Canada (Nematoda: Paurodontidae)

Males and females of Paurodontella auriculata n. sp. are described and illustrated and the genus emended. The species is characterized by a short, robust body of 355-525 μm, a stylet length of 7-8 μm, lateral field with 5-6 incisures, and a conoid, attenuated tail 1.5 times the vulva-anus distance. Primary characters used in emending the genus are asymmetrical stylet knobs, absence of lateral lips, a deep slit-like amphid dividing the submedian lips to base of head, where open lateral sides are covered by a large auriform cuticular flap, and variable length of the basal esophageal bulb stem and male bursa.     

Coronostoma claireae n. sp. (Nematoda: Rhabditida: Oxyuridomorpha: Coronostomatidae) from the Indigenous Milliped Narceus gordanus (Chamberlain, 1943) (Diplopoda: Spirobolida) in Ocala National Forest,Florida

Twenty-four individuals of Narceus gordanus (Diplopoda: Spirobolidae) were collected in Ocala National Forest, FL, between November 2013 and July 2014. Each specimen was dissected to extract the intestine, which was removed and examined for parasitic nematodes. Coronostoma claireae n. sp. was collected from the hindgut and midgut of 10 specimens, and its morphology was examined with brightfield, differential interference contrast, phase contrast, and scanning electron microscopy. This species is separated from other Coronostoma spp. by the following characteristics: body length less than 3 mm; head sense organs pit-like; first annule long, extending past middle of corpus, width similar to that of second annule; basal bulb pyriform; eggs larger than 60 × 50 µm. This species is the first North American record for the genus Coronostoma, which is removed from Thelastomatoidea: Thelastomatidae and reassigned to Coronostomatidae on the basis of presumed apomorphies. A key is provided for known Coronostoma spp. The superfamily Coronostomatoidea is re-established for Coronostomatidae and Traklosiidae.     

Spread and potential host range of the invasive oak lace bug [Corythucha arcuata (Say, 1832) – Heteroptera: Tingidae] in Eurasia

1. The North American oak lace bug feeds on leaves of ‘white oaks” in its native range. In Europe, it was first discovered in northern Italy in 2000. In recent years, it has subsequently spread rapidly and population outbreaks have been observed in several European countries. In the present study, we summarize the steps of its expansion.
2. To predict its potential host range, we checked 48 oak species in 20 sentinel gardens in seven countries between 2013 and 2018.
3. In total, 27 oak species were recorded as suitable hosts; 13 of them are globally new ones, 23 out of the 29 in section Quercus (～ white oaks, an intrageneric taxonomic unit within genus Quercus), including Asian oaks, native to Japan, Korea and China, and four out of five in section Cerris (another intrageneric unit of the same genus), were accepted as hosts. None of the species in section Lobatae (red oaks) or in the Ilex group was accepted.
4. Host records were also collected in forest stands of 10 countries. We found 11 oak species that were infested. Outbreak populations were most commonly found on Quercus robur, Quercus frainetto, Quercus petraea and Quercus cerris, comprising widespread and outstandingly important oaks species in Europe.
5. Based on our findings, we conclude that suitable hosts for oak lace bug are present in most of Europe and Asia. This means that a lack of hosts will likely not restrict further range expansion.

     

Morphology,Phylogeny, and Diversity of Trichonympha (Parabasalia: Hypermastigida) of the Wood‐Feeding Cockroach Cryptocercus punctulatus

ABSTRACT. Trichonympha is one of the most complex and visually striking of the hypermastigote parabasalids—a group of anaerobic flagellates found exclusively in hindguts of lower termites and the wood‐feeding cockroach Cryptocercus—but it is one of only two genera common to both groups of insects. We investigated Trichonympha of Cryptocercus using light and electron microscopy (scanning and transmission), as well as molecular phylogeny, to gain a better understanding of its morphology, diversity, and evolution. Microscopy reveals numerous new features, such as previously undetected bacterial surface symbionts, adhesion of post‐rostral flagella, and a distinctive frilled operculum. We also sequenced small subunit rRNA gene from manually isolated species, and carried out an environmental polymerase chain reaction (PCR) survey of Trichonympha diversity, all of which strongly supports monophyly of Trichonympha from Cryptocercus to the exclusion of those sampled from termites. Bayesian and distance methods support a relationship between Trichonympha species from termites and Cryptocercus, although likelihood analysis allies the latter with Eucomonymphidae. A monophyletic Trichonympha is of great interest because recent evidence supports a sister relationship between Cryptocercus and termites, suggesting Trichonympha predates the Cryptocercus‐termite divergence. The monophyly of symbiotic bacteria of Trichonympha raises the intriguing possibility of three‐way co‐speciation among bacteria, Trichonympha, and insect hosts.     

Paraiotonchium muscadomesticae n. sp. (Tylenchida: lotonchiidae) a Parasite of the House Fly (Musca domestica) in Brazil and a Key to Species of the Genus Paraiotonchium

Paraiotonchium muscadomesticae n. sp., a parasite of the house fly, Musca domestica L., is described and illustrated from material collected in Brazil. The life cycle of P. muscadomesticae is similar to that of P. autumnale (Nickle), consisting of alternating gamogenetic and parthenogenetic generations. Paraiotonchium muscadomesticae n. sp. can be distinguished from P. nicholasi Slobodyanyuk, P. autumnale (Nickle) Slobodyanyuk, and P. crassirostris (Yatham &Rao) Siddiqi by the shorter body length of young heterosexual females, 652 g.m (530-709) for P. muscadomesticae compared to 750 μm or more (801-1,050) for the others. Paraiotonchium muscadomesticae is close to P. nicholosi but differs from it by V ratio and spicule length (V = 80-84; spicule = 16-21 p.m in P. muscadomesticae compared to V = 73-78; spicule = 25-35 μm in P. nicholasi). Paraiotonchium muscadomesticae and P. nicholasi differ from all species of this genus by the absence of a bursa on males of these two species.     

Description of Pratylenchus gutierrezi n. sp. (Nematoda: Pratylenchidae) from Coffee in Costa Rica

A lesion nematode, Pratylenchus gutierrezi n. sp., collected from the roots of coffee in the Central Plateau of Costa Rica, is described and illustrated. Its relationships to Pratylenchus flakkensis, P. similis, and P. gibbicaudatus, the only other species of the genus having two head annules, males, or spermatheca with sperm, and an annulated tail terminus, is discussed. Other distinctive characters are its posterior vulva (mean of 80%); its prominently rounded stylet knobs, low head, and subcylindrical tail. SEM observations provide additional details of females and males, especially face views, which show for the first time sexual dimorphism.     

Globins Synthesize the Second Messenger Bis-(3′-5′)-Cyclic Diguanosine Monophosphate in Bacteria

Globin-coupled sensors are heme-binding signal transducers in Bacteria and Archaea in which an N-terminal globin controls the activity of a variable C-terminal domain. Here, we report that BpeGReg, a globin-coupled diguanylate cyclase from the whooping cough pathogen Bordetella pertussis, synthesizes the second messenger bis-(3′-5′)-cyclic diguanosine monophosphate (c-di-GMP) upon oxygen binding. Expression of BpeGReg in Salmonella typhimurium enhances biofilm formation, while knockout of the BpeGReg gene of B. pertussis results in decreased biofilm formation. These results represent the first identification a signal ligand for any diguanylate cyclase and provide definitive experimental evidence that a globin-coupled sensor regulates c-di-GMP synthesis and biofilm formation. We propose that the synthesis of c-di-GMP by globin sensors is a widespread phenomenon in bacteria.