First-instar Nymphs Research Articles

Ants prey on cicada hatchlings

ABSTRACT Temperate-zone cicadas are characterised among insects by their long-lived underground nymphal stages, which live for 5–20 years or more. Here we report the extensive occurrence of above-ground predation on eggs and first-instar nymphs of the common Japanese brown cicada, Graptopsaltria nigrofuscata, by colonial ants in a city park. Predation on eggs and first-instar nymphs by ants may be a major source of above-ground mortality rate in a population of this Japanese cicada species.

Sugar feeding in triatomines: a new perspective for controlling the transmission of Chagas disease.

Introduction: Triatomines are vectors of Trypanosoma cruzi, the etiological agent of Chagas disease. Currently, there is no vaccine against this disease. Thus, control of the insect vector population is the main strategy available to reduce the number of cases. Triatomines are considered obligate hematophagous, but different alternative feeding behaviors were described, such as haemolymphagy or plant feeding. Methods: To determine the preference for sugar feeding in nymphs and adults of Rhodnius prolixus, the insects were exposed a piece of cotton containing bromophenol blue plus sucrose. In addition, we offered several sugars for different species of triatomines, and tested sugar meals as a route of delivery of insecticides in first-instar nymphs of R. prolixus. The effect of sugar feeding on the physiology of these different species of triatomines was recorded. Results: First instar nymphs ingested sucrose more strongly than other stages, and showed high mortality rates. In different species of triatomines, sucrose induced an ingestion, but engorgement varied according to the species. R. prolixus nymphs showed an indiscriminate intake of various sugars, with very different physiological effects. Furthermore, ingesting different combinations of insecticides + sugar significantly reduced insect survival. Discussion: In summary, we described for the first-time sugar feeding as a widespread behavior in several species of triatomines, and the possibility of the use of toxic sugar baits for the control of these vectors. The knowledge of feeding behavior in these insects can be fundamental for the development of new strategies to control Chagas disease.

A review of the Margarodidae sensu stricto (Hemiptera: Coccomorpha) in China, with descriptions of three new species

The research history of the family Margarodidae Cockerell sensu stricto (Hemiptera: Coccomorpha) from China is reviewed. Four species of Porphyrophora Brandt and three species of Neomargarodes Green from China are described and illustrated, including three new species: Neomargarodes chenopodium Zheng & Wu, sp. nov. based on the morphology of the adult female, first-instar nymph and second-instar female and male nymphs (cysts); Porphyrophora ejinensis Zheng & Wu, sp. nov. based on the adult female, second-instar female nymph (cyst) and third-instar female nymph (cyst); and Porphyrophora neimonggolensis Zheng & Wu, sp. nov. based on the adult female. Porphyrophora ningxiana Yang, 1979, stat. rest. is resurrected from synonymy under Porphyrophora sophorae (Archangelskaya, 1935), and lectotypes of Neomargarodes gossypii Yang, 1979 and P. ningxiana Yang are designated. A record of Porphyrophora ussuriensis Borchsenius, 1949 from China was found to be based on a misidentification. An identification key to genera and species of Margarodidae s.s. found in China is provided, based on adult female morphology.

Identification and expression analysis of four sHsp genes in Sogatella furcifera under abiotic stress

Sogatella furcifera is a typical r-strategist insect with strong adaptability and one of the major pests in rice cultivation. Small heat shock proteins (sHsp) play a vital role in insects responding to external abiotic stress. However, little is known about the role of sHsp in the defense against abiotic stress in S. furcifera. In this study, four sHsp genes (SofHsp20.7, SofHsp21.6, SofHsp21.7, and SofHsp21.8) were identified from S. furcifera, and their gene expression patterns were analyzed at different developmental stages, temperature stress, insecticide exposure, and UV-A irradiation. The results indicated that four sHsp were expressed at various developmental stages of the S. furcifera, with the highest transcription levels in the first-instar nymphs, fourth day fifth instar nymphs, third-day adult females, and eggs, respectively. High-temperature stress (30 °C and 40 °C) significantly induced the expression of all four sHsp genes, while low-temperature stress (10 °C) reduced their expression. Sublethal concentrations (LC10 and LC25) of buprofezin increased the expression levels of SofHsp20.7 and SofHsp21.8. Under UV-A irradiation, the S. furcifera also significantly induced the expression of all four sHsp genes, with the highest expression observed at 90 min after exposure to the stress. These results suggest that sHsp genes are essential for the resistance or tolerance of S. furcifera to high temperature, buprofezin, and UV-A irradiation. This research provides a foundation for understanding the molecular mechanisms underlying the S. furcifera adaptation to abiotic stress.

Laboratory Study to evaluate the efficiency of Nano-loaded tobacco aqueous extract on the different roles of Ommatissus lybicus De Berg

A laboratory study is conducted to evaluate the efficiency of the aqueous extract of nano- chitosan loaded tobacco plants and laboratory-made. When O. lybicus eggs were treated with an aqueous extract of nano- chitosan loaded tobacco plants at two concentrations (10-15) ppm, recorded the highest mortality rates reached (21.2-37) %, respectively. Furthermore, the highest egg mortality rates reached (47.8_66.6) % after (14_21) days. The same concentrations above also affected the mortality rates of first-instar nymphs, which amounted to (30.3_53.3%), respectively. The concentration (15) ppm had the highest significant differences at mortality rate reaching (58.3_70.0) % after (5_7) days. The mortality rates in third-instar nymphs reached (28.9-37.5%) at the concentration of (15) ppm, the highest mortality rates reached (39.9_44.6_40.3) % after (3_5_7) days. The mortality rates in the fifth instar nymphs amounted to (22.6_29.1) %, respectively, as they were the highest mortality rates at a concentration of (15) ppm after (5) days, reaching (39.1) %.

Functional responses of two species of predatory mites (Acari: Phytoseiidae) to eggs and first-instar nymphs of Bactericera Gobica Logniova (Homoptera: Psyllidae).

The goji berry psyllid, Bactericera gobica Logniova (Homoptera: Psyllidae), is one of the most important pests on goji berry plants (Lycium barbarum L.), whose fruits are widely used in traditional Chinese medicine and food. However, chemical control is still the predominant control strategy of this pest. Recently, two species of predatory mites, Neoseiulus setarius Ma, Meng & Fan and Neoseiulus barkeri Hughes were found to be associated with B. gobica in China. To assess their predation potential against B. gobica, the functional responses of these two phytoseiid species feeding on different densities (2, 4, 8, 12, 16, 24 and 32 individuals) of B. gobica eggs and 1st instar nymphs were compared at a temperature of 25ºC ± 1º C. Logistic regression analysis revealed that both predatory mite species exhibited type Holling-II functional responses on eggs and 1st instar nymphs of B. gobica, with the predation number increased for both predators as the density of prey increased. Overall, N. setarius consumed more prey compared to N. barkeri across all levels of prey densities. Meanwhile, the highest attack rate (α = 0.0283), the lowest handling time (Th = 1.1324h prey- 1), and the highest estimated maximum predation rate (T/Th = 21.19 prey day- 1) were all observed for N. setarius fed with 1st instar nymphs of B. gobica. These findings suggest that it is worthy considering utilizing N. setarius and N. barkeri as candidate biocontrol agents of B. gobica, with N. setarius appearing to be a more effective predator than N. barkeri.

Silica and Selenium Nanoparticles Attract or Repel Scale Insects by Altering Physicochemical Leaf Traits.

Although nanoparticles have gained attention as efficient alternatives to conventional agricultural chemicals, there is limited knowledge regarding their effects on herbivorous insect behavior and plant physicochemistry. Here, we investigated the effects of foliar applications of nano-silica (SiO2NPs) and nano-selenium (SeNPs), and bulk-size silica (SiO2) on the choice behavior of the arrowhead scale insect on mandarin orange plants. One leaf of a bifoliate pair was treated with one of the three chemicals, while the other was treated with water (control). The respective SiO2, SeO2, calcium (Ca), and carbon (C) content levels in the leaf epidermis and mesophyll were quantified using SEM-EDX (or SEM-EDS); leaf toughness and the arrowhead scale density and body size were measured. First-instar nymphs preferred silica-treated leaves and avoided SeNP-treated leaves. SiO2 content did not differ between control and SiO2NP-treated leaves, but was higher in bulk-size SiO2-treated leaves. The SiO2 level in the control leaves was higher in the SiO2NP treatment compared with that in the control leaves in the bulk-size SiO2 treatment. Silica-treated leaves increased in toughness, but SeNP-treated leaves did not; leaf toughness increased with mesophyllic SiO2 content. The insect density per leaf increased with leaf toughness, SiO2 content and, in the SiO2NP treatment, with epidermal C content. There was no correlation between SeO2 content and insect density. This study highlights the potential uses of SeNPs as an insect deterrent and of silica for enhancing leaf toughness and attracting scale insects.

Pest categorisation of Lepidosaphes malicola.

The EFSA Panel on Plant Health performed a pest categorisation of Lepidosaphes malicola (Hemiptera: Diaspididae), the Armenian mussel scale, for the territory of the European Union, following commodity risk assessments of Prunus persica and P. dulcis plants for planting from Türkiye, in which L. malicola was identified as a pest of possible concern. L. malicola is a polyphagous insect of temperate and arid areas, feeding on more than 60 plant species belonging to 26 families. Important crops significantly affected by L. malicola in parts of Asia include stone fruits (Prunus armeniaca, P. persica), pome fruits (Malus domestica, Pyrus communis), grapes (Vitis vinifera), pomegranate (Punica granatum), walnuts (Juglans regia) and ornamental plants (Berberis spp., Cornus spp., Jasminum spp., Ligustrum spp.). L. malicola has two generations annually. The overwintered eggs hatch from late May to early June. First-instar nymphs crawl on the host plant for a short period, then settle to feed. Nymphs reach maturity in late summer or early autumn. Plants for planting, fruits and cut flowers provide potential pathways for entry into the EU. Host availability and climate suitability suggest that southern, central and some parts of northern EU countries would be suitable for the establishment of L. malicola. Despite being a pest in Armenia, Iran and Tajikistan, there is no evidence of it being a pest in Türkiye. L. malicola was detected in Bulgaria and Greece over 30 years ago, but there have been no records since, and its status is uncertain. Its ability to cause an impact in the EU is also uncertain. It is not listed in Annex II of the Commission Implementing Regulation (EU) 2019/2072. Phytosanitary measures are available to reduce the likelihood of entry. Except for the criterion of having an economic or environmental impact, for which there is great uncertainty, L. malicola satisfies all other criteria that are within the remit of EFSA to assess for it to be regarded as a potential Union quarantine pest.

The structure and morphogenic changes of antennae of Spilococcus alhagi (Hall) (Hemiptera: Coccoidea: Pseudococcidae) in different instars

To better understand the antennal morphology and sensilla distribution of Spilococcus alhagi (Hall) in different instars, the antennae are examined using light microscopy and scanning electron microscopy. The results show that the antennae of S. alhagi could be differentiated in different instars based on their stucture, number of flagellomere, and sensillar distribution. Functional antennae of S. alhagi appear in first instar nymphs, adult females, and adult males as many scale insects. The antennae of first-instar nymphs comprise six segments, and each antenna has 62–71 sensilla of eight types, including sensilla basiconica (SB), one type of sensilla trichoidea (ST1), two types of sensilla companiform (SCa, sSCa), two types of sensilla coeloconica (SCo1, SCo2) and two types of sensilla chaetica (SCh1, SCh2). The antennae of adult females have eight segments, but each antenna has 164–188 sensilla of the same eight types as the first instar nymphs. The antennae of adult males are more developed, and each antenna contains ten segments and 670–725 sensilla of eleven types, including knobbed seta sensilla (Ks), intersegmental sensilla (Ins), two types of sensilla trichoidea (ST1, ST2), two types of sensilla companiform (SCa, sSCa), two types of sensilla coeloconica (SCo1, SCo2) and three types of sensilla chaetica (SCh1, SCh2, bSCh). Of these, four types of sensilla, viz., Ks, ST2, Ins, bSCh are only observed on the antennae of adult males. The prepupa-like and pupa-like male nymphs both possess simplified antennae, and exhibit four types of sensilla (ST1, SCa, SCh1, SCh2). Based on these results, the morphogenic changes and potential functions of antennae of S. alhagi in different instars are discussed.

A new species of Discochiton Hodgson & Williams (Hemiptera: Coccomorpha: Coccidae) on bamboo from Myanmar.

The adult female and first-instar nymph of a new species of Discochiton Hodgson & Williams, 2018, Discochiton bambusae Choi & Lee sp. n. are described and illustrated. They were collected on the culms of Bambusa tulda (Poaceae: Bambusoideae) in Myanmar. The adult female has several unique morphological features, such as a large body, up to 15 mm long; legs much reduced; and sclerotized plates forming submedial bands or patches on the venter. Furthermore, the adult female has more marginal radial lines and stigmatic spines than are found in other Discochiton species. The first-instar nymph is also much larger than those of other Discochiton species, and is also distinct in having tibial setae, and a greater number of spiracular disc-pores and marginal setae compared to those of other species of Discochiton.

Contact Toxicity, Antifeedant Activity, and Oviposition Preference of Osthole against Agricultural Pests.

Osthole, the dominant bioactive constituent in the Cnidium monnieri, has shown acute pesticidal activities. However, its detailed toxicity, antifeedant, and oviposition preference effects against agricultural pests have not been fully understood, limiting its practical use. This study aimed to investigate the contact toxicity, antifeedant activity, and oviposition preference of osthole against three agricultural pests (Tetranychus urticae, Myzus persicae, and Bactrocera dorsalis). Our results showed that the Cnidium monnieri (L.) Cusson (CMC) has a high osthole content of 11.4 mg/g. Osthole exhibited a higher level of acute toxicity against the T. urticae to four other coumarins found in CMC. It showed significant pesticidal activity against T. urticae and M. persicae first-instar nymphs and adults in a dose-dependent manner but not against B. dorsalis adults. Osthole exposure reduced the fecundity and prolonged the developmental time of the T. urticae and M. persicae. Leaf choice bioassays revealed potent antifeedant activity in the T. urticae and M. persicae. Furthermore, the female B. dorsalis showed a distinct preference for laying eggs in mango juice with 0.02 mg/mL osthole at 48 h, a preference that persisted at 96 h. These results provide valuable insights into the toxicity, repellent activity, and attractant activity of osthole, thereby providing valuable insights into its potential efficacy in pest control.

A new genus and species of the scale insect family Qinococcidae (Hemiptera: Coccomorpha) from China.

A new genus of Qinococcidae, Abrococcus Zheng & Wu gen. n. is established for a new species Abrococcus cunninghamia Zheng & Wu sp. n., which was collected on Cunninghamia lanceolata (Cupressaceae) from Guizhou Province, P. R. China. Descriptions and illustrations are provided for the adult female and first-, second- and third-instar female nymphs. Keys to the adult females and first-instar nymphs of the genera of Qinococcidae and known developmental stages of A. cunninghamia are provided.

Acute toxicity of two insecticides on two species of Chagas disease vectors

The control of triatomine vectors of Chagas disease is mainly based on the use of pyrethroid insecticides. Because chemical control is the primary method for managing these insects, it is crucial to diversify the range of products utilized to mitigate the risk of resistance development. This study evaluated the toxicity of two insecticides with different modes of action on Triatoma dimidiata Latreille and T. pallidipennis Stal first and third instar nymphs. Our study focused on the effects of two insecticides, buprofezin (a growth regulator) and flunocamid (an anti-feeder), on the mortality rate of triatomine bugs in a laboratory setting. Moreover, we investigated how direct and indirect (film method) exposure to these insecticides impacted the survival of the insects. Flonicamid emerged as a promising insecticide for triatomine control since it caused 100% mortality in first-instar nymphs 48 h after direct exposure. While, in third instar nymphs, the maximum mortality was 88% at 72 h after exposure. Our result can be used as a basis for future triatomine control plans.

Characterization and Functional Analysis of Toll Receptor Genes during Antibacterial Immunity in the Green Peach Aphid Myzus persicae (Sulzer).

The insect Toll receptor is one of the key members of the Toll signaling pathway, which plays an indispensable role in insect resistance to pathogen infection. Herein, we cloned and characterized five Toll receptor genes from Myzus persicae (Sulzer), which were found to be highly expressed in the first-instar nymphs and adults (both wingless and winged) at different developmental stages. Expressions of MpToll genes were highest in the head, followed by the epidermis. High transcription levels were also found in embryos. Expressions of these genes showed different degrees of positive responses to infection by Escherichia coli and Staphylococcus aureus. The expression of MpToll6-1 and MpToll7 significantly increased after infection with E. coli, whereas the expression of MpToll, MpToll6, MpToll6-1, and MpTollo continuously increased after infection with S. aureus. RNA interference-mediated suppressed expression of these genes resulted in a significant increase in the mortality of M. persicae after infection with the two bacterial species compared with that in the control group. These results suggest that MpToll genes play vital roles in the defense response of M. persicae against bacteria.

Pest categorisation of Paracoccus marginatus.

The EFSA Panel on Plant Health performed a pest categorisation of Paracoccus marginatus (Hemiptera: Sternorrhyncha: Pseudococcidae), the papaya scale, for the EU. It is native to Central America and since the 1990s, it has spread rapidly in mainly tropical areas of the Caribbean, islands in the Indian and Pacific Oceans, Africa and southern Asia. Large populations were detected in northern Israel in 2016. It has not been reported within the EU. It is not listed in Annex II of Commission Implementing Regulation (EU) 2019/2072. It reproduces sexually and there are up to 11 generations per year in India. The estimated minimum, optimum and maximum temperature thresholds for the adult females are 13.9, 28.4 and 32.1°C, respectively. First-instar nymphs may move to neighbouring plants by crawling, or be passively dispersed by wind, or hitchhiking on clothing, equipment or animals. It is highly polyphagous, feeding on plants in 172 genera and 54 families. It is an important pest of custard apple (Annona spp.), papaya (Carica papaya) and Hibiscus spp. It also feeds on a wide range of plants cultivated in the EU such as eggplant (Solanum melongena), avocado (Persea americana), citrus (Citrus spp.), cotton (Gossypium hirsutum), grapevine (Vitis vinifera), guava (Psidium guajava), mango (Mangifera indica), passionfruit (Passiflora edulis), pomegranate (Punica granatum), pepper (Capsicum annuum) and tomato (Solanum lycopersicum). Plants for planting, fruits, vegetables and cut flowers are the main potential pathways for entry of P. marginatus into the EU. Climatic conditions in the warmest areas of Cyprus, Greece, Italy and Spain, where host plants occur, would likely allow this species to successfully establish and spread. Reductions in yield and quality of some cultivated hosts including Annona spp., Hibiscus spp. and papaya are anticipated if establishment occurs. Phytosanitary measures are available to reduce the likelihood of entry and spread. P. marginatus meets the criteria that are within the remit of EFSA to assess for this species to be regarded as a potential Union quarantine pest.

Aphagy and vestigial stylets in first-instar nymphs of Aradidae (Hemiptera, Heteroptera)

Aradidae are known for their remarkably long stylets, coiled at rest in the anterior part of the head. However, previous reports indicated that at least some species lacked stylets during the first nymphal instar. A more detailed examination of Aradus betulae 1st-instar nymphs showed that their mandibular and maxillary stylets are abnormally short, not coiled, improperly interlocked, and clearly non-functional. The anteclypeus is relatively small and its internal diverticulum, which accommodates the stylet coil in the older stages, is vestigial. In contrast, the labium, labrum, food canal, and associated structures and muscles, including protractors and retractors of the stylets, are all normally developed. First-instar nymphs of Aradidae are the first known Heteroptera with non-functional mouthparts. To explain this phenomenon, a hypothesis is proposed which links previously unexplained records of non-feeding (but endowed with regular, functional mouthparts) 1st-instar nymphs of various pentatomomorphan families with the special role of that stage in acquiring microbial gut symbionts. A presumed loss of symbionts in the ancestors of Aradidae may have led to reduction of the now useless stylets in the first instar, which retained aphagy, despite a spectacular elongation of stylets in the older, feeding instars.

New genera and species of felt scales (Hemiptera: Coccomorpha: Eriococcidae), with descriptions of new species and immature instars of described species

In this work, emphasis is placed on the Eriococcidae (Hemiptera: Coccomorpha) of the Nearctic Region including the immature instars of many species not previously described, two new genera (Carphococcus Miller and Stocks and Ypofloiococcus Miller and Stocks), and 11 new species (Acanthococcus pennyae Miller and Stocks, Carph. apodus Miller and Stocks, Carpochloroides eugeniae Miller and Stocks, Ovaticoccus betsyae Miller and Stocks, Ov. gordoni Miller and Stocks, Ov. haigi Miller and Stocks, Ov. maryfoleybensonae Miller and Stocks, Ov. telotrichus Miller and Stocks, Ov. tuttlei Miller and Stocks, Ov. villanuevorum Miller and Stocks and Y. libeauae Miller and Stocks). In addition to the new taxa, descriptions and illustrations are provided for adult females, adult males and/or immature instars of Ac. arenosus (Cockerell), Ac. coccineus (Cockerell), Ac. dennoi Miller and Miller, Ac. gallicolus (Cockerell & Rohwer), Ac. hoyi Miller and Miller, Ac. kemptoni (Parrott), Apezococcus idiastes Ferris, Carpo. mexicanus Ferris, Cryptococcus fagisuga Lindinger, Cr. williamsi Kosztarab and Hale, Hypericicoccus hyperici (Ferris), Ov. agavacearum Pellizzari and Kozár, Ov. agavium (Douglas), Ov. cornutus (Ferris), Ov. densus (Miller), Ov. eriogoni (Miller), Ov. exoticus Pellizzari and Kozár, Ov. neglectus (Cockerell), Ov. peruvianus (Granara de Willink & Díaz), Ov. salviae Miller, Ov. sanguineus (Miller), Ov. tippinsi Miller and Miller, Ov. variabilis Miller, Spiroporococcus braggi (Cockerell & Robinson), S. yuccae (Ferris) and Xerococcus foquieriae Ferris. Lectotype designations are made for Ap. idiastes. Carpo, mexicanus and H. hyperici. New collection data are provided for Ov. californicus McKenzie, Ov. johnsoni (Miller), Ov. mackenziei Miller, Ov. parvispina (Chaffin) and Ov. viscosa (Kondo). Dichotomous keys are given for: determination of most eriococcid instars of both sexes; Nearctic genera of the Eriococcidae based on adult females; adult females, second-instar females, second-instar males, and first-instar nymphs of Ovaticoccus Kloet 1944; and the seven species of Acanthococcus Signoret 1875 treated here, based on first-instar nymphs. Oregmopyga Hoy 1963 and Cornoculus Ferris 1955 are treated as junior subjective synonyms of Ovaticoccus. Atriplicia Cockerell and Rohwer 1909 has been placed previously as a junior synonym of Eriococcus but here is regarded as a junior subjective synonym of Acanthococcus. We treat 44 species; new descriptions are provided for 101 treated instars, and detailed line drawings are given for all but three of them. The following species, listed in ScaleNet as occurring in the Nearctic Region, are transferred to Acanthococcus from Eriococcus Targioni Tozzetti 1868: Acanthococcus actius Miller and Miller 1993 rev. comb.; Ac. arenariae Miller and Miller 1993 rev. comb.; Ac. barri Miller 1991 rev. comb.; Ac. beshearae Miller and Miller 1993 rev. comb.; Ac. dennoi Miller and Miller 1993 rev. comb.; Ac. droserae Miller, Liu and Howell 1992 rev. comb.; Ac. epacrotrichus Miller and Miller 1992 rev. comb.; Ac. froebeae Miller 1991 rev. comb.; Ac. gallicolus (Cockerell & Rohwer 1909) comb. n.; Ac. hoyi Miller and Miller 1992 rev. comb.; Ac. mackenziei Miller and Miller 1992 rev. comb.; Ac. macrobactrus Miller and Miller 1992 rev. comb.; Ac. megaporus Miller and Miller 1993 rev. comb.; A. mesotrichus Miller and Miller 1993 rev. comb.; Ac. microtrichus Miller and Miller 1992 rev. comb.; Ac. monotrichus Miller and Miller 1993 rev. comb.; Ac. ophius Miller and Miller 1993 rev. comb.; Ac. stauroporus Miller and Miller 1992 rev. comb.; Ac. washingtonensis Miller and Miller 1992 rev. comb.; and Ac. whiteheadi Miller 1991 rev. comb. In addition, two species are transferred to Acanthococcus from Rhizococcus Signoret: Ac. coccineus (Cockerell 1894a) rev. comb. and Ac. kemptoni (Parrott 1900) rev. comb. Three images of water color paintings by Mary Foley Benson are included.

Vital statistics of the introduced species Triatoma infestans (Klug, 1834) (Hemiptera: Reduviidae) in western Mexico under laboratory conditions

Triatoma infestans, one of the most important vectors of Trypanosoma cruzi to humans, has recently been discovered introduced in Mexico. Some of the most important biological parameters to estimate the vectorial capacity of a triatomine, such as the hatching of eggs, life cycle, feeding and defecation behaviors for each instar of a population of T. infestans introduced into Mexico are reported. The egg-to-adult development times of the three studied cohorts had a mean of 215.7 days. The mean total number of blood meals required to molt from first-instar nymphs to adults was 11.7. The cumulative mortality was 30.8%. The highest mortality rate was recorded for third-instar nymphs (10.3%), whereas the lowest rate (0.8%) was recorded for first-instar nymphs. All studied specimens began feeding as soon as a blood meal source was offered, showing "aggressive" behavior. Feeding times were ˃ 10 min for all instars, increasing according to instar, in a similar pattern to the development times and the required blood meals before molting. Most (57.7 -82.5%) of the studied specimens of the first- to third-instar nymphs and adults of T. infestans defecated when feeding (WF). The average number of eggs laid per female per day was 0.9, with an eclosion rate of 96.4%. The results of most of the studied parameters confirm the importance of T. infestans wherever it is found because of its potential high capacity for transmitting T. cruzi to hosts. Active entomological surveillance should be carried out in the area of the first discovery of the introduced T. infestans and its surroundings to avoid the dissemination of this effective vector species in Mexico.

Description of a new ant- and stingless-bee-loving species of Cryptostigma Ferris (Hemiptera: Coccomorpha: Coccidae) from Ecuador living inside internodes of Cecropia (Urticaceae), with an updated key to the adult females and first-instar nymphs of the genus

A new soft scale species, Cryptostigma cecropiaphilum Kondo & Roubik, sp. nov. (Hemiptera: Coccomorpha: Coccidae), is described from specimens collected from inside hollow branches (internodes) of Cecropia ficifolia Warb. ex Snethl and Cecropia sciadophylla Mart. (Urticaceae), in Orellana province, Ecuador. The new species was found in association with three mutualistic hymenopterans: two species of Plebeia Schwarz, subgenus Nanoplebeia Engel (Hymenoptera: Apidae: Meliponini), and Azteca sp. (Hymenoptera: Formicidae: Dolichoderinae). The new species of coccid is described based on the morphology of the adult female and first-instar nymph. Keys to the known adult females and first-instar nymphs of Cryptostigma Ferris are provided.

The role of neuropeptides in regulating ecdysis and reproduction in the hemimetabolous insect Rhodnius prolixus.

In ecdysozoan animals, moulting entails the production of a new exoskeleton and shedding of the old one during ecdysis. It is induced by a pulse of ecdysone that regulates the expression of different hormonal receptors and activates a peptide-mediated signalling cascade. In Holometabola, the peptidergic cascade regulating ecdysis has been well described. However, very little functional information regarding the neuroendocrine regulation of ecdysis is available for Hemimetabola, which display an incomplete metamorphosis. We use Rhodnius prolixus as a convenient experimental model to test two hypotheses: (1) the role of neuropeptides that regulate ecdysis in Holometabola is conserved in hemimetabolous insects; and (2) the neuropeptides regulating ecdysis play a role in the regulation of female reproduction during the adult stage. The RNA interference-mediated reduction of ecdysis triggering hormone (ETH) mRNA levels in fourth-instar nymphs resulted in lethality at the expected time of ecdysis. Unlike in holometabolous insects, knockdown of eth and orcokinin isoform A (oka) did not affect oviposition in adult females, pointing to a different endocrine regulation of ovary maturation. However, eth knockdown prevented egg hatching. The blockage of egg hatching appears to be a consequence of embryonic ecdysis failure. Most of the first-instar nymphs hatched from the eggs laid by females injected with dsRNA for eclosion hormone (dsEH), crustacean cardioactive peptide (dsCCAP) and dsOKA died at the expected time of ecdysis, indicating the crucial involvement of these genes in post-embryonic development. No phenotypes were observed upon corazonin (cz) knockdown in nymphs or adult females. The results are relevant for evolutionary entomology and could reveal targets for neuropeptide-based pest control tools.