Pentatomidae Research Articles

Fruit Phenology of Two Hazelnut Cultivars and Incidence of Damage by Halyomorpha halys in Treated and Untreated Hazel Groves

Over the past decade, Halyomorpha halys has become one of the main threats to hazelnut production. Its trophic activity makes kernels inedible due to strongly detrimental effects on the organoleptic quality. Its management in Italy is still tricky due to the lack of effective native biocontrol agents and authorized and effective insecticides. A field test was performed on San Giovanni (SG) and Tonda Romana (TR) cultivars (early and late ripening, respectively) to assess the intensity of cimiciato damage with different pest management approaches (no insecticide and integrated pest management, IPM). Moreover, phenological analysis of fruits and the monitoring of stink bug species by traps and plant beating were carried out. In the untreated plots, the SG cv showed a higher cimiciato incidence with respect to the late TR cv (40% SG–NI vs. 23% TR–NI). This was probably due to the different phenological phases in which stink bugs injured the fruits. In fact, stink bug bites provoke different kinds of injuries (blanks, shriveled, and cimiciato) according to the fruit’s development period. Indeed, in the period of highest insect occurrence in the field, the fruits of the early cv (SG) were in kernel expansion, a phenological phase in which bug injuries are more likely in cimiciato defects. Lastly, the IPM did not provide sufficient fruit protection (19% SG–IPM vs. 11% TR–IPM). The interaction between the phenological development of hazelnuts and the brown marmorated stink bug represents a critical aspect in understanding and implementing effective strategies for controlling this key pest on hazelnut trees.

Ecological zoning of Euschistus heros in Brazil based on the net reproductive rate at different temperatures and relative-humidity levels.

The Neotropical brown stink bug, Euschistus heros (Fabricius, 1798) (Hemiptera: Pentatomidae), is one of the major insect pests in soybean crops, causing severe damage; however, some aspects of its biology that are essential for management remain unknown. To aid in the management of E. heros, the present study investigated the fertility life table of this species at 7 temperatures (18, 20, 22, 25, 28, 30, and 32 ± 1 °C) and 4 relative-humidity levels (30, 50, 70, and 90 ± 10%). Based on the net reproductive rate, R0, we developed an ecological zoning for this pest in Brazil, to identify climatically favorable areas for population growth. Our results indicated that the most favorable range is between 25 and 28 °C and above 70% RH. The ecological zoning indicated that farmers should be more concerned in the northern and Midwest regions, which include the state of Mato Grosso, the largest soybean and corn producer in Brazil. These results provide valuable information, indicating the hotspots most likely to be attacked by the Neotropical brown stink bug.

Effect of Insect Growth Regulator Insecticides Novaluron, Teflubenzuron and Lufenuron on the Morphology and Physiology of Euschistus heros

The Neotropical brown stink bug, Euschistus heros (F.) (Heteroptera: Pentatomidae), is an important pest that damages soybean, especially in the central-west region of Brazil. The effect of insect growth regulator insecticides on fourth-instar nymphs and adults of the neotropical brown stink bug was evaluated under laboratory and greenhouse conditions, respectively. In the laboratory, the insecticides (doses in g a.i. ha-1) novaluron (20.0 and 40.0), teflubenzuron (26.2 and 52.5), and lufenuron (20.0 and 40.0), in addition to the control (water), were tested on fourth-instar nymphs of E. heros and their development were followed to adulthood. Mortality, number of adults with and without deformities, and fecundity were determined. In a greenhouse, the effects of the same insecticides on the adult of the stink bug were evaluated by determining the fecundity and viability of the eggs laid. The fourth-instar nymphs of E. heros, when exposed to either dose of the tested insecticides presented mortality and insects with deformations, as well as reduced fecundity of females that reached adulthood. In the trial with adult E. heros, all tested insecticides reduced stink bug fecundity. In the same way, the viability of the produced eggs was reduced in all the chemical treatments, except for novaluron at the lowest dose tested, in which egg viability did not differ from the control treatment. Based on the obtained results, one can infer that the growth-regulator insecticides evaluated, although usually more suitable for the control of caterpillars, can interfere negatively in the development and reproduction of the neotropical brown stink bug, thus constituting a complementary alternative for the management of this pest.

Analyzing On-Farm Spatiotemporal Distribution of Halyomorpha halys (Stål) (Hemiptera: Pentatomidae) Populations from a Precision Agriculture Perspective.

The brown marmorated stink bug, Halyomorpha halys Stål (Hemiptera: Pentatomidae), is native to Japan, China, Taiwan, and Korea. Its dispersion from Asia to the United States of America and Europe caused serious damage to fruit, vegetables, and high-value crops. In Greece, damages are reported in kiwi orchards in the regions of Pieria and Imathia, which are the main production areas of kiwifruit. Greek kiwifruit production is expected to increase twofold within the next years. The aim of this research is to study the terrain and canopy properties that may have an impact on the development of H. halys populations. Thus, five kiwi orchards in total were selected in the regions of Pieria and Imathia. Τen traps were installed from early June to late October within each selected kiwi orchard-two types of traps at every side of the orchards and the center. The installed traps were examined weekly and the number of the captured H. halys was recorded. During the same days, sentinel satellite images were analyzed to calculate the vegetation index, NDVI (Normalised Difference Vegetation Index), and NDWI (Normalised Difference Water Index). The results showed population variability within the kiwi orchards since the population of H. halys was higher in areas with high NDVI and NDWI values. Additionally, our research revealed that H. halys prefers to develop populations at higher altitudes at both regional and field scales. The results of this research can be used to reduce damages by H. halys in kiwi orchards using different rates of pesticides depending on the prediction of the population size. There are multiple benefits of the proposed practice, such as a reduction in the production cost of kiwifruits, an increase in farmers' profit, and environmental protection.

Releasing and tracking the distribution of adventive Trissolcus japonicus (Hymenoptera: Scelionidae) in Virginia.

Adventive populations of Trissolcus japonicus (Ashmead), an egg parasitoid of the invasive agricultural pest, brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), have been detected in the United States since 2014. Given its importance as an H. halys biocontrol agent, efforts to redistribute T. japonicus began within some US states. Our surveillance for T. japonicus in northwestern Virginia in 2016-2017 yielded annual detections only in 1 county. Thus, to promote its broader establishment, releases of H. halys egg masses parasitized by T. japonicus from Virginia occurred in 2018 (2 releases) and 2020 (1 release) at 9 sites throughout Virginia's tree fruit production regions. Monitoring of T. japonicus and H. halys, using yellow sticky cards deployed in H. halys host trees and pheromone-baited sticky traps, respectively, was conducted from 2018 to 2022. Annual captures of H. halys adults and nymphs appeared to reflect adequate populations to support T. japonicus establishment across most or all sites. Prerelease monitoring yielded a single T. japonicus at 1 site. By 2022, T. japonicus was detected at or near 7 of the remaining 8 release sites, with first detections varying between 1 and 2 yr from the releases in 2018 and 2020. Captures at most sites were very low, but establishment at several locations was indicated by detections in 2-4 seasons. In 2022, T. japonicus surveillance at 11 additional sites in northwestern Virginia yielded detections at all locations, including those at which it had not been detected in 2016-2017, providing evidence for its range expansion.

The Use of Ngapi Nut Peel (Pithecellobium jiringa Prain) Extract as a Natural Pesticide to Control Stink Bugs (Leptocorisa oratorius)

Ngapi nut peel is an organic waste that is often found at traditional markets which has not been fully utilized and can pollute the environment. The utilization of ngapi nut peel extract to control stink bugs was carried out. The purpose of this study was to obtain LC50 values and compounds that can eradicate stink bugs. Ngapi nut peel was extracted with methanol using the maceration method, the extract were analyzed by using GC-MS, phytochemical test was used to determine secondary metabolite and total phenolic by using the Follin-Ciocalteau method. The spray method was used to determined LC50 on stink bugs. The results showed that methanol extract positively contained flavonoid, phenolic, saponin and terpenoid. Total phenolic value was 0.65 mg GAE/g DW. GC-MS showed compounds that have the potential as natural pesticides such as 2,4-Dimethyl-6-phenyl-1,3,5-triazine; 3-(4-Methoxypheny l,2-propenoic acid; Undecanoic acid; Phthalic acid. LC50 test for 12 and 24 hours were found on concentrations 24.4174 g/L and 17.3101 g/L. The methanol extract of ngapi nut peel on concentrations of 35 g/L showed the highest percentage 87% of stink bugs mortality at 24 hours. It can be concluded that extract can control the stink bugs.

イネカメムシ（カメムシ目：カメムシ科）の水田での発生消長と卵巣の発育状況

We investigated the seasonal occurrence of the rice stink bug, Niphe elongata (Hemiptera: Pentatomidae), in paddy fields and the ovarian development of females collected from fields in Shiga Prefecture, Japan. Early in August, when the rice ears of medium-maturing varieties emerged, adult bugs migrated to the paddy field, and the females laid eggs. The eggs hatched, and nymphs grew into adults. When late-maturing rice varieties started heading in late August, the adults entered the paddy field, and the females laid eggs. The eggs hatched, and the nymphs became adults. Therefore, in Shiga Prefecture, the life cycle of the rice stink bug produces two generations in 1 year. In September, no females had mature eggs in their ovaries, and adult bugs were believed to overwinter.

Wildflower plantings have mixed effects on insect herbivores and their natural enemies

Flower strips are advocated as a strategy to promote beneficial insects as well as the services they deliver to adjacent crops. Flower strips have, however, often been developed separately for pollinators and natural enemies and, additionally, little consideration has been given to effects on insect herbivores. We sampled insect herbivores, their natural enemies and parasitism of pest eggs using vacuum sampling, sticky cards and egg cards in nine pairs of bee-attractive wildflower plantings and control field borders, as well as in adjacent tomato and watermelon crop fields in Yolo County, California 2015–2016. Control field borders had a higher total number of herbivores on sticky traps than did wildflower plantings, a pattern that was driven by more aphids, hoppers, psyllids and whiteflies, whereas wildflower plantings had more lace bugs and Lygus bugs. The total number of herbivores in the adjacent crop fields did not differ between treatments, but there were more leaf beetles near (at 10 m but not 50 m from) wildflower plantings. Control field borders had a higher total number of predators, driven by more big-eyed bugs, lady beetles and minute pirate bugs, whereas spiders were more common in wildflower plantings. The total number of predators in adjacent crop fields was, however, higher in those next to wildflower plantings, which was driven by more minute pirate bugs. Parasitoid wasps were more common in wildflower plantings and at 10 m but not 50 m into adjacent crop fields. Stink bug egg parasitism rate did not differ between treatments, either in the borders or in the crop fields. In conclusion, wildflower plantings clearly affect the insect herbivore and natural enemy community, but do so in a highly taxon-specific manner, which can lead to both positive and negative outcomes for pest control as a result.

Utilization of Papaya Seeds as an Ingredient for Making Environmentally Friendly Insecticides Against Sangit Weed

Papaya (Carica Papaya) is a plant that is often found in tropical areas, one of which is in Indonesia. Inside the papaya seeds there is a karpain content, the karpain content is able to eradicate the stink bug pest that usually attacks papaya plants. This study used an experimental method in which this method tested the karpain content in papaya seeds. Making a bioinsecticide formula with a ratio of 25 ml and 75 ml; 50 ml and 50 ml and 75 ml and 25 ml. based on research and analysis of field data from the trial results showed that papaya seed extract (Carica papaya) at doses of 25%, 50%, 75%, and 100% had an effect on the death of walang sangit so that the higher the carpain content in papaya seeds, the more effective at eradicating insecticides.

Entomophages of the Colorado Potato Beetle, Population Dynamics of Perillus bioculatus Fabr. and Its Compatibility with Biological and Chemical Insecticides

Modern plant biosecurity strategies include the use of a wide range of living organisms regulating the number, development and spread of harmful organisms at an economically safe level. We aimed to study the species composition of entomophages of the Leptinotarsa decemlineata Say and their efficiency in pest control. We observed the population dynamics of the stink bug Perillus bioculatus Fabr. and the Colorado potato beetle from 2013 to 2015. Besides, the species composition of entomophages of the Colorado potato beetle in Krasnodar Krai (a region in southwestern Russia) was researched in 2013–2015. The study showed that with a ratio of P. bioculatus: Colorado beetle 1:10–1:15, the efficiency of the entomophage is about 98%. In addition to P. bioculatus, there are other insects that feed on the Colorado potato beetle. Among them, it is worth noting Zicrona caerulea L., Polistes gallicus L., representatives of the Coccinellidae family, etc. The food base and parasitic activity of scelionid ovi-eaters and phasia flies are the main biotic factors influencing the number of predatory bugs. The possibility of combined use of P. bioculatus and preparations of biological origin was studied. The survival rate of adult P. bioculatus under the use of insecticides based on Bacillus thuringiensis var. thuringiensis and Streptomyces avermitilis (ex., Burg et al.) Kim and Goodfellow was 97% and 91%; that of older nymphs—58% and 52%, respectively. Chemical preparations destroyed all age stages of the predator.

First Description of the Nuclear and Mitochondrial Genomes and Associated Host Preference of Trichopoda pennipes, a Parasitoid of Nezara viridula.

Trichopoda pennipes is a tachinid parasitoid of several significant heteropteran agricultural pests, including the southern green stink bug, Nezara viridula, and leaf-footed bug, Leptoglossus phyllopus. To be used successfully as a biological control agent, the fly must selectively parasitize the target host species. Differences in the host preference of T. pennipes were assessed by assembling the nuclear and mitochondrial genomes of 38 flies reared from field-collected N. viridula and L. phyllopus. High-quality de novo draft genomes of T. pennipes were assembled using long-read sequencing. The assembly totaled 672 MB distributed among 561 contigs, having an N50 of 11.9 MB and a GC of 31.7%, with the longest contig at 28 MB. The genome was assessed for completeness using BUSCO in the Insecta dataset, resulting in a score of 99.4%, and 97.4% of the genes were single copy-loci. The mitochondrial genomes of the 38 T. pennipes flies were sequenced and compared to identify possible host-determined sibling species. The assembled circular genomes ranged from 15,345 bp to 16,390 bp and encode 22 tRNAs, two rRNAs, and 13 protein-coding genes (PCGs). There were no differences in the architecture of these genomes. Phylogenetic analyses using sequence information from 13 PCGs and the two rRNAs individually or as a combined dataset resolved the parasitoids into two distinct lineages: T. pennipes that parasitized both N. viridula and L. phyllopus, and others that parasitized only L. phyllopus.

First report of Colletotrichum fioriniae infections in brown marmorated stink bugs, Halyomorpha halys

An epizootic caused by fungal pathogens occurred among Halyomorpha halys, brown marmorated stink bugs, while they were overwintering, with infections also occurring after overwintering. We report that one of the two pathogens responsible was Colletotrichum fioriniae (Marcelino & Gouli) Pennycook; a species well known as a plant pathogen and endophyte and which has only previously been reported naturally infecting elongate hemlock scales, Fiorinia externa. To prove pathogenicity, H. halys adults challenged with conidia died from infections and the fungus subsequently produced conidia externally on cadavers.

First record of Telenomus turesis (Walker), native egg parasitoid of invasive brown mamorated stink bug [Halyomorpha halys Stal (Hemiptera: Pentatomidae)] in Turkey

Halyomorpha halys (Hemiptera: Pentatomidae) Doğu Asya (Çin, Japonya, Kore ve Tayvan) kökenli bir türdür ve doğal yaşam alanlarında önemli bir polifag zararlı olup, yayılış gösterdiği alanları kısa zaman içerisinde yüksek bir popülasyon meydana getirerek istila etmekte ve tarımsal üretim için önemli bir tehdit oluşturmaktadır. Türkiye’de özellikle Karadeniz sahil şeridi boyunca yayılış gösterdiği alanlar içerisinde başta fındık olmak üzere pek çok üründe önemli kalite ve verim kaybına sebep olabilir. Bu çalışma, Sakarya’da farklı habitatlarda H. halys'in yerli yumurta parazitoitlerini ve bu türlerin etkinliklerini belirlemeyi amaçlamaktadır. Bu amaçla, arazi şartlarında elde edilen bir günlük yaştaki 20 yumurta paketi (600 yumurta) 9 farklı lokasyonda farklı bitkilere asılmış ve 4 gün sonra toplanarak laboratuvara getirilmiştir. Toplanan yumurtaların genel parazitlenme oranı %7,5 olmasına rağmen, bu yumurtalardan başarılı bir şekilde yalnızca üç parazitoit çıkışı meydana gelmiştir. Morfolojik olarak teşhisleri yapılan bu parazitoitler, sitokrom c oksidaz alt birim I genine (CO1) dayalı moleküler teşhis ile doğrulanarak, Telenomus turesis (Walker) olduğu belirlenmiştir. H. halys’in yerli yumurta parazitoit türü, bu çalışma ile Türkiye’de ilk kez rapor edilmektedir. Bu kapsamda istilacı türün ülkemizde yayılış gösterdiği alanlarda doğal düşman faunasının araştırılması, mücadele için önemli aşamalardan birisi olup daha fazla araştırmaya ihtiyaç duyulmaktadır. Ek olarak, uzun vadeli sürdürülebilir yaklaşım olan klasik biyolojik mücadele kapsamında, ithalatı gerçekleştirilen Trissolcus japonicus (Ashmead)’un hızlı ve kontrollü bir şekilde kitlesel üretimine geçilmesi ve salımı yüksek derece önem arz etmektedir.

Nymph development and adult feeding on, and damage to, immature siliquae of canola by different species of stink bugs.

Studies were conducted in the laboratory and in the greenhouse with the objective of evaluating nymph development, adult body weight gain, and damage of different species of pentatomids feeding on fruit (hereafter referred to as siliqua) of canola, Brassica napus (L.) var. oleifera. Nymphs of Nezara viridula (L.) were able to reach adulthood feeding on siliquae (93.3% survivorship), while nymphs feeding on siliquae that had their seeds removed showed arrested development, only reaching the 4th instar and did not complete development to adulthood. Adults of N. viridula gained body weight feeding on canola siliquae, particularly during the first two weeks of adult life, dropping weight thereafter. Adults of another species of pentatomid, Diceraeus furcatus (F.), also gained body weight, while adults of Euschistus heros (F.) lost weight. N. viridula adults caused significantly greater damage to seeds (shrunken and with rotten aspect) within siliqua and to the siliqua walls (whitish spots with lesions in the form of starbursts, called rosettes) compared to D. furcatus and to E. heros. The amount of damaged seeds caused by N. viridula adults during the first week of adult life was greater (ca. 60%) compared to those of older females 32days of age (27%). Damage symptons caused by the feeding activity on siliqua walls (commonly known as rosettes) reached up to 10% of the total area with similar injury rates for N. viridula adults of different ages. The majority of N. viridula (70%) caused rosette, while only 20% of E. heros and 5% of D. furcatus produced similar damage.

First record of the predatory stink bug species Picromerusgriseus (Dallas) (Hemiptera, Heteroptera, Pentatomidae, Asopinae) in Japan, with an illustrated key to the Japanese species of the genus Picromerus Amyot & Serville.

The predatory stink bug genus Picromerus Amyot & Serville, 1843 (Hemiptera, Heteroptera, Pentatomidae, Asopinae) comprises 11 species found in the Northern Hemisphere. In Japan, two species have been recorded to date. However, an easy-to-understand identification method, such as an illustrated key, is lacking. Currently, Picromerusgriseus (Dallas, 1851) has been recorded in Bangladesh, Bhutan, China, Indonesia, Myanmar, Pakistan and Taiwan, but not in Japan. Picromerusgriseus was recorded in Japan for the first time, based on a single individual collected from grasslands around the fields of Ishigaki Island of the Ryukyu Islands, which belong to the Oriental Region. This discovery represents the easternmost record of the species. An illustrated key to the species of Picromerus occurring in Japan is also provided.

Diversity of stink bugs (Hemiptera: Heteroptera: Pentatomoidea) in the Brazilian Pampa and theParque Estadual de Itapuã, Rio Grande do Sul.

Biological surveys represent important contributions to the knowledge of species diversity, conservation, taxonomy, and biogeography. Few surveys of stink bugs and allied groups (Pentatomoidea) were produced in Brazil, especially regarding the Brazilian Pampa, an overlooked biome. Here, a list of Pentatomoidea species of the Brazilian Pampa is presented for the first time, composed of seven families and 152 species. The results of five years of sampling in the Parque Estadual de Itapuã (PEI) are also presented. A total of 693 individuals were sampled, representing 41 species, 29 genera, and five families of Pentatomoidea. Pentatomidae presented a higher richness (28 species), followed by Cydnidae, Scutelleridae, Dinidoridae, and Megarididae. The most abundant species collected in the PEI was Brachystetus geniculatus (Fabricius) sampled in Bromelia balansae Mez (32.76%), followed by Oebalus poecilus (Dallas) found in Persicaria hydropiper (Linnaeus) (11.99%), Pallantia macula (Dallas) collected in B. balansae (10.92%), Dinidor saucius Stål (8.57%) in Smilax cf. campestris Griseb., and Caonabo pseudoscylax (Bergroth) (5.35%) found in Homolepis glutinosa (Sw.) Zuloaga & Soderstrom. This is the first time that a list of species is presented for the Brazilian Pampa and Parque Estadual de Itapuã, providing a baseline to develop further studies with Pentatomoidea in the biome.

Within-field spatial patterns of Euschistus servus and Nezara viridula (Hemiptera: Pentatomidae) in field corn.

A complex of stink bugs, primarily the brown stink bug, Euschistus servus (Say) (Hemiptera: Pentatomidae) , and the southern green stink bug, Nezara viridula (L.) (Hemiptera: Pentatomidae) , are the most damaging insect pests of field corn, Zea mays L., in the southeastern United States. Characterizing the spatial patterns of these highly mobile, polyphagous pests is critical for developing efficient and effective sampling plans. In 2021 and 2022, stink bugs and their injury were assessed biweekly from emergence through R2 in 20 corn fields. The spatial analysis by distance indices (SADIE) showed that aggregation patterns were identified primarily in adult populations of both E. servus and N. viridula, and in nymphal populations of both species to a lesser extent. Aggregation patterns were also identified in early vegetative injury, but not in ear injury assessed at R2. The spatial association of stink bugs and their injury varied with corn phenological stage. A lack of spatial association between stink bug populations early in the season and vegetative injury suggests a need for intensive sampling, particularly in fields with increased residue from cover crops. Results of this study illustrate the variability in spatial patterns of stink bugs in corn, which can help to improve sampling plans for decision-making in IPM programs.

Effects of Irradiation on Biology and Mating Behaviour of Wild Males of Brown Marmorated Stink Bug Using a 6 MV Medical Linear Accelerator

The brown marmorated stink bug, Halyomorpha halys, is a pentatomid bug of Eastern Asian origin that became an economically relevant pest in the Eurasian and American continents. Management of this species is limited to use of chemical insecticides: an inefficient method due to the strong adaptability of the target pest. The sterile insect technique (SIT) is potentially a valid tactic in the search for nontoxic alternatives. In this work, we investigated the suitability of mass-trapped overwintering males, collected during the aggregation phase before the winter diapause, for their release as competitive sterile males in an SIT programme. Differently from previous studies, irradiation was applied with a linear accelerator device that produced high-energy photons. Following a similar scientific protocol with newly emerged irradiated males, the effects of X-ray irradiation on physiological parameters (longevity, fecundity and fertility) were assessed. In addition, behavioural bioassays were carried out in no-choice conditions to evaluate if irradiation interferes with mating processes. The results are very encouraging; the effects of the irradiation at 32 Gy did not differ from the controls in the longevity or fecundity of the exposed overwintering adults. The hatching rate of the eggs laid by the fertile females that had mated with the irradiated males was less than 5%. The results of behavioural bioassays showed that the irradiation did not cause a significant impact on the quality of the sterile males. More research is warranted to evaluate the mating competitiveness of sterile males in semi-field and field conditions.

Confirmatory evaluation of eFUME for control of brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae).

The governments of Australia and New Zealand require a phytosanitary treatment to control adult brown marmorated stink bug, Halyomorpha halys (Stål) (Hemiptera: Pentatomidae), as overwintering aggregations have been intercepted in the importation pathway of various nonhorticultural consignments, including vehicles. The commercialized fumigant, eFUME, a 16.7% by mass dilution of ethyl formate in carbon dioxide, resulted in complete control of ca. 1,000 field-collected, naturally diapausing adult H. halys in each of 3 independent trials at 10 ± 0.5 °C (x¯±2s) when ethyl formate levels in enclosure headspace were maintained steady-state at ca. 14.5 mg/liter for 4 h to yield Ct exposures ranging from 57.9 to 63.1 mg/liter h. Consistent with previous findings where greenhouse reared H. halys were controlled using laboratory formulations of this ethyl formate-carbon dioxide mixture, these confirmatory methods and results further inform technical and operational features of commercial practice.

Trade-Offs between Temperature and Fitness in Euschistus heros (Fabricius) (Hemiptera: Pentatomidae): Implications for Mass Rearing and Field Management

The brown stink bug, Euschistus heros (Fabricius, 1798) (Hemiptera: Pentatomidae), is one of the most abundant soybean stink bug pests in Brazil. Temperature is a key factor that affects its development and reproduction, and fluctuating temperatures may impact the development and reproduction of E. heros differently from those under constant temperatures. The objective of this study was to evaluate the influence of constant and fluctuating temperature on the biological characteristics of E. heros in three successive generations. Treatments consisted of six constant temperatures (19 °C, 22 °C, 25 °C, 28 °C, 31 °C and 34 °C) and four fluctuating temperatures (25:21 °C, 28:24 °C, 31:27 °C, and 34:30 °C) evaluated for three successive generations. Second-stage nymphs were evaluated daily, and after they reached the adult stage, they were separated by sex, and the individual weight (mg) and pronotum size (mm) were recorded. After pair formation, eggs were collected to evaluate the pre-oviposition period, total number of eggs, and egg viability. The duration of the nymphal stage was reduced with an increase in both constant and fluctuating temperatures; however, at constant temperatures of 19 °C, 31 °C and 34 °C and fluctuating temperatures of 28:24 °C, there was no reproduction in adults. The base temperature and total degree day requirement for nymphal development were 15.5 °C and 197.4 dd, respectively. Pre-oviposition period (d), number of eggs per female, and viability of eggs (%) were affected by temperature across the generations. The multiple decrement life table analysis revealed that mortality was highest during the molting of the second-stage nymphs. These findings have important implications for E. heros' laboratory mass-rearing programs and for its management in fields.