Developmental response of the beneficial predator Podisus maculiventris to change in dietary ascorbic acid concentration

We report here the effects of a range of ascorbic acid concentrations (0.07, 0.3, 3.0, and 30.0 g l^?1) in artificial diets on growth rates, adult weights, fecundity, and survival over two generations of the predatory stink bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae). Overall, a dietary level of 3.0 g l^?1 gave the shortest developmental times over two generations. The likelihood of egg hatch at one ascorbic acid concentration compared to another concentration suggested that egg hatch increased as the concentration of ascorbic acid increased from 0.07 to 3.0 g l^?1 and then declined from 3.0 to 30.0 g l^?1. The combination of the maximum egg oviposition at 0.3 and 3.0 g l^?1, egg hatch at 3.0 g l^?1, and survival at 0.07 and 0.3 g l^?1 suggests an overall superior performance at a concentration between 0.3 and 3.0 g l^?1. Depletion of ascorbic acid below 3.0 g l^?1 or addition of ascorbic acid above 3.0 g l^?1 lowered the likelihood of egg hatch, which became more pronounced in the second generation. This is consistent with previously published information for phytophagous insects.     

Effects of sequential mating by males on reproductive output of the stinkbug predator, Podisus nigrispinus

Reproductive output of the stinkbug predator Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) was investigated as a function of the number of matings that the male had made with a range of females. After being placed with a female, virgin males were most likely to mate within 12 hours, while non-virgin males were most likely to mate within 12–24 hours. Although males lost weight during their first mating, the weights of mated and unmated males were not significantly different throughout their lifetime. Longevity was significantly greater for unmated males (36.0 days) than for mated males (29.8 days). Survival curves for both mated and unmated males were Type II. The capacity of males to transfer sperm to virgin females was not affected by previous matings. From 65.7 to 76.4% of eggs were viable and 206.7 to 274.6 nymphs were produced per female. Regardless of the number of matings that the male had made, females that had mated only once exhausted their stored sperm progressively and produced an increasing proportion of infertile eggs, which peaked at the end of their lives. These results show that P. nigrispinus females need more than one mating to maintain fertility, but their performance is not affected by the number of previous matings that the male has made or by male weight. Thus, the strategy of pairing with males multiple times improved production efficiency by increasing output and reducing food waste in mass production systems. This is achieved by temporarily pairing females at intervals of about 20 days during their entire lifetime.     

Dissemination of the biocontrol agent Vairimorpha necatrix by the spined soldier bug, Podisus maculiventris

The ability of the spined soldier bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae), to disseminate infective forms of two lepidopteran pathogens, Vairimorpha necatrix (Kramer) (Microspora: Microsporidia) and Lacanobia oleracea granulovirus (LoGV) was investigated. Individual female P. maculiventris that had fed on Lacanobia oleracea L. (Lepidoptera: Noctuidae) larvae, infected with V. necatrix, excreted approximately 6 × 10⁸V. necatrix spores during the subsequent 7 days. Excreted spores were fed to L. oleracea larvae, causing 100% mortality, indicating that the spores remained viable after passing through the gut of the predator. Podisus maculiventris that had fed on V. necatrix or LoGV‐infected larvae were allowed to defecate on the foliage of tomato plants, prior to the infestation of the plants with L. oleracea or Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) larvae. This proved to be an effective way of infecting the pest larvae with the pathogens, particularly when five predatory bugs were used per plant. After 20 days, the number of S. littoralis and L. oleracea surviving on the plants was reduced by 75% and 61%, respectively. Female P. maculiventris maintained on V. necatrix‐infected prey showed reduced egg production and longevity, whilst those fed on LoGV‐infected prey showed only reduced egg production. The potential for P. maculiventris to disseminate insect pathogens is discussed in the context of improved biological control of lepidopteran pests.     

Searching behavior and time budgets of the predator Podisus maculiventris

Searching behavior of the predaceous insect Podisus maculiventris (Say) (Heteroptera: Pentatomidae) was investigated in the laboratory to verify assumptions made in a predator search model. Female predators were placed into an arena containing 30 lima bean plants (Phaseolus lunatus L.), each having five numbered leaflets. Prey were third-instar larvae of Mexican bean beetle (Epilachna varivestis Mulsant) at two densities. Predators were observed for 4 h periods as they searched the plant canopy. Results showed that predators searched a greater area and for longer at low prey density than at high prey density. Predators apparently searched plants without using cues, did not search areas of the canopy repeatedly after attacks, and spent approximately 1 h handling prey. Predators spent more time resting than searching, and attack rates were negatively correlated with rest time, but were not correlated with search time. Long resting periods by predators may be a result of energy conservation. The implications for using predators such as P. maculiventris against pests in crops are (i) the predators' searching behavior limits the number of prey attacked, and (ii) the predator may be able to persist at low prey densities better than species with different searching behaviors.     

Genetic variation in field and laboratory populations of the spined soldier bug,Podisus maculiventris

The predatory spined soldier bug, Podisus maculiventris (Say) (Heteroptera: Pentatomidae), is an economically important and highly valued biological control agent. There is substantial information on the biology, ecology, behavior, and rearing of this stink bug. However, virtually nothing is known of its genetic variation, in natural or domesticated populations. To address this lacuna, we used amplified fragment length polymorphism (AFLP) to assess the genetic variability of field and laboratory populations. Four AFLP universal primer combinations yielded a total of 209 usable loci. The AFLP results showed greater genetic variability between populations from Missouri and Mississippi (both USA), and relatively low variability within Missouri populations. We infer little genetic isolation among Missouri field populations and within laboratory populations, but a significant genetic isolation between Missouri and Mississippi populations.     

Maternal age and egg weight affect offspring performance in the predatory stink bug Podisus nigrispinus

To investigate influences of maternal age and egg weight on developmental time and body weight of offspring in the Neotropical pentatomid Podisus nigrispinus, a study was carried out using large (0.36 mg) and small (0.32 mg) eggs of young (two-week- old) females and large eggs of old (seven-week-old) females. Incubation period of eggs was influenced only by egg weight, i.e. small eggs took a relatively shorter time to hatch. Both maternal age and egg weight had significant effects on total nymphal and egg-to- adult developmental times. Overall, offspring of young parents had shorter developmental times. None of the developmental periods were significantly affected by sex. No significant differences were found among various offspring groups for percentages of egg hatch, nymphal survival, and sex ratio. Variation of egg weight in relation to the number of eggs per day observed within the first month of life suggests a trade-off between weight of individual eggs and oviposition rate. It is concluded that for mass production of the predators in view of their use in augmentative biocontrol programmes, young parents (2–4 weeks old) should be preferred.     

Temperature influence on the reproduction of Podisus nigrispinus, a predator of the noctuid larva Alabama argillacea

The influence of temperature on thereproduction and longevity of Podisusnigrispinus (Dallas) (Heteroptera:Pentatomidae) fed with Alabamaargillacea (Hübner) (Lepidoptera:Noctuidae) larvae was studied. This predatorwas reared at constant temperatures of 20, 23,25, 28, 30 and 33 ± 0.2 °C, all atrelative humidity of 60 ± 10%, and aphotoperiod of L:D 14:10. Fecundity of P.nigrispinus at the various temperatures rangedfrom 401.2 (33 °C) to 841.3 (28 °C) eggs/female. The preoviposition,oviposition peak, and declining ovipositionperiods of P. nigrispinus were affectedby temperature [preoviposition period: 4.0 (33 °C) to 13.2 (20 °C) days;duration of oviposition peak period: 9.0 (33 °C) to 33.0 (20 °C) days; andduration of declining oviposition period: 16.0(33 °C) to 46.0 (20 °C) days].Longevity of females and males of P.nigrispinus ranged from 28.4 (33 °C) to88.6 (20 °C) days, and from 42.7 (33 °C); to 114.3 (20 °C) days,respectively. These data are useful in relationto the development of population dynamicsmodels to underpin programmes of biologicalcontrol.     

Evidence for intraguild predation by Podisus maculiventris on a ladybeetle, Coleomegilla maculata: Implications for biological control of Colorado potato beetle, Leptinotarsa decemlineata

The potential for intraguild predation (IGP) between larval and adult life stages of twopolyphagous arthropod predators common in NorthAmerican agroecosystems was studied in thelaboratory. Predators examined were the spinedsoldier bug, Podisus maculiventris Say,and the twelve-spotted ladybeetle, Coleomegilla maculata Lengi. A shared preyitem, eggs of the Colorado potato beetle (CPB),Leptinotarsa decemlineata Say, was alsoprovided to the predators, both to provide analternate food source and to quantify theimpact of IGP on the potential for pestsuppression by these two predators. Experimentswere conducted on single potato leaves inplastic cup arenas, and, subsequently, in cagesenclosing whole potato plants. IGP occurredasymmetrically, with P. maculiventrisadults and nymphs only attacking C. maculata larvae. Even though ladybeetle adultswere generally smaller than soldier bug adults,they were never preyed upon. This appears to bethe first documented case of a coccinellidshowing differential larval and adult immunityto attack by a larger invertebrate predator.The impact of IGP, when it did occur, on CPBegg consumption was equivocal. IGP did notconsistently influence levels of predation onthe eggs. Conversely, even when IGP did notoccur, predation on CPB eggs by both predatorstogether did not increase significantly overlevels inflicted by either predator alone. Theimplications for biological control of CPB bythese predators, which are being considered foraugmentative release in potato and tomato cropsin the United States, are discussed.     

Impact of Genetically Modified Potato Expressing Plant-Derived Insect Resistance Genes on the Predatory Bug Podisus maculiventris (Heteroptera: Pentatomidae)

The effects of the transgene proteins Galanthus nivalis agglutinin (GNA) and cowpea trypsin inhibitor (CpTI) on the predatory stinkbug Podisus maculiventris were studied under laboratory conditions. When the P. maculiventris were provided with tomato moth (L. oleracea) larvae injected with either GNA or CpTI at a dose of 10 μg day^-1, growth was significantly reduced and, as a consequence, female adult weight was also significantly reduced. For GNA-fed and CpTI-fed P. maculiventris, this weight reduction was 11.3 and 16.6%, respectively. Males, however, were not significantly affected. Female bugs that had not been exposed to the transgene proteins as nymphs, however, showed no reduction in fecundity when these adults were provided with prey injected with either GNA or CpTI at this same dose. When provided with hosts that had been reared on transgenic plants expressing either GNA or CpTI, no effects on the survival of nymphs were observed and only small, largely non-significant, reductions in weights were recorded throughout preadult development. Male nymphs fed on the GNA-fed prey did, however, exhibit a significant lengthening of preadult development of 0.8 days. The subsequent adults showed significantly reduced egg production for the GNA treatment. The results indicate that P. maculiventris may suffer some indirect adverse effects from foraging for prey in crops expressing either GNA or CpTI, due to prey being of inferior quality, rather than to direct toxicity of the transgene products themselves.     

Effects of diet on development and reproduction of the predatory pentatomids Picromerus bidens and Podisus maculiventris

The effects of five diets (larvae of Galleria mellonella L., larvae of Spodoptera littoralis (Boisduval), eggs of Ephestia kuehniella Zeller, cysts of Artemia franciscana Kellogg and an artificial diet based on bovine meat) on development, survival and reproduction of two predatory stinkbugs, Picromerus bidens L. and Podisus maculiventris (Say), were studied in the laboratory. Both species successfully completed immature development on the foods offered, except for P. bidens on cysts of A. franciscana. Significant effects of diet on developmental duration were found in both species. Total developmental time from second instar to adult ranged from 25.0 to 41.5 days and from 18.7 to 46.0 days in P. bidens and P. maculiventris, respectively. Nymphal survival of P. maculiventris was superior to that of P. bidens on all diets tested. Nymphal survival of P. maculiventris was greater than 92% on all diets except on A. franciscana cysts, yielding only 50% survival to adulthood. Survival of P. bidens fed on eggs of E. kuehniella was higher than that of conspecifics fed on caterpillar prey or artificial diet (89% on flour moth eggs vs. 68 and 80% on G. mellonella and S. littoralis and only 50% on meat diet). Fresh weight of newly emerged females of both pentatomids was affected by the diet offered to the predators during their nymphal stage. Females of P. maculiventris produced viable eggs on all diets except on cysts of A. franciscana and had mean fecundities of 691, 436, 608 and 344 eggs per female on S. littoralis, G. mellonella, E. kuehniella eggs and the meat diet, respectively. Females of P. bidens laid eggs only on live prey with mean fecundities of 94 and 38 eggs per female on S. littoralis and G. mellonella, respectively. The results indicate a lower nutritional plasticity of P. bidens as compared with P. maculiventris. An erratum to this article can be found at     

Effect of microsporidian infection in Lacanobia oleracea (Lep., Noctuidae) on prey selection and consumption by the spined soldier bug Podisus maculiventris (Het., Pentatomidae)

Abstract:  The predatory behaviour of Podisus maculiventris was investigated when this bug was presented with Lacanobia oleracea larvae infected with the microsporidian pathogen Vairimorpha necatrix . In choice tests, adult predatory bugs attacked V. necatrix -infected L. oleracea prey in similar numbers to uninfected larvae. Exposure to infected prey during nymphal development increased the rate at which adult bugs attacked diseased L. oleracea larvae. Fifth instar P. maculiventris nymphs, however, attacked infected prey in the majority of cases (>80% of occasions). Consumption of healthy and infected prey was measured for both adult and nymphal bugs. Over the course of 1 week, the mean number of V. necatrix -infected prey eaten by P. maculiventris adults (7.0 ± 0.82) was approximately twice the number of uninfected prey consumed (3.8 ± 0.42). Similarly, the number of prey larvae attacked by the bug over the course of the final nymphal stadium was also increased, with 2.9 ± 0.42 uninfected larvae eaten as opposed to 4.9 ± 0.27 V. necatrix -infected prey. However, small-scale investigations into the rate of P. maculiventris reduced small populations of L. oleracea indicated that the combination of the predator and pathogen would produce, at best, an additive effect.     

Host plant and the predator Podisus nigrispinus: when the defense compounds of the plant affect the third trophic level

Many herbivorous insects can overcome chemical plant defenses, using the plant's defensive products for their own good, as a defense against predators. Eucalyptus spp. (Myrtaceae), recently introduced in Brazil, are rich in secondary compounds; however, there are reports that these plants have been suffering from population outbreaks of defoliating Lepidoptera in Brazil. The predator Podisus nigrispinus (Dallas) (Hemiptera: Pentatomidae) has been used against herbivorous insects in eucalyptus plantations, but little is known about its establishment in the field. This study aims to investigate whether the effectiveness of this predator may be affected indirectly by compounds of eucalyptus plants, when compared to guava, Psidium guajava L., a Brazilian native species of Myrtaceae. Thus, we evaluated the performance of P. nigrispinus on larvae of Thyrinteina arnobia (Stoll) (Lepidoptera: Geometridae) reared on eucalyptus (exotic species) or guava plants (native species). Podisus nigrispinus performance (reproduction and survival) was better on larvae fed on guava than on larvae fed on eucalyptus. It is possible that the negative effect on the predator's development occurred because of the plants’ secondary compounds appropriated by caterpillars, due to the short coevolutionary history between eucalyptus and the predator. The data suggest that the chemical compounds that could help the plant's defenses against herbivores may also affect their natural enemies, especially when the interaction between plant and natural enemy involves an exotic plant recently introduced into the insect's habitat.     

Comparison of susceptibility of pest Euschistus servus and predator Podisus maculiventris (Heteroptera: Pentatomidae) to selected insecticides

Susceptibility of the brown stink bug, Euschistus serous (Say), and the spined soldier bug, Podisus maculiventris (Say), to acetamiprid, cyfluthrin, dicrotophos, indoxacarb, oxamyl, and thiamethoxam, was compared in residual and oral toxicity tests. Generally, susceptibility of P. maculiventris to insecticides was significantly greater than or not significantly different from that of E. servus. Cyfluthrin and oxamyl were more toxic to the predator than to E. servus in residual and feeding tests, respectively. Dicrotophos is the only compound that exhibited both good residual and oral activity against E. servus, but even this toxicant was more toxic to the predator than to the pest in oral toxicity tests. Feeding on indoxacarb-treated food caused high mortality for both nymphs and adults of P. maculiventris. In contrast, E. servus was unaffected by feeding on food treated with this compound. Insecticide selectivity to P. maculiventris was detected only with acetamiprid for adults in residual toxicity tests and for nymphs in oral toxicity tests. Because insecticide selectivity to P. maculiventris was limited, it is extremely important to conserve P. maculiventris in cotton fields by applying these insecticides for control of brown stink bugs only when the pest reaches economic threshold.     

The control of Malpighian tubule secretion in a predacious hemipteran insect, the spined soldier bug Podisus maculiventris (Heteroptera, Pentatomidae)

Spined soldier bugs, Podisus maculiventris, are heteropteran insects that feed voraciously on other insects, particular the soft bodied larval forms of Lepidoptera and Coleoptera. The response of P. maculiventris Malpighian tubules (MTs) to serotonin and known diuretic and antidiuretic peptides has been investigated, and is compared with that of MT from the hematophagous and phytophagous heteropteran bugs Rhodnius prolixus and Acrosternum hilare, respectively. A CRF-related peptide diuretic hormone (DH) from the termite Zootermopsis nevadensis (Zoone-DH) stimulated MT secretion, which was reversed by a member of the CAP_2b family of peptides from A. hilare (Acrhi-CAP_2b-2), an antidiuretic effect. Serotonin had no effect on secretion, neither did a representative calcitonin-like DH, kinin, tachykinin-related peptide, and an antidiuretic factor from the mealworm Tenebrio molitor (Tenmo-ADFb) in both P. maculiventris or A. hilare. Serotonin is a DH in R. prolixus, and its lack of effect on MT from P. maculiventris and A. hilare suggests this is an adaptation to hematophagy. On the other hand, the antidiuretic activity of members of the CAP_2b family in all three bugs is consistent with this being a heteropteran feature rather than a specialism for hematophagy.     

Time related decay in prey antigens ingested by the predator Podisus maculiventris (Hemiptera,Pentatomidae) as detected by ELISA

Summary Individual nymphs of the predaceous pentatomid Podisus maculiventris Say were each fed a single first instar Douglas Fir tussock moth larva, Orgyia pseudotsugata McDunnough, and held without further feeding at constant temperature for a known number of days before being frozen. Enzyme-linked immunosorbent assay, ELISA, was used to examine these predators for the presence of prey antigens. The concentration of prey antigens in these predators declined at a linear rate over the 7 days they were held post-feeding. Detectable antigens remained in 50% of the predators after three days at 24°C. On the day in which the prey was consumed (day 0) only 80% of the unstarved predators had detectable prey antigens which suggests the possibility of instinctive killing of prey with little or no subsequent ingestion. The amount of prey antigen in molted and unmolted predators was not statistically distinguishable; although molting interrupts feeding, digestion of the antigen(s) employed in this study seems to be continuous.This research was supported in part by USDA/Forest Service Cooperative Agreement No. 226 and is Technical Paper No. 5849 of the Oregon Agricultural Experiment Station     

Influence of predator density,diet and living substrate on developmental fitness of Orius laevigatus

Mass rearing of Orius laevigatus on non‐insect foods could substantially increase the cost‐effectiveness of the production of this biological control agent which is largely based on the use of expensive eggs of the Mediterranean flour moth Ephestia kuehniella. In this study, the effect of substrate quality and predator density on nymphal development of O. laevigatus fed on E. kuehniella eggs, honeybee pollen or an egg yolk based artificial diet was assessed using several types of substrates as shelter materials in the rearing containers (wax paper, bean pod or no extra substrate). In general, E. kuehniella eggs proved to be a nutritionally superior food compared to pollen and artificial diet. Pollen supported nymphal development of O. laevigatus better than the artificial diet. Overall, increasing nymphal density resulted in higher mortality, which may be due in part to cannibalism. The addition of a bean pod compensated for the nutritionally suboptimal artificial, but had a negative effect when O. laevigatus was fed on pollen. The non‐insect foods tested could not adequately replace lepidopteran eggs as a food source for O. laevigatus but they may be useful as an alternative food or in a part of the rearing process.     

Interaction between Podisus maculiventris and Harmonia axyridis two predators used in augmentative biological control in greenhouse crops

Intraguild predation (IGP) betweenthe pentatomid Podisus maculiventris(Say) and the coccinellid Harmoniaaxyridis (Pallas) in the absence or presenceof the extraguild prey Spodopteralittoralis (Boisduval) and Myzuspersicae (Sulzer) was studied in thelaboratory. Interactions were asymmetric infavor of the pentatomid. Podisusmaculiventris readily fed upon eggs and larvaeof H. axyridis, but adult beetles wererarely attacked. Success of attacks by P.maculiventris was stage dependent, fourthinstars and adults being more successful inkilling ladybeetle larvae than second instars.Attacks by H. axyridis on the pentatomidwere rare and none of them were successful. Theeffect of introducing extraguild prey on thelevel of IGP was tested both in petri dishesand on caged sweet pepper plants. Whensufficient numbers of S. littoralislarvae were present to satiate the pentatomid,predation on H. axyridis larvae decreasedsignificantly, indicating that the coccinellidis a less preferred or less vulnerable prey.When the aphid M. persicae was presentedas extraguild prey, levels of IGP were notaltered. Nymphs of P. maculiventrissuccessfully completed development whenexclusively fed on larvae of H. axyridis,but developmental time was longer than onlepidopteran prey. No pentatomid nymphs reachedadulthood on aphids alone. IGP by P.maculiventris on H. axyridis may be ofsome importance in greenhouse crops, where bothpredators are being used increasingly inaugmentative biological control programs.Nonetheless, it is expected that in practicelarger larvae and adults of H. axyridiswill escape most attacks by the pentatomid.     

中国蝽科名录与有关学名变动Ⅰ.益蝽亚科(半翅目: 异翅亚目)

本文为中国蝽科(Pentatomidae)审核名录的第一部分,包括全部已知中国分布的益蝽亚科(Asopinae) 种类的学名、异名、分布(中国分布包括省级记录)、以及有关学名变动的简要说明.     

五种蝽科昆虫的细胞分类学研究（半翅目：异翅亚目）

研究了5种中国蝽科昆虫的核型和染色体的减数分裂行为,并采用核型分析软件对第一次减数分裂中期的染色体进行核型分析。结果表明：驼蝽Brachycerocoris camalus Costa、滴蝽Dybowskyia reticulata(Dallas）和红玉蝽Hoplistodera pulchra Yang3个种的染色体组成均为2n（♂）＝14,具有X－Y性别决定机制;减数分裂行为比较一致,但在中期－Ⅰ时,常染色体和性染色体的排列方式各不相同,可为蝽科昆虫的形态分类及系统发育提供有用的证据。二星蝽Eysarcoris guttiger(Thunberg）的染色体组成为2n（♂）＝15,具有X1X2Y性别决定机制,进一步证明了在半翅目昆虫的性染色体进化中碎片化过程起着很重要的作用;黑斑二星蝽Eysarcoris fabricii(Kirkaldy）的染色体组成为2n（♂）＝16,具有X－Y性别决定机制。后2种的核型结果,可为二星蝽属分类的进一步研究提供参考。     

六种蝽象的染色体研究（半翅目：蝽科）

研究了6种蝽象的核型和减数分裂行为。结果表明：6个种的染色体组成均为2n(♂)=14, 具有X-Y性别决定机制;减数分裂行为比较一致,但在中期-Ⅰ常染色体和性染色体的排列方式具有种的特异性,可为蝽科昆虫的形态分类及系统发育提供有用的证据。