Evaluation of Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) as parasitoid of the Sarsina violascens Herrich-Schaeffer (Lepidoptera: Lymantriidae)

This is the first report on the parasitoid Palmistichus elaeisis, genus Eulophidae, found in the field parasitizing pupae of defoliating eucalyptus. Lepidopterous pests occur in eucalyptus plantations in Brazil, reaching high population levels. Due to the complexity of pest control in eucalyptus forests, alternative control methods have been proposed, for instance biological control through use of parasitoids. Natural enemies play an important role in regulating host populations because their larvae feed on the eggs, larvae, pupae or adults of other insects. The parasitic Hymenoptera are important agents in biological control programs against forest pests, and may provide economic and environmental benefits. The generalist endoparasitoid Palmistichus elaeisis Delvare and LaSalle, 1993 (Hymenoptera: Eulophidae) can develop in its host’s pupae, which overcome the host’s physiology and can therefore be used for biological control of agricultural and forest pests. This study aimed to evaluate the impact of P. elaeisis as a pupal parasitoid of S. violascens in providing a potential alternative to chemical control of the pest and creation of an alternative host. The experiment was developed in the Laboratory for Biological Control of Forest Pests, Universidade Estadual Paulista "Julio Mesquita Filho”. Parasitoids used in this test were originally collected on pupae of E. eucerus. (Lepidoptera: Riodinidae) in eucalyptus plantations at Lençois Paulistas, São Paulo state, Brazil, in 2011. Thereafter, a laboratory culture has been maintained, using pupae of Spodoptera frugiperda (J. E. Smith) (Lep.: Noctuidae) as hosts. S. violascens eggs were collected in a eucalyptus clonal plantation in Sao Paulo state (Brazil). Larvae were reared under ambient conditions on Eucalyptus urophylla S.T. Blake (Myrtaceae) leaves. The following parameters were determined: parasitism level, numbers of emerged and non-emerged parasitoids and duration of egg-adult cycle. The S. violascens pupae were dissected to evaluate the non-emerged parasitoids. The parasitism level reached 100%, with a 100% emergence rate. It was verified that 113.2±0.8 parasitoids emerged per individual pupa versus only 0.7±0.1 that did not emerge. The P. elaeisis egg-adult cycle was 20.3±0.6 days in S. violascens pupae. This opens new perspectives for utilizing this parasitoid in biological control programs against caterpillars important to forestry. Sarsina violascens in Brazil.

Produção semissólida de metarhizium anisopliae e beauveria bassiana em diferentes substratos e efeito da radiação ultravioleta e da temperatura sobre propágulos desses entomopatógenos

The present study was aimed to evaluate different (semi-solid) media for the production of Metarhizium anisopliae and Beauveria bassiana propagules, and to evaluate the tolerance of these propagules to ultraviolet radiation and temperature. The experiments were performed at the Biological Control Laboratory of the Instituto Biológico at Campinas, São Paulo, Brazil. For both fungi, 6 repetitions were performed for each of the 17 treatments: corn starch, full rice, parboiled rice, type-1 rice, type-2 rice, oat flakes, canjiquinha [grits], wheat flour, raw cassava flour, yellow corn flour, special wheat flour, corn flour, corn in grains, cassava starch, soy in grains, crushed wheat, and turf. The viability analysis was done in plastic plates containing BDA. For the bioassays involving exposure to ultraviolet light and temperature, BDA was also used for viability analysis, and each treatment was exposed to the UV radiation for 0, 25 and 50 seconds, the temperature exposure being at 20, 25, 30 and 35º C. Using a Potter tower, 2 mL of fungus suspension from each treatment was inoculated to the Diatraea saccharalis caterpillars. Regarding the sporulation, the largest concentrations of M. anisopliae and B. bassiana were found for the treatments with parboiled rice, type-1 rice, type-2 rice, yellow corn flour, corn flour and crushed wheat. The viability of all treatments was superior to 94.00%. Also, the longer the duration of the exposition to the UV, the smaller the number of fertile conidia. At 35o C, a significant loss of conidia viability was observed, and all the treatments presented some level of virulence.

Produção de conídios do fungo entomopatogênico Metarhizium anisopliae em diferentes condições de cultivo e em biorreator de bandeja

Pós-graduação em Microbiologia - IBILCE

Resistência de genótipos de palma de óleo (Elaeis guineensis Jacq.) ao ataque de Opsiphanes invirae Hübner, 1808 (lepidoptera: nymphalidae) no Estado do Pará

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Produção de conídios do fungo entomopatogênico Metarhizium anisopliae em diferentes condições de cultivo e em biorreator de bandeja

Pós-graduação em Microbiologia - IBILCE

Resistência de genótipos de palma de óleo (Elaeis guineensis Jacq.) ao ataque de Opsiphanes invirae Hübner, 1808 (lepidoptera: nymphalidae) no Estado do Pará

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Immature stages of Calycopis bellera (Hewitson) and C-janeirica (Felder) (Lepidoptera, Lycaenidae, Theclinae, Eumaeini): Taxonomic significance and new evidence for detritivory

Details of egg, larval, and pupal morphology are described and illustrated for Calycopis bellera (Hewitson) and C. janeirica (Felder), with a special emphasis on larval chaetotaxy. Wild-caught Calycopis females laid eggs on dead leaves in the laboratory, and the caterpillars successfully completed development on an artificial agar diet to which no leaves were added. Males and females of the sexually dimorphic C. bellera had been previously placed in different genera or different species groups. Calycopis janeirica had been chronically misidentified (and misspelled C. jeneirica). Males and females of this species appear to be correctly associated for the first time. Whereas C. bellera has five larval instars-as reported previously for C. caulonia-C. janeirica has four. Morphological characters of the immatures of C. bellera and C. janeirica are summarized in a table and compared with those of other reared Calycopis species.

Bioactivity of neem nanoformulations on tomato pinworm

The use of insecticide plants is an important tool in the management of insect pests. Aiming to control Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), neem nanoformulations were evaluated. After estimating the LC50 for a commercial neem oil formulation, selection bioassays were performed with 22 nanoformulations. In order to do that, newly emerged caterpillars were fed on leaflets treated with nanoformulation solutions for 10 days. The effect on the development and longevity of the insect was evaluated with the two most promising nanoformulations, aqueous NC40 and powdered NC40 (NC 40 = Poly- -hydroxibutirate nanocapsules). The LC50 for neem oil was estimated in 0.20% or 1.31mgL(-1) of azadiractin. The nanoformulations aqueous NC40 and powdered NC40 affected the insect development.

Natural history of an ant-plant-butterfly interaction in a Neotropical savanna

Non-myrmecophilous lepidopteran larvae using plants bearing ant attractants such as extrafloral nectaries are good models for studying morphological and behavioural mechanisms against ant predation. Udranomia spitzi (Hesperiidae) is a butterfly whose larvae feed on leaves of Ouratea spectabilis (Ochnaceae), a plant with extrafloral nectaries. We described the early stages of U. spitzi, and used field observations and experiments to investigate the defensive strategies of caterpillars against predatory ants. Larvae pass through five instars and pupation occurs inside larval leaf shelters. Ant-exclusion experiments revealed that the presence of ants did not affect significantly caterpillar survival. Predation experiments showed that vulnerability to ant predation decreased with increase in larval size. The present study showed that predatory ants are not as relevant as demonstrated for other systems, and also illustrates how observational data and field experiments can contribute to a better understanding of the biology and ecology of a species of interest.

EVALUATION OF IN VITRO AND IN VIVO EFFECTS OF SEMIPURIFIED PROTEINASE INHIBITORS FROM THEOBROMA SEEDS ON MIDGUT PROTEASE ACTIVITY OF LEPIDOPTERAN PEST INSECTS

We have characterized in vitro and in vivo effects of trypsin inhibitors from Theobroma seeds on the activity of trypsin- and chymotrypsin-like proteins from Lepidopteran pest insects. The action of semipurified trypsin inhibitors from Theobroma was evaluated by the inhibition of bovine trypsin and chymotrypsin activities determined by the hydrolysis of N-Benzoyl-DL-Arginine-p-Nitroanilide (BAPA) and N-Succinyl-Ala-Ala-Pho-Phe p-Nitroanilide (S-(Ala)2ProPhe-pNA). Proteinase inhibitor activities from Theobroma cacao and T. obovatum seeds were the most effective in inhibiting trypsin-like proteins, whereas those from T. obovatum and T. sylvestre were the most efficient against chymotrypsin-like proteins. All larvae midgut extracts showed trypsin-like proteolytic activities, and the putative trypsin inhibitors from Theobroma seeds significantly inhibited purified bovine trypsin. With respect to the influence of Theobroma trypsin inhibitors on intact insects, the inclusion of T. cacao extracts in artificial diets of velvet bean caterpillars (Anticarsia gemmatalis) and sugarcane borer (Diatraea saccharalis) produced a significant increase in the percentage of adult deformation, which is directly related to both the survival rate of the insects and oviposition.

Description of the Pupa and Redescription of the Imagines of Geyeria decussata and their Association with Bromeliads in Southern Brazil (Lepidoptera: Castniidae)

ALBERTONI F F [Fed Univ, Florianopolis, Brazil], MORAES S S [Mus Zool USP, Sao Paulo, Brazil], STEINER J [Fed Univ. Florianopolis, Brazil] & ZILLIKENS A [Univ Tubingen, Germany]: Description of the Pupa and Redescription of the Imagines of Geyeria decussata and their Association with Bromeliads in Southern Brazil (Lepidoptera: Castniidae). - Entomol Gener 34 (1-2): 061-074: Stuttgart 2012-09. - [Article] Bromeliads can serve as a resource for numerous arthropods, especially insects. Caterpillars of the moth Geyeria decussata (Godart 1824) were recorded in the leaf rosettes of the bromeliads Wittrockia superba, Vriesea philippocoburgii and Aechmea nudicaulis. The larvae were feeding on the leaf bases, eventually killing the plants. In addition to life history data a description of the pupa and a re-description of the imagines are provided here. These findings constitute new records of larval hosts for this species and confirm a close association of castniid moths and bromeliads.

The relationship between leaf nitrogen, nitrogen metabolites and herbivory in two species of Nyctaginaceae from the Brazilian Cerrado

Guapira graciliflora and Neea theifera are taxonomically related species of the tribe Pisoneae. Both species are found in the same environment, the Brazilian Cerrado, and therefore, are subjected to similar selective pressures. These species occur in oligotrophic environments, yet contain high concentrations of nitrogen in their leaves. The present study was carried out to investigate the ecological role of nitrogen in herbivory on these species. The differences in the N content, compositions of secondary N-metabolites, mechanical resistance, and water content between their leaves indicate that these species have different adaptations as defense mechanisms. In both species, their high nitrogen content seems to promote herbivory. The presence of secondary nitrogen metabolites does not prevent the species from suffering intense damage by herbivores on their early leaves. The herbivory rates observed were lower for mature leaves of both species than for young leaves. In G. graciliflora, nutritional content and leaf hardness are the most important variables correlated with reduction of herbivory rates, whereas in N. theifera, N compounds are also correlated with herbivory rates. Despite the differences in the strategies of these two species, they exhibit a similar efficiency of protection against natural enemies because their total herbivory rates are similar. The difference in their N defense allocation may imply benefits for survival under Cerrado conditions. We briefly discuss the oligotrophic habitat conditions of the studied plants and possible advantages of their strategies of N accumulation and metabolic uses. (C) 2011 Elsevier B.V. All rights reserved.

The role of abscisic acid and water stress in root herbivore-induced leaf resistance

Herbivore-induced systemic resistance occurs in many plants and is commonly assumed to be adaptive. The mechanisms triggered by leaf-herbivores that lead to systemic resistance are largely understood, but it remains unknown how and why root herbivory also increases resistance in leaves. To resolve this, we investigated the mechanism by which the root herbivore Diabrotica virgifera induces resistance against lepidopteran herbivores in the leaves of Zea mays. Diabrotica virgifera infested plants suffered less aboveground herbivory in the field and showed reduced growth of Spodoptera littoralis caterpillars in the laboratory. Root herbivory did not lead to a jasmonate-dependent response in the leaves, but specifically triggered water loss and abscisic acid (ABA) accumulation. The induction of ABA by itself was partly responsible for the induction of leaf defenses, but not for the resistance against S. littoralis. Root-herbivore induced hydraulic changes in the leaves, however, were crucial for the increase in insect resistance. We conclude that the induced leaf resistance after root feeding is the result of hydraulic changes, which reduce the quality of the leaves for chewing herbivores. This finding calls into question whether root-herbivore induced leaf-resistance is an evolved response. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Jasmonate-dependent depletion of soluble sugars compromises plant resistance to Manduca sexta

Jasmonates regulate plant secondary metabolism and herbivore resistance. How they influence primary metabolites and how this may affect herbivore growth and performance are not well understood. We profiled sugars and starch of jasmonate biosynthesis-deficient and jasmonate-insensitive Nicotiana attenuata plants and manipulated leaf carbohydrates through genetic engineering and in vitro complementation to assess how jasmonate-dependent sugar accumulation affects the growth of Manduca sexta caterpillars. We found that jasmonates reduce the constitutive and herbivore-induced concentration of glucose and fructose in the leaves across different developmental stages. Diurnal, jasmonate-dependent inhibition of invertase activity was identified as a likely mechanism for this phenomenon. Contrary to our expectation, both in planta and in vitro approaches showed that the lower sugar concentrations led to increased M. sexta growth. As a consequence, jasmonate-dependent depletion of sugars rendered N. attenuata plants more susceptible to M. sexta attack. In conclusion, jasmonates are important regulators of leaf carbohydrate accumulation and this determines herbivore growth. Jasmonate-dependent resistance is reduced rather than enhanced through the suppression of glucose and fructose concentrations, which may contribute to the evolution of divergent resistance strategies of plants in nature.

Less is More: Treatment with BTH and Laminarin Reduces Herbivore-Induced Volatile Emissions in Maize but Increases Parasitoid Attraction

Chemical plant strengtheners find increasing use in agriculture to enhance resistance against pathogens. In an earlier study, it was found that treatment with one such resistance elicitor, BTH (benzo-(1, 2, 3)-thiadiazole-7-carbothioic acid S-methyl ester), increases the attractiveness of maize plants to a parasitic wasp. This surprising additional benefit of treating plants with BTH prompted us to conduct a series of olfactometer tests to find out if BTH and another commercially available plant strengthener, Laminarin, increase the attractiveness of maize to three important parasitic wasps, Cotesia marginventris, Campoletis sonorensis, and Microplitis rufiventris. In each case, plants that were sprayed with the plant strengtheners and subsequently induced to release volatiles by real or mimicked attack by Spodoptera littoralis caterpillars became more attractive to the parasitoids than water treated plants. The elicitors alone or in combination with plants that were not induced by herbivory were not attractive to the wasps. Interestingly, plants treated with the plant strengtheners did not show any consistent increase in volatile emissions. On the contrary, treated plants released less herbivore-induced volatiles, most notably indole, which has been reported to interfere with parasitoid attraction. The emission of the sesquiterpenes (E)-β-caryophyllene, β-bergamotene, and (E)-β-farnesene was similarly reduced by the treatment. Expression profiles of marker genes showed that BTH and Laminarin induced several pathogenesis related (PR) genes. The results support the notion that, as yet undetectable and unidentified compounds, are of major importance for parasitoid attraction, and that these attractants may be masked by some of the major compounds in the volatile blends. This study confirms that elicitors of pathogen resistance are compatible with the biological control of insect pests and may even help to improve it.