Rafael Coelho Ribeiro

Body weight and protein content in the haemolymph of females of the zoophytophagous predator Brontocoris tabidus (Heteroptera: Pentatomidae) with different diets and ages

The effect of different diets [1. Tenebriomolitor L. (Coleoptera: Tenebrionidae) pupae; 2. T. molitor pupae and Eucalyptus cloeziana plants; 3. T. molitor pupae and Eucalyptus urophylla plants; and 4. T. molitor pupae and guava plants (Psidium guajava L.)] on the body weight and the protein content of haemolymph of Brontocoris tabidus (Signoret) (Heteroptera: Pentatomidae) females were analyzed. Fifteen days old females of B. tabidus were heavier on plants and T. molitor pupae than only with pupae of this prey. Twent-one days old females of this predator were heavier with E. cloeziana or guava plants and lower with E. urophylla and T. molitor pupae or only with pupae of this prey. The body weight of 15 and 21 days old females of B. tabidus was similar in most treatments and lower with E. urophylla and T. molitor pupae. Fifteen days old females of this predator were heavier when fed on T. molitor pupae and guava plants than those 21 days old. The protein content in the haemolymph of females of this predator was similar in all diets and ages. The phytophagy increased the body weight, but not the protein content in the haemolymph of females of the predator B. tabidus.ZusammenfassungDer Einfluss verschiedener Diäten [1. Puppen von Tenebrio — molitor L. (Coleoptera: Tenebrionidae), 2. T. molitor -Puppen und Eucalyptus cloeziana, 3. T. molitor -Puppen und Eucalyptus urophylla sowie 4. T. mo l it or-Puppen und Guavenbäume (Psidium guajava L.)] auf das Körpergewicht und den Protein- gehalt der Hämolymphe von Weibchen der Raubwanze Bron- tocoris tabidus (Signoret) (Heteroptera: Pentatomidae) wurde untersucht. Fünfzehn Tage alte Weibchen der Raubwanze waren schwerer in Gegenwart von Pflanzen und T. molitor - Puppen als nur mit den Puppen als Nahrung. Einundzwanzig Tage alte Weibchen waren schwerer in Gegenwart von E. clo- eziana oder Guavenpflanzen alleine und leichter mit E. uro- phylla und T. m o l it or -Puppen oder nur mit den Käferpuppen. Das Gewicht der 15 und 21 Tage alten Wanzenweibchen unterschied in den meisten Varianten nicht, war aber geringer in den Varianten mit E. urophylla und T. molitor -Puppen. Fünfzehn Tage alte Weibchen waren schwerer als 21 Tage al- te, wenn ihnen T. molitor und Guavenpflanzen zur Verfügung standen. Der Proteingehalt der Hämolymphe der Wanzenweib- chen war bei allen Nahrungs- und Altersvarianten ähnlich. Die Phytophagie erhöhte zwar das Körpergewicht der räuberischen Wanzen, nicht aber den Proteingehalt der Hämolymphe.

Fertility and Life Expectancy of a Predatory Stinkbug to Sublethal Doses of a Pyrethroid

Podisus distinctus (Heteroptera: Pentatomidae) is an important predator used in biological control of eucalypt defoliating caterpillars, exposed the insecticides. Lower doses of permethrin not affect the values of generation time (T), time necessary to double the population in number of individuals (DT) and intrinsic rate of population increase (rm). Moreover, females of P. distinctus derived from nymphs treated with lower doses of permethrin were more fertile, triggering the effect hormetic in net reproductive rates (Ro). Results showed that low permethrin doses can be used alongside the predatory stinkbug in Integrated Pest Management programs.

Salivary Gland Histology of the Predator Supputius cincticeps (Heteroptera: Pentatomidae)

ABSTRACT Feeding behavior can explain how predaceous Pentatomidae use different food sources as a result of ecological and evolutionary changes. This study describes the salivary glands of adults of the predator Supputius cincticeps (Stål) (Heteroptera: Pentatomidae) to assist in understand the feeding habits of this natural enemy. A pair of principal and accessory glands in the prothorax form the salivary system of S. cincticeps. The principal glands are bilobed with a spherical anterior lobe and are smaller than the posterior lobe, which has a prolonged sack form. The accessory glands are present in a long and tubular form that arises from the terminal portion of the curved accessory duct. The salivary system of S. cincticeps presents the same morphological pattern of other Asopinae predators.

New Record of Grasshopper (Orthoptera: Acrididae & Romaleidae) Defoliators and Population Dynamics of Insects on Crops of Heliconia spp in the Amazon

ABSTRACT Despite the expansion of floriculture, little is known about insects associated to this crop in northern Brazil. The objective was to identify the main species of defoliator grasshoppers, associated to crops of Heliconia spp. in the northeastern region of State of Pará, Brazil , in the municipalities of Castanhal, Belém and Benevides, from Aug 2004 to Mar 2005. Representatives with higher abundances in these municipalities were the orders Coleoptera, Thysanoptera, Hemiptera and Orthoptera. The collected species of Orthoptera were Cornops frenatum frenatum (Marshall) and Eutropidacris cristata L. (Orthoptera: Acrididae), Prionolopha serrata L. and Chromacris speciosa Thunberg (Orthoptera: Romaleidae), which present a substantial potential to damage heliconias crop in northeastern Pará, Brazil.

TRICHOSPILUS DIATRAEAE (HYMENOPTERA: EULOPHIDAE): A POTENTIAL BIOLOGICAL CONTROL AGENT OF LEPIDOPTERAN PESTS OF OIL PALM IN THE BRAZILIAN AMAZON

SUMMARY The expansion of oil palm (Elaeis guineensis) monoculture may favor insect pests such as the caterpillars of Opsiphanes invirae Hübner, Brassolis sophorae L. (Lepidoptera: Nymphalidae) and Eupalamides cyparissias (Fabricius) (Lepidoptera: Castniidae). The objective of this study was to evaluate the potential of Trichospilus diatraeae Cherian & Margabandhu (Hymenoptera: Eulophidae) to parasitize pupae of lepidopteran pests of oil palm. Groups of fifty females of T. diatraeae were maintained inside test tubes with one pupa of one of the following hosts: O. invirae, B. sophorae or E. cyparissias for 48 h. Trichospilus diatraeae parasitized the 3 Lepidopteran species, but reproduced only on O. invirae and B. sophorae. These results suggest that this parasitoid, of polyphagous habit, may represent an alternative for the control of lepidopteran pests of oil palm in the Brazilian Amazon.

Effects of astilbin from Dimorphandra mollis (Fabaceae) flowers and Brazilian plant extracts on Sitophilus zeamais (Coleoptera: Curculionidae)

Abstract Botanical extracts can be an alternative to synthetic insecticides for pest management, owing to their efficiency and environmental safety. The lethal times (LT50 and LT90), loss of grain weight, and repellence of Sitophilus zeamais (Coleoptera: Curculionidae) were evaluated when extracts from 5 plant species from the Brazilian Cerrado biome [Adenocalymma nodosum (Bignoniaceae) leaves, astilbin from Dimorphandra mollis (Fabaceae) flowers, Psychotria prunifolia (Rubiaceae) leaves, Senna obtusifolia (Fabaceae) leaves, and Tithonia diversifolia (Asteraceae) flowers] were applied to a surface and to food. The weevils exposed to a surface treated with extracts from T. diversifolia flowers (106.43 h) and P. prunifolia leaves (119.68 h) at 2% (m.v-1) presented the lowest LT50 and LT90 values, respectively. Corn grains treated with the extract from P. prunifolia leaves at 2% (w.w-1) exhibited fastest mortality of S. zeamais individuals with lower values of LT50 and LT90 than the other treatments. All the botanical extracts repelled S. zeamais after 30 min of application; however, the extracts from S. obtusifolia leaves, P. prunifolia leaves, and T. diversifolia flowers at 2% (m.v-1) repelled this insect after 6 min. Moreover, at 90 and 120 min after the beginning of the experiment, the extracts from P. prunifolia leaves and T. diversifolia flowers repelled the adult weevils. The extracts from A. nodosum leaves, P. prunifolia leaves, and T. diversifolia flowers applied to corn grains showed class III repellency according to the Preference Index for S. zeamais and less grain weight loss, when compared with astilbin from D. mollis flowers and S. obtusifolia leaves. Therefore, it was concluded that the extracts from T. diversifolia flowers and P. prunifolia leaves were the most promising in controlling S. zeamais, with the potential for application in programs for the integrated management of this pest.

Psorocampa denticulata (Lepidoptera: Notodontidae) Pupae as an Alternative Host for Palmistichus elaeisis (Hymenoptera: Eulophidae)

Summary Psorocampa denticulata Schaus (Lepidoptera: Notodontidae) is a pest of Eucalyptus species (Myrtales: Myrtaceae) in Brazil. The pre-pupa stage of this species is present in the soil surrounding infested trees for up to 6 mo during the dry season and can be collected and stored in large numbers. The potential use of P. denticulata pupae as an alternative host for rearing the parasitoid Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) was tested in the laboratory. Up to 24-h-old P. denticulata pupae (787.40 ± 78.29 mg) were individually exposed to twenty 72-h-old P. elaeisis females for 48 h. These exposed pre-pupae were individually transferred to a glass tube for the emergence either of parasitoid progeny or of the adult lepidopteran. The parasitism and emergence rates of P. elaeisis from P. denticulata pupae were 100 and 90%, respectively. The life cycle (egg to adult) was 22.22 ± 0.49 days, and the number of progeny of this parasitoid was 734.55 ± 54.56 per host. We concluded that this generalist parasitoid could be mass reared on P. denticulata pupae and released as part of an integrated program to manage lepidopteran pests in eucalyptus plantations.

Epidermis Associated with Wax Secretion in the Harpactor angulosus (Hemiptera: Reduviidae)

ABSTRACT Beginning at the third instar, the generalist predator Harpactor angulosus (Lepeletier & Serville) (Reduviidae: Harpactorinae) appears gray in color because of the presence of a whitish particulate wax-like material covering all body segments. In this study, we tested the hypothesis that epidermal cells are responsible for the secretion of the wax-like substance onto the cuticle of H. angulosus. The integument of third instar to the adults of H. angulosus have no external structures specialized in wax secretion, as the wax particles are deposited in a filamentous manner. Third to fourth instars and adult stages have a single-layered epidermis composed of columnar cells. In contrast, lack of wax deposit on the body surface of first and second instars is associated with flattened epidermal cells. The columnar epidermal cells are characterized by a well-developed nucleus, basal cell surface with large infoldings, and a cytoplasm rich in vacuoles. These vacuoles are negative for the presence of carbohydrates and proteins, but strongly positive for the presence of lipids. The structural features of the epidermis and the presence of lipid droplets suggest that lipid metabolism is active within the epidermis from the third instar to the adult of H. angulosus. This is the first record of a glandular epidermis associated with wax secretions in Reduviidae.

Palmistichus elaeisis (Hymenoptera: Eulophidae) parasitizing pupae of the passion fruit pest Agraulis vanillae vanillae (Lepidoptera: Nymphalidae)

Summary Agraulis vanillae vanillae L. (Lepidoptera: Nymphalidae) is a pest of Passiflora species (Malpighiales: Passifloraceae). The parasitism of A. vanillae vanillae pupae by Palmistichus elaeisis Delvare & LaSalle (Hymenoptera: Eulophidae) was evaluated. Ten 72-h-old mated P. elaeisis females were confined for 48 h with each 24-h-old A. vanillae vanillae pupa. These exposed pupae were transferred to glass tubes until the emergence of the parasitoid adults. The percentages of parasitism and emergence, number that emerged, sex ratio, body size, width of the head capsule, and longevity of P. elaeisis females and males were similar to those of P. elaeisis reared with various other hosts. These results this indicated that it is practical to rear this parasitoid with A. vanillae vanillae pupae to provide the parasitoid for use in biological control programs.

Damage by Homalinotus depressus in commercial coconut palm crops in the Amazonian region of Brazil

The coconut palm (Cocos nucifera L., Arecaceae) has great economic and social importance for many industrial and non-industrial products. Pests can reduce its productivity and cause its death. In 2005, larvae and adults of a Curculionidae were observed damaging the floral stalk of coconut palms in commercial plantations in the municipality of Moju, Pará State, in the Brazilian Amazon. Insects were identified as the black coconut bunch weevil, Homalinotus depressus (L.) (Coleoptera: Curculionidae: Cholini). This is the first report of this pest damaging coconut palms in Brazil.