RESUMO
The genus Diabrotica has over 400 described species, the majority of them neotropical. However, only three species of neotropical Diabrotica are considered agricultural pests: D. speciosa, D. balteata, and D. viridula. D. speciosa and D. balteata are polyphagous both as adults and during the larval stage. D. viridula are stenophagous during the larval stage, feeding essentially on maize roots, and polyphagous as adults. The larvae of the three species are pests on maize, but D. speciosa larvae also feed on potatoes and peanuts, while D. balteata larvae feed on beans and peanuts. None of these species express a winter/dry season egg diapause, displaying instead several continuous, latitude-mediated generations per year. This hinders the use of crop rotation as a management tool, although early planting can help in the temperate regions of the distribution of D. speciosa. The parasitoids of adults, Celatoria bosqi and Centistes gasseni, do not exert much control on Diabrotica populations, or show potential for inundative biocontrol plans. Management options are limited to insecticide applications and Bt genetically modified (GM) maize. Other techniques that show promise are products using Beauveria bassiana and Heterorhabditis bacteriophora, semiochemical attractants for monitoring purposes or as toxic baits, and plant resistance.
RESUMO
Epigeic coleopteran species are linked by complex trophic webs and implicated in several ecosystem services for agriculture. Although there are reports of ground-dwelling Coleopterans inhabiting main extensive agroecosystems, their assemblages in horticultural crops in Argentina have been little explored. We examined the community structure of epigeal Coleoptera assemblages of Curculionidae, Carabidae, Staphylinidae and Coccinellidae species, in lettuce and tomato crops located in Northern Buenos Aires province, over a 3-year sampling period (2010 to 2013) by using pit-fall traps. Crop species and cycles, and phytosanitary measures (conventional and organic farming), were main factors considered as influencing the insect species composition, abundance and seasonal occurrence in the assemblages. Seventy coleopteran species were identified. The curculionids Ceutorhynchini sp. and Phyrdenus muriceus (Germar), the carabid Scarithes anthracinus Dejean, the coccinelid Eriopis connexa (Germar) and the staphylinids Aleochara sp. and Aleochara obscurus Bernhauer are the most common species in lettuce and tomato crops in the region studied. Especially the carabids, staphylinids and E. connexa are known act as natural enemies of several pests in the agroecosystems studied. Coleopteran assemblages found in lettuce differed from those associated to tomato crops, being the cropping season the main factor that influenced the community structure.
Assuntos
Besouros , Lactuca , Solanum lycopersicum , Animais , Argentina , EcossistemaRESUMO
Knowledge of Argentinian Camptosomata has largely remained static for the last 60 years since the last publication by Francisco de Asis Monrós in the 1950's. One hundred and ninety Camptosomata species (182 Cryptocephalinae and 8 Lamprosomatinae) in 31 genera are recorded herein from Argentina. Illustrated diagnostic keys to the subfamilies, tribes, subtribes and genera of Argentinian Camptosomata, plus species checklists and illustrations for all genera of camptosomatan beetles cited for each political region of Argentina are provided. General notes on the taxonomy and distribution, as well as basic statistics, are also included. This study provides basic information about the Camptosomata fauna in Argentina that will facilitate in the accurate generic-level identification of this group and aid subsequent taxonomic revisions, and phylogenetic, ecological, and biogeographic studies. This information will also facilitate faunistic comparisons between neighboring countries. Two nomenclatural acts are proposed: Temnodachrys (Temnodachrys) argentina (Guérin, 1952), comb. n., and Metallactus bivitticollis (Jacoby, 1907), comb. n. The following are new records for Argentina: Stegnocephala xanthopyga (Suffrian, 1863) and Lamprosoma azureum Germar, 1824. Currently, the most diverse camptosomate tribe in Argentina is Clytrini, with almost twice the number of species of Cryptocephalini. New records for Argentina are predicted.
RESUMO
Some species of Colaspis Fabricius are well-known pests of several crops in Argentina. In this contribution, we describe a new species within this genus: Colaspis caligula n. sp., found in association with Vitis vinifera (Linnaeus) crops. We provide descriptions and illustrations of the mature larva, pupa and adult, as well as notes on its diagnostic characters, life cycle, and the damages produced to the plants.
Assuntos
Besouros/anatomia & histologia , Besouros/classificação , Vitis/parasitologia , Distribuição Animal/fisiologia , Animais , Argentina , Besouros/fisiologia , Feminino , Larva/anatomia & histologia , Larva/classificação , Masculino , Especificidade da EspécieRESUMO
Kuschelina bergi (Harold, 1881) is being studied to be evaluated as a natural enemy of Phyla nodiflora var. minor (Hook.) N. O'Leary & Múlgura (Verbenaceae), an invasive weed in Australia. Eggs, and 1(st) and 3(rd) instar larvae are described and illustrated for the first time. The following characters distinguish Kuschelina bergi: presence of two medial setae in prosternum, mesosternum and metasternum, absence of tubercle on sternum I and eight setae in abdominal segment IX. The 3(rd) instar larvae of Kuschelina bergi resemble Kuschelina gibbitarsa (Say) larvae: the body shape and details of mouthparts are similar, but the morphology of the mandible is different, as is the tarsungulus which has a single seta. Differences between Kuschelina bergi and other known larvae of Oedionychina are discussed. New biological data based on laboratory rearing and field observation are also presented and discussed.
RESUMO
Flea beetles of alligator weed, Alternanthera philoxeroides (Martius) Grisebach (Amaranthaceae), were collected in Argentina, Uruguay, Paraguay, and Brazil. Species in the genera Disonycha Chevrolat, Agasicles Jacoby, Systena Chevrolat and Phenrica Bechyné were frequently found on this weed. Phenrica littoralis (Bechyn6) was the most abundant within this genus. The male is described and the holotype female is redescribed adding new diagnostic characters of the mouthparts, hind wings, metendosternite, and male and female genitalia. Larva and pupa are described and illustrated for the first time providing data for future phylogenetic studies in the subtribe Disonychina.