The gene transformer-2 of Anastrepha fruit flies (Diptera, Tephritidae) and its evolution in insects

Abstract Background In the tephritids Ceratitis, Bactrocera and Anastrepha, the gene transformer provides the memory device for sex determination via its auto-regulation; only in females is functional Tra protein produced. To date, the isolation and characterisation of the gene transformer-2 in the tephritids has only been undertaken in Ceratitis, and it has been shown that its function is required for the female-specific splicing of doublesex and transformer pre-mRNA. It therefore participates in transformer auto-regulatory function. In this work, the characterisation of this gene in eleven tephritid species belonging to the less extensively analysed genus Anastrepha was undertaken in order to throw light on the evolution of transformer-2. Results The gene transformer-2 produces a protein of 249 amino acids in both sexes, which shows the features of the SR protein family. No significant partially spliced mRNA isoform specific to the male germ line was detected, unlike in Drosophila. It is transcribed in both sexes during development and in adult life, in both the soma and germ line. The injection of Anastrepha transformer-2 dsRNA into Anastrepha embryos caused a change in the splicing pattern of the endogenous transformer and doublesex pre-mRNA of XX females from the female to the male mode. Consequently, these XX females were transformed into pseudomales. The comparison of the eleven Anastrepha Transformer-2 proteins among themselves, and with the Transformer-2 proteins of other insects, suggests the existence of negative selection acting at the protein level to maintain Transformer-2 structural features. Conclusions These results indicate that transformer-2 is required for sex determination in Anastrepha through its participation in the female-specific splicing of transformer and doublesex pre-mRNAs. It is therefore needed for the auto-regulation of the gene transformer. Thus, the transformer/transfomer-2 > doublesex elements at the bottom of the cascade, and their relationships, probably represent the ancestral state (which still exists in the Tephritidae, Calliphoridae and Muscidae lineages) of the extant cascade found in the Drosophilidae lineage (in which tra is just another component of the sex determination gene cascade regulated by Sex-lethal). In the phylogenetic lineage that gave rise to the drosophilids, evolution co-opted for Sex-lethal, modified it, and converted it into the key gene controlling sex determination.

A new species of spider fly in the genus Sabroskya Schlinger from Malawi, with a key to Acrocerinae world genera (Diptera, Acroceridae)

In this paper we diagnose the genus Sabroskya Schlinger, 1960 and describe Sabroskya schlingeri sp. n. from Malawi. We also provide dichotomous keys to species of Sabroskya and to world genera of the subfamily Acrocerinae, both extant and extinct.

Ecological Aspects of Phlebotomines (Diptera: Psychodidae) in Endemic Area of Visceral Leishmaniasis, Campo Grande, State of Mato Grosso do Sul, Brazil

Aspects of phlebotomine behavior were investigated in the city of Campo Grande, Mato Grosso do Sul state. The insects were captured weekly during December 2003 to November 2005, with Centers for Disease Control light traps at seven different sites including forests and residential areas. In total, 11,024 specimens (7,805 males and 3,219 females) were collected, from which 9,963 (90.38%) were identified as Lutzomyia longipalpis, the proven vector of American visceral leishmaniasis agent. The remaining 9.62% comprised 21 species. L. longipalpis was the most frequent species in all sampled sites, and the first in the ranking of standardized species abundance index. In residential areas this species clearly predominated in the peridomicile (90.96%), in contrast to the intradomicile (9.04%); in animal shelters, it was more numerous in hen houses and prevailed at ground level, inside, and at forest edge around the residences; this aspect is worrying because this insect may remain sheltered in forested environments during the use of insecticides in homes. In the forest environment, other probable or proven vector of cutaneous leishmaniasis agents were also captured such as Lutzomyia whitmani (=Nyssomyia whitmani, sensu Galati), Lutzomyia antunesi (=Nyssomyia antunesi, sensu Galati), and Lutzomyia flaviscutellata (=Bichromomyia flaviscutellata, sensu Galati).

Parasitoids (Braconidae) associated with Anastrepha (Tephritidae) in host fruits on the Southern coast of Bahia, Brazil

Among the organisms acting in the natural biological control of tephritids, members of the family Braconidae are the most active form of natural parasite, and in Neotropical regions, members of Opiinae are the main control agents of Anastrepha. The objective of this work was to discover the percentage of parasitism and the species of braconid associated with fruit trees growing in cities on the southern coast of Bahia. During the period of August, 2005 to March, 2008, hosts fruits of fruit flies from several plant species were collected and from the fruits the following species of Anastrepha were obtained: A. fraterculus, A. obliqua, A. bahiensis, A. serpentina, A. sororcula and A. zenildae. Of the total of 838 specimens of braconids, 21.36% were of the species Utetes anastrephae (Viereck), obtained from yellow mombin, carambola, guava, mango and pitanga; 4.42% were of the species Asobara anastrephae (Muesebeck) obtained from the fruits of the yellow mombin, carambola and guava, and only one example of Opius bellus Gahan (0.12%) that came from a guava sample. The species Doryctobracon areolatus (Szepligeti) (74.10%) was predominant and emerged from puparia from all the host fruits collected, probably due to the greater efficiency of this species in locating tephritid larvae. The mean percentage of parasitism by Anastrepha spp. was 4.45%.

Feasibility of Using a Caribbean Screwworm for SIT Campaigns in Brazil

The screwworm, Cochliomyia hominivorax (Coquerel), remains one of the most damaging parasites of livestock in South America, causing millions of dollars in annual losses to producers. Recently, South American countries demonstrated interest in controlling this pest using the Sterile Insect Technique, and a pilot-project was conducted near the Brazil-Uruguay border in 2009. Since molecular studies have suggested the existence of C. hominivorax regional groups, crossing tests were conducted to evaluate mating competitiveness, mating preference and reproductive compatibility between a C. hominivorax strain from the Caribbean (Jamaica-06) and one from Brazil. Mating rates between Jamaican males and Brazilian females ranged between 82 and 100%, and each male inseminated from 3.3 to 3.95 females. Sterile males, regardless of the strain, competed equally against the fertile males for Brazilian females. Jamaican sterile males and Brazilian fertile males mated randomly with fertile or sterile females. No evidence of genetic incompatibility or hybrid dysgenesis was found in the hybridization crosses. Mating barriers should not compromise the use of Jamaican sterile males for Sterile Insect Technique campaigns in Brazil.

BILATERAL ANOMALY IN EVANDROMYIA EVANDROI (DIPTERA: PSYCHODIDAE: PHLEBOTOMINAE) CAPTURED IN VICENCIA MUNICIPALITY, NORTHERN RAINFOREST REGION OF PERNAMBUCO STATE, BRAZIL

Approximately 800 species of phlebotomine sand flies, many of which are vectors of Leishmania, have been described. Besides morphological similarities within groups, the occurrence of anomalies within a species may lead to an erroneous description of new species. This paper describes one phlebotomine sand fly, Evandromyia evandroi, with a symmetrical bilateral anomaly in the number of spines on the gonostyle. In this specimen, the anomalous spine is located in the external region of gonostyle, inserted between the upper external and the lower external spines. It is important to document morphological anomalies, so as to avoid erroneous sand fly identifications.

Mannheimsia Beyer (Diptera: Phoridae): description of a new species, redescription of Mannheimsia stricta and studies on hypopygial morphology

Mannheimsia conica, sp. nov., is described, M. stricta redescribed and the hypopygial morphology including the phallus of all four Mannheimsia species is illustrated and discussed. A table with the different phallus terminology used in the main studies of this structure in Phoridae is presented. Uniformization of phallus terminology is suggested.

Description of Two New Sand Fly Species Related to Nyssomyia antunesi (Diptera, Psychodidae, Phlebotominae)

Both sexes of two new Brazilian phlebotomine sand flies of the genus Nyssomyia Barretto 1962 [= Lutzomyia (Nyssomyia) sensu Barretto], Nyssomyia delsionatali n. sp. and Nyssomyia urbinattii n. sp., presenting close affinity with Nyssomyia antunesi (Coutinho), are described and illustrated. N. delsionatali n. sp was captured on the edge of a riparian Amazonian forest on the Juruena river in the northwest of Mato Grosso state and N. urbinattii n. sp in a riparian Amazonian forest on the Teles Pires river between Mato Grosso and Para states. Some measurements of both sexes of N. antunesi and illustration of the male genitalia and the female spermathecae as well as an identi_cation key for males and females of the genus Nyssomyia are provided.

INHIBITION OF OVIPOSITION BY NEEM EXTRACT: A BEHAVIORAL PERSPECTIVE FOR THE CONTROL OF THE MEDITERRANEAN FRUIT FLY (DIPTERA: TEPHRITIDAE)

The behavioral inhibitory effect of methanol extracts from neem leaves (Azadirachta indica A. Juss) at different concentrations (0, 10,000, 18,000, 32,000 and 56,000 ppm) was evaluated using naive and experienced medflies (Ceratitis capitata (Wied.)) ovipositing on the fruits of grape cv. 'Italia'. The grapes were immersed in the specific treatments and were exposed for 24 h to 3 pairs of female and male medflies, both nave and experienced, in a choice test. At concentrations >= 18,000 ppm, the extract that was applied to the grapes inhibited oviposition. The previous experience with treated grapes did not affect the response of the medflies. This study is the first step toward the application of the behavior control of the medflies as a tool in grape vineyards. The potential for using oviposition inhibitory in behavioral control of C. capitata are discussed.