A Study of the Pupal Development of Five Forensically Important Flies (Diptera: Brachycera).

Holometabolous insects undergo complete metamorphosis, and hence, they have different phases of development (egg, larva, pupa, and adult), which occupy distinct ecological niches. The pupae of several fly species are surrounded by the puparium, which is a rigid structure, usually formed by the integument of the last larval instar. The puparium presents unique characteristics distinct from those of the larval and adult phases. During intrapuparial development, it is possible to distinguish at least four fundamental and continuous steps, namely: 1) larval-pupal apolysis, 2) cryptocephalic pupa, 3) phanerocephalic pupa, and 4) pharate adult. The objective of this work was to describe the external morphology of the distinct phase of development for five species that were collected, identified, and raised in the laboratory; intrapuparial development was studied by fixing immature specimens at regular intervals; the morphological analyses were performed with the aid of both light and scanning electron microscopy. Under the conditions established (27 ± 1.0 or 23 ± 1.0°C, 60 ± 10% relative humidity, 12 h of photoperiod), the minimum time for intrapuparial development was: 252 h for Megaselia scalaris (Loew 1966) (Phoridae), 192 h for Piophila casei (Linnaeus 1758) (Piophilidae), Fannia pusio (Wiedemann 1830) (Fanniidae), and Musca domestica (Linnaeus 1758) (Muscidae), and 96 h for Chrysomya megacephala (Fabricius 1794) (Calliphoridae). Intrapuparial development has defined steps, and distinct species responded differently to the same environmental conditions. In addition, it is possible to establish a sequential rule without ignoring the specific characteristics of each taxon.

Description of the male of Laneella perisi (Mariluis) (Diptera: Calliphoridae) n. comb.

The male Laneella perisi (Mariluis) n. comb. is described based on specimens collected in the Cordillera Oriental (1,370-1,450 m asl), Florencia-Suaza, Caquetá, Colombia. A key to separate the two species of the genus Laneella and illustrations of the male genitalia and female abdomen, terminalia, and spermatheca are also presented.

Morphological and cytochemical aspects of spermatozoa in the genus Cochliomyia (Diptera: Calliphoridae).

The objective of this study was to characterize, structurally and ultrastructurally, the spermatozoa of the screwworm flies Cochliomyia hominivorax and Cochliomyia macellaria. To visualize the ultrastructure of microtubules and identify basic proteins, techniques such as the tannic acid fixation and the cytochemical method of ethanolic phosphotungstic acid (EPTA) were used. These methods of fixation are important because they reinforce the evidence of the protofilaments present in the microtubular wall and identify basic proteins, respectively. With the tannic acid fixative it was possible to observe a significant number of microtubules in the cell cytoplasm during spermiogenesis. Microtubules were observed in all regions of spermatids (head, 'overlap' zone and tail). The EPTA technique highlighted the presence of basic proteins on the border of the nucleus and nuclear envelope in the two species analyzed, and in the centriolar adjunct and on the border of mitochondrial derivatives in C. macellaria. The axoneme is of a conventional insect type with a 9 + 9 + 2 microtubular arrangement and the spermatozoa of C. hominivorax and C. macellaria are similar to those described for other Brachycera. The spermatozoa are long and thin in these two species, ∼190 µm in length, of which the head region measures ∼26 µm in C. hominivorax and 29 µm in C. macellaria. A polymorphism was observed in C. hominivorax and C. macellaria. These features are consistent with the structural diversity of the dipteran spermatozoa, constituting an essential tool for understanding the complex variations found in the Diptera order.

Myiasis by screw worm Cochliomyia hominivorax (Coquerel) (Diptera: Calliphoridae) in a wild maned wolf Chrysocyon brachyurus (Mammalia: Canidae), in Brasília, Brazil.

In April 2009, a wild maned wolf, Chrysocyon brachyurus, was captured in an area of cerrado in Brasília, DF, Brazil, with screw worm maggots in external wounds. Fifty larvae were bred in the laboratory and eight adults of Cochliomyia hominivorax (Coquerel) emerged 10 days after pupation. This is the first report of a myiasis by C. hominivorax in a free-living maned wolf in Brazil.

Structure and ultrastructure of spermatozoa of Chrysomya megacephala (Diptera: Calliphoridae).

The spermatozoa of Chrysomya megacephala are similar to those described for other Brachycera. In this species, the spermatozoa are long and thin, measuring about 590microm in length, of which the head region measures approximately 60microm. The head includes a monolayered acrosome with electron-lucid material, and the shape of the nucleus, in cross-sections, varies from circular to oval with completely condensed chromatin. The centriole was observed in the zone of flagellar implantation, below the "peg" region. In the region of overlap, the followings structures are observed: nucleus, centriolar adjunct, mitochondrial derivatives and axoneme. The two mitochondrial derivatives are of different lengths but similar diameter. The axoneme is of a conventional insectan type with a 9+9+2 microtubular arrangement, with accessory tubules flanked by the electron-dense intertubular material. The male internal reproductive tract consists of testis, vas deferens, seminal vesicle, accessory glands and ejaculatory duct.