Muscles-bearing of sting apparatus in social wasps and their relationship with the autotomy (Hymenoptera: Vespidae: Polistinae)

The musculature that sustains the stinging organ was studied in three species of social wasps using scanning electron microscopy technique. It were observed some differences among species in which sting autotomy occurs and in which it does not. These differences were related to the diameter,length and position of insertion of these muscles.

Induction of the split sting trait in Africanized Apis mellifera (Hymenoptera : Apidae) by cold treatment of pupae

Split sting is the name given to a nonfunctional honey bee sting characterized by lancets not attached to the stylet. It has appeared in a mutant line in Brazil, and has provoked interest as a possible means to reduce honey bee colony defensiveness. We induced this alteration in Africanized Apis mellifera L. workers and queens by maintaining pupae at 20 degrees C. In particular, we determined the pupal phase most susceptible to alterations in the sting caused by cold treatment, and we investigated whether this treatment also affected survival to the adult phase and wing morphology. The highest frequency of split sting was detected in workers treated at the pink-eyed pupal phase. The lowest frequency was observed in the bees treated at the oldest worker pupal phase studied (brown-eyed pupae with lightly pigmented cuticle). Both queen pupal phases tested (white and pink-eyed pupae) were equally sensitive and produced high percentages of adults with split sting. However, the 20 degrees C treatment of workers and queens, at the different pupal phases, resulted in high frequencies of adults with deformed wings. Also, fewer workers and queens treated at the earlier pupal stages reached adult emergence. There was also an arrest in developmental time, corresponding to the period of cold treatment.

Heritability of sting characters in Africanized honeybees

In this paper we proposed to estimate the heritability of seven morphological characters that compose the sting apparatus ofthe Africanized honeybee workers. An experimental design to estimate genetic parameters was based on the method developed by Oldroyd and Moran. This method was modified to eliminate within-colony environmental effects associated with the additive genetic variance. The estimated h2 values ranged from 0.17 ± 0.11 (maximum width of bulb of sting stylet and height of the valve of right lancet) to 0.74 ± 0.30 (length of the lancet).

Bacterial contamination of the catfish (Cathorops agassizii - Valenciennes, 1839 and Genidens genidens - Agassiz, 1829) sting

This work aimed to study the bacterial contamination in stings of the catfish Genidens genidens and Cathorops agassizii found in the São Vicente estuarine system (São Paulo State, Brazil). For bacteriological analyses, we used fish samples distributed into a group of 50 specimens (25 C. agassizii and 25 G. genidens) and a group of 14 specimens (7 C. agassizii and 7 G. genidens). Results showed contamination of 13 different bacterial species of Enterobacteriaceae, being Klebsiella pneumoniae the most frequent bacteria (26.80%) followed by Enterobacter sp and Escherichia coli (16.27%), and Serratia marcescens, Serratia sp. and Proteus mirabilis (1.16%). Gram-positive bacteria as well as fungi were not detected in the samples. According to the Gram-negative species characterized and with regard to the environmental conditions, it can also be considered that accidents with these catfish stings may develop significant acute secondary infections in humans.

Description and morphometry of the sting apparatus in the three worker casts of Acromyrmex subterraneus brunneus (Formicidae, Attini)

We studied the morphometry of the sting apparatus of Acromyrmex subterraneus brunneus workers by dissection and mounting of the structures on slides, and present here a brief description and illustrations. Sting apparatus examinations showed differences in size, but without morphological differences. The seven morphometric variables studied permitted grouping of the Ac. subterraneus brunneus workers into the following three groups: cluster 1 - consisting of 85, 39 large, 45 medium and 1 small workers; cluster 2 - consisting of 44 small workers, and cluster 3 - consisting of 6 large workers. This study demonstrated that all worker castes follow the same morphological pattern, although functional characteristics of the sting apparatus should be highlighted.

Marine catfish sting causing fatal heart perforation in a fisherman

Many marine catfish have serrated bony stings (spines), which are used in defense against predators, on the dorsal and pectoral fins. While catfish-induced injuries are generally characterized by the pain associated with envenomation, the stings in some species are sufficiently long and sharp to cause severe penetrating trauma. Most injuries are to the hands of victims, commonly fishermen. We report the death of a fisherman caused by myocardial perforation from a catfish sting. To our knowledge, this is the first such description in the medical literature.

The Usefulness of the Sting Apparatus in Phylogenetic Reconstructions in Vespids, with Emphasis on the Epiponini: More Support for the Single Origin of Eusociality in the Vespidae

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

BIOCHEMICAL VARIABILITY BETWEEN VENOMS FROM DIFFERENT HONEYBEE (APIS-MELLIFERA) RACES

1. The comparison of molecular exclusion cromatography profiles of venoms from sting apparatuses of Apis mellifera ligustica, Apis mellifera adansonii and Africanized honey-bees in Sephadex G-100 revealed both qualitative and quantitative differences.2. The venoms from A.m. ligustica and A.m. adansonii presented, respectively, three and two peaks characteristic of each sub-species, while Africanized honey-bee was characterized by the absence of eight peaks common to the former.3. The polypeptides with M(r) in the range from 100,000 to 7500 da correspond respectively to 62.0%, 66.6% and 68.7% of total proteins from the venon of A.m. ligustica, A.m. adansonii and Africanized honey-bees, while the peptidic fraction with M(r) range from 4100 to 2000 da corresponds to 11.4%, 32.4% and 10.2% of venom protein, respectively.

Pustular dermatosis caused by fire ant (Solenopsis invicta) stings in a dog

This paper reports a case of spontaneous fire ant sting dermatitis in canine. The skin lesions consisted of nonfollicular, grouped pustules in the abdominal region. Several fire ants were found attached to the lesional skin. Histopathological findings included an intraepidermal neutrophilic pustule and predominantly neutrophilic interstitial dermatitis. An extensive area of collagen degeneration was also observed below the epidermal pustule. These clinical and histopathological findings are remarkable similar to those observed in fire ant stings in humans.

Frequency and gravity of human envenomations caused by marine catfish (suborder siluroidei): a clinical and epidemiological study

Introduction and objectives: Catfish occur in marine and freshwater environments worldwide. They have three serrated venomous bony stings in the dorsal and pectoral fins that are used for defence against predators and are refilled by glandular tissues under the epithelium. However, some catfishes do not have poisonous glands next to the sting and cause traumatic wounds without poisoning. The objective of this study was to provide data for, and comment on, the epidemiological and clinical problems caused by marine catfish.Patients and methods: the authors have observed, followed and documented 127 injuries caused by marine catfish stings during different phases of the envenoming over a time period of 8 years at three points along the Western Atlantic Ocean coast.Results: the patients presented intense pain during the acute phase of envenoming and complications, such as bacterial and fungi infections and retention of bony fragments, in the later phase. Immersion of the affected extremity in hot water was used in about 20% of cases with excellent results.Discussion: Injuries caused by marine catfish are common (about 20% of injuries caused by marine animals in a series of more than 700 injuries recorded by the author) and cause intense pain and later complications. Immersion of the affected extremity in hot water results in improvement in the acute phase, but does not prevent the appearance of secondary infection or foreign body reactions. (c) 2006 Elsevier Ltd. All rights reserved.

Africanized honeybee stings: how to treat them

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

HISTORICAL PERSPECTIVE and HUMAN CONSEQUENCES of AFRICANIZED BEE STINGS IN THE AMERICAS

In 1956, Africanized bees began to spread in the American continent from southern Brazil, where original African bees mated with European bees. A few years later, in 1990, these Africanized bees reached the United States and were found in Texas. Currently, these hybrid bees are found in several North American states and will probably reach the Canadian border in the future. Although the presence of Africanized bees had produced positive effects on Brazilian economy, including improvement in crop pollination and in honey production, turning Brazil into a major exporter, the negative impacts-such as swarming, aggressive behavior, and the ability to mass attack-resulted in serious and fatal envenomation with humans and animals. Victims of bee attacks usually develop a severe envenomation syndrome characterized by the release of a large amount of cytokines [interleukins (IL) IL-1, IL-6, IL-8], and tumor necrosis factor (TNF). Subsequently, such cytokines produce an acute inflammatory response that triggers adverse effects on skeletal muscles; bone marrow; hepatic and renal functions; and cardiovascular, central nervous, and immune systems. Finally, the aim of the present review is to study historical characteristics and current status of Africanized bees' spread, the composition of their venom, the impact of the bees on the Brazilian economy and ecology, and clinical aspects of their stings including immune response, and to suggest a protocol for bee sting management since there is no safe and effective antivenom available.

Tropical dermatology: Venomous arthropods and human skin Part II. Diplopoda, Chilopoda, and Arachnida

Members of arthropod classes Chilopoda (centipedes), Diplopoda (millipedes), and Arachnida (spiders and scorpions) cause tissue injury via bites, stings, and/or a release of toxins. A few members of the Acari subclass of Arachnida (mites and ticks) can transmit a variety of infectious diseases, but this review will cover the noninfectious manifestations of these vectors. Dermatologists should be familiar with the injuries caused by these arthropods in order to initiate proper treatment and recommend effective preventative measures. (J Am Acad Dermatol 2012;67:347.e1-9.)

Changes in the morphology and ultrastructure of the Dufour's gland during the life cycle of the bumble bee queen, Bombus terrestris L-(Hymenoptera : Bombini)

The Dufour's gland is found closely associated with the sting apparatus of all female hymenopterans, playing multiple roles among bees. In some species of Bombus the gland may be involved in production of nestmate recognition pheromones, but in B. terrestris its function is not certain yet. The morphology of the :Dufour's gland of B. terrestris queens and the ultrastructural features of its cells were studied in different ages and behavioural stages using routine transmission electron microscopy. Measurements of the length and the diameter of the gland in the same conditions were also made. The Dufour's gland of the queen increases significantly in size (both in length and in diameter) with age and reproductive activity the ultrastructural features of the gland show electrondense material that comes from the haemolymph. This material is also present in the intercellular spaces, and is conducted to the subcuticular space, to be released directly into the glandular lumen. Hence at least part of the secretion is probably taken up directly from the haemolymph. The ultrastructural features indicate a more active phase of the gland corresponding to the period of egg-laying of the queen, and a decrease in activity when the queen is in hibernation as well as after the competition point. In conclusion, the gland is probably involved in reproduction, more specifically, in the marking off eggs.

Morphohistological study of the venom gland in workers of the ant Pachycondyla striata F. Smith (Hymenoptera : Ponerinae)

Themorphology of the venom gland in workers of the ant Pachycondyla striata (F. Smith) (Hymenoptera: Ponerinae) consists of an elongated sac that is directly connected to the sting apparatus. Three distinct regions compose this gland: the external secretory portion, composed by a secretory filament that bifurcates to originate another two; the internal secretory portion, which is represented by the convoluted gland from which rises the excretory duct that liberates the venom; and the storage portion, consisting of a large sac-shaped reservoir. The histology showed that the gland possesses a strong musculature on its distal third. Underneath these muscle layers, we noted the presence of an epithelium that envelops the internal wall of the reservoir. The presence of a convoluted gland as well as secretion inside the reservoir was also noted.