Dermestid Larvae Research Articles

Farmed crickets (Orthoptera: Gryllidae) raised with dermestids (Coleoptera: Dermestidae) suffer from reduced and delayed growth, but not enough to explain reports of dramatic yield loss.

The mass production of insects for food and feed is an expanding North American industry. Facilities that mass rear insects are at risk of pest infestations because the optimal environmental conditions for rearing beneficial species may also support the development of pest species. Here, we present the first recorded results detailing the interactions between dermestids and farmed crickets. Cricket farms have reported extremely low harvest yield during heavy dermestid infestations, but the exact reasons for this low yield are unknown. Many dermestid larvae are covered in dense, detachable, barbed setae called hastisetae, which are used by the larvae as an active trapping system against arthropod predators. We designed a series of experiments to test the hypotheses that a dermestid pest of cricket farms, black larder beetle (Dermestes ater DeGeer (Coleoptera: Dermestidae)), may be directly impacting Gryllodes sigillatus Walker (Orthoptera: Gryllidae) yield through the physical effects of hastisetae ingestion and/or indirectly impacting cricket yield through competition for fishmeal, a primary source of protein in conventional cricket feed. Our predictions that G. sigillatus life history and survival would be negatively affected by dermestids were largely refuted. Females fed infested diets grew less mass, but not smaller body size, compared to females fed uninfested diets. We also found that while G. sigillatus experienced delayed growth early in life after living with dermestids, they were able to tolerate living with, and consuming, dermestid larvae. We discuss how these findings have led to new hypotheses concerning how dermestid infestations drive reductions in cricket farm yield.

Effects of experimental modification of temperature and humidity on abundance of dermestid beetles in nests of blue tits

AbstractMany factors may affect the diversity and abundance of arthropods in their natural habitats including changes in temperature and humidity. Sometimes, large arthropods remain undetected in unsuspected habitats such as bird nests. Here, we explore the effects of an experiment modifying temperature and relative humidity inside the nest of a troglodyte bird species, the blue tit, Cyanistes caeruleus (L.) (Passeriformes: Paridae), on the abundance of dermestid beetles (Coleoptera: Dermestidae) inhabiting the nests. Ten taxa were identified, six at the species level and four—based on larval stages—at the genus level. Most of the dermestids found in the larval stage were nidicolous dermestids of the genus Anthrenus. Specimens of necrobiont dermestids (those that feed on carcasses in both the larval and adult stages) were found in lower numbers, and almost always in adult stages. The abundance of dermestid larvae found in blue tit nests where the temperature or the humidity were experimentally increased was significantly higher than in the control nests. In addition, adult necrobiont dermestids of genus Dermestes appeared more frequently in those nests where corpses of blue tit nestlings were found.

Experimental Evidence of Bone Lesions Due to Larder Beetle Dermestes maculatus (Coleoptera: Dermestidae).

Simple SummaryLarvae of the larder beetle Dermestes maculatus (Coleoptera: Dermestidae, De Geer, 1774) resemble caterpillars but actually feed on dry tissues of dead animals, and sometimes on human corpses. To hide and metamorphose into adult beetles, these larvae dig deep tunnels called pupation chambers. These holes and pits are usually observed in skins, horns, furs, or surrounding materials such as wood. They have also been reported on archaeological bones and experimentally observed on fresh pig bones, but never on humans. In this context, we investigated whether larder beetle larvae could also dig pupation chambers in human bones, and under which conditions this could occur. For this purpose, we placed medieval dry human bones as well as fresh calf and beef bones (control) with Dermestes maculatus larvae. After 1 month, we observed tunnels corresponding to pupation chambers only on dry human bones, and under conditions of high larval density. Despite these results being preliminary, they are, nonetheless, of particular interest in a forensic context, as they could help to understand taphonomic bone modifications or even the chronology of mass grave deposals.Dermestid beetles (Coleoptera: Dermestidae) are necrophagous insects feeding on mummified carcasses. After six to seven molts, the larvae stop feeding and dig pupation chambers to hide and safely evolve into adults. Such pupation chambers have already been observed on archaeological mammals’ bones, but the attribution and interpretation of these osteological lesions lack experimental evidence in a forensic context. To observe whether dermestid larvae dig pupation chambers in human bones, 20 or 40 Dermestes maculatus (De Geer, 1774) larvae were placed in a dermestarium with different types of bones varying in species (Bos taurus or human), age (adult or immature), and preservation method (fresh or dry). Our results show that dermestid larvae caused multiple lesions, including larval mandible traces on cortical bone, cortical perforations, drilling of pupation chambers, destruction of the trabecular network, and the perforation of cartilage. Bone destruction was mainly observed on aged dry bones, while fresh bones only exhibited soft tissue and superficial cartilage lesions. According to these results, pupation chambers could indicate the simultaneous presence of several corpses at different decomposition stages, or the addition of new corpses while others were already skeletonized. These conclusions are particularly important in the case of mass graves, where chronology is sometimes difficult to establish.

Papules, pustules, and rhinoconjunctivitis in a 4-year-old

Papules, pustules, and rhinoconjunctivitis in a 4-year-old

Occurrence, ecological function and medical importance of dermestid beetle hastisetae.

Hastisetae are a specific group of detachable setae characterizing the larvae of Megatominae (Coleoptera: Dermestidae), commonly known as carpet and khapra beetles. These setae are located on both thoracic and abdominal tergites and they are the primary defense of the larva against invertebrate predators. According to previous studies, the main purpose of hastisetae is to work as a mechanical obstacle, but they are also capable to block and kill a predator. Hastisetae, single or aggregate, function as an extremely efficient mechanical trap, based on an entangling mechanism of cuticular structures (spines and hairs) and body appendages (antennae, legs and mouthparts). It is believed that this defensive system evolved primarily to contrast predation by invertebrates, however it has been observed that hastisetae may affect vertebrates as well. Although information on the impacts of vertebrate predators of the beetles is lacking, hastisetae have been shown to be a possible threat for human health as an important contaminant of stored products (food and fabric), work and living environment. Review of past and recent literature on dermestid larvae has revealed that despite these structures indicated as one of the distinctive characters in species identification, very little is known about their ultrastructure, evolution and mechanism of action. In the present work, we will provide the state of knowledge on hastisetae in Dermestidae and we will present and discuss future research perspectives intended to bridge the existing knowledge gaps.

Methods of biological maceration in the preparation of bat skulls: benefits and limitations

Osteologic collections are used as an aid to scientific and teaching activities, to provide information on specific vertebrate characteristics, such as body support, posture, mode of locomotion, feeding habits and ecological niche. Known techniques for cleaning entire skeletons or mammalian skulls vary according to the destination of the material, the objective of the study, the taxonomic group, and the size of the specimen. The objective of this study was to test three different methods of maceration for cleaning bat skulls (traditional biological maceration, controlled biological maceration using Dermestes maculatus and controlled biological maceration using necrophagous fly larvae). The methods were carried out during five consecutive months, and the minimum and maximum times taken by each method were recorded and documented. Cleaning by fly larvae was the least costly method; the whole process was carried out during the preparation of the osteologic material. The flies ovulated directly on the pieces and the time spent was relatively short. Cleaning by dermestid larvae also resulted in clean parts in a short period, however, its culture needs specific maintenance conditions, since the size of the colony oscillates according to environmental temperature.

The exploitation of fresh remains by Dermestes maculatus De Geer (Coleoptera, Dermestidae) and their ability to cause a localised and prolonged increase in temperature above ambient

This article discusses the ability of adults of the coleopteran beetle Dermestes maculatus (De Geer) to colonise fresh remains. It also considers whether colonisation results in localised thermogenesis in a similar manner to that induced by blowfly larvae.In the laboratory, adult D. maculatus instantly colonised fresh killed rats and mice. The adults entered the oral cavity within 1–2 h and the eyes and ears were among the first parts of the body consumed. Egg laying occurred on the torso and head within an hour of death and eggs hatched within 3–4 days. The larvae remained on the body whilst the adults (>70%) rested in the surrounding wood chippings when not feeding or laying eggs. Larvae grew rapidly on the dead bodies and some were starting to pupate within 28 days.The dermestids consumed the corpses predominantly from the head downwards and weight loss correlated with the number of larvae produced. In both rats and mice, colonisation of the abdominal region was associated with an increase in temperature. The maximum abdominal temperature and the length of time the temperature remained 1 °C or more above ambient correlated with the number of larvae produced. This rise in temperature would probably be sufficient to increase the rate of development of dermestid larvae and that of any other invertebrate or microbe in the region. In the absence of dermestids, the internal temperature rarely rose 1 °C above ambient.Although there are previously published accounts of dermestid beetles consuming fresh corpses, they are reputed to favour older desiccated remains. This paper confirms that D. maculatus rapidly consumes and reproduces on fresh remains. The fact that dermestid beetles are seldom found on fresh remains under field conditions is therefore probably a result of inter-specific competition among decomposing insects rather than food preference. This information could be useful when determining the forensic significance of D. maculatus recovered from dead bodies.

Ancient hastisetae of Cretaceous carrion beetles (Coleoptera: Dermestidae) in Myanmar amber

Hastisetae are extremely elaborate and intricate insect setae that occur solely on dermestid larvae (Coleoptera: Dermestidae). The present work characterizes hastisetae found in mid-Cretaceous amber from Myanmar and compares them to hastisetae found on extant dermestid larvae. The presence of hastisetae in Myanmar amber shows that lineages of dermestid beetles had already developed hastisetae by the mid-Cretaceous and their presence allows us to follow the evolutionary development of this particular arthropod structure over the past 100 million years. Hastisetae attached to a parasitic wasp in the same piece of amber indicates that ancient dermestid beetles used their hastisetae for defense, similar to their function today.

Evidence of scavenging on remains of the gomphothere Haplomastodon waringi (Proboscidea: Mammalia) from the Pleistocene of Brazil: Taphonomic and paleoecological remarks

Abstract This study reports implications of different tooth marks left by carnivorous mammals on long bones of Haplomastodon waringi from the Quaternary of Aguas de Araxa, Minas Gerais, Brazil. Analyses of gnawing damage by ursids, felids, and canids have shown that these groups produce pits on bone surfaces when the gnawing is superficial, and punctures more often when the prey is intensely consumed. Scratches or scoring marks are most often associated with gnawing by canids, which may spend a long time gnawing the bones, leading to differential tooth marking. The gomphothere bones at Aguas de Araxa did not result from predation, but are a consequence of a local mass mortality in a period of low environmental humidity, with little water and a scarcity of food. Canids frequently act as opportunistic scavengers during periods when herbivores face food shortages. Previous studies of necrophagous dermestid larvae indicate that the gomphothere carcasses of Aguas de Araxa were exposed for a long period of time after death. These insects are the last consumers of a carcass because they act only when the body fat is completely lost. Thus, the gomphothere carcasses at Aguas de Araxa suffered canid necrophagy in the early stages of decomposition, possibly during a drought period. Thereafter, the gomphothere carcasses would have been exposed for a period about 230 days until the final burial event.

The effect of sun‐drying on the infestation of the African catfish(Clarias gariepinus)by post‐harvest insects in the Lake Chad district of Nigeria

Abstract Studies involving a survey of infestation of the African catfish, Clarias gariepinus (dried for 4 days and stored for more than 30 days), obtained from the fish market in Maiduguri, northeastern Nigeria, as well as the direct exposure of freshly caught catfish to three sun‐drying regimes, i.e. 1 day, 7 days and 14 days (stored for further 30 days under laboratory conditions) were carried out over a 5‐month period. Variations in weather conditions during the period were: daytime temperatures, 32–39.9°C; night temperatures, 23.1–27.7°C; and relatively humidity, 40–69%. There was a preponderance of dermestid larvae over adults and calliphorid maggots in fish samples dried for 4 days, 7 days and 14 days. Catfish dried for 1 day harboured significantly higher numbers of maggots compared with the numbers of dermestid larvae and adults. There were significant decreases in the numbers of maggots as drying time increased, suggesting a practical possibility for the protection of dried catfish against maggo...

Comparative Analysis of Cuticular Hydrocarbons from the Ectoparasitoids Cephalonomia waterstoni and Laelius utilis (Hymenoptera: Bethylidae) and Their Respective Hosts, Cryptolestes ferrugineus (Coleoptera: Cucujidae) and Trogoderma variabile (Coleoptera: Dermestidae)

Cuticular hydrocarbons have been identified from the immatures and adults of two bethylid wasps and their larval beetle hosts. Cephalonomia waterstoni Gahan is host specific on Cryptolestes ferrugineus (Stephens), whereas Laelius utilis Cockerell is commonly associated with a variety of dermestid larvae, including Trogoderma variabile Ballion. The cuticular hydrocarbons of C. waterstoni larvae consist of n-alkanes (C21-C33), 2-, 3-, 5-, 7-, 11-, and 13-methyl alkanes, one dimethyl alkane (11,15-dimethyl C27), and a C31 monoene and diene. The cuticular hydrocarbon composition of their beetle host differs somewhat, consisting of n-alkanes (C25-C32), 3-, 5-, 11-, and 13-methyl alkanes, a series of Z-8/Z-9-monoenes, and a series of dienes with the double bonds separated by 12 methylene units. No dimethyl alkanes are present in the C. ferrugineus larvae. Considerable ontogenetic changes in cuticular hydrocarbon composition occur when C. waterstoni eclose to adults. Although both sexes contain the same major cuticular hydrocarbons, their relative abundances vary. In addition to n-alkanes (C23-C27), 2-, 3-, and 5-methyl alkanes, 5,15-, 5,17-, and 5,19-dimethyl alkanes, and a series of Z-11-monoenes are present in both sexes. In addition, the males possess small quantities of Z-7-monoenes. The males have the monoenes as their major components, whereas the females have the 5-methyl alkanes and the dimethyl alkanes as their major components. The cuticular hydrocarbon composition of L. utilis and its host T. variabile differs considerably from the Cephalonomia-Cryptolestes pairing. The major components of the Laelius larvae consist of n-alkanes (C23-C33), 3-, 5-, 13-, and 15-methyl alkanes, and a series of Z-9-monoenes. The T. variabile larval hydrocarbons consist only of n-alkanes (C22-C35) and 3-, 5-, and 13-methyl alkanes. No unsaturated components were detected. As with C. waterstoni, considerable ontogenetic changes in hydrocarbon composition occur for L. utilis upon adult eclosion. Unlike C. waterstoni, however, only slight differences in composition occur between the sexes. The adult Laelius hydrocarbons consist of n-alkanes (C21-C29), 2-, 3-, 7-, 9-, and 13-methyl alkanes, and a series of Z-9-monoenes.

Protection of museum textiles and leather against the dermestid beetle (Coleoptera, Dermestidae) by means of antifeedants

Investigations of the chemical receptor capability of the dermestid larvae demonstrated that they have a poor olfactory sense. Antifeedant preparations are, therefore, an effective method of protection for museum objects against migrating dermestid larvae. A persistent antifeedant, the well-known insect repellent carboxide (hexamethylene carbamide) was selected from 50 compounds as a result of the current investigation. The impregnation of packing and other materials with carboxide solutions will prevent infestation with dermestid larvae. The use of antifeedants in the museum in cases of infestation is a component part of the complex system of protection of museum objects against Dermestidae which has been developed at the biological section of the Research Institute for Restoration (VNIIR) in Moscow.

Insect Infestation in Grain Loaded in Railroad Cars at Primary Elevators in Southern Manitoba, Canada

Infestation by the rusty grain beetle, Cryptolestes ferrugineus (Stephens), was found in the grain loaded in 47 (38%)of 125 railroad cars in 1977 and in 72 (53%)of 136 cars in 1978 at primary elevators near Winnipeg, Manitoba. The grain loaded in about half of the cars contained larvae only. Mites were found in the grain loaded in 78 and 90% of the railroad cars in 1977 and 1978, respectively. Other insects found, in order of decreasing frequency, were psocids, dermestid larvae, and fungus beetles. Oryzaephilus surinamensis (L.), Tribolium castaneum (Herbst), Palorus subdepressus (Wollaston), Tenebrio molitor (L.), and Sitophilus granarius (L.) were found in the grain loaded in five or fewer cars in 1977 and 1978. No more than 6% of the infested carloads found at primary elevators were detected by inspectors at terminal elevators. Less than 5% of the carloads of grain sampled contained rusty grain beetles from grain delivered directly from the farm.

The protection of smoke-dried freshwater fish from insect damage during storage in Zambia

An emulsion containing 0·018 per cent pyrethrins and 0·036 per cent piperonyl butoxide, applied to smoke-dried freshwater fish in Zambia, prevented infestation by Dermestes ater and D. maculatus (partly by repelling adults) but became ineffective 8–12 weeks after application. An emulsion containing 0·125 per cent malathion gave good control for 8 weeks, but left up to 43 ppm active ingredient in Tilapia spp. 8 weeks after treatment, and fish became littered with dead dermestid adults. Pyrethrum dust gave relatively poor protection and a silica-based dust was ineffective. Brining to give 8–10 per cent salt in the final product did not prevent infestation although it reduced damage due to dermestid larvae. Fish treated with pyrethrins emulsion or brine were superior in condition compared with untreated fish after 12 weeks storage. A taste panel preferred brined fish to untreated fish but could not distinguish brined from pyrethrins-treated fish. Bacterial counts indicated that both brined and pyrethrins-treated fish were virtually sterile after 12 weeks storage, but bacterial loads on control fish were also low, 6600–60,000/cm 2. The pyrethrins emulsion treatment was shown to be economically very attractive, and was considered to be most appropriate in Zambia.

The Toxicity of Malathion and Fenthion to Dermestid Larvae as Influenced by Various Surfaces12

Concrete and other alkaline surfaces, commonly present in processing plants and warehouses, often reduce the toxicity of insecticides. Dermestid larvae were exposed to painted, waterproofed, and untreated surfaces sprayed with formulations of either malathion or fenthion. Pretreating surfaces with certain materials minimized insecticide detoxification.

Laser Effects on Two Insects

AbstractDermestid larvae, Trogoderma versicolor (Creutzer), and adult American cockroaches, Periplaneta americana (Linné), were affected by ruby laser pulses of two intensities, 0.06 ± 0.04 per 10−7 second duration and 0.57 ± 0.06 joules per 0.2 milliseconds. Laser impact areas were 1.5 mm. in diameter. The first intensity, directed at cephalic regions of dermestid larvae, caused mortality in 3–48 hours. The same intensity directed at larval mid-abdominal areas caused visible outer integument and body-hair scorching, cessation of feeding, growth rate, and movement, and loss of negative phototactic responses. Directed at posterior abdominal regions of larvae, it caused damage to the epidermal layer noticeable in four succeeding moults. It caused temporary (10-15 min.) immobility and loss of negative phototaxis when directed at pro-thoracic regions of cockroach adults. P. americana adults were more severely affected by the second laser treatment, exhibiting immobility, loss of negative phototaxis, and cessation of eating. Total mortality in the five treated specimens occurred in 8-14 days as compared with 45-68 days in controls.

Studies on the Digestion of Wool by Insects VII. Some Features of Digestion in Three Species of Dermestid Larvae and a Comparison with Tineola Larvae

Three species of dermestid larvae (Anthrenocerus australis, Anthrenus verbasci, and Attagenus piceus) are shown to be capable of digesting wool.

THE DERMESTID, TROGODERMA VERSICOLOR CREUTZER, A NEW PEST OF DRIED MILK PRODUCTS

Early in 1933, Dr. E. G. Hood of the Dairy and Cold Storage Branch, Dominion Department of Agriculture, submitted to the Dominion Entomologist some specimens of dermestid insect larvae taken in a dried milk establishment at Princeton, Ont. These insects which were passed to me, resembled larvae of the buffalo carpet beetle. Adult beetles that emerged late in March and in April, however, showed the species to beTrogoderma versicolorCreutzer (det. W. J. Brown).