Cockroach Species Research Articles

Winner and loser effects in lobster cockroach contests for social dominance

In the context of animal aggression, the winner/loser effect is a cross-taxa phenomenon. In the present study, the effect of social contest experience on winning and losing subsequent encounters was investigated in the furious male lobster cockroach, Nauphoeta cinerea. Dominant and subordinate individuals were generated as the result of an encounter between two socially naïve males (SNMs); the winner and loser were designated as 1st encounter dominants and 1st encounter subordinates, respectively. With these dominants and subordinates, three experiments were conducted: (I) the original pair met in a re-encounter, (II) the 1st encounter dominants and subordinates were paired with an inexperienced SNM, (III) the 1st encounter dominants and subordinates were paired with an experienced individual of the same rank. Each experiment was conducted at 1 week, 2 weeks, 3 weeks, 4 weeks and 5 weeks after the 1st encounter fight. Juvenile hormone (JH) III titer was monitored in all individuals before and after each subsequent encounter. Our results showed that, in the original pairing and in the pairing with SNMs, the probability that a 1st encounter dominant (or subordinate) would win (or lose) the subsequent encounter fit well with the 95% confidence interval of the theoretical criteria proposed by Begin et al. (1969), indicating the existence of the winning/losing effect. However, this effect was inconsistent along the five-week observation period. For all 1st encounter dominants, at each week after the 1st encounter, the before subsequent encounter JH III titers distribution was significantly different from that on the 1st encounter day; the distributions of before subsequent encounter JH III titers could be further clustered into two groups, the higher JH III group and the lower JH III group, which were significantly correlated with subsequent winning and losing, respectively. For the 1st encounter subordinates, the distributions of before subsequent encounter JH III titers were not significantly different from that of SNMs, but the titer distributions were significantly shifted to a higher level compared to the 1st encounter day. Compared with before subsequent encounter, the after subsequent encounter hemolymph JH III level was significantly increased in winners and significantly decreased in losers. From these data, we propose that instability of the winner and loser effects may occur due to physiological costs and recovery; this instability may partly explain why the social hierarchy is unstable in this cockroach species.

First records of the parthenogenetic Surinam cockroach Pycnoscelus surinamensis (Insecta: Blattodea: Blaberidae) for Central Europe

AbstractSixteen species of cockroaches have been reported for Austria so far. This study is the first record of the parthenogenetic Surinam cockroach, Pycnoscelus surinamensis (L.) for Austria (and thus Central Europe). The species is natively distributed in Indo‐Malaysia but has been unintentionally introduced in many, mainly tropical, countries throughout the world. Sequencing the DNA barcoding region revealed that all Austrian P. surinamensis samples had the same haplotype, which they shared with samples from the United States of America, Guyana and French Polynesia, indicating that all these samples/populations belong to the same clonal lineage. Even though in temperate regions, the occurrence of P. surinamensis is currently limited to greenhouses, we advocate proper monitoring of the populations with respect to global warming and the expected increasing independence of this species from greenhouses that comes along with it.

Global spread of the German cockroach, Blattella germanica

Most people consider cockroaches to be quintessential urban pests, even though very few of the 5000 cockroach species live in urban areas. The German cockroach is the most widespread and common cockroach in urban areas, however how this invasive species has spread globally is poorly understood. We reviewed the published and grey literatures, and museum data, to document the spread of the German cockroach, and how it may have interacted with other urban cockroach species. We found that the German cockroach likely originated from South Asia, was introduced into Europe no later than the 18th century, from where it invaded worldwide. The spread of the German cockroach was facilitated by the improvement of transportation technologies, especially from colonial trading, and indoor heating in cooler climates. Studies of population genetics have found that once introduced into a new location, the German cockroach spread rapidly through local expansion, and this could be within single (large, multiple-story) buildings. This local expansion resulted in displacement of other urban cockroach species, likely due to their small size requiring fewer resources, shorter generation times and so faster evolution, especially for pesticide resistance. These findings may help to identify new pest management methods. Future research could use genetic tools at larger scales to map distribution routes across the globe and interaction with pesticides and the evolution of resistance.

Genome analyses of uncultured TG2/ZB3 bacteria in 'Margulisbacteria' specifically attached to ectosymbiotic spirochetes of protists in the termite gut.

We investigated the phylogenetic diversity, localisation and metabolism of an uncultured bacterial clade, Termite Group 2 (TG2), or ZB3, in the termite gut, which belongs to the candidate phylum 'Margulisbacteria'. We performed 16S rRNA amplicon sequencing analysis and detected TG2/ZB3 sequences in 40 out of 72 termite and cockroach species, which exclusively constituted a monophyletic cluster in the TG2/ZB3 clade. Fluorescence in situ hybridisation analysis in lower termites revealed that these bacteria are specifically attached to ectosymbiotic spirochetes of oxymonad gut protists. Draft genomes of four TG2/ZB3 phylotypes from a small number of bacterial cells were reconstructed, and functional genome analysis suggested that these bacteria hydrolyse and ferment cellulose/cellobiose to H2, CO2, acetate and ethanol. We also assembled a draft genome for a partner Treponema spirochete and found that it encoded genes for reductive acetogenesis from H2 and CO2. We hypothesise that the TG2/ZB3 bacteria we report here are commensal or mutualistic symbionts of the spirochetes, exploiting the spirochetes as H2 sinks. For these bacteria, we propose a novel genus, 'Candidatus Termititenax', which represents a hitherto uncharacterised class-level clade in 'Margulisbacteria'. Our findings add another layer, i.e., cellular association between bacteria, to the multi-layered symbiotic system in the termite gut.

Potency of Cockroaches (Periplaneta americana and Blattella germanica) as Vector of Salmonellosis on Ships in Baubau Port

ABSTRACT Cockroaches are insects that act as mechanical vectors of pathogenic agents to humans such as Salmonella sp. The aim of this study was to identify the presence of Salmonella sp. in cockroach bodies on cargo and passenger ships. This research was conducted at Baubau Port from October to December 2017. A total of 24 ships were examined consisting of 12 passenger ships and 12 cargo ships. Cockroaches were collected from rooms inside each ship namely galley, bridge, deck and bathroom. A total of 3 196 cockroaches caught consisting of Periplaneta americana (69.50%), Blattella germanica (29.60%), Periplaneta brunnea (0.66%), Pseudophorapsis sp. (0.03%), Pycnoscelus surinamensis (0.03%), Periplaneta australasiae (0.03%), and Neuphoeta cinerea (0.03%). The presence of Salmonella sp. were examined for cockroach species with a large number of population, namely Periplaneta americana and Blattella germanica. A total of 95.3% of the 42 cockroaches examined in the laboratory contained Salmonella sp.. Based on this research it can be concluded that the cockroaches collected from the ships leaning at Baubau Port can serve as a vector of salmonellosis for both ship crew and passengers. Keywords: Cockroaches, Ships, Salmonella sp, Salmonellosis

A Review on the Insecticide Resistance of Three Species of Cockroaches (Blattodea: Blattidae) in Iran.

In Iran, there are four pest domestic species of cockroaches: Periplaneta americana (Linnaeus, Blattodea: Blattidae), Blatta orientalis (Linnaeus, Blattodea: Blattidae), Blattella germanica (Linnaeus, Blattodea: Blattidae), and Supella longipalpa (Fabricius, Blattodea: Blattellidae). The aim of this study was to compile and review studies conducted on insecticide resistance of domestic cockroaches in Iran to assess the current knowledge and gaps. Twenty insecticides were used in susceptibility testing of cockroaches. The bioassay methods varied, and included surface contact (exposure tests), topical applications and feeding studies on baits. Resistance ratio (RR) stated in the reviewed studies showed that B. germanica was resistant (RR > 10) to DDT, permethrin, and cypermethrin, while P. americana and S. longipalpa were categorized as low levels of resistance (RR = 1-2). S. longipalpa is newly reported from houses in some areas of Iran, including Tehran, and there are very few studies on its' biology, ecology and insecticidal resistance. Most studies used adult cockroaches, while the susceptibility status of nymphs was evaluated only in few studies. Use of different test methods and lack of a World Health Organization (WHO) updated procedure, including revised/updated insecticide diagnostic dosages and test kits. The lack of susceptible strains of cockroaches was a major challenge in the assessment of data. A comprehensive national program for monitoring susceptibility of household pests to insecticides in Iran is of great concern and is highly recommended.

Control of American Cockroach (Periplaneta americana) in Municipal Sewage Disposal System, Central Iran

Cockroaches consists of 4000 species, of which 40 species are serious domestic pests. They have involved the mechanical transmission of various pathogenic viruses, bacteria, and protozoans to humans. This study aimed to determine different control methods of P. americana in sewage system of Esfahan City, central Iran using different insecticides recommended by WHO. Totally, 164 manholes with at least more than three cockroaches were selected until 2017 for this study. The species of cockroaches were identified; the adults and nymphs were counted and recorded. Each sewer shaft was assigned to one treatment method in an ascending order of number of cockroaches counted, coding the treatment method with paint on the lower part of the wall near the manhole cover. The manhole shafts were then inspected at 1 and 5 months' post-treatment. Data analyzed by statistical methods. Almost all of the products (Excluding boric acid with bait formulation) resulted in appropriate control within one month of application. The appropriate products for chemical control of cockroaches were the chlorpyrifos 5% Emulsifiable Concentrate (EC), diazinon 5% (EC), diazinon 0.05% (EC) and cypermethrin 5% Fog. These pesticides achieved an optimal reduction of population providing more than 90% control of cockroaches for five consecutive months. The emulsifiable concentrates and fog formulations in the control were more successful compared to other methods and this was penetration deep into the hiding places of cockroaches.

Genome analysis of new Blattabacterium spp., obligatory endosymbionts of Periplaneta fuliginosa and P. japonica

The successful adaptation of cockroaches is, in part, dependent of the activity of their obligatory endosymbionts, Blattabacterium spp., which are involved in uric acid degradation, nitrogen assimilation and nutrient provisioning. Their strategic localization, within bacteriocytes in the proximities of uric acid storage cells (urocytes), highlights their importance in the recycling of nitrogen from urea and ammonia, end-products not secreted by their host insects. In this study, we present the complete genome sequence of two new Blattabacterium spp. from Periplaneta fuliginosa (BPfu) and P. japonica (BPja), and detailed comparison with other Blattabacterium strains from different cockroach species. The genomes of BPfu and BPja show a high degree of stability as showed with for other Blattabacterium representatives, only presenting a 19-kb fragment inversion between BPja and BPfu. In fact, the phylogenomics showed BPja as an ancestor species of BPfu, BPLAN (P. americana) and BBor (Blatta orientalis), in congruence with their host cockroach phylogeny. Their functional profile is similar and closest to the omnivorous strain BBge (Blattella germanica). Interesting, BPja possesses the complete set of enzymes involved sulfate assimilatory pathway only found in BBge and BMda (Mastotermes darwiniensis). The newly sequenced genomes of BPja and BPfu emphasise the remarkable stability of Blattabacterium genomes supported by their long-term coevolution and obligatory lifestyle in their host insect.

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Front cover: The cover image taken of the Australian cockroach species Macropanesthia rhinoceros is based on the Research Paper Multiple abiotic factors correlate with parallel evolution in Australian soil burrowing cockroaches by Perry G. Beasley-Hall et al. DOI: 10.1111/jbi.13233. Photo Credit: Yi-Kai Tea, University of Sydney.

Pest Cockroaches May Overcome Environmental Restriction Due to Anthropization.

Our species have altered their surroundings since its early dispersion on Earth. Unfortunately, thanks to human-modified habitats, several pest organisms such as domiciliary insects have expanded their distributions. Moreover, pest-related microorganisms may also be aided by anthropization. Pest cockroaches are globally distributed and capable of carrying several diseases. We explored if urbanization may buffer environmental conditions allowing pest insects to expand their distribution. Specifically, we suggest that human settlements may generate suitable microhabitats for synanthropic cockroaches, helping them to survive and establish with disregard to overall climatic restrictions. To test this idea we studied the distribution of pest cockroaches spanning the length of Chilean territory. Chile, along its 4270 km length north to south extent, is a country offering a formidable sampling of Earth's climatic diversity accompanied by dense urbanizations. We studied entomological collections and spatially analyzed pest cockroach distribution found in Chile and discovered that synanthropic cockroach populations are consistently concentrated near most urban developed zones of the country and not limited by overall temperature. Furthermore, health-concern pest cockroach species were widely distributed in Chilean territory, found even in its most southern urban centers as well as Easter Island. Therefore, these disease vectors could exist even in isolated and extreme climatic zones as long as urbanization provides the adequate microhabitat. We discuss the need for further research in order to assess if these distributions can be extrapolated to the pathogenic strains these pest insects may be carrying as reported in other regions of the planet.

Cockroach Associated Foodborne Pathogens: Distribution and Antibiogram

Cockroaches are among the most common pests in public dwellings and health facilities. Owing to their close association with man and all his surroundings they are consideredas potential carrier and transmitter of human diseases. In hospital, cockroaches are the possible vector of nosocomial infection, specially for the transmission of drug resistant bacteria. The aim of the present study was to identify the major cockroach species, to isolate common foodborne pathogens from cockroach and to determine the antibiotic susceptibility pattern of isolated bacteria. This casecontrol study was conducted on cockroaches captured from hospital, restaurants and houses in Dhaka city, from a period of July to December 2014. A total of 450 cockroaches were collected. Among these 300 cockroaches (150 from hospital and 150 from restaurants) were considered as case and 150 cockroaches from houses were enrolled as control group. All (100%) cockroaches were identified as Blattellagermanica. Examination of external surface and gut homogenates showed that all (100%) cockroaches carried bacteria, while carriage rate of fungi and parasites were 28.2% and 3.7% respectively. Of 1901 isolated bacteria, Escherichia coli (15.3%), Pseudomonas aeruginosa (14.4%) and Salmonella spp.(12.9%) were the predominant bacteria. Other bacteria of medical relevance included,Shigella spp. (6.4%), Klebsiella spp. (8.8%), Proteus spp. (9.6%) and Staphylococcus aureus (4.3%). Antibiotic resistance pattern showed high resistance rate (62.4%) of bacterial isolates to different antibiotics. Additionally, 1051(55.3%) of the isolates were multi drug resistant (MDR) strains, which were resistant to 5-14 antibiotics. The findings of this study revealed that, cockroaches are potential source of pathogenic microorganisms including multi drug resistant bacterial strains, which could be a major threat to public health. Hence, effective preventive and control measures are required to minimize cockroach related infections.Bangladesh Med Res Counc Bull 2018; 44(1):30-38

Isolation and identification of some gram-negative bacteria from cockroaches collected from hospital, restaurant and slum areas of Dhaka city, Bangladesh

The study was conducted to identify the bacteriological quality from different species of cockroaches in three study areas in Dhaka city. A total of 15 cockroaches was collected from three different selected study areas, viz. Penang Restaurant of Bakshi Bazar, Sir Salimullah Medical College Mitford Hospital and Urban slum of Kamalapur, Dhaka. Using detection keys, the cockroaches were identified as Periplaneta americana (53.33%), Blatella germanica (40%) and Blatta orientalis (6.67%). All of 15 cockroaches were used to isolate bacteria from external body surface and alimentary tract. A total of 48 isolates was obtained from these three species of cockroaches. Out of them 29 (60.42%) isolates were obtained from P. americana, 17 (35.42%) from B. germanica, and 2 (4.16%) from B. orientalis. Three Gram negative bacteria, viz. Klebsiella sp., Escherichia coli and Pseudomonas sp. were isolated from alimentary canal and external surface. On the external body surface 71.43% isolates were E. coli, 21.43% were Pseudomonas sp. and 7.14% were Klebsilella sp. In case of alimentary tract, 55.89% isolates were Pseudomonas sp., 23.52% were E. coli, and the rest 20.59% were Klebsiella sp. Comparison between study areas showed that the food handling area yielded maximum number (41.67%) of isolates and the urban slum yielded minimum number (25%) of isolates. In food handling isolates, 45% were Klebsiella, whereas E. coli and Pseudomonas sp. were 40% and 15%, respectively. In Hospital, E. coli was the most common (50%), followed by Klebsiella (37.5%) and Pseudomona sp. (12.50%). In urban slum, 41.67% isolates were Klebsiella sp., 41.67% were Pseudomonas sp. and 16.66% were E. coli. This study shows that cockroaches carry several Gram-negative bacteria on their body surface and alimentary tract and play a role in bacterial transmission to human.J. Biodivers. Conserv. Bioresour. Manag. 2017, 3(2): 63-68

Multiple abiotic factors correlate with parallel evolution in Australian soil burrowing cockroaches

AbstractAimThe ways in which abiotic factors contribute to parallel evolution—the evolution of similar, derived phenotypes in independent, closely related lineages—remain understudied. Australian cockroaches of the subfamilies Panesthiinae (“wood feeders”) and Geoscapheinae (“soil burrowers”) are two closely related groups that provide a striking example of parallel evolution of burrowing behaviour. The ancestral wood‐feeding panesthiines migrated from Asia ~20 million years ago before soil burrowing was independently acquired multiple times in the derived geoscapheines. Here, we investigate whether specific abiotic factors were associated with the parallel evolution of soil burrowing behaviour, and whether divergence events of geoscapheines from panesthiine ancestors are consistent with niche conservatism or divergence.LocationThe Australian mainland, including the areas in which selected Australian Panesthiinae and Geoscapheinae cockroach species are distributed.MethodsWe generated environmental niche models for members of the Australian Geoscapheinae and Panesthiinae using presence‐only data and abiotic variables related to temperature, precipitation, and soil composition from BioClim and the Australian Soil Resource Information System. We used an existing phylogenetic framework to compare environmental niche models and tested for niche conservatism versus divergence. Morphological convergence was assessed by a regression analysis and principal components analysis of leg segment and body dimensions in soil burrowers and wood feeders.ResultsWe found no relationship between niche similarity and time since divergence, and only limited evidence for phylogenetic signal with respect to the environmental variables examined. We found that soil burrowing behaviour is consistently correlated with thirteen abiotic factors associated with aridity, including a wider range of temperatures and lower precipitation levels. Evidence for convergence in leg morphology and body dimensions across soil burrowers was found.Main conclusionsOur results are consistent with soil burrowing behaviour evolving in response to ancient aridification events following the arrival of the Panesthiinae in Australia. Our results suggest a scenario of niche divergence between soil burrowers and each of their wood feeding sister taxa. There is evidence for morphological convergence on a “shovel‐like” protibiotarsus in the Geoscapheinae that would aid in burrowing into soil.

Gut bacteria of cockroaches are a potential source of antibacterial compound(s)

The bacteria isolated from unusual dwellings such as the cockroaches' gut are a useful source of antibacterial and antiamoebal molecules. These are remarkable findings that will open several avenues in our search for novel antimicrobials from unique sources. Furthermore studies will lead to the identification of molecules to develop future antibacterials from insects.

Broad infectivity of Leidynema appendiculatum (Nematoda: Oxyurida: Thelastomatidae) parasite of the smokybrown cockroach Periplaneta fuliginosa (Blattodea: Blattidae).

Host specificity of parasites is important for the understanding of evolutionary strategies of parasitism that would be a basis of predictions of the disease expansion when parasitized hosts invade new environments. The nematode order Oxyurida is an interesting parasite group for studying the evolution of parasitism as it includes parasites of both invertebrates and vertebrates. In our survey, we found that the smokybrown cockroach Periplaneta fuliginosa was primarily infected with only one nematode species Leidynema appendiculatum. In two cases, L. appendiculatum was isolated from two additional cockroach species Pycnoscelus surinamensis, sold in Japan as a reptile food, and Blatta lateralis, captured in the field and cultured in the laboratory. Inoculation of L. appendiculatum into three additional cockroach species P. japonica, Blattella nipponica, and P. surinamensis also resulted in parasitism. Infection prevalence was high, and timing of postembryonic development from hatched nematode larva to mature adult in these hosts was identical with that in P. fuliginosa. While ecological interactions strongly determine the host range, such broad infectivity is still possible in this parasitic nematode.

The genomic and functional landscapes of developmental plasticity in the American cockroach

Many cockroach species have adapted to urban environments, and some have been serious pests of public health in the tropics and subtropics. Here, we present the 3.38-Gb genome and a consensus gene set of the American cockroach, Periplaneta americana. We report insights from both genomic and functional investigations into the underlying basis of its adaptation to urban environments and developmental plasticity. In comparison with other insects, expansions of gene families in P. americana exist for most core gene families likely associated with environmental adaptation, such as chemoreception and detoxification. Multiple pathways regulating metamorphic development are well conserved, and RNAi experiments inform on key roles of 20-hydroxyecdysone, juvenile hormone, insulin, and decapentaplegic signals in regulating plasticity. Our analyses reveal a high level of sequence identity in genes between the American cockroach and two termite species, advancing it as a valuable model to study the evolutionary relationships between cockroaches and termites.

First molecular genetic evidence for automictic parthenogenesis in cockroaches

Parthenogenesis is an asexual mode of reproduction that plays an important role in the evolution of sex, sociality, and reproduction strategies in insects. Some species of cockroach exhibit thelytoky, a type of parthenogenesis in which female offspring are produced without fertilization. However, the cytological and genetic mechanisms of parthenogenesis in cockroaches are not well understood. Here we provide the first molecular genetic evidence that cockroaches can reproduce through automixis. Using the American cockroach Periplaneta americana, we performed microsatellite analysis to investigate the genetic relationship between parthenogenetically produced nymphs and the parent virgin females, and found that all parthenogenetic offspring were homozygous for autosomal microsatellite markers, whereas the female parents were heterozygous. In addition, flow cytometry analysis revealed that the parthenogenetic offspring were diploid. Taken together, our results demonstrate that P. americana exhibits automixis-type thelytoky, in which diploidy is restored by gamete duplication or terminal fusion. These findings highlight the unique reproduction strategies of cockroaches, which are more varied than was previously recognized.

Transoceanic Dispersal and Plate Tectonics Shaped Global Cockroach Distributions: Evidence from Mitochondrial Phylogenomics.

Following the acceptance of plate tectonics theory in the latter half of the 20th century, vicariance became the dominant explanation for the distributions of many plant and animal groups. In recent years, however, molecular-clock analyses have challenged a number of well-accepted hypotheses of vicariance. As a widespread group of insects with a fossil record dating back 300 My, cockroaches provide an ideal model for testing hypotheses of vicariance through plate tectonics versus transoceanic dispersal. However, their evolutionary history remains poorly understood, in part due to unresolved relationships among the nine recognized families. Here, we present a phylogenetic estimate of all extant cockroach families, as well as a timescale for their evolution, based on the complete mitochondrial genomes of 119 cockroach species. Divergence dating analyses indicated that the last common ancestor of all extant cockroaches appeared ∼235 Ma, ∼95 My prior to the appearance of fossils that can be assigned to extant families, and before the breakup of Pangaea began. We reconstructed the geographic ranges of ancestral cockroaches and found tentative support for vicariance through plate tectonics within and between several major lineages. We also found evidence of transoceanic dispersal in lineages found across the Australian, Indo-Malayan, African, and Madagascan regions. Our analyses provide evidence that both vicariance and dispersal have played important roles in shaping the distribution and diversity of these insects.

Phylogenetic Diversity and Single-Cell Genome Analysis of "Melainabacteria", a Non-Photosynthetic Cyanobacterial Group, in the Termite Gut.

Termite guts harbor diverse yet-uncultured bacteria, including a non-photosynthetic cyanobacterial group, the class “Melainabacteria”. We herein reported the phylogenetic diversity of “Melainabacteria” in the guts of diverse termites and conducted a single-cell genome analysis of a melainabacterium obtained from the gut of the termite Termes propinquus. We performed amplicon sequencing of 16S rRNA genes from the guts of 60 termite and eight cockroach species, and detected melainabacterial sequences in 48 out of the 68 insect species, albeit with low abundances (0.02–1.90%). Most of the melainabacterial sequences obtained were assigned to the order “Gastranaerophilales” and appeared to form clusters unique to termites and cockroaches. A single-cell genome of a melainabacterium, designated phylotype Tpq-Mel-01, was obtained using a fluorescence-activated cell sorter and whole genome amplification. The genome shared basic features with other melainabacterial genomes previously reconstructed from the metagenomes of human and koala feces. The bacterium had a small genome (~1.6 Mb) and possessed fermentative pathways possibly using sugars and chitobiose as carbon and energy sources, while the pathways for photosynthesis and carbon fixation were not found. The genome contained genes for flagellar components and chemotaxis; therefore, the bacterium is likely motile. A fluorescence in situ hybridization analysis showed that the cells of Tpq-Mel-01 and/or its close relatives are short rods with the dimensions of 1.1±0.2 μm by 0.5±0.1 μm; for these bacteria, we propose the novel species, “Candidatus Gastranaerophilus termiticola”. Our results provide fundamental information on “Melainabacteria” in the termite gut and expand our knowledge on this underrepresented, non-photosynthetic cyanobacterial group.

Efektivitas Minyak Atsiri Serai Wangi (Combypogon nardus) Sebagai Insektisida Alami Untuk Kecoa Amerika (Periplaneta americana)

ABSTRAK Cockroaches are one of the most common types of insects around our neighborhood, and it is one of the most dangerous insects because some species of cockroaches are known to transmit disease in humans such as tuberculosis, typhoid, asthma, cholera, and hepatitis. Eradication of cockroaches can be done physically and chemically, the use of chemical-based insecticides can cause respiratory problems. In an insecticide drug containing natural ingredients contain essential oils, the content of essential oil compounds serve as an anti-insect drug on citronella. This study aimed to determine the effect of essential oils of citronella fragrance to cockroaches. This type of research was experimental. The population in this study were cockroaches (Periplaneta americana) obtained from the houses of villagers of Tanjung, Sampang, Madura. The total sample was 32 adult stage cockroaches. Data analysis was using free T test with error rate of 5% or 0,05.The results showed that cockroaches stopped moving with an average of 15.75. Based on T test results showed the significant results of 0.00 which was smaller than 0.05 then H0 was rejected Ha was accepted. It can be concluded that the essential oils of citronella fragrance have an effect on the death of cockroaches. Keywords: Cockroach, Essential Oil Of Citronella Fragrance (Cymbopogon nardus)