Fertilization and egg production in the bed-bug, Cimex lectularius L.

Parasitology ◽  
1939 ◽  
Vol 31 (2) ◽  
pp. 193-199 ◽  
Author(s):  
Kenneth Mellanby
Keyword(s):  
High Temperature ◽  
Egg Production ◽  
Ovarian Development ◽  
Corpus Allatum ◽  
Cimex Lectularius ◽  
Minimum Amount ◽  
Egg Development ◽  
Bed Bug ◽  
Dry Air ◽  
Definite Period

Previous workers have described the curious method by which the female bed-bug is fertilized. They have suggested that the large quantity of sperm injected serves some function other than that of fertilizing the egg.The rate of metabolism of the virgin bug is much less than that of the fertilized female.Ovarian development never occurs until the female has been fertilized. After fertilization, egg development is apparently controlled by a hormone produced by the corpus allatum.Living sperm will always be found in the spermathecae of females which are laying fertile eggs.The so-called imperfect eggs produced when the sperm is exhausted are normal save for being unfertilized. They have been considered as malformed because of their tendency to shrivel quickly in dry air.Sperm remains viable in the female for a definite period depending on the temperature. This period is longer at low than at high temperature. Provided a certain minimum amount of sperm is introduced (this minimum is less than the quantity introduced by a well-nourished male at one copulation), the period of viability of sperm is the same no matter how many eggs are produced. The number of eggs depends only on the amount of food taken.There is no evidence that the sperm serves any nutritive function in the female.

HWD No. 3

Alloy Digest ◽  
1958 ◽  
Vol 7 (7) ◽  
Keyword(s):  
Fracture Toughness ◽  
High Temperature ◽  
Tensile Properties ◽  
Heat Treating ◽  
Minimum Amount ◽  
Temperature Performance ◽  
Aisi Type ◽  
Hot Work Steel

Abstract HWD No. 3 is an air-hardening hot work steel recommended for dies where a minimum amount of distortion during hardening is required. It is equivalent to AISI Type H13. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness and creep. It also includes information on high temperature performance as well as forming, heat treating, and joining. Filing Code: TS-72. Producer or source: Firth Sterling Inc..

scholarly journals Widespread Mutations in Voltage-Gated Sodium Channel Gene of Cimex lectularius (Hemiptera: Cimicidae) Populations in Paris

2021 ◽  
Vol 18 (2) ◽  
pp. 407
Author(s):  
Mohammad Akhoundi ◽  
Dahlia Chebbah ◽  
Denis Sereno ◽  
Anthony Marteau ◽  
Julie Jan ◽  
...  
Keyword(s):  
Single Point ◽  
Cimex Lectularius ◽  
Single Point Mutation ◽  
Homozygous Mutation ◽  
Knockdown Resistance ◽  
Bed Bugs ◽  
Bed Bug ◽  
Channel Gene ◽  
Blood Sucking ◽  
The Status

Bed bugs, Cimex lectularius and C. hemipterus, are common blood-sucking ectoparasites of humans with a large geographical distribution, worldwide. In France, little is known about the status of bed bugs’ infestation and their resistance to insecticides, particularly, pyrethroids. Here, we aimed to find mutations in the kdr gene, known to be involved in resistance to insecticides. We gathered bed bugs from various infested locations, including 17 private houses, 12 HLM building complex, 29 apartments, 2 EHPAD, and 2 immigrants’ residences. A total of 1211 bed bugs were collected and morphologically identified as C. lectularius. Two fragments of the kdr gene, encompassing codons V419L and L925I, were successfully amplified for 156 specimens. We recorded sense mutation in the first amplified fragment (kdr1) in 89 out of 156 (57%) samples, in which in 61 out of 89 (68.5%) sequences, a change of valine (V) into leucine (L) V419L was observed. Within the second fragment (kdr2), a homozygous mutation was recorded in 73 out of 156 (46.7%) specimens at the codon 925. At this position, 43 out of 73 (58.9%) specimens had a sense mutation leading to the replacement of leucine (L) by isoleucine (I). Among 162 mutant sequences analyzed (89 for the kdr1 fragment and 73 for the kdr2 one), we detected single point mutation in 26.6%, while 73.4% presented the mutation in both kdr1 and kdr2 fragments. All modifications recorded in bed bug populations of Paris are described to be involved in the knockdown resistance (kdr) against pyrethroids.

The Behavioral Response to Heat in the Common Bed Bug,Cimex lectularius (Hemiptera: Cimicidae)

2021 ◽  
Author(s):  
Raymond Berry
Keyword(s):  
Petri Dish ◽  
Cimex Lectularius ◽  
Bed Bugs ◽  
Bed Bug ◽  
Host Interaction ◽  
Video Images ◽  
Spherical Ball ◽  
The Common ◽  
Vertebrate Hosts

AbstractThe bed bug, Cimex lectularius L., is a common ectoparasite found to live among its vertebrate hosts. Antennal segments in bugs are critical for sensing multiple cues in the environment for survival. To determine whether the thermo receptors of bed bugs are located on their antennae; innovative bioassays were created to observe the choice between heated and unheated stimuli and to characterize the response of bugs to a heat source. Additionally, the effect of complete antenectomized segments on heat detection were evaluated. Heat, carbon dioxide, and moisture are cues that are found to activate bed bug behavior; a temperature at 38°C was used to assess the direction/degree at which the insect reacts to the change in distance from said stimulus. Using a lightweight spherical ball suspended by air through a vacuum tube, bed bugs and other insects are able to move in 360° while on a stationary point. Noldus EthoVision XT was used to capture video images and to track the bed bugs during 5-min bioassays. A bioassay was created using four Petri dish arenas to observe bed bug attraction to heat based on antennae segments at 40°C. The purpose of this study was to evaluate the effects of heat on complete antenectomized segments of the antennae. The results in this experiment suggest that bed bugs detect and are attracted to heat modulated by nutritional status. Learning the involvement of antennae segments in heat detection will help identify the location and role of thermoreceptors for bed bug host interaction.

scholarly journals A Linkage Map and QTL Analysis for Pyrethroid Resistance in the Bed Bug Cimex lectularius

2016 ◽  
Vol 6 (12) ◽  
pp. 4059-4066 ◽  
Author(s):  
Toby Fountain ◽  
Mark Ravinet ◽  
Richard Naylor ◽  
Klaus Reinhardt ◽  
Roger K Butlin
Keyword(s):  
Insecticide Resistance ◽  
Candidate Gene ◽  
Linkage Map ◽  
Pyrethroid Resistance ◽  
Cimex Lectularius ◽  
Future Research ◽  
Potential Candidate ◽  
Pest Species ◽  
Diverse Range ◽  
Bed Bug

Abstract The rapid evolution of insecticide resistance remains one of the biggest challenges in the control of medically and economically important pests. Insects have evolved a diverse range of mechanisms to reduce the efficacy of the commonly used classes of insecticides, and finding the genetic basis of resistance is a major aid to management. In a previously unstudied population, we performed an F2 resistance mapping cross for the common bed bug, Cimex lectularius, for which insecticide resistance is increasingly widespread. Using 334 SNP markers obtained through RAD-sequencing, we constructed the first linkage map for the species, consisting of 14 putative linkage groups (LG), with a length of 407 cM and an average marker spacing of 1.3 cM. The linkage map was used to reassemble the recently published reference genome, facilitating refinement and validation of the current genome assembly. We detected a major QTL on LG12 associated with insecticide resistance, occurring in close proximity (1.2 Mb) to a carboxylesterase encoding candidate gene for pyrethroid resistance. This provides another example of this candidate gene playing a major role in determining survival in a bed bug population following pesticide resistance evolution. The recent availability of the bed bug genome, complete with a full list of potential candidate genes related to insecticide resistance, in addition to the linkage map generated here, provides an excellent resource for future research on the development and spread of insecticide resistance in this resurging pest species.

The relationship between crop size and egg production in Rhodnius prolixus

1986 ◽  
Vol 64 (12) ◽  
pp. 2654-2657 ◽  
Author(s):  
K. G. Davey ◽  
I.-K. Maimets ◽  
R. P. Ruegg
Keyword(s):  
Egg Production ◽  
Initial Rate ◽  
Important Determinant ◽  
Virgin Female ◽  
Corpus Allatum ◽  
Current Paper ◽  
Linear Rate ◽  
Crop Size ◽  
The Difference ◽  
The Relationship

Earlier work showed that the number of eggs produced by a virgin female is smaller than that produced by a mated female. The current paper shows that this results not from a difference in rates of egg production, but from the operation of the same linear rate for different times. Denervating the corpus allatum in virgin females extends the time over which the same rate of egg production operates, thus indicating that the inhibition of egg production in virgin females results from a nervous inhibition of the corpus allatum. The initial rate of emptying of the crop is also approximately linear in both virgin and mated females. Later, crop emptying slows in virgins and remains linear in mated females. When these relationships are disturbed by plugging the anus of females before feeding, the rate of crop emptying in virgins more closely resembles that in mated females, and the difference in egg production between mated and virgin females disappears. These results are put into the context of a hypothesis which predicts that the degree of distension of the crop is an important determinant of the length of time that the corpus allatum remains active.

Memoirs: The function of the Corpus Allatum in the Growth and Reproduction of Rhodnius Prolixus (Hemiptera)

1936 ◽  
Vol s2-79 (313) ◽  
pp. 91-121
Author(s):  
V. B. Wigglesworth
Keyword(s):  
Adult Female ◽  
Normal Activity ◽  
Inhibitory Effect ◽  
Corpus Allatum ◽  
The Body ◽  
Egg Development ◽  
Accessory Glands ◽  
Degree Of Differentiation ◽  
Moulting Hormone ◽  
Transplantation Experiments

The Corpus Allatum and Moulting in Bhodnius. 1. The stretching of the cuticle which initiates moulting is necessary only as a stimulus for the secretion of the moulting hormone. The hormone so produced will induce moulting in unfed nymphs. 2. The simultaneous moulting of joined insects is dependent on the continuity of the epidermis established between them. But moulting can be induced by the medium of the blood without contact between the tissues. 3. The moulting hormone from Rhodnius will induce moulting in bugs of the allied genus Triatoma and in the bed-bug, Cimex. The epidermis of these joined insects grows together during the process. 4. Some rather indirect experimental evidence that the corpus allatum secretes the moulting hormone is given. 5. The corpus allatum secretes the ‘inhibitory hormone’ which prevents metamorphosis in the earlier nymphal stages. Fifth-stage nymphs with the corpus allatum of 3rd- or 4th-stage nymphs implanted in them give rise to ‘6th-stage’ nymphs. These ‘6th-stage’ nymphs may give rise to ‘7th-stage’ nymphs when they moult again. In some transplantation experiments the characters all over the body may be intermediate between nymph and adult; or nymphal characters may only be developed near the implant. 6. The inhibitory effect is non-specific as between Rhodnius, Triatoma, and Cimex. 7. The corpus allatum also determines the characters of each nymphal instar by limiting the degree of differentiation towards the adult form which occurs during the moult. 8. In the phenomenon of ‘inhibition of metamorphosis’ there seem to be two elements: (i) deposition of the new cuticle follows rapidly upon the initiation of growth and hence differentiation of the adult characters is arrested; (ii) so long as differentiation is arrested in this way the cells are capable of renewed growth and will respond again to the ‘moulting hormone’. 9. Whether the ‘moulting hormone’ is chemically distinct from the ‘inhibitory hormone’ is not proved. The Corpus Allatum and Reproduction in Rhodnius. 1. In the adult female the corpus allatum is necessary for the production of ripe eggs. The secretion from the corpus allatum of Triatoma females will cause egg development in Rhodnius. 2. In the absence of this secretion the oocytes continue to grow so long as they are connected to the nurse cells. They die and are absorbed when their nutrition is taken over by the follicular cells. 3. The moulting hormone of the nymphal stages will not cause egg development in the adult female; nor will the egg-forming hormone induce moulting. 4. The corpus allatum in the adult male is necessary for the normal activity of the accessory glands. Its secretion will induce egg development in the adult female; and the secretion from the female will activate the accessory glands of the male.

scholarly journals Detectable IgG against a Cimex lectularius allergen after a report of bed bug bites among NYC children

2019 ◽  
Vol 143 (2) ◽  
pp. AB236 ◽  
Author(s):  
Adnan Divjan ◽  
Hadler A. daSilva ◽  
Luis M. Acosta ◽  
Andrew G. Rundle ◽  
Andrzej Weichsel ◽  
...  
Keyword(s):  
Cimex Lectularius ◽  
Bed Bug
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