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Oviposition behaviour of singly mated females of Dysdercus koenigii in relation to their duration of mating. A -Inter-oviposition period between two successive egg batches and the female response; B -Number of egg batches laid and the female response; 24hM -24h mated females; 48hM -48h mated females; 72hM -72h mated females.
Source publication
Adults of Dysdercus koenigii remain in continuous copula for up to 72h. The adaptive significance of prolonged copulation in the reproductive bioactivities of D. koenigii was investigated by a series of interrupted mating experiments. The adults were allowed to mate for a specified duration, after which mating was forcibly terminated. The study ind...
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Context 1
... order to ascertain the influence of mating duration on the lifetime reproductive programming of females, parameters like the inter-oviposition period, the number of eggs laid in each batch and the hatching success of each batch were assessed. The data in Fig. 4B reveal a striking difference in the number of egg batches laid by females of different mating status. The 72h mated females laid up to six batches, whereas females mated for 24h and 48h laid a maximum four. It was also observed that 48% of the 72h mated females laid four egg batches, whereas only 28% of 48h mated females and only 4% of ...
Context 2
... of egg batches laid by females of different mating status. The 72h mated females laid up to six batches, whereas females mated for 24h and 48h laid a maximum four. It was also observed that 48% of the 72h mated females laid four egg batches, whereas only 28% of 48h mated females and only 4% of 24h mated females laid the same number of batches (Fig. 4B). The results also showed that there was a striking difference in the inter-oviposition period in the three groups of females (Fig. 4A). The rate of oocyte development appeared to be faster in the females mated for 72h. These females, therefore, laid their first egg batch after an average period of 6.4 days, and usually laid subsequent ...
Context 3
... 24h and 48h laid a maximum four. It was also observed that 48% of the 72h mated females laid four egg batches, whereas only 28% of 48h mated females and only 4% of 24h mated females laid the same number of batches (Fig. 4B). The results also showed that there was a striking difference in the inter-oviposition period in the three groups of females (Fig. 4A). The rate of oocyte development appeared to be faster in the females mated for 72h. These females, therefore, laid their first egg batch after an average period of 6.4 days, and usually laid subsequent batches after an interval of 5-6 days. In contrast, the first egg batch in the 24h mated females was delayed for up to 12 days, with ...
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Females and males of the abundant heteropteran species Pyrrhocoris apterus (L.) mate with the larger of the available partners. The male benefits from copulation with a large female, which is more productive than a small female. However, the benefit to females from copulation with a large male has not yet been investigated. Overwintered sexually im...
Citations
... Dysdercus koenigii (Hemiptera: Pyrrhocoridae), the red cotton bug, is one of the major global insect pests of cotton crops. Immature nymphs as well as adults, with the capability to disperse rapidly, transmit cotton-staining fungi as well as suck the moisture and oil contents from the cotton leaves, seeds and immature buds at a widespread scale, reducing the crop yield extensively (Gupta et al., 2019;Karar et al., 2020Karar et al., , 2021Saeed & Abbas, 2020;Sahayaraj & Fernandez, 2017). Chemical interventions are the predominant and most preferred means to control pests due to their rapid action and toxic effects. ...
Dysdercus koenigii, a global cotton pest, inflicts significant crop losses via sucking the moisture and oil contents from leaves and seeds. The growing environmental hazards with conventional pesticides have led to the exploration of nanotechnology to formulate alternative products and nanoemulsions as suitable insecticide delivery vehicles for target pests. We formulated nanoemulsions using β-cyfluthrin (a pyrethroid) and DMSO (Dimethyl sulfoxide) in 1:2, 1:4, 1:6, 1:8 and 1:10 proportions. The nanoemulsions (NE) were characterized morphologically and biophysically (size, pH, viscosity, PDI and zeta potential) by Transmission Electron Microscopy, Dynamic Light Scattering and Zeta Potential Analyzer. Each NE was transparent, stable, had 11.4–174.1 nm droplet size and, optimal PDI and zeta potential. The spherical and monodispersed 1:2 β-cyfluthrin + DMSO NE was found as the most optimal formulation inducing 100% mortality in D. koenigii fifth instars after 24 h; the NE (LD50 = 3.536 mg/L) displayed 44% higher efficacy than the β-cyfluthrin alone (LD50 = 5.059 mg/L). The LD50 dose of the 1:2 NE enhanced the activity of α-esterase, β-esterase, glutathione-S-transferase, and acetylcholinesterase in nymphs in comparison with β-cyfluthrin alone. The β-cyfluthrin nanoemulsion can act as a potential tool to manage D. koenigii after thorough field assessment and evaluation of the impact on non-target organisms.
... 36,37 In Dysdercus koenigii, Togo hemipterus and Nysius huttoni, however, researchers found that fecundity was positively correlated with the duration of mating. [38][39][40] Sublethal exposure to imidacloprid in E. heros enhanced the duration of mating and resulted in increased fecundity. 41 In the present study, the duration of mating for the ♂c × ♀t and ♂t × ♀t pairings significantly increased relative to the control pair. ...
BACKGROUND
Mating is an essential factor that governs the size of insect populations that reproduce sexually. The extensive application of insecticides has both lethal and sublethal effects on the physiology and mating behavior of insect natural enemies. The predatory bug Cyrtorhinus lividipennis is a natural enemy of planthopper and leafhopper populations in the rice ecosystem. Unfortunately, the effects of insecticides on the mating behavior of C. lividipennis are not well‐understood.
RESULTS
The mating behavior of C. livdipennis consisted of mounting, antennal touch and mating attempts, genital insertion, adjustment of posture, and separation of the mating pair. Approximately 82.5% of the C. lividipennis mating pairs displayed their first mating at 12–36 h postemergence. Mating activity occurred throughout a 24‐h period, with peak activity at 12:00–14:00 h, and the mean duration of mating was 48.75 min. Sublethal exposure to imidacloprid increased mating latency. Compared with the controls, the duration of courtship, pre‐mating and adjusting posture for males treated with imidacloprid were prolonged. The duration of mating for females treated with imidacloprid was prolonged relative to untreated controls. The fecundity and daily spawning capacity of females treated with imidacloprid were higher than the untreated controls.
CONCLUSION
Our results provide insight into the mating process of C. lividipennis. Imidacloprid prolonged the duration of mating, which may explain the enhanced reproductive output in C. lividipennis females treated with imidacloprid. These findings will be useful in both rearing C. lividipennis and deploying this natural enemy in rice fields. © 2024 Society of Chemical Industry.
... Currently, it has received attention in studies of behavioral ecology and evolutionary biology, owing to its importance in sexual conflict and sexual selection [3]. Previous studies have shown that the copulation duration is a key component of reproductive fitness in insects, especially in species where the amount of sperm transferred is proportional to the copulation duration; longer copulations often result in greater fecundity and greater fertility, and as a consequence, increase their reproductive potential [4][5][6][7]. ...
... The increase in reproductive output may be directly related to more sperm being transferred, which supports the ejaculate transfer hypothesis. These results are consistent with earlier studies of other coleopteran, dipteran, and heteropteran species [6,21,44]. According to our observation, male and female D. helophoroides were paired in opposite straight-line positions during copulation and separated once they had finished mating. ...
The gregarious ectoparasitic beetle Dastarcus helophoroides (Fairmaire) is considered a primary biocontrol agent for controlling several cerambycid pests in East Asian countries. A thorough study of reproductive behavior is a prerequisite for the mass production of natural insect predators. Nonetheless, little attention has been given to this ectoparasitic beetle. We performed a series of trials to assess whether the adult copulation duration, a key behavioral trait, is differentially influenced by physiological and ecological factors, including body size, mating history, kinship, sex ratio, mating sequence, feeding status, ambient temperature, photoperiod, and time of day. Additionally, the effect of the copulation duration on the reproductive output of this beetle was also investigated. The results indicated that the copulation duration varied considerably, ranging from 1.12 min to 16.40 min and lasting for an average of 9.11 ± 0.12 min. Females with longer copulations laid more eggs and had a greater proportion of eggs hatched. Medium-sized individuals copulated significantly longer than small- and large-sized individuals. The copulation durations were significantly longer when both sexes experienced an asymmetric mating history than when both sexes experienced a symmetric mating history. Inbred couples copulated significantly longer than outbred couples. In terms of the adult sex ratio, increasing the density of females (polygamous group) or males (polyandrous group) led to significantly longer copulation durations than those in the monogamous group. The copulation durations gradually decreased with increasing the mating sequence and temperature. Food-absence couples copulated significantly longer than food-presence couples. The mean copulation duration of the scotophase was significantly longer than that of the photophase. These results demonstrate that all of the analyzed factors emerge as important factors influencing the copulation duration, ultimately affecting the reproductive outputs in this ectoparasitic beetle.
... Among these pests, Red cotton bug, Dysdercus koenigii (Hemiptera: Pyrrhocoridae) is regarded as one of the major global pests causing severe economic loss. Immature nymphs as well as adults capable of rapid dispersal, suck the moisture and oil contents from the cotton leaves and seeds at a widespread scale reducing the crop yield extensively (Sahayaraj & Fernandez, 2017;Gupta, Shazad, & Kumar, 2019;Saeed & Abbas, 2020;Karar et al, 2020;Karar et al, 2021). ...
... The culture was maintained under the controlled conditions of 28 ± 2 °C, 80 ± 5% RH (Relative Humidity), and 14 h of light and 10 h of darkness. Adults and different nymphal stages were kept in separate sterilized glass jars of 1L capacity, containing sterilized cotton seeds and cotton swabs soaked in autoclaved water so as to minimize the risk of infection in the insects (Gupta et al, 2019). The food was changed on alternate days while the jars were changed twice a week in order to maintain hygienic conditions throughout the mass rearing of the culture. ...
Dysdercus koenigii is a major global pest of cotton that causes severe economic loss. Among several control measures, pyrethroids are frequently used toxicants because of high efficacy at low dosages and relative safety. Since haemocytes are biomarkers of the physiological response and immunity of insect which determine the insecticide efficacy, the current study assessed the effect of a pyrethroid, β-cyfluthrin, on the total and differential haemocyte counts of D. koenigii. Haemolymph was collected from the fifth instars after the topical application of β-cyfluthrin (0.8, 1.6, 3.2, 6.4 and 12.8 mg/L) on the thoracic tergum. The haemolymph of control nymphs revealed 5270 haemocytes/mm3 which decreased instantly by 1.4-3.1-fold on β-cyfluthrin exposure; more reduction observed at lower dosages. Increase in exposure duration and β-cyfluthrin dosages fluctuated the count considerably, eventually raising them at lower dosages and diminishing at higher dosages. Among five kinds of haemocytes recorded in the haemolymph, the β-cyfluthrin exposure increased %prohaemocytes count; diminished %granulocytes and %plasmatocytes count while spherulocyte and oenocyte counts were inconsistent. The alterations in haemocyte counts indicate the immunity response trigger in D. koenigii due to β-cyfluthrin-induced stress. Further investigations may decipher the mechanisms involved and help to formulate the strategies for its management in fields.
... Mating in Dysdercus koenigii lasts up to 72 h which enhances fecundity, fertility and organized oviposition behaviour and curtail preoviposition time (GUPTA et al 2019). Our studies indicate that mating had a pronounced effect on the ovarian growth and rate of vitellogenesis. ...
The ovaries of Dysdercus koenigii are consisted of meroistic telotrophic ovarioles. Each ovariole can be differentiated into tropharium and vitellarium. The tropharium contains stem line oogonia, newly formed oocytes, trophocytes, prefollicular cells and follicular cells. The vitellarium possesses 10-12 developing oocytes. The developing oocytes are connected to the trophocytes, present in the tropharium, by nutritive cords. During premating period, the ovarioles change, resulting in increase the number of oocytes in the vitellarium. The developing oocytes in the initial stage of development are surrounded by columnar follicular cells, which are subsequently changed to cuboidal and squamous cells in a sequence. The process of vitellogenesis was initiated after 48 h of adult development with the appearance of perioocytic space. There was deposition of yolk material at the periphery of oocytes in the ovarioles of 72 h old females. The further development of oocytes and vitellogenesis remained suspended up to 12-14 days in the virgin females. On the other hand, mating stimulates the oocyte development and process of vitellogenesis. There were distinct morphometric and histological changes in the ovarioles as a consequence of mating; dimensions of vitellarium and oocytes of the mated female increased drastically. However, the size of tropharium and number of oocytes present in the vitellarium largely remained unchanged. The process of vitellogenesis also resumed followed by mating stimulus. Therefore, the oocytes were laden with yolk material; at this stage, the surrounded follicular layer is replaced by chorion.
Reproductive fitness of Dysdercus koenigii Fabricius as influenced by the Ocimum sanctum Linn. leaf hexane extract was assessed by observing mating behaviour, fecundity and fertility of the adults developed from the treated fifth instar nymphs. O. sanctum leaf hexane extract affected the mating behaviour of both males and females of D. koenigii. The male exhibited reduced sexual activity which resulted in decreased percent successful mating. There was a decrease in the number of males attempting mounting and the number of mounting attempts; an increase in time taken in order to mate successfully was also reported. The females showed drastic changes in the mating receptivity; in most of the cases, the treated females were non-responsive to the courting males. They often showed mate rejection behaviour which was characterized by shaking of their abdomen and kicking to the courting males with the help of hind legs. Maximum aberration in mating behaviour was seen in the mating pairs, where both the mating partners were treated. Also, the O. sanctum leaf hexane extract impaired oviposition and egg hatchability in a dose-dependent manner. There was a decrease in the number of egg batches and eggs laid by the treated female. Although, the females laid fertile eggs, a significant decrease in the percent egg hatchability was reported in the treated females. The present studies indicated that the O. sanctum leaf hexane extract drastically reduced the reproductive fitness of D. koenigii, and hence potentially may be used in ‘integrated pest management’ of D. koenigii and similar heteropteran insect pests.
