Seven-spotted Ladybird Beetle Research Articles

Morphological and structural characteristics of the elytra reduce impact damage to ladybird beetles

Beetle elytra act as natural protective covers and effectively shield their flexible abdomens and fragile hindwings from damage. The existing studies have attributed this contribution of the elytra to its honeycomb structures. In this combined experimental and theoretical study, we used the seven-spotted ladybird beetle to demonstrate that both biological morphology and the hollow structure of the dome-like elytra combined to reduce damage during falling. The falling ladybird beetles had a high probability (59.52%) of hitting the ground with the costal edge of the elytra. This strategy could assist with converting the translational energy into rotational kinetic energy, resulting in the reduction of the impulse during falling. In addition, the hollow structures on the elytra could further absorb the residual impact energy. In the future, this biological paradigm could be used as a basis for the development of falling/landing techniques for advanced robots.

Efficacy of Sulfoxaflor 12%SC Against Aphids Complex and <i>Coccinella septempunctata</i> L. in Wheat

Efficacy of dosages of sulfoxaflor 12%SC were evaluated for the control of foliar aphids under Contract Research Project on wheat during rabi seasons of 2014-15 and 2015-16 at the research farm of ICAR- Indian Institute of Wheat and Barley Research, Karnal, Haryana. The standard check insecticides thiamethoxam 25WDG and quinalphos 25EC were included along with sulfoxaflor, and all the treatments were found to be significantly superior. The incidence of aphids/ shoot/ plant was significantly less with sulfoxaflor 12 SC @ 24, 27 and 30 g a.i./ ha with 94.54, 95.27 and 96.03% reduction, respectively; these being at par with each other, followed by thiamethoxam 25WDG @ 12.5 g a.i./ ha and quinalphos 25EC @ 250 g a.i./ ha. The seven-spotted ladybird beetle Coccinella septempunctata L. was the main natural enemy observed in the crop, and its counts were the least (1.50/ m2) with thiamethoxam 25WDG @ 12.5 g a.i./ha at 14 DAS. The pooled data revealed that the yield was significantly more with sulfoxaflor 12SC @ 24, 27 and 30 g a.i./ ha (52.21, 52.62 and 54.32 q/ ha) followed by thiamethoxam 25WDG @ 12.5 g a.i./ ha (49.87 q/ ha) which was at par with quinalphos 25EC @ 250 g a.i./ ha (47.73 q/ha). Considering incremental cost benefit ratio, sulfoxaflor 12% SC @30 g a.i/ ha (1:2.70) is the most economical, and no phytotoxicity symptoms were observed at its doses @30 and 60 g a.i/ ha.

An improved artificial diet for larvae of the seven-spotted ladybird beetle Coccinella septempunctata L.

The seven-spotted ladybird beetle, Coccinella septempunctata, is an important predator of soft-bodied insect pests that can be reared on both natural and artificial diets. In this study, an artificial diet for larvae was optimized by using a four-factor and three-level orthogonal design. Shrimp, pollen, lard, and honey were selected as the four key factors, and their effects on larval survival, development, and pupation were assessed. The results showed that an increased shrimp content of 21.85% in the diet could shorten developmental time and increase larval survival. Increased pollen content of 4.86% improved both pupation and survival, and a lard content of 3.03% shortened developmental time and increased survival and pupation success. The biological indices of ladybird larvae were optimal when honey content was 10.02%.

Surface chemistry of the ladybird beetle adhesive foot fluid across various substrates.

Nature has coevolved highly adaptive and reliable bioadhesives across a multitude of animal species. Much attention has been paid in recent years to selectively mimic these adhesives for the improvement of a variety of technologies. However, very few of the chemical mechanisms that drive these natural adhesives are well understood. Many insects combine hairy feet with a secreted adhesive fluid, allowing for adhesion to considerably rough and slippery surfaces. Insect adhesive fluids have evolved highly specific compositions which are consistent across most surfaces and optimize both foot adhesion and release in natural environments. For example, beetles are thought to have adhesive fluids made up of a complex molecular mixture containing both hydrophobic and hydrophilic parts. We hypothesize that this causes the adhesive interface to be dynamic, with molecules in the fluid selectively organizing and ordering at surfaces with complimentary hydrophobicity to maximize adhesion. In this study, we examine the adhesive fluid of a seven-spotted ladybird beetle with a surface-sensitive analytical technique, sum frequency generation spectroscopy, as the fluid interacts with three substrates of varied wettabilities. The resulting spectra present no evidence of unique molecular environments between hydrophilic and hydrophobic surfaces but exhibit significant differences in the ordering of hydrocarbons. This change in surface interactions across different substrates correlates well with traction forces measured from beetles interacting with substrates of increasing hydrophobicities. We conclude that insect adhesion is dependent upon a dynamic molecular-interfacial response to an environmental surface.

Biological control of mustard aphid, Lipaphis erysimi (Kaltenbach, 1843) through seven-spotted ladybird beetle, Coccinella septempunctata (Linnaeus, 1758) under laboratory conditions

The research study was conducted at the Entomology Laboratory, Department of Zoology, SALU, Khairpur during, 2017-18. Among biological parameters such as; fecundity, fertility, and egg hatching % of a predator, seven-spotted ladybird beetle were 143, 165 and 86, respectively. Whereas; the results of the biology of seven-spotted ladybird beetle show that the first larval stage took up (4.08) days to develop into a second stage that took up (5.32) days, the third stage (6.80) days and the fourth stage (8.00) days to convert into pupae (6.04) days. The overall female days were observed up to (43.76) and the male (39.36). After hatching, the 1st larval stage consumed up to (2) aphids whereas; the 2nd stage (19), the 3rd larval stage (34) with the 4th stage (48) per day, later on, these larvae were converted into pupal stage thus, the adult stage consumed (40) aphids at per day. The ANOVA showed considerable differences in feeding efficiency of Seven-spotted ladybird beetle on aphids under laboratory conditions at (P<0.05). It is concluded; the ladybird beetle, C. septempunctata is well known as a good biological control agent because of predation in nature that has a short life cycle which is also a good character. Thus, the above-mentioned species can be fruitfully used to minimize the sucking insect pests under mustard crop. Keywords: Biology; Feeding behavior; Predator; Sucking pest http://dx.doi.org/10.19045/bspab.2019.80114

Repeated inversions within a pannier intron drive diversification of intraspecific colour patterns of ladybird beetles

How genetic information is modified to generate phenotypic variation within a species is one of the central questions in evolutionary biology. Here we focus on the striking intraspecific diversity of >200 aposematic elytral (forewing) colour patterns of the multicoloured Asian ladybird beetle, Harmonia axyridis, which is regulated by a tightly linked genetic locus h. Our loss-of-function analyses, genetic association studies, de novo genome assemblies, and gene expression data reveal that the GATA transcription factor gene pannier is the major regulatory gene located at the h locus, and suggest that repeated inversions and cis-regulatory modifications at pannier led to the expansion of colour pattern variation in H. axyridis. Moreover, we show that the colour-patterning function of pannier is conserved in the seven-spotted ladybird beetle, Coccinella septempunctata, suggesting that H. axyridis’ extraordinary intraspecific variation may have arisen from ancient modifications in conserved elytral colour-patterning mechanisms in ladybird beetles.

Influence of lethal and sublethal exposure to clothianidin on the seven-spotted lady beetle, Coccinella septempunctata L. (Coleoptera: Coccinellidae)

The seven-spotted ladybird beetle, Coccinella septempunctata L., as a dominant predator of aphids, has played a crucial role in integrated pest management (IPM) strategies in agricultural ecosystems. To study the risk of insecticides to C. septempunctata, the neonicotinoid clothianidin was selected for evaluation of its influence on C. septempunctata at lethal and sublethal doses. The LR50 (application rate causing 50% mortality) in the exposed larvae decreased from 19.94 to 5.91 g a.i. ha−1, and the daily HQ (hazard quotient) values increased from 3.00 to 10.15, indicating potential intoxication risks. We also determined NOERs (No Observed Effect application Rates) of clothianidin on the total developmental time (10 g a.i. ha−1), survival (2.5 g a.i. ha−1) and pupation (5 g a.i. ha−1). Moreover, clothianidin at a NOER of 2.5 g a.i. ha−1 did not profoundly affect adult emergence, fecundity or egg hatchability. The total effect (E) assessment also showed that clothianidin at 2.5 g a.i. ha−1 was slightly harmful to C. septempunctata. These results suggested that clothianidin would impair C. septempunctata when applied at over 2.5 g a.i. ha−1 in the field. Conservation of this biological control agent in agricultural ecosystems thus requires further measures to decrease the applied dosages of clothianidin.

Influence of ambient humidity on the attachment ability of ladybird beetles (Coccinella septempunctata).

Many insects possess adhesive foot pads, which enable them to scale smooth vertical surfaces. The function of these organs may be highly affected by environmental conditions. Ladybird beetles (Coccinellidae) possess dense tarsal soles of tenent setae, supplemented with an adhesive fluid. We studied the attachment ability of the seven-spotted ladybird beetle (Coccinella septempunctata) at different humidities by horizontal traction experiments. We found that both low (15%) and high (99%) relative humidities lead to a decrease of attachment ability. The significantly highest attachment forces were revealed at 60% humidity. This relationship was found both in female and male beetles, despite of a deviating structure of adhesive setae and a significant difference in forces between sexes. These findings demonstrate that not only dry adhesive setae are affected by ambient humidity, but also setae that stick due to the capillarity of an oily secretion.

Intraspecific differences in plant chemotype determine the structure of arthropod food webs.

It is becoming increasingly appreciated that the structure and functioning of ecological food webs are controlled by the nature and level of plant chemicals. It is hypothesized that intraspecific variation in plant chemical resistance, in which individuals of a host-plant population exhibit genetic differences in their chemical contents (called 'plant chemotypes'), may be an important determinant of variation in food web structure and functioning. We evaluated this hypothesis using field assessments and plant chemical assays in the tansy plant Tanacetum vulgare L. (Asteraceae). We examined food webs in which chemotypes of tansy plants are the resource for two specialized aphids, their predators and mutualistic ants. The density of the ant-tended aphid Metopeurum fuscoviride was significantly higher on particular chemotypes (borneol) than others. Clear chemotype preferences between predators were also detected. Aphid specialist seven-spotted ladybird beetles (Coccinella septempunctata) were more often found on camphor plants, while significantly higher numbers of the polyphagous nursery web spider (Pisaura mirabilis) were observed on borneol plants. The analysis of plant chemotype effects on the arthropod community clearly demonstrates a range of possible outcomes between plant-aphid-predator networks. The findings help to offer a deeper insight into how one important factor--plant chemical content--influences which species coexist within a food web on a particular host plant and the nature of their trophic linkages.

Phototactic Behavior ofCoccinella septempunctataL. (Coleoptera: Coccinellidae)

We studied the behavioral response of the seven-spotted ladybird beetle, Coccinella septempunctata L., (Coleoptera, Coccinellinae) to various light wavelengths and intensities. Significant differences in the phototactic responses of beetles to 15 wavelengths of monochromatic light and white light were found. High phototactic response rates were observed to red light (649 nm) and ultraviolet (UV) light (340 nm), whereas low response rates were seen to green light, the species thus exhibiting a U-shaped response across the spectrum. The beetle also showed variation in response to 10 different illumination intensities. For a range of light intensities from 10 to 190 lux, beetles were generally more sensitive to ultraviolet light (340 nm) and red light (649 nm) than green light (510 nm) or white light. Differences in beetle response to various specific wavelengths were smallest in dim light (10 lux). The responses to ultraviolet and red light compared to those to green and white light were higher across all light intensity levels tested. The phototactic response to illumination intensity was correlated with light wavelengths, but there was no common trend across the three wavelengths of monochromatic light and white light. This experiment will help provide a scientific basis for the development of selected color traps used in insect pest management.

Slippery pores: anti-adhesive effect of nanoporous substrates on the beetle attachment system.

Traction experiments with adult seven-spotted ladybird beetles Coccinella septempunctata (L.) were carried out to study the influence of surface structure on insect attachment. Force measurements were performed with tethered walking insects, both males and females, on five different substrates: (i) smooth glass plate, (ii) smooth solid Al(2)O(3) (sapphire) disc, and (iii-v) porous Al(2)O(3) discs (anodisc membranes) with the same pore diameter but different porosity. The traction force of beetles ranged from 0.16 to 16.59 mN in males and from 0.32 to 8.99 mN in females. In both sexes, the highest force values were obtained on smooth solid surfaces, where males showed higher forces than females. On all three porous substrates, forces were significantly reduced in both males and females, and the only difference within these surfaces was obtained between membranes with the highest and lowest porosity. Males produced essentially lower forces than females on porous samples. The reduction in insect attachment on anodisc membranes may be explained by (i) possible absorption of the secretion fluid from insect adhesive pads by porous media and/or (ii) the effect of surface roughness. Differences in attachment between males and females were probably caused by the sexual dimorphism in the terminal structure of adhesive setae.

Relative Occurrence and Abundance of Mustard Aphid, Lipaphis erysimi (Kalt.) and Their Predators on Rainbow and Oscar Canola Varieties

The studies on the relative occurrence and abundance of mustard aphid, Lipaphis erysimi (Kalt.) revealed that aphid appeared on leaves during 3rd week of January and on the inflorescences during 2nd week of February and continued up to harvesting on both the varieties. The peak populations (42.7) and (28.7) per leaf on Rainbow and Oscar varieties were recorded. Whereas, the peak populations (7.5) and (6.6) per inflorescences were recorded on these varieties. The higher mean population ranges (9.2 to 28.7) and (25.1 to 42.7) per leaf on Oscar and Rainbow and (3.9 to 6.6) and (2.3 to 7.6) per inflorescence were recorded from February 15 to March 5. The temperature range of 16.5 to 20.6 °C, seems to have favored the pest multiplication. The predator species such as, green lacewing beetle, Chrysoperla cornea (Stephens), eleven-spotted ladybird beetle, Coccinella undecimpunctata (Linn.) and seven-spotted ladybird beetle, Coccinella septempunctata (Linn.) were recorded when the pest population of aphids was sufficiently developed on the canola varieties.

HABITAT DISPLACEMENT OF NORTH AMERICAN LADYBIRDS BY AN INTRODUCED SPECIES

How introduced species displace native species is often poorly understood. Various studies suggest that several species of native ladybird beetles (Coleoptera: Coccinellidae) have declined in abundance in particular habitats (especially crops) and/or geographic regions following the colonization of North America by the seven-spotted ladybird beetle (Coccinella septempunctata L.). However, the factors responsible for such declines are unclear. Long-term sampling of alfalfa fields in northern Utah revealed that as C. septempunctata established itself and increased in numbers, densities of native species decreased significantly over the period 1992–2001. The decline in numbers of native ladybirds mirrored a decline in numbers of their principal prey in alfalfa, pea aphids. Field experiments with induced aphid outbreaks were conducted to test the hypothesis that dispersing native adults have shifted their foraging efforts away from alfalfa as the introduced species has increased in numbers and depressed prey availability. As predicted by the hypothesis, native ladybirds rapidly reaccumulated in alfalfa when prey became abundant. Their presence was brief, however, as they and especially the more numerous C. septempunctata quickly suppressed experimental aphid outbreaks. The ratio of densities within experimental plots with high aphid numbers to densities in the surrounding field was greater for native ladybirds than for C. septempunctata. Also, densities of native ladybirds varied more closely with aphid densities among fields in late May 2001 than did densities of C. septempunctata. Hence, native ladybirds appear especially responsive to local aphid density. C. septempunctata's impact on aphid density in alfalfa appears to have reduced significantly the degree to which the habitat retains foraging native adults. Thus, introduced species may influence the distribution and abundance of native competitors not only by reducing survivorship in local habitats, but also by altering the dynamics of dispersal and habitat use across the landscape.