Aphidophagous Ladybird Beetle Research Articles

Prey species mediated slow and fast development in two aphidophagous ladybird beetles

Prey species mediated slow and fast development in two aphidophagous ladybird beetles

Crowding as a possible stress factor in food choice of aphidophagous ladybird beetle, Propylea dissecta (Mulsant)

Crowding induces behavioural and lasting morphological and chromatic changes in insects. This study examined how larval rearing density of Propylea dissecta (Mulsant, 1850) affected food choice and development duration, hypothesising that larvae under stress will opt for lower quality food as larval density increases. Larvae were reared at various densities under three crowding treatments: direct physical, indirect physical, and chemical tracks. In each treatment, larvae experienced crowding at densities of 0, 2, 4, 6, 8, 10, and 12 individuals per arena. Fourth stage larvae were provided with food choice of aphids, heterospecific eggs, and conspecific eggs. Significant effect of crowding on total development duration, first consumption time, and first food consumption was observed. Decrease in development duration at densities of 4 and 6 and increase in development duration at low and high densities were observed in direct physical crowding. Indirect physical and chemical crowding yield the shortest development duration at densities of 8, 10, and 12, when compared to low and moderate crowding. First encounter time increased with increasing chemical tracks concentration, while first consumption time decreases with crowding across all groups. First consumed food was also significantly influenced by crowding, suggesting a negative impact on larval food choice. Our results indicate that crowding among larvae leads to a longer development duration and show less selectivity in their food choices.

Prey species restrict limb regenerative growth in a ladybird beetle, Cheilomenes sexmaculata: allocation costs of regeneration?

ABSTRACT In aphidophagous ladybird beetles, amputation of limbs in the larval stage leads to limb regeneration in adults. Regeneration is an energetically expensive phenomenon, and altering prey species may have profound consequences on this process. Therefore, we hypothesised that the quality of prey species will impact the ability to regenerate the lost limbs in Cheilomenes sexmaculata. For this experiment, we reared the larvae of C. sexmaculata on two aphid prey species: Aphis craccivora, which is the most preferred good-quality aphid, and A. nerii, which is the least preferred, poor-quality aphid. Although regeneration occurred in both dietary regimes, the extent of regeneration was higher in the beetles fed on A. craccivora. The length of the regenerated legs was shorter than the control/unamputated beetles, and it was further reduced when the prey species was of poor-quality indicating additional utilisation of resources for tissue repair and regeneration. Regeneration delayed pupal duration, post-amputation developmental duration and relative growth rate (RGR). Poor diet negatively affected developmental durations and RGR. Our results indicate prey dependency on regeneration and highlight energetic demands of regeneration and its associated developmental allocation costs.

Coccinellid predation efficiency on Aphis gossypii (Hemiptera: Aphididae) under laboratory conditions.

In this study, we investigated the biological aspects and predation efficiency of 3 aphidophagous ladybird beetles, Coccinella novemnotata, Hippodamia variegata, and Coccinella septempunctata, on the cotton aphid, Aphis gossypii, reared on cucumber plants (Cucumis sativus L. cultivar barracuda) under laboratory conditions. The developmental periods of C. novemnotata, H. variegata, and C. septempunctata were observed to be 16.00 ± 0.25, 16.00 ± 0.25, and 20.58 ± 0.40 days, respectively. The larvae of these ladybird beetles consumed an average of 218.93 ± 8.86, 254.77 ± 8.86, and 537.36 ± 10.49 aphids, respectively. Fourth-instar larvae were particularly efficient, consuming 53.68%, 52.68%, and 52.64% of total aphids for C. novemnotata, H. variegata, and C. septempunctata, respectively. Adult emergence rates were promising, with 91.67%, 100.00%, and 92.86%, accompanied by sex ratios of 63.64%, 53.84%, and 61.54%, respectively. Notably, a single female of C. novemnotata, H. variegata, and C. septempunctata consumed an average of 2,215.30, 2,232.00, and 3,364.50 aphids, respectively, over its lifespan. Coccinella septempunctata demonstrated the highest predation efficiency among the 3 species, suggesting its potential for biological control of A. gossypii in both open fields and greenhouses, promoting sustainable agricultural practices.

Dietary conditioning on aphids and conspecific eggs in the ladybirdMenochilus sexmaculatusFabricius influences cannibalistic food choices in subsequent generations

AbstractMenochilus sexmaculatus, a generalist aphidophagous ladybird beetle, is one of the potential biocontrol agents of multiple aphid species. This beetle exhibits cannibalism among different life stages. A laboratory experiment was conducted by conditioning the larvae and adults on their natural prey that is aphids, or the conspecific eggs for five generations to assess whether cannibalism was affected by prior cannibalistic experiences or not. Adults of the fifth generation were provided with a choice of aphids and eggs. The time of first prey encounter and prey first encountered along with latency to consume prey and prey first consumed were recorded. Non‐cannibalistic individuals preferred aphids over eggs, while cannibalistic individuals showed no preference. The time of first prey encounter and consumption were similar for aphids and eggs irrespective of the diet they were reared on. To assess the long‐term effects, offspring developmental duration and body weight were recorded across generations. Similar developmental duration of immature stages was recorded in the first and second generations of cannibalistic and non‐cannibalistic lines; however, prolonged developmental duration was recorded in cannibalistic lines when compared with non‐cannibalistic ones of later generations. Offspring of later generations developed faster in both lines. The offspring body weight of the second and fourth generations of both lines was found to be similar. However, a decline in body weight was recorded in cannibalistic offspring of the first, third and fifth generations when compared with non‐cannibalistic ones. A decline in the body weight of offspring across generations was observed in both lines. The findings suggest thatM. sexmaculatusrearing diet influences its preference for prey and that long‐term dietary conditioning can affect different fitness components. This could potentially reduce their effectiveness in biocontrol.

Female choice of mates in the aphidophagous ladybird beetle, Hippodamia variegata (Coleoptera: Coccinellidae): the effect of male age, sexual status and familiarity

Mating involves the transfer of sperm to females. Female reproductive investment is based on gamete numbers as well as gamete size. Females are more selective than males and this selection is based on numerous factors, like a male’s age, sexual status and familiarity. Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae) is an important natural enemy of many insect pests such as aphids, psyllids, whiteflies and mealybugs in many countries. We investigated female mate choice in Hippodamia variegate caging females with: (i) a young and a middle-aged male, (ii) a virgin and mated male and (iii) a novel and a familiar male. Time to and duration of copulation were recorded. Females preferred to mate with middle-aged and familiar males and did not differentiate between previously mated and virgin males. Females copulated quicker and for longer with young or familiar males.

Provision of small sterile eggs is a circumstance-dependent maternal investment in sibling cannibalism in the ladybird beetle Harmonia axyridis (Coleoptera: Coccinellidae)

Many aphidophagous ladybird beetles lay clusters of eggs and sibling cannibalism occurs at hatching. Larvae that hatch early tend to cannibalize undeveloped eggs and those that hatch late. The cannibalized eggs, especially those that are sterile, represent a maternal investment in the cannibal and are regarded as "trophic" eggs, which increase their chances of surviving. The characteristics of cannibalized eggs, however, are poorly studied. In this study, I determined the sizes of eggs that developing and undeveloped eggs within egg clusters of Harmonia axyridis (Coleoptera: Coccinellidae). Developing eggs were significantly larger (on average 3.45% larger) than the undeveloped sterile ones, which were mainly small. Furthermore, the hatchability of eggs was also significantly associated with their size, inclusive of the maternal effects. These results indicate that the production of relatively small sterile eggs functions as circumstance-dependent maternal investment in improving the survival of the first instar larvae to hatch in each egg cluster.

Are the effects of hunger stage-specific? A case study in an aphidophagous ladybird beetle.

Food availability is a fundamental factor determining an animal's potential fitness. Carry-over effects of food limitation from development to adulthood are known to influence reproduction, ageing, and tolerance to stress. We have examined the effect of stage-specific variation (before adult emergence or pre-emergence, post-emergence and post-mating) in food availability in Propylea dissecta (Mulsant). Larvae were reared separately on two different pre-emergence food regimes (abundant or restricted) until pupation. Newly emerged adults were further split into two groups and placed on abundant or restricted post-emergence regimes. After mating, females were split and reared on any one of two post-mating regimes. The results revealed that: (i) time to commence mating declined with increased food availability in pre- and post-emergence stages, (ii) mating duration increased with food availability post-emergence, (iii) highest reproduction output was observed in individuals who had abundant food pre- and post-emergence. However, food availability at the time of oviposition also had a strong influence on fecundity. Solo bouts of scarcity, regardless of which stage suffered them, were effectively managed in at least two of the three stages (pre-emergence, post-emergence, post-mating) had abundant food.

Geographic variation in the habitat preference of a scarce predatory insect: evolutionary and conservation perspectives

1. While there has been considerable focus on prey occurrence as a factor determining the habitat preference of predators, the roles of other factors related to the habitat are less well characterised.2. In aphidophagous ladybird beetles (Coleoptera: Coccinellidae), a number of species are more restricted in the habitats in which they live than are their prey. A number of such ladybirds appear to show geographic variation in habitat preference.3. To better understand these phenomena, this study considered geographic variation in habitat preference in one such species, the 5‐spot ladybird Coccinella quinquepunctata. Because of this ladybird's scarcity, a combination of over 20 years' observations, habitat surveys and online data was used to reach the study's conclusions.4. The data collected indicate that the ladybird is specialised in pioneer habitats close to water, but broadens its range to non‐riverine pioneer habitats in north‐west continental Europe, where it is likely that a damper (micro)climate allows it to do so. Thus, microclimatic factors appear to be important in determining the habitat of this and probably other predators that are not constrained by prey occurrence.5. Although threatened by river management elsewhere, in north‐western Europe, this species clearly benefits from human activity, which creates many of the disturbed habitats it colonises there. This finding provides further support for the contention that many ladybirds are net beneficiaries of human influence, although they are often characterised as threatened.

Carotenoids of dragonflies, from the perspective of comparative biochemical and chemical ecological studies

Carotenoids of 20 species of dragonflies (including 14 species of Anisoptera and six species of Zygoptera) were investigated from the viewpoints of comparative biochemistry and chemical ecology. In larvae, β-carotene, β-cryptoxanthin, lutein, and fucoxanthin were found to be major carotenoids in both Anisoptera and Zygoptera. These carotenoids were assumed to have originated from aquatic insects, water fleas, tadpoles, and small fish, which dragonfly larvae feed on. Furthermore, β-caroten-2-ol and echinenone were also found in all species of larvae investigated. In adult dragonflies, β-carotene was found to be a major carotenoid along with lutein, zeaxanthin, β-caroten-2-ol, and echinenone in both Anisoptera and Zygoptera. On the other hand, unique carotenoids, β-zeacarotene, β,ψ-carotene (γ-carotene), torulene, β,γ-carotene, and γ,γ-carotene, were present in both Anisoptera and Zygoptera dragonflies. These carotenoids were not found in larvae. Food chain studies of dragonflies suggested that these carotenoids originated from aphids, and/or possibly from aphidophagous ladybird beetles and spiders, which dragonflies feed on. Lutein and zeaxanthin in adult dragonflies were also assumed to have originated from flying insects they feed on, such as flies, mosquitoes, butterflies, moths, and planthoppers, as well as spiders. β-Caroten-2-ol and echinenone were found in both dragonfly adults and larvae. They were assumed to be metabolites of β-carotene in dragonflies themselves. Carotenoids of dragonflies well reflect the food chain during their lifecycle.

Influence of Crapemyrtle aphid, Tinocallis kahawaluokalani (Hemiptera: Aphididae) on population characteristics of three aphidophagous ladybird beetles

The crapemyrtle aphid, Tinocallis kahawaluokalani is a common sap-sucking insect pest of crapemyrtle plant, Lagerstroemia indica L. (Pers.) (Myrtales: Lythraceae). The life history and population characteristics of three aphidophagous ladybird beetles (Coccinella septempunctata, Menochilus sexmaculatus and Oenopia sauzeti) were studied on T. kahawaluokalani based on two sex life table theories. Results reveal that immature survival, total longevity of adult and reproductive parameters was higher for C. septempunctata than to M. sexmaculatus and O. sauzeti. The population dynamic parameters including net reproductive rate (R0), intrinsic rate of increase (r) and finite rate of increase (λ) were higher for C. septempunctata and M. sexmaculatus than those for O. sauzeti. The intrinsic rate of increase ‘r’ as a key fitness parameter for three aphidophagous predators on T. kahawaluokalani in increasing order was C. septempunctata > M. sexmaculatus > O. sauzeti. These results suggested that C. septempunctata and M. sexmaculatus have more potential to control T. kahawaluokalani. The information obtained from current study may also be useful in using T. kahawaluokalani for mass rearing of these beetles in the laboratory.

Weight dynamics in females of invasive and autochthonous populations of Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae) during the induction of reproductive diapause

Under natural conditions, predatory insects often faced the shortage of food caused by an increase in the predator population density and/or a decrease in the prey population density. Experimental studies demonstrated that females of two laboratory strains that originated from autochthonous (the Russian Far East) and invasive (Krasnodar territory of Russia) populations of the aphidophagous ladybird beetle, Harmonia axyridis showed two responses to the absence or shortage of aphids. The first response, termination of oviposition, was observed in several days after transfer to the poor diet, it was independent of photoperiod, and it was stronger in females of the invasive line. The second response, induction of reproductive diapause, was observed in 20 days after transfer to the poor diet, it interacted with the long-day photoperiodic response, and it was stronger in females of the autochthonous line. The induction of reproductive diapause (in comparison with a simple termination of oviposition) is a more basic and less easily reversible physiological process. Thus, we conclude that under natural conditions, females of invasive populations terminate oviposition with the first signs of a shortage of aphids more quickly than females of autochthonous populations and also more quickly start oviposition again with an increase in prey population density. Possibly, these features can be considered as adaptations to new, less stable and less predictable environmental conditions. DOI: 10.1134/S0013873816080029

Prey species modify interactions within two predator conspecific and heterospecific combinations: A case study using two sympatric Coccinella species (Coleoptera: Coccinellidae)

Multiple interactions (antagonistic/additive/synergistic) occurring within predatory combinations, determine the suitability of combinations in suppressing the aphid pests. In the present study such interactions within larval (fourth instars) and adult (10-day old females) combinations were assessed using two aphidophagous ladybird beetles — Coccinella septempunctata (L.)/C7 and Coccinella transversalis (F.)/Ct, on pea aphid, Acyrthosiphon pisum (Harris), bean aphid, Aphis craccivora Koch and mustard aphid, Lipaphis erysimi (Kaltenbach). Experiments were conducted to study the influence of prey species on predatory interactions of ladybirds kept within conspecific/heterospecific combinations; and to test the hypothesis whether predatory combinations tested on one prey species would perform equally on the other prey species. Results revealed that the performance of predators within combinations varied on different prey. Larval Ct+Ct and C7+Ct combinations had additive effects on L. erysimi and antagonistic effects on A. pisum and A. craccivora. Similarly, adult Ct+Ct combination exhibited an additive effect on A. craccivora and antagonistic effects on A. pisum and L. erysimi. Moreover, heterospecific combinations inflicted higher prey consumption, and had a higher conversion efficiency and body biomass gain than conspecific combinations; and despite causing higher prey consumption, adult combinations showed lower conversion efficiencies and body biomass gain than the larval combinations. Thus, efficacy of predatory combinations needs to be tested on target prey prior to the release of predatory combinations in the fields. Moreover, multi-species assemblages of ladybirds may provide better biological control of aphids compared to single species.

Do defensive chemicals facilitate intraguild predation and influence invasion success in ladybird beetles?

Egg predation and cannibalism are believed to be common phenomena among many species of aphidophagous predatory ladybird beetles despite the presence of alkaloid based defensive chemicals in all life stages. We identified defensive chemicals from eggs of three congeneric species, one introduced into North America (Coccinella septempunctata L.), and two native (C. transversoguttata richardsoni Brown, and C. novemnotata Herbst), and examined the effects of ingested defensive chemicals on first instars. Ingested congeneric alkaloids were not toxic to first instars, likely because the three congeners produce the same principal alkaloids, precoccinelline and coccinelline, in similar amounts. First instars of the three congeners accumulated alkaloids ingested through egg cannibalism and congeneric predation. Egg consumption doubled the amount of alkaloids in first instars when they fed on conspecific or congeneric eggs, in comparison to a pea aphid diet. No detrimental effects of ingested congeneric alkaloids on development or survival of first instars were observed among these congeners. Chemical defenses of eggs are therefore not likely to be important in favoring the invasive species, C. septempunctata, in interactions with these native congeneric species. Because the invasive species is the most aggressive predator, having the same types of alkaloids may facilitate disproportionate intraguild predation on native congeners by C. septempunctata thereby potentially enhancing the invasion success of this introduced species.

Biological traits and life table parameters of variegated lady beetle, Hippodamia variegata (Coleoptera: Coccinellidae) on three aphid species

The aphidophagous ladybird beetle, Hippodamia variegata (Goeze) (Coleoptera: Coccinellidae), is a dominant predator in various crop systems. Its life history was studied when fed on three aphid prey, viz. Aphis gossypii Glover, Aphis fabae Scopoli and Macrosiphum rosae (L.), under laboratory conditions, 25 ± 1 °C, 65 ± 5 % RH and a photoperiod of 16L:8D. The immature development period was shortest (15.2 days) when A. gossypii was used as prey and longest (18.9 days) on A. fabae. Adult coccinellids had the shortest longevity on A. fabae (64.8 days). The higher and lower mean daily fecundity was recorded for A. fabae (12.4 eggs) and M. rosae (6.2 eggs), respectively. The highest (291.0 eggs) and lowest (183.2 eggs) net reproduction rates (R0) were observed on A. fabae and M. rosae, respectively. Mean generation time (T) on rose aphid was significantly longer (33.4 days) than on the two other preys. The intrinsic rate of increase (rm) was affected by the R0 value, and it was highest on A. fabae (0.183) and lowest on M. rosae (0.156). Based on rm as an index of suitability of prey species, A. fabae was the most suitable prey for H. variegata. Our finding may provide basic information for developing aphid biological control programs.

Stage and age-specific predation in four aphidophagous ladybird beetles

In the present study, stage- and age-specific predatory patterns and nutritional ecology attributes of four co-occurring aphidophagous ladybirds, namely, Coccinella septempunctata (L.), Coccinella transversalis F., Cheilomenes sexmaculata (F.) and Propylea dissecta (Mulsant) on pea aphid, Acyrthosiphon pisum (Harris) were investigated. Despite their lower consumption rates, smaller ladybirds (C. sexmaculata and P. dissecta) and earlier instars were efficient converters of aphid prey with higher relative growth rates, over the respective larger ladybirds (C. septempunctata and C. transversalis) and fourth instars. The consumption rates of pea aphids by the larvae increased with stage, but with a decline in the later part of the fourth instars, just prior to pupation. Adult females of early age groups (between 2 and 7 days) had higher consumption rates than later age groups in all the four species. Further in adult females, consumption rates decrease with increase in age, but without significant changes in conversion efficiencies and relative growth rates.

Duration of development and survival of larvae of Coccinella transversalis (Coleoptera: Coccinellidae) fed on aphids and alternative foods

Food in providing essential nutrients for development and sustaining longevity is an important determinant in the survival of organisms. The aphidophagous ladybird beetle Coccinella transversalis is common in the Oriental region and feeds on a wide range of aphids that infest and seriously reduce the yield of agricultural crops. The availability of aphids fluctuates throughout the year, being usually present at the end of July and decreasing at the end of March. In this study C. transversalis was fed on essential (aphids) and alternative foods. The development was fastest with high larval survival when larvae were fed on A. craccivora followed by U. compositae , L. erysimi , A. gossypii , R. maidis , H. setariae , and H. coriandri . The alternative foods used were mealy bugs (coccids), honey, sugar syrup and pollen, however only the former two supported the survival and development.

Determining Diets of Ladybird Beetles (Coleoptera: Coccinellidae) from Contents of Frass

AbstractAmong the methods to evaluate field diets of insect predators is frass analysis. The potential of this infrequently used method was explored for determining prey consumption by adult ladybird beetles (Coleoptera: Coccinellidae) in alfalfa, Medicago sativa L., fields. A laboratory experiment revealed that at 20°C, within 48 h after consumption of prey [either pea aphids, Acyrthosiphon pisum (Harris), or larvae of the alfalfa weevil, Hypera postica (Gyllenhal)], almost all prey fragments had been voided by adults of five ladybird beetle species commonly occurring in Utah alfalfa fields. Among the five ladybird beetle species, aphid and weevil fragments were detected in frass of 80–95 and 29–73% of adults, respectively. A second laboratory experiment with adults of the most common of these predators (the introduced Coccinella septempunctata L.) more fully identified and enumerated diagnostic fragments for specific types of prey (aphids, weevil larvae, and conspecific larvae) as they occurred in frass. Frass pellets from the consumption of alfalfa weevil and conspecific larvae most often contained diagnostic cuticle and setae, and less often mandibles and head capsules. Frass from the consumption of pea aphids most often contained antennae and legs, and less often mouthparts, eyes, and tarsal claws. These laboratory results provide a foundation for using and interpreting the results of frass analysis as a technique to assess field diets of aphidophagous ladybird beetles in alfalfa.

Effects of mixed prey on the development and demographic attributes of a generalist predator, Coccinella septempunctata (Coleoptera: Coccinellidae)

Coccinella septempunctata Linnaeus, 1758 (Coleoptera: Coccinellidae) is an aphidophagous ladybird beetle species with cosmopolitan distribution. However, it may also thrive on arthropods other than aphids, when the latter are not readily available. Certain life history traits and demographic attributes of C. septempunctata were determined using seven different diets with different alternations and proportions of an aphid, Lipaphis erysimi (Kaltenbach,1843) and a mite, Tetranychus urticae Koch, 1836, in the laboratory (at 25±0.5°C, 65±5% RH and a photoperiod of 16 h L:8 h D).The larval duration was longest (12.61±6.17 days) when fed an alternating diet of two days aphid/two days mite. Adult longevity was longest (78.65±1.09 days) when fed aphids only and shortest (3.17±1.25 days) when fed mites only. Life expectancy (ex) was highest (111 days) when adults were fed only aphids and lowest (11.3 days) when fed only mites. Survival rates of ladybird beetles were positively related to an increasing ratio of aphids in their diet. Their ability to prey on both aphids and mites indicates the effectiveness of C. septempunctata as a biological control agent on plants infested with these two pests.

Seasonal changes in the number of adults of two aphidophagous ladybird beetles, Coelophora inaequalis and Menochilus sexmaculatus (Coleoptera: Coccinellidae), in citrus orchards on the northern part of Okinawa Island, southwestern Japan

Seasonal changes in the number of adults of two aphidophagous ladybird beetles, Coelophora inaequalis and Menochilus sexmaculatus (Coleoptera: Coccinellidae), in citrus orchards on the northern part of Okinawa Island, southwestern Japan