Aridifolia Sinensis Research Articles

Climate Change, Succession, and Reproductive Success of a Praying Mantid

AbstractWe examined the adult phase of the Chinese praying mantid, Tenodera aridifolia sinensis (Saussure) (Mantodea: Mantidae) at the end of five growing seasons spanning two decades (1999–2018) in a successional old field. Sex ratio, which is generally male-biased by the time all members of a cohort are adults, exhibited a steady decline in proportion of males and eventual reversal by 2016, even though the calendar time of the study did not vary among years. Increasing length and warmth of the growing season resulted in earlier maturation, so we were seeing later portions of the adult phase at the same calendar time over successive years. This result is consistent with the earlier-published hypothesis that global warming can reduce fitness by warming and extending the growing season: earlier maturation results in earlier oviposition, which in turn causes eggs to hatch before onset of winter, thereby dying before egg diapause can occur. This may push the latitudinal distribution of this, and of other univoltine semelparous insects, farther north as the climate continues to warm. Reproductive output for the population, measured as total number of eggs produced by a cohort, peaked in 2004 at 8,514 and then fell to 226 by 2018, as did estimated numbers of adults. This decline was probably due to shrinkage of the open field area where prey were more abundant, by more than 2/3 as cedar trees replaced herbaceous vegetation during plant secondary succession. This is consistent with the hypothesis that succession limits the residence time in a habitat for these mantids.

Cohabiting With the Enemy: Comparative Population Ecology of Two Mantid Species in a Successional Old Field.

Two praying mantids, Tenodera aridifolia sinensis Saussure and Tenodera angustipennis Saussure, are commonly found in the same old-field habitats in the eastern United States and in much of temperate zone Asia. Naturally established populations of these two species were studied intensively over two consecutive years (2010 and 2011) in an old field in southeastern Virginia, to compare life history features relevant to how they coexist, or whether one or the other of them is likely to be more successful in the same habitat. Populations of both species declined about 50% from 2010 to 2011 (adults from 47 to 21 for T. a. sinensis; 37 to 20 for T. angustipennis), but T. a. sinensis oviposited 10 oothecae and T. angustipennis only one in 2011. Tenodera a. sinensis was more abundant in the study site in both years, hatched earlier, and matured and oviposited earlier than T. angustipennis. Fewer females of both species survived to maturity in 2011 than in 2010, possibly indicating a reduction in prey or habitat suitability in 2011. We suggest that T. angustipennis will always be at a disadvantage as a result of its smaller body size, because of interspecific predation (and potentially competition) from its congener, lower clutch size, and susceptibility to egg parasitism. Further, environmental variability across field habitats and years profoundly affects populations of both species in successional old fields.

Dispersion and Temperature-Associated Orientation of Chinese Mantis (Mantodea: Mantidae) Egg Cases

Abstract The Chinese mantis, Tenodera aridifolia sinensis (Saussure), is a univoltine tritrophic predator of old fields, now widespread after its introduction into North America more than a century ago. In 3 y of study of a population in eastern Virginia, we observed several unusual features in this oldfield insect: >90% of egg cases deposited in shrubs and trees, many at heights >2 m, not on goldenrods and similar herbaceous plants as previously reported. Egg cases were nonrandomly oriented (to the south) but with no significant association between compass orientation and days to hatching of young. Egg cases were randomly dispersed but least dense in patches without woody plants, the opposite of expectation for an oldfield insect. Finally, smaller egg cases yielded fewer and later-hatching young when oriented towards the south. A parsimonious explanation is that some females produce >1 egg case in eastern Virginia, with later egg cases being smaller and with fewer eggs because of reduced food intake. Fur...

Coexistence of Two Congeneric Praying Mantids: A 7-Year Field Study of Reproductive Success and Failure.

Two species of Asian praying mantids, Tenodera angustipennis (Saussure) and Tenodera aridifolia sinensis (Saussure), which have become common to old fields in the northeastern United States, share a common resource base that raises the question of how they can coexist in the same habitat. We studied the reproductive output measured by numbers of oothecae of naturally established populations of these two species in an old field during 7 yr (2009–2015) of secondary succession. During the initial herbaceous vegetation-dominated stage, T. angustipennis oothecae were more abundant than those of its congener, but numbers steadily declined, until it had nearly disappeared by 2014. In contrast, numbers of T. a. sinensis oothecae increased from 2007 until 2014, and then sharply declined in 2015. The steady increase in abundance of this species throughout most of the successional development during the study may be owing to greater diversity of plant species used for oviposition. We believe that the most likely reasons for the continuous decline in T. angustipennis were a combination of intraguild predation by the larger T. a. sinensis, and egg parasitism by the wasp Podagrion mantis, which is not able to parasitize oothecae of T. a. sinensis. The later decline in T. a. sinensis may reflect the fact that the site had become dominated by trees, and neither of these species is typically found in forest habitats.

The Ontogenetically Variable Trophic Niche of a Praying Mantid Revealed by Stable Isotope Analysis.

Praying mantids have been shown to exert strong influences on arthropod community composition. However, they may not occupy the same trophic level throughout their lives. Trophic shifting over a life cycle could explain the documented variation in results from field studies, but specific interactions of predators within food webs have been difficult to determine simply by comparing control and treatment assemblages in field experiments. We examined the trophic position of the Chinese praying mantid, Tenodera aridifolia sinensis (Saussure), using stable isotope analysis (SIA). We measured the δ(13)C and δ(15)N of field-collected arthropods, and of laboratory groups of mantids fed known diets of these arthropods chosen from the most abundant trophic guilds: herbivores (sap feeders and plant chewers), and carnivores. We also collected mantids from the field over a growing season and compared their SIA values to those of the laboratory groups. Both δ(13)C and δ(15)N of mantids fed carnivorous prey (spiders or other mantids) were higher than those fed herbivores (grasshoppers). SIA values from field-collected mantids were highly variable, and indicated that they did not take prey from trophic guilds in proportion to their abundances, i.e., were not frequency-dependent predators. Further, δ(15)N decreased from a high at egg hatch to a low at the third instar as early nymphs fed mainly on lower trophic levels, and increased steadily thereafter as they shifted to feeding on higher levels. We suggest that the community impact of generalist predators can be strongly influenced by ontogenetic shifts in diet.

Macroscopic characteristics of the praying mantis electroretinogram

We described the macroscopic characteristics of the praying mantis ERG in three species, Tenodera aridifolia sinensis, Sphodromantis lineola, and Popa spurca. In all cases, when elicited by square wave light pulses longer than 400ms, light adapted (LA) ERGs consisted of four component waveforms: a cornea negative transient and sustained ON, a cornea negative transient OFF, and a cornea positive sustained OFF. The former two ON, and the latter OFF components were attributed to photoreceptor depolarization and repolarization, respectively. Metabolic stress via CO2 induced anoxia selectively eliminated the transient OFF (independent of its effect on the other components) suggesting the transient OFF represents activity of the lamina interneurons on which the photoreceptors synapse. Dark adapted (DA) ERGs differed from LA ERGs in that the sustained ON and OFF amplitudes were larger, and the transient ON and OFF components were absent. Increased stimulus durations increased the amplitudes and derivatives of, and decreased the latencies to the maximum amplitudes of the OFF components. Increasing stimulus intensity increased the amplitude of the sustained ON and OFF components, but not the transient OFF. These results suggest that the mantis’ visual system displays increased contrast coding efficiency with increased light adaptation, and that there are differences in gain between photoreceptor and lamina interneuron responses. Finally, responses to luminance decrements as brief a 1ms were evident in LA recordings, and were resolved at frequencies up to 60Hz.

Defensive Roles of (E)-2-Alkenals and Related Compounds in Heteroptera

We examined whether shared volatiles found in various heteropteran species and developmental stages function to repel predators. The nymphal dorsal abdominal gland secretions of Riptortus pedestris (Heteroptera: Alydidae) and Thasus acutangulus (Heteroptera: Coreidae), and the metathoracic scent gland secretion of Euschistus biformis (Heteroptera: Pentatomidae) adults were identified by gas chromatography/mass spectrometry (GC/MS). (E)-2-Hexenal, 4-oxo-(E)-2-hexenal (4-OHE), and (E)-2-octenal were found in all three species and deemed likely candidates for repelling predators. In addition to (E)-2-alkenals, the adult E. biformis secreted (E)-2-hexenyl acetate, (E)-2-octenyl acetate, and four hydrocarbons. We evaluated the potential predator repellent properties of these compounds and compound blends against a generalist, cosmopolitan insect predator, the Chinese praying mantid (Mantodea: Mantidae: Tenodera aridifolia sinensis). Mantids that experienced (E)-2-hexenal, (E)-2-octenal, and (E)-2-octenyl acetate moved away from the site of interaction, while 4-OHE and (E)-2-hexenyl acetate did not affect mantid behavior. The compound blends did not have additive or synergistic repellency effects on predator behavior. Compound repellency was not related to compound volatility. Instead, the repellent effect is likely related to predator olfaction, and the affinity of each compound to receptors on the antennae. Our results also suggest the repellents might intensify the visual defensive signals of aposematism (T. acutangulus nymphs) and mimicry (R. pedestris nymphs) in heteropteran bugs.

Examinations of Female Pheromone use in Two Praying Mantids,Stagmomantis limbataandTenodera Aridifolia Sinensis(Mantodea: Mantidae)

AbstractFemale pheromones were examined in two species of praying mantids: Stagmomantis limbata Hahn and the Chinese mantid, Tenodera aridifolia sinensis Saussure. As in other mantids, females of both of these species are poor flyers or flightless, whereas males are flight-capable. Yet, they differ in ecology and biogeography, with the study population of S. limbata (native to Nearctic region) occurring at low density in desert habitat, and the study population of T. aridifolia sinensis (native to Indomalaya region) occurring at high density in humid woodlands. For both species, we designed field experiments to allow for the attraction of males via chemical signals while controlling for visual cues. Both species show evidence of female-emitted pheromones. In S. limbata, females in covered field cages attracted males, whereas large insects (cockroaches) in covered cages and covered empty cages failed to attract any males. In a second experiment with S. limbata, males were preferentially attracted to well-fed females over poorly-fed females, suggesting that pheromone emission is an “honest” signal of female receptivity in this species. Male arrivals in S. limbata were significantly clustered in the first few hours after sunrise. In T. aridifolia sinensis, covered females (female chemical cues) attracted more males than paired covered controls (empty), and attracted more males than uncovered conspecific males (male chemical and visual cues). Females in uncovered cages (female chemical and visual cues) attracted more males than covered females and more than uncovered controls (empty). This last result highlights the dual importance of chemical and visual information in mantid mating behavior. Female-emitted pheromones are certainly important in long-distance attraction in mantids, whereas visual cues and signals become important at shorter range.

Visual Targeting of Forelimbs in Ladder-Walking Locusts

Accurate limb placement helps animals and robots to walk on substrates that are uneven or contain gaps. Visual information is important in controlling limb placement in walking mammals but has received little attention in insects. We investigated whether desert locusts walking along a horizontal ladder use vision to control limb placement. High-speed video analysis showed that locusts targeted their front legs to specific rungs in the absence of any previous contact, suggesting that visual information alone is sufficient for targeting single steps. Comparison between the proportions of missed steps before and after monocular occlusion showed that monocular visual information was used to place the ipsilateral but not the contralateral front leg. Accurate placement also depended upon mechanosensory inputs from the antennae and proprioceptive feedback from the ipsilateral but not the contralateral forelimb. Locusts also compensated for the loss of inputs to one eye by altering their stepping pattern. Changing the rung position after initiation of a step showed that targeting of the front leg depends on visual information acquired before but not during a step. The trajectory was only modified after missing the rung. Our data show that locusts walking in environments where footholds are limited use visual and mechanosensory information to place their front legs.

Do exotic generalist predators alter host plant preference of a native willow beetle?

Abstract1 Selection can favour herbivores that choose host plants benefitting their offspring either by enhancing growth rates or by increasing larval defences against native predators. For exotic predator species that feed on herbivores, their success with invading new habitats may depend upon overcoming defences used by native prey. Whether exotic predators can alter herbivore host choice has remained unexamined. Therefore, we compared the efficacy of larval defence by Chrysomela knabi (a native beetle species) that had fed on two native willow hosts: Salix sericea (a phenolic glycoside (PG)‐rich species) and Salix eriocephala (a PG‐poor species), when attacked by exotic generalist predators. In addition, the preference and performance of C. knabi on S. sericea and S. eriocephala was examined.2 Chrysomela knabi preferred and performed better on S. sericea. In a common garden, adult C. knabi were nine‐fold more common and oviposited five‐fold more frequently on S. sericea than on S. eriocephala. In the laboratory, adult feeding preference on leaf discs and survival rates of larvae were both greater on S. sericea, and time to pupation was shorter.3 Chrysomela knabi larvae produced significantly more salicylaldehyde when fed S. sericea leaves than when fed S. eriocephala leaves. Additionally, those larvae with greater salicylaldehyde had reduced predation by two exotic generalist predators, Harmonia axyridis larvae and juvenile Tenodera aridifolia sinensis.4 The results obtained in the present study suggest that selection favoured the preference of C. knabi for PG‐rich willow plants because larvae grew and survived better and that selection by common exotic generalist predators would reinforce this preference.

Mate attraction by females in a sexually cannibalistic praying mantis

We studied mate attraction by females of the praying mantid, Tenodera aridifolia sinensis, testing honest signaling of mate availability versus deceptive signaling to attract males for sexual cannibalism. We experimentally varied female diet and mating history and measured the rate of attraction of a wild population of males to caged females. Honest signaling theory predicts that virgin females will attract males at the greatest rate whereas deceptive signaling predicts that hungry females (which are more likely to cannibalize males) will attract more males, particularly among non-virgin females. Our results show that hungry females did not attract more males than well-fed females. Indeed, the opposite was true: hungry females attracted significantly fewer males. Moreover, hungry females were no more likely than well-fed females to attract males subsequent to mating, and mated females attracted males at a lower rate than did virgin females. We also observed female T. aridifolia sinensis and male Mantis religiosa arriving at the caged females and we discuss the significance of these observations. The results refute the hypothesis of deceptive signaling and show that mate attraction signals of female T. aridifolia sinensis are honest indicators of female mate availability and a lower risk of sexual cannibalism.

Complicity or Conflict over Sexual Cannibalism? Male Risk Taking in the Praying Mantis Tenodera aridifolia sinensis

Male complicity versus conflict over sexual cannibalism in mantids remains extremely controversial, yet few studies have attempted to establish a causal relationship between risk of cannibalism and male reproductive behavior. We studied male risk-taking behavior in the praying mantid Tenodera aridifolia sinensis by altering the risk imposed by females and measuring changes in male behavior. We show that males were less likely to approach hungrier, more rapacious females, and when they did approach, they moved more slowly, courted with greater intensity, and mounted from a greater distance. Similarly, when forced to approach females head-on, within better view and better reach of females, males also approached more slowly and courted with greater intensity. Thus, males behaved in a manner clearly indicative of risk avoidance, and we support the hypothesis of sexual conflict over sexual cannibalism.

Complicity or Conflict over Sexual Cannibalism? Male Risk Taking in the Praying Mantis Tenodera aridifolia sinensis

Male complicity versus conflict over sexual cannibalism in mantids remains extremely controversial, yet few studies have attempted to establish a causal relationship between risk of cannibalism and male reproductive behavior. We studied male risk‐taking behavior in the praying mantid Tenodera aridifolia sinensis by altering the risk imposed by females and measuring changes in male behavior. We show that males were less likely to approach hungrier, more rapacious females, and when they did approach, they moved more slowly, courted with greater intensity, and mounted from a greater distance. Similarly, when forced to approach females head‐on, within better view and better reach of females, males also approached more slowly and courted with greater intensity. Thus, males behaved in a manner clearly indicative of risk avoidance, and we support the hypothesis of sexual conflict over sexual cannibalism.

Cues Used in Patch Selection by Praying Mantis Nymphs (Mantodea, Mantidae)

Abstract Visual and chemical cues may provide predators with information on the abundance and quality of prey in a particular area. In a laboratory study we investigated if general cues of prey and prey habitat had an effect on the patch selection and orientation of Chinese praying mantis nymphs (Tenodera aridifolia sinensis Saussure). For location, juvenile mantids spent more time on the side of the arena with chemical cues from crickets relative to a blank control and more time on the side with brightly colored images of flowers relative to a “grass” control. For orientation, individuals spent more time oriented toward moving crickets and images of flowers than control sides of the arenas. Use of these cues may aid mantis nymphs in locating prey in nature.

Chemical Cues from an Introduced Predator (Mantodea, Mantidae) Reduce the Movement and Foraging of a Native Wolf Spider (Araneae, Lycosidae) in the Laboratory

Exotic predators are sometimes introduced into agricultural ecosystems to aid in biological control of crop pests. Besides direct effects, such as consumption, introduced predators can have indirect effects on smaller predators and herbivores through chemically mediated shifts in behavior. We tested whether the chemical cues of Tenodera aridifolia sinensis (the Chinese praying mantis) affected the movement and foraging of the native wolf spider Pardosa milvina. Comparisons of behavior in paired-treatment arenas revealed that P. milvina spent a greater amount of time immobile, had a greater residence time, and moved at a significantly slower speed on T. a. sinensis cues relative to a blank control. While this reduced movement may reduce the probability of predation, it has a cost in terms of foraging. P. milvina gained less mass and had a smaller increase in abdomen width after foraging in microcosms containing T. sinensis cues relative to blank controls. The response of P. milvina to chemical cues of mantids is similar to the response of this small wolf spider to chemical cues from a larger, coexisting wolf spider predator. While these effects appear important in the lab, further studies are needed to evaluate the impact of cues on populations of P. milvina in the field.

Life History, Environment, and Deme Extinction in the Chinese Mantid <I>Tenodera aridifolia sinensis</I> (Mantodea: Mantidae)

We studied four demes of the Chinese praying mantid, Tenodera aridifolia sinensis Saussure, in southwestern Virginia for periods ranging from one to six growing seasons to determine life history parameters and population dynamics of this introduced univoltine species. Survival from egg hatch to imago averaged 5%, but there was no significant relationship between initial and adult densities, both of which were highly variable within and among demes. The lowest survival rates (including two deme extinctions) occurred in years where precipitation during the first 2 mo after egg hatch was >50% below a 30-yr mean. Most mortality occurs during the juvenile stadia as a function of food limitation; therefore, dry conditions may have exacerbated this condition. Fecundity was not related to density of adults, but females that were food limited had lower fecundities than those not food limited. Replacement rate, R, averaged ≈1.0 but also was highly variable and was not a significant predictor of densities in successive years. Our results, combined with those from a Maryland study, indicate that deme extinction can be caused by extreme abiotic conditions: cool temperatures delay maturation and curtail reproduction before killing frost, and drought can reduce survival of nymphs to the imago, both of which adversely affect reproductive success. Intrinsic vagility is low, so metapopulation persistence of this and other species with similar life histories may be at risk if climate change increases the rate of deme extinction beyond interdeme dispersal rates.

Pollen Feeding and Fitness in Praying Mantids: The Vegetarian Side of a Tritrophic Predator

Although the importance of omnivory in food webs has been established, the community niche of generalist arthropod predators such as praying mantids is usually assumed to be at most bitrophic, feeding on herbivores and other carnivores. As with most predators, mantids often are food limited in nature. Flowering plants in their environment offer mantids an opportunity to obtain high-protein pollen, a potential vegetarian alternative to their normal arthropod prey. Although some arthropod predators have been shown to feed occasionally on pollen, the extent to which they gain fitness from this behavior is unclear, and often assumed to be minor. In replicated laboratory tests, Chinese mantids, Tenodera aridifolia sinensis (Saussure), actively fed on pollen just after hatching, and on pollen-laden insects as adults. Pollen feeding enhanced fitness of these mantids by: 1) preventing starvation of nymphs at egg hatch in the absence of normal insect prey; 2) increasing body mass of nymphs fed pollen in addition to normal prey; and 3) allowing adults that were fed both pollen and insects to maintain the same fecundity on fewer insect prey than those fed insects alone. These predators are therefore tritrophic because the extent of their omnivory includes a fitness-enhancing plant product in addition to herbivore and carnivore prey. Pollen feeding may explain higher fecundity of females located on flowers, and also may enable these and other generalist predators to maintain high population densities when animal prey are scarce, which has potential consequences for the rest of the community.

The Roles of Vision and Antennal Olfaction in Enemy Avoidance by Three Predatory Heteropterans

We examined the relative importance of vision and antennal olfaction in enemy avoidance by three heteropterans. Jumping spiders (Phidippus spp.) served as enemies of Nabicula subcoleoptrata (Kirby) and Nabis americoferus Carayon, and praying mantids (Tenodera aridifolia sinensis Saussure) were used as enemies of Sinea diadema (F.). In a greenhouse study, the number of bugs surviving enclosure with spiders or mantids was compared among individuals without vision, without antennal olfaction and controls after 0.5, 1, 4, and 24 h. For Nabicula subcoleoptrata and S. diadema, vision appeared to be of primary importance in avoiding capture by enemies. In contrast, most Nabis americoferus were killed by spiders and no significant difference in survival existed among the treatment groups. The importance of vision in predator avoidance is in contrast with a recently documented reliance on antennal olfaction for prey location in these species. Thus, stimuli from prey and predators may be segregated to maximize the efficiency of sensory information processing.

Podagrion sp. (Hymenoptera:Torymidae), an Egg Parasitoid of Mantids in Nagaland

The eggs of Tenodera aridifolia sinensis (Saussure) were parasitised by Podagrion sp. in Nagaland. The per cent oothecae parasitised was 28 and 40.6 during 1987 and 1988, respectively.

Adult Dispersal of Tenodera aridifolia sinensis (Mantodea: Mantidae)

Adult male and female mantids, Tenodera aridifolia sinensis Saussure, exhibited similar dispersal in a large, natural field population. Distance and frequency of movement of bee-tagged individuals was the same for each sex, and neither sex demonstrated a significant directional bias. Therefore, contrary to the findings of an earlier study, females can move as far on the ground as males can fly during their adult lives under natural circumstances. Neither males nor females moved farther than 70 m from the point at which they were originally tagged, which may explain the disjunct local distribution of this geographically widespread, introduced species.