Most people are able to identify praying mantids in our landscapes and think of them as a cool beneficial insect, a “guardian against pests.” But a closer look reveals a more complicated picture. Both native mantids and non-native invasive mantids inhabit our landscape and can have a significant impact on pollinators and the ecosystems they support.
Many refer to a member of this insect group as “praying mantis” but mantis refers to the specific genus, while the term mantid refers to a larger group of insects that appear to be praying when at rest. This creature looks quite tranquil, sitting quietly with its praying pose, forelegs upraised, camouflaged, waiting for some unsuspecting insect or other small animal to wander by. The mantid’s neck allows the head to rotate 180 degrees to scan the area. When the insect wanders by, the praying mantid quickly snags a meal, using the long spines on the upper insides of its forelegs to hold its prey. Mantids do kill harmful plant-eating pests, but as generalist, ambush predators, they also kill virtually everything else, including beneficial insects. “They just eat whatever is moving and within their reach,” said Michael Maxwell, a behavioral ecologist at National University in La Jolla, California.
Identifying Invasive Mantids
The Chinese mantis (Tenodera sinensis) and the European mantis (Mantis religiosa) are the two most prevalent invasive species of mantids found in Virginia and the eastern United States. The Chinese mantid is believed to have been accidentally introduced to the U.S. in 1896 on a shipment of plants to Pennsylvania. In the 1930s, European mantid egg cases were purposely sold for garden pest control and as a biological control agent for the spongy moth, then called the gypsy moth, in the eastern U.S.
After developing adult wings, the Chinese mantid can reach five inches long. Its brown or green coloration provides effective camouflage, and its wings extend the entire length of its abdomen. The European mantid is about three to four inches long and is usually greener in color than the Chinese mantid. Like many invasive species, their aggressive nature poses a threat to the native Carolina mantis (Stagmomantis carolina), which is more brown than green in color and much smaller at two inches long. Its wings cover only two-thirds of the abdomen. The larger invasive species outcompete the Carolina mantis for food and will even eat the Carolina mantis. Thus, the smaller, native Carolina mantid (Stagmomantis carolina) is seen much less frequently and is relatively uncommon.
The Impact of Mantids
Scientific studies have demonstrated some of the effects of mantids on pollinators and their habitat. In a study published in 2014, Michael Maxwell found that the largest single component of the diet of the native mantid Stagmomantis limbata was honeybees, a species in decline. Maxwell and his colleagues have also documented 147 cases of praying mantids catching birds, mostly hummingbirds, which are pollinators. Maxwell noted that the mantises often sit on flowers waiting to kill insects and other prey.
Chinese mantids are so large and abundant they consume a large number of beneficial pollinators and other native species including small birds, reptiles and amphibians as well as the smaller native Carolina mantis. Erin E. Wilson Rankin and colleagues found that “Overall, both T. sinensis and M. religiosa fed on a diversity of diet items in old fields. Mantids preyed upon species that filled a variety of ecological roles, with the majority (>75%) of their diet being herbivores, predators and pollinators regardless of whether mantids were included as prey.”
The horticulture team at the Brooklyn Bridge Park in New York made similar findings, noting that the large Chinese mantids indiscriminately consume large numbers of beneficial insects, such as bumblebees, flower flies, butterflies, and other pollinators. This 85-acre public waterfront park is managed as wildlife habitat with primarily native plants, using organic techniques and encouraging biodiversity through research and experimentation. The Brooklyn team observed numerous large mantids on flowering plants in summer and fall and often found a pile of discarded monarch butterfly wings on the ground below. They also reported that the larger the mantid, the larger the prey they will eat. And of course, the more mantids there are, the more prey they consume. Concluding that predation pressure from mantids was becoming a significant threat to many of the insects attracted to the park, the Brooklyn team has begun to mitigate the problem by selectively removing and destroying the egg cases – called ootheca – of the non-native mantids.
Help Control Invasive Mantids
Destroying the egg cases (“ootheca”) of the Chinese and European species before they hatch can help keep populations in check. Because the egg cases are formed in late summer/early fall, scout your landscape in winter to find the egg cases. They can be attached to a variety of woody shrubs, herbaceous plant stems, twigs or even fence posts. Freezing winter temperatures kill any remaining adults but the egg cases provide protection. Mantid nymphs emerge when temperatures again reach approximately 70° in the spring.
Control depends on identifying which egg cases (ootheca) belong to invasive mantids. The female covers her eggs with a foamy substance that hardens into a texture similar to Styrofoam. Depending on the species, the egg case contains hundreds of eggs. The photo guide below can help with identifying invasive versus native mantid egg cases. The ootheca of the Chinese mantis, most commonly sighted, is puffy, round to cube shape with a foamy texture. It is ping-pong ball size and straw brown in color. The ootheca of the native Carolina mantis is elongated and slender. It is relatively smooth and has a sequence of lighter and darker brown stripes. Both the European mantis and the Carolina mantis ootheca have a similar elongated shape, but the European mantis egg case is not as flattened or as smooth in texture. The major difference is the color of the egg cases. The European mantis ootheca is solid pale brown with no striping while the Carolina mantis is greyer in color with a white midrib. The egg masses of the nonnative mantids can be crushed or cut open and submerged in water, tied up in a garbage bag or better yet, fed to chickens.
Protect Native Mantids
If you find the ootheca of the native Carolina mantis, do not disturb the egg masses. Although they are generalist predators, they are small in size and have less of an impact than the invasive mantids.
Don’t Buy the Invasive Mantids
Garden and pet stores continue to aid in the spread of the invasive species by marketing them as a form of garden pest control. Encouraging the population growth of these invasive species can be detrimental to our native Carolina mantis, as well as to our overall pollinator populations. Don’t buy invasive mantids. Let’s give our native species the opportunity to thrive without added competition.
As North Carolina Extension Agent, Debbie Roos states, “Getting rid of the predominant invasive Chinese and European mantids egg cases annually will hopefully help reduce predation pressure and help maintain a better balance of species. It doesn’t make sense for us to create habitat for pollinators and other beneficial insects, only to let the invasive generalist predators feasting unchecked on the critters the habitat has attracted.” By controlling the nonnative mantids and by supporting our region’s only native mantid, we will maintain the balance she advocates and better manage our landscapes for biodiversity. Gardeners can think of this as “weeding insects” in much the same way we weed unwanted plants.
Featured Photo: Carolina mantid, Kansas Department of Agriculture, Bugwood.org
SOURCES and additional reading:
“Managing Pollinator Habitat: Reducing Invasive Mantids at Brooklyn Bridge Park,” Bella Ciabattoni, Pawel Pieluszynski, https://www.ecolandscaping.org/03/landscape-challenges/pest-management/managing-pollinator-habitat-reducing-invasive-mantids-at-brooklyn-bridge-park/
“Bird Predation By Praying Mantises: A Global Perspective,” bioone.org/journals/the-wilson-journal-of-ornithology/pdf (Nyffeler, Martin, Maxwell, Michael R., and Remsen, J. V., The Wilson Journal of Ornithology, 129(2) : 331-344)
“The Invasive Mantis Species,” Brandywine Conservancy, https://www.brandywine.org/conservancy/blog/invasive-mantis-species
“Get to know your local mantis,” University of Maryland Extension https://marylandgrows.umd.edu/2022/11/09/get-to-know-your-local-mantis/
“Challenging the Conventional Wisdom About Praying Mantids,” Debbie Roos, North Carolina State Extension, https://growingsmallfarms.ces.ncsu.edu/2023/03/challenging-the-conventional-wisdom-about-praying-mantids/
“Praying Mantids,” Gary Watkins and Ric Bessin, Student and Extension Specialist, https://entomology.ca.uky.edu/ef703
Watu wengi wanaweza kutambua mantids kuomba katika mandhari yetu na kufikiri ya yao kama baridi wadudu manufaa, <unk>mlinzi dhidi ya wadudu.<unk> Lakini kuangalia karibu inaonyesha picha ngumu zaidi. Mantids ya asili na mantids ya uvamizi wa nje wanaishi katika mazingira yetu na wanaweza kuwa na athari kubwa kwa pollinators na mifumo ya ikolojia wanayounga mkono. "Wengi huita mnyama wa aina hii ""praying mantis"" lakini ""mantis"" inahusu jamii hususa, wakati neno ""mantid"" linahusu kundi kubwa la wadudu ambao wanaonekana kuomba wakati wa kupumzika." Mnyama huyu anaonekana kuwa mtulivu kabisa, ameketi kimya kimya na hali yake ya kuomba, miguu ya mbele imepandishwa, imefichwa, akingojea wadudu au wanyama wengine wadogo wasio na shaka wapite. Kwa mfano, shingo ya mantidi inaweza kuzunguka kwa digrii 180 ili kuweza kugundua eneo la mnyama huyo. Wakati wadudu hao wanapopita, wao huchukua chakula haraka kwa kutumia miiba mirefu iliyo kwenye sehemu ya juu ya miguu yao ya mbele ili kushikilia mawindo yao. Mantidi huua wadudu wanaokula mimea, lakini kama wanyama wanaowinda, wao huua kila kitu, kutia ndani wadudu wenye manufaa. "Wanakula tu chochote kinachoendelea na kilicho karibu nao", akasema Michael Maxwell, mtaalamu wa ikolojia ya tabia katika Chuo Kikuu cha Kitaifa huko La Jolla, California. Mantis ya China (Tenodera sinensis) na Mantis ya Ulaya (Mantis religiosa) ni aina mbili za mantids zinazopatikana katika Virginia na mashariki mwa Marekani. Mnyama huyo wa China aliwasili Marekani mwaka 1896 wakati wa usafirishaji wa mimea ya Pennsylvania. Katika miaka ya 1930, mayai ya mantid ya Ulaya yaliuzwa kwa makusudi kwa ajili ya kudhibiti wadudu wa bustani na kama wakala wa udhibiti wa kibiolojia kwa nondo wa spongy, kisha aitwaye nondo wa gypsy, katika mashariki mwa Marekani. Rangi yake ya kahawia au ya kijani-kibichi huficha vizuri, na mabawa yake huenea kwenye sehemu yote ya tumbo lake. Mnyama huyo wa Ulaya ana urefu wa sentimeta tatu hadi nne na kwa kawaida ana rangi ya kijani kibichi kuliko yule wa China. Kama spishi nyingi za uvamizi, asili yao ya uhasama inawakilisha tishio kwa mnyama wa asili wa Carolina (Stagmomantis carolina), ambaye ni rangi ya kahawia kuliko kijani na ni mdogo zaidi kwa urefu wa inchi mbili. Mabawa yake hufunika thuluthi mbili tu ya tumbo. Spishi kubwa za uvamizi hushindana na mnyama anayeitwa Carolina mantis kwa ajili ya chakula na hata hula mnyama anayeitwa Carolina mantis. Kwa hiyo, mnyama mdogo anayeitwa Carolina mantid (Stagmomantis carolina) haonekani mara nyingi na ni nadra sana. Athari za Mantids Uchunguzi wa kisayansi umeonyesha baadhi ya athari za mantids juu ya pollinators na mazingira yao. Katika utafiti uliochapishwa mwaka 2014, Michael Maxwell aligundua kwamba sehemu kubwa ya chakula cha mantid ya asili ya Stagmantis limbatus ilikuwa nyuki, spishi inayopungua. Maxwell na wenzake pia wamethibitisha visa 147 vya mantids kuomba kukamata ndege, hasa hummingbirds, ambayo ni pollinators. Maxwell aliona kwamba mara nyingi ndege hao huketi juu ya maua wakingojea kuwaua wadudu na wanyama wengine wanaowinda. Mantidi za China ni kubwa sana na nyingi sana, zinatumia idadi kubwa ya vimelea na spishi nyingine za asili, ikiwa ni pamoja na ndege wadogo, wanyama wanaotambaa na amfibia, na vilevile mnyama mdogo wa asili wa Carolina. Erin E. Wilson Rankin na wenzake walipata kwamba <unk> Kwa ujumla, wote T. sinensis na M. religiosa walikula vitu mbalimbali vya chakula katika mashamba ya zamani. Mantidi walikuwa wakila wanyama wa aina mbalimbali, na asilimia 75 ya chakula chao kilikuwa cha wanyama wanaokula mimea, wadudu na wadudu wanaopiga chavua, bila kujali kama walikula mimea ya aina hiyo au la.Timu ya wakulima wa Brooklyn Bridge Park huko New York ilifanya uchunguzi kama huo, ikisema kwamba wadudu wakubwa wa China wanakula wadudu wengi wenye manufaa, kama vile nyuki, nzi wa maua, vipepeo, na wadudu wengine wanaopiga chavua. Hifadhi hii ya umma ya maji ya ekari 85 inasimamiwa kama makazi ya wanyama wa porini na mimea ya asili, kwa kutumia mbinu za kikaboni na kuhamasisha utofauti wa kibiolojia kupitia utafiti na majaribio. Timu ya Brooklyn iliona mantids nyingi kubwa kwenye mimea yenye maua wakati wa kiangazi na vuli na mara nyingi ilipata rundo la mabawa ya vipepeo wa monarch yaliyotupwa chini. Pia waliripoti kwamba kadiri mantid inavyozidi kuwa kubwa, ndivyo wanavyozidi kula mawindo makubwa. Na bila shaka, kadiri mantidi wanavyokuwa wengi, ndivyo wanavyokula mawindo mengi zaidi. Kwa kuhitimisha kwamba shinikizo la kuwinda kutoka kwa mantids lilikuwa likigeuka kuwa tishio kubwa kwa wadudu wengi waliovutiwa na mbuga hiyo, timu ya Brooklyn imeanza kupunguza tatizo hilo kwa kuondoa na kuharibu kwa hiari kesi za mayai - zinazoitwa ootheca - za mantids zisizo za asili. Kusaidia Kudhibiti Mantids Invasive Kuangamiza kesi za mayai (ootheca) ya spishi za Kichina na Ulaya kabla ya kuanguliwa kunaweza kusaidia kudumisha idadi ya watu chini ya udhibiti. Kwa sababu vifuniko vya mayai hufanyizwa mwishoni mwa majira ya kiangazi au mapema vuli, angalia mazingira yako wakati wa majira ya baridi kali ili upate vifuniko vya mayai. Zinaweza kushikamana na vichaka mbalimbali vyenye mbao, shina la mimea yenye nyasi, matawi au hata nguzo za uzio. Joto kali sana wakati wa majira ya baridi kali huua watu wazima wowote wanaobaki lakini vifuniko vya mayai hutoa ulinzi. Nymphs ya Mantida huibuka wakati joto linapofikia karibu 70 ° C katika majira ya kuchipua. Udhibiti unategemea kutambua ni kesi zipi za mayai (ootheca) ni za mantids za uvamizi. Mwanamke hufunika mayai yake kwa kitu chenye umajimaji ambacho huimarika na kuwa na umbo linalofanana na Styrofoam. Ikitegemea spishi, sanduku la mayai lina mamia ya mayai. Mwongozo wa picha hapa chini unaweza kusaidia katika kutambua visa vya mayai ya mantid ya uvamizi dhidi ya ya asili. Ootheca ya mantis ya Kichina, ambayo huonekana kwa kawaida, ni ya mviringo, yenye umbo la mviringo hadi mviringo yenye umbo la povu. Ni ukubwa wa mpira wa ping-pong na rangi ya kahawia ya nyasi. Mnyama anayeitwa Carolina mantis ana umbo la mviringo na ni mwembamba. Ni laini kwa kulinganisha na lina mfululizo wa mistari nyepesi na nyeusi ya kahawia. Mantis ya Ulaya na Mantis ya Carolina ootheca zina umbo la mviringo, lakini mayai ya Mantis ya Ulaya hayana umbo la mviringo au la laini. Tofauti kuu ni rangi ya vifuniko vya mayai. Mantis ootheca ya Ulaya ni ya rangi ya kahawia nyeupe bila mistari wakati mantis wa Carolina ni wa rangi ya kijivu na midrib nyeupe. Mazao ya mantids ya asili yanaweza kuvunjwa au kukatwa wazi na kuzamishwa ndani ya maji, kufungwa katika mfuko wa taka au, bora zaidi, kulishwa kwa kuku. Ukipata ootheca ya mnyama anayeitwa Carolina mantis, usivurugie mayai yake. Ingawa wao ni wawindaji wa jumla, wao ni wadogo kwa ukubwa na wana athari ndogo kuliko mantids za uvamizi. Don't Buy the Invasive Mantids Bustani na maduka ya wanyama wa kipenzi yanaendelea kusaidia katika kuenea kwa spishi za uvamizi kwa kuziuza kama aina ya udhibiti wa wadudu wa bustani. Kuchochea ukuaji wa idadi ya spishi hizi za uvamizi kunaweza kuwa na madhara kwa mnyama wetu wa asili wa Carolina, na pia kwa idadi yetu ya jumla ya pollinators. Usitumie mantids za uvamizi. Hebu tupe spishi zetu za asili fursa ya kusitawi bila ushindani wa ziada. Kama North Carolina Extension Agent, Debbie Roos anasema, "Kufungua kesi za mayai ya mantids ya China na Ulaya ya uvamizi kila mwaka itasaidia kupunguza shinikizo la kuwinda na kusaidia kudumisha usawa bora wa spishi. "Hakuna maana kwa sisi kuunda makazi kwa ajili ya pollinators na wadudu wengine manufaa, tu kuruhusu invasive generalist predators feasting unchecked juu ya critters makazi imevutia. ""Kwa kudhibiti mantids nonnative na kwa kusaidia mkoa wetu tu mantid asili, tutahifadhi usawa yeye inasaidia na bora kusimamia mandhari yetu kwa ajili ya bioanuwai. """ Watunza-bustani wanaweza kufikiria jambo hilo kuwa "kuondoa wadudu" kwa njia ileile ambayo sisi huondoa mimea isiyofaa. "Kama ilivyoelezwa katika makala ya ""Kupunguza Mipaka ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea ya Mimea.""""