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Happenings in the insect world
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by Alice Cason
on December 11, 2021 at 6:38 AM
Please see the Xerces Society website for "Tropical Milkweed a no grow." Tropical milkweed disrupts the migration which is essential to the survival of the Monarch. Washing OE with water does not eliminate the virus and its effects.
by Mona L Miller
on December 12, 2021 at 5:45 AM
Native Versus Tropical Milkweed  
Remember, all milkweeds collect OE (Ophryocystis elektroscirrha) spores. Plants don't make their own OE spores. Monarch adults visiting the plants drop the spores onto the plants. OE is more prevalent in the fall. There are evergreen milkweeds in southern states in late fall and winter that also collect OE spores. Please don't bash tropical milkweeds. It is a native to Mexico and Central Mexico, where it is used year round. Tropical is also used by migrating Monarchs in the spring and fall. Monarchs migrating through Mexico in the spring and fall lay eggs on tropical milkweeds. I wonder if their offspring will continue the journey north.  
 
"Tropical Milkweed and the injurious effects of well-meaning people" by Jeffrey Glassberg, President of the North American Butterfly Association http://nababutterfly.com/wordpress/wp-content/uploads/2015/04/Tropical-Milkweed.pdf  
 
Frankly pulling out tropical milkweed when Monarchs need milkweed is absolutely insane. Milkweed can be sprayed with water to wash off OE spores. I contacted several scientists and asked them if OE had any way to attached to the plants, only one had an answer: perhaps the tiny spores can get caught in the hairs. Tropical milkweed has smooth leaves. All milkweeds should be washed prior to feeding to Monarch caterpillars. Tropical milkweeds don't have hairy leaves to catch and hold spores. Or you can cut it back and allow it to regrow. Cutting back is best done by only cutting back one third of your plants at one time that way you will still have milkweed available. Do not cut back milkweed, if there are eggs or caterpillars present because this will deprive them of food. Once cut back, cover with garden cloth (Information on using Light Weight Garden Fabric https://www.gardeners.com/how-to/row-covers/5111.html) to allow it to regrow. If left uncovered, Monarchs will still visit and lay on stems of milkweed.  
 
Cutting back tropical milkweed is not recommended in south Florida where there are residential non-migratory monarch populations. See info on the south Florida group about not cutting back tropical south of Orlando: https://nickiebodv.blogspot.com/2015/03/welcome.html  
 
Cutting back tropical milkweed in late fall to winter in some areas gets rid of any OE spores and promotes new clean growth. It isn't the plant causing the OE, it is the butterflies that have the OE dropping the spores on the plants. Those OE spores can also drop on nectar and other milkweed host plants. Research has shown that Monarchs that eat tropical milkweed plants are more resistant to OE. "Patterns of Host-Parasite Adaptation in Three Populations of Monarch Butterflies Infected with a Naturally Occurring Protozoan Disease: Virulence, Resistance, and Tolerance" http://www.jstor.org/stable/10.1086/673442#mobileBookmark  
 
It has also been shown that parents eating tropical milkweed gain a resistance to OE and their offspring are even more resistant. Monarchs that eat tropical milkweed plants also produce less tachinid flies. And, are more noxious to predators due to the higher level of toxins in tropical milkweed. "Trans?generational parasite protection associated with paternal diet" https://besjournals.onlinelibrary.wiley.com/doi/full/10.1111/1365-2656.12289  
 
Plant natives, but don't give tropical milkweed a bad rap. I find that tropical and african milkweeds are very medicinal for Monarchs. They actually prefer them. If given a choice between natives and tropicals, Monarchs usually choose the more toxic tropical varieties. They will usually lay on swamp over common. Swamp is more toxic. They will usually choose common over butterfly weed. Common is more toxic. “How butterflies self-medicate” https://www.ted.com/talks/jaap_de_roode_how_butterflies_self_medicate/transcript?language=en#t-17545  
 
First identified in the 1960s, this is the first research that was published on “Ophryocystis elektroscirrha sp. n., a Neogregarine Pathogen of the Monarch Butterfly Danaus plexippus (L.) and the Florida Queen Butterfly D. gilippus berenice Cramer”R. E. McLAUGHLIN and JUDITH MYERShttps://www.researchgate.net/profile/Judith-Myers-3/publication/229980142_Ophryocystis_elektroscirrha_sp_n_a_Neogregarine_Pathogen_of_the_Monarch_Butterfly_Danaus_plexippus_L_and_the_Florida_Queen_Butterfly_D_gilippus_berenice_Cramer1/links/5f99e497299bf1b53e4ed39e/Ophryocystis-elektroscirrha-sp-n-a-Neogregarine-Pathogen-of-the-Monarch-Butterfly-Danaus-plexippus-L-and-the-Florida-Queen-Butterfly-D-gilippus-berenice-Cramer1.pdf?origin=publication_detail  
 
“Host Diet Affects the Morphology of Monarch Butterfly Parasites”Kevin Hoang, Leiling Tao, Mark D. Hunter, Jacobus C. de Roode” Abstract  
Understanding host–parasite interactions is essential for ecological research, wildlife conservation, and health management. While most studies focus on numerical traits of parasite groups, such as changes in parasite load, less focus is placed on the traits of individual parasites such as parasite size and shape (parasite morphology). Parasite morphology has significant effects on parasite fitness such as initial colonization of hosts, avoidance of host immune defenses, and the availability of resources for parasite replication. As such, understanding factors that affect parasite morphology is important in predicting the consequences of host–parasite interactions. Here, we studied how host diet affected the spore morphology of a protozoan parasite (Ophryocystis elektroscirrha), a specialist parasite of the monarch butterfly (Danaus plexippus). We found that different host plant species (milkweeds; Asclepias spp.) significantly affected parasite spore size. Previous studies have found that cardenolides, secondary chemicals in host plants of monarchs, can reduce parasite loads and increase the lifespan of infected butterflies. Adding to this benefit of high cardenolide milkweeds, we found that infected monarchs reared on milkweeds of higher cardenolide concentrations yielded smaller parasites, a potentially hidden characteristic of cardenolides that may have important implications for monarch–parasite interactions.” https://bioone.org/journals/journal-of-parasitology/volume-103/issue-3/16-142/Host-Diet-Affects-the-Morphology-of-Monarch-Butterfly-Parasites/10.1645/16-142.full  
 
I don’t know why, but I have found African Milkweed, Asclepias physocarpa to be very medicinal. I did a little experiment to prove this. I introduced sickly caterpillars to the plant. I kept them enclosed in organza bags outside. Monarch caterpillars that weren't thriving were able to grow successfully and pupate after they were introduced to the african milkweed, Asclepias physocarpa. This post has the details: https://www.facebook.com/mona.miller.73/posts/10216149671373840  
 
“Milkweeds, monarch butterflies and the ecological significance of cardenolides” Stephen B. Malcolm https://www.researchgate.net/profile/Stephen-Malcolm/publication/226101016_Milkweeds_monarch_butterflies_and_the_ecological_significance_of_cardenolides/links/5b9ff04645851574f7d25661/Milkweeds-monarch-butterflies-and-the-ecological-significance-of-cardenolides.pdf?origin=publication_detail (scroll down to read on this link). I did find in this article that tropical milkweed, Asclepias curassavica, has the highest level of toxins.
by Mona L Miller
on December 12, 2021 at 6:02 AM
The Xerces Society actually recommends some non native plants in some of their seed mixes for orchards and vineyards. So does Monarch Watch at the University of Kansas for butterfly gardens.  
 
"Pollinator Conservation Seed Mixes"  
Please scroll down on this website: https://www.xerces.org/pollinator-conservation/pollinator-conservation-seed-mixes  
“…this seed mix has been formulated based on field trials and monitoring conducted by the Xerces Society and other conservation partners. This mix contains native and non-native forbs, brassicas and legumes. It consists of early-maturing annual species,..”  
 
Monarch Watch also recommends some non natives in their plant lists for butterflies: https://www.monarchwatch.org/garden/plant-lists.html  
Those include “Butterfly Bush, Buddleia davidii Flutterby series – only plant male sterile varieties shrub; non-sterile varieties can be invasive.” And “Tropical milkweed, Asclepias curassavica” for the Northeast: https://www.monarchwatch.org/garden/plant-list-monarchwatch.pdf  
They also have native and non native recommendations for Texas: https://www.monarchwatch.org/garden/plant-list-tx-monarchwatch.pdf  
 
Why are these groups recommending a combination of natives and non natives? It is because experts who know the needs of butterflies and other pollinators recommend these plants to keep gardens blooming. Yes, our gardens should be a majority of natives, but that doesn’t mean that we exclude all exotic plants. Do you know what I am noticing this year with the horrible heat and drought, native plants aren’t coping. They are zooming through their blooming period, while many exotics are still blooming and will continue blooming. I think our priority should be to keep our pollinators fed. I see myths pushed that exotic plant nectar is not good quality or the plants aren’t host plants. Well, our native insects are evolving to use these exotic plants because some of our natives are either blooming too early or too late for them to use as food. These are my observations.
 
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